From: Chet Ramey Date: Mon, 12 Jan 2015 15:56:22 +0000 (-0500) Subject: commit bash-20141219 snapshot X-Git-Tag: bash-4.4-alpha~33 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5e37553a07bf23189623f41d48e45221f55a3e6a;p=thirdparty%2Fbash.git commit bash-20141219 snapshot --- diff --git a/CWRU/CWRU.chlog b/CWRU/CWRU.chlog index f8d85a253..b431ea1dd 100644 --- a/CWRU/CWRU.chlog +++ b/CWRU/CWRU.chlog @@ -7615,3 +7615,42 @@ builtins/declare.def . Will eventually be contingent on compatibility level > 43, but not there yet + 12/15 + ----- +lib/sh/Makefile.in + - add missing dependencies for shmatch.o. Pointed out by Sergey + Mikhailov + + 12/16 + ----- +{execute_cmd,subst}.c + - W_ASSIGNINT: remove, not used any more + +execute_cmd.c + - fix_assignment_words: don't look for `-i' option and set W_ASSIGNINT + flag any more; doing things a different way + - shell_expand_word_list: instead of using W_ASSIGNINT flag, since it + doesn't take into account all options that can transform values on + assignment (-l/-u/-c can also), go through option arguments looking + for options that need special handling and add them to the `opts' + array for make_internal_declare to use. Fixes bug with constructs + like `declare -al foo=(UPONE UPTWO UPTHREE)' not being lowercased on + assignment reported by Linda Walsh + + 12/18 + ----- +lib/readline/readline.c + - rl_internal_char: when we read EOF on a non-empty line, check for + signals and invoke any readline signal handling and any application- + installed signal hook + + 12/20 + ----- +lib/readline/readline.c + - rl_internal_char: if we read EOF on a non-empty line, set c to + _rl_eof_char the first time through. If we read EOF the next time, + return EOF from readline(). If callbacks are defined, this returns + EOF immediately, since lastc isn't available. Fix for problem + most recently identified by Jiri Kukacka , + it has come up in the past + diff --git a/CWRU/CWRU.chlog~ b/CWRU/CWRU.chlog~ new file mode 100644 index 000000000..573dbdd1e --- /dev/null +++ b/CWRU/CWRU.chlog~ @@ -0,0 +1,7653 @@ + 2/14/2011 + --------- +[bash-4.2 released] + + 2/15 + ---- +lib/glob/gmisc.c + - fix wmatchlen and umatchlen to avoid going past the end of the + string on an incomplete bracket expression that ends with a + NUL. Partial fix for bug reported by Clark Wang + + 2/16 + ---- +subst.h + - new string extract flag value: SX_WORD. Used when calling + extract_dollar_brace_string to skip over the word in + ${param op word} from parameter_brace_expand + +subst.c + - change parameter_brace_expand to add SX_WORD to flags passed to + extract_dollar_brace_string + - change parameter_brace_expand to use SX_POSIXEXP for all non-posix + word expansion operators that treat single quotes as special, not + just % and # + - change extract_dollar_brace_string to initialize dolbrace_state to + DOLBRACE_WORD if SX_WORD flag supplied and we shouldn't use + DOLBRACE_QUOTE. Fixes bug reported by Juergen Daubert + +doc/{bash.1,bashref.texi} + - document the exact expansions here strings undergo + + 2/17 + ---- +lib/readline/vi_mode.c + - make sure that `dd', `cc', and `yy' call vidomove_dispatch from + rl_domove_read_callback. Fixes bug reported by Clark Wang + + +lib/readline/callback.c + - make sure _rl_internal_char_cleanup is called after the + vi-motion callbacks (rl_vi_domove_callback) in rl_callback_read_char. + Companion to above fix + +doc/{bash.1,bashref.texi} + - make sure that the text describing the rhs of the == and =~ + operators to [[ states that only the quoted portion of the pattern + is matched as a string + + 2/18 + ---- +lib/glob/gmisc.c + - better fix for umatchlen/wmatchlen: keep track of the number of + characters in a bracket expression as the value to increase + matchlen by if the bracket expression is not well-formed. Fixes + bug reported by Clark Wang + +subst.c + - change expand_string_for_rhs so that it sets the W_NOSPLIT2 flag + in the word flags. We will not perform word splitting or quote + removal on the result, so we do not want to add quoted nulls if + we see "" or ''. Fixes bug reported by Mike Frysinger + + + 2/19 + ---- +variables.c + - new function, int chkexport(name), checks whether variable NAME is + exported and remakes the export environment if necessary. Returns + 1 if NAME is exported and 0 if not + - call chkexport(name) to get tzset to look at the right variable in + the environment when modifying TZ in sv_tz. Don't call tzset if + chkexport doesn't indicate that the variable is exported + +variables.h + - new extern declaration for chkexport + + +{parse.y,builtins/printf.def} + - call sv_tz before calling localtime() when formatting time strings + in prompt strings or using printf. Fixes bug reported by + Dennis Williamson + +execute_cmd.c + - modify fix of 2/9 to add casts when those variables are passed to + functions; some compilers throw errors instead of warnings. Report + and fix from Joachim Schmitz + +support/shobj-conf + - add a stanza for nsk on the Tandem from Joachim Schmitz + + +{shell,lib/readline/shell}.c + - Tandem systems should use getpwnam (getlogin()); for some reason + they don't do well with using getuid(). Fix from Joachim Schmitz + + + 3/1 + --- +variables.c + - make sure that the return value from find_variable is non-null + before trying to use it in chkexport. Fixes bug reported by + Evangelos Foutras + + 3/3 + --- +parse.y + - when adding $$ to the current token buffer in read_token_word(), + don't xmalloc a buffer for two characters and then strcpy it, just + copy the characters directly into the token buffer. Fix from + Michael Whitten + +execute_cmd.c + - fix expand_word_unsplit to add the W_NOSPLIT2 flag to the word to + be expanded, so "" doesn't add CTLNUL. Similar to fix of 2/18 to + expand_string_for_rhs. Fixes bug reported by Nathanael D. Noblet + and Matthias Klose + +parse.y + - fix extended_glob case of read_token_word to allocate an extra + space in the buffer for the next character read after the extended + glob specification if it's a CTLESC or CTLNUL. Report and fix from + Michael Witten + - fix shell expansions case of read_token_word to allocate an extra + space in the buffer for the next character read after the shell + expansion if it's a CTLESC or CTLNUL. Report and fix from + Michael Witten + - TENTATIVE: fix read_token_word to reduce the amount of buffer space + required to hold the translated and double-quoted value of $"..." + strings. Report and fix from Michael Witten + - change code around got_character and got_escaped_character labels to + make sure that we call RESIZE_MALLOCED_BUFFER before adding the + CTLESC before a CTLESC or CTLNUL, and before adding the character if + we're not adding a CTLESC. Report and fix from + Michael Witten + +subst.c + - new param flags value, PF_ASSIGNRHS, mirrors W_ASSIGNRHS, noting that + parameter expansion is on rhs of assignment statement. That inhibits + word splitting + - change param_expand to call string_list_dollar_at with quoted == 1 + if PF_ASSIGNRHS is set, so it will quote IFS characters in the + positional parameter before separating them with the first char of + $IFS. This keeps the rhs from being split inappropriately. Fixes + bug reported by Andres Perera + + 3/4 + --- +lib/readline/bind.c + - add a missing free of `names' in rl_function_dumper. Bug report + and fix from Michael Snyder + + 3/5 + --- +lib/readline/rltty.c + - change rl_deprep_terminal so it uses fileno (stdin) for the tty fd + if rl_instream is not set, like rl_prep_terminal + + 3/6 + --- +lib/readline/display.c + - fix rl_message to use a dynamically-allocated buffer instead of a + fixed-size buffer of 128 chars for the `local message prompt'. Bug + report and fix from Micah Cowan + + 3/7 + --- +jobs.c + - add sentinel to wait_sigint_handler so it only sets wait_sigint_received + if waiting_for_child is non-zero; otherwise, it restores the old + SIGINT handler and sends itself the SIGINT + - set waiting_for_child around the calls to waitchld that use it to + synchronously wait for a process + - change logic that decides whether or not the child process blocked + or handled SIGINT based on whether or not waitpid returns -1/EINTR + and the shell receives a SIGINT and the child does not exit. If + the child later exits due to SIGINT, cancel the assumoption that it + was handled + - instead of testing whether or not the child exited due to SIGINT + when deciding whether the shell should act on a SIGINT it received + while waiting, test whether or not we think the child caught + SIGINT. If it did, we let it go (unless the shell has it trapped); + if it did not catch it, the shell acts on the SIGINT. Fix from + Linus Torvalds , bug report originally + from Oleg Nesterov + + 3/8 + --- +shell.c + - initialize no_line_editing to 1 if READLINE is not defined -- we + can't have line editing without readline + + 3/12 + ---- +lib/readline/signals.c + - add SIGHUP to the set of signals readline handles + +lib/readline/doc/rltech.texi + - document that SIGHUP is now part of the set of signals readline + handles + +lib/readline/input.c + - if _rl_caught_signal indicates that read() was interrupted by a + SIGHUP or SIGTERM, return READERR or EOF as appropriate + - call rl_event_hook, if it's set, if call to read in rl_getc + returns -1/EINTR. If rl_event_hook doesn't do anything, this + continues the loop as before. This handles the other fatal + signals + +execute_cmd.c + - add a couple of QUIT; calls to execute_disk_command and + execute_simple_command to improve responsiveness to interrupts + and fatal signals + +input.c + - rearrange getc_with_restart so that the return values from read() + are handled right + +parse.y + - don't need to set terminate_immediately in yy_stream_get, since + getc_with_restart checks for terminating signals itself + - since readline returns READERR on SIGHUP or SIGTERM, don't need + to set terminate_immediately. Still doesn't handle other + signals well -- will have to check that some more + +bashline.c + - new function, bash_event_hook, for rl_event_hook. Just checks for + terminating signals and acts on them using CHECK_TERMSIG. + - set rl_event_hook to bash_event_hook + +builtins/read.def + - take out setting terminate_immediately; add calls to CHECK_TERMSIG + after read calls + +doc/{bash.1,bashref.texi} + - move the text describing the effect of negative subscripts used to + reference indexed array elements to the paragraphs describing + ${parameter[subscript]}, since that's where they are implemented. + Pointed out by Christopher F. A. Johnson + +arrayfunc.[ch],subst.c + - array_expand_index now takes a new first argument: a SHELL_VAR * + of the array variable being subscripted. Can be used later to fully + implement negative subscripts + + 3/14 + ---- +lib/glob/glob.c + - fix mbskipname to not turn the directory entry name into a wide char + string if the conversion of the pattern to a wide char string fails + - fix mbskipname to call skipname if either the pattern or the filename + can't be converted into a wide-char string + +lib/glob/xmbsrtowcs.c + - fix xdupmbstowcs2 to handle return value of 0 from mbsnrtowcs and + short-circuit with failure in that case. Fixes bug reported by + Roman Rakus + + 3/15 + ---- +bashline.c + - new variable, bash_filename_quote_characters to store the value + assigned to rl_filename_quote_characters so it can be restored + if changed. + - change bashline_reset and attempt_shell_completion to restore + rl_filename_quote_characters if not set to default + + 3/22 + ---- +lib/glob/glob.c + - wdequote_pathname falls back to udequote_pathname if xdupmbstowcs + fails to convert the pathname to a wide-character string + +lib/glob/xmbsrtowcs.c + - xdupmbstowcs2: change to fix problem with leading '\\' (results in + nms == 0, which causes it to short-circuit with failure right + away). Fixes bug pointed out by Werner Fink + - xdupmbstowcs2: compensate for mbsnrtowcs returning 0 by taking the + next single-byte character and going on + - xdupmbstowcs2: change memory allocation to increase by WSBUF_INC + bytes; try to avoid calls to realloc (even if they don't actually + result in more memory being allocated) + + 3/24 + ---- +doc/{bash.1,bashref.texi} + - slightly modify BASH_SUBSHELL description based on complaint from + Sam Liddicott + + 3/25 + ---- +trap.c + - change free_trap_strings to not call free_trap_string for signals + that are being ignored, like reset_or_restore_signal_handlers. + Fixes bug reported by Satoshi Takahashi + + 3/26 + ---- +lib/readline/rltypedefs.h + - remove old Function/VFunction/CPFunction/CPPFunction typedefs as + suggested by Tom Tromey + +lib/readline/rlstdc.h + - move defines for USE_VARARGS/PREFER_STDARG/PREFER_VARARGS from + config.h.in to here because declaration of rl_message in + readline.h uses the defines. This makes it hard for another packages + to use after the header files are installed, since config.h is not + one of the installed files. Suggested by Tom Tromey + + + 3/27 + ---- +print_cmd.c + - change indirection_string from a static buffer to a dynamic one + managed by indirection_level_string(), so we don't end up truncating + PS4. Suggested by Dennis Williamson + +lib/readline/shell.c + - change sh_set_lines_and_columns to use static buffers instead of + allocating the buffers to pass to setenv/putenv + +lib/readline/terminal.c + - change _rl_get_screen_size to not call sh_set_lines_and_columns if + ignore_env == 0 + - _rl_sigwinch_resize_terminal: new function to just retrieve terminal + size, ignoring environment + +lib/readline/rlprivate.h + - new external declaration for _rl_sigwinch_resize_terminal() (currently + unused) + +lib/readline/signals.c + - rl_sigwinch_handler: set _rl_caught_signal to SIGWINCH + - rl_sigwinch_handler: don't immediately call rl_resize_terminal; just + leave _rl_caught_signal set for RL_CHECK_SIGNALS to handle + - _rl_signal_handler: call rl_resize_terminal if sig == SIGWINCH. + Should fix hang when sending multiple repeated SIGWINCH reported by + Henning Bekel + + 3/29 + ---- +lib/sh/snprintf.c + - include math.h for any defines for isinf/isnan + - use code from gnulib documentation to implement isinf/isnan if they + are not defined + +configure.in + - don't check for isinf or isnan; c99 says they're macros anyway + +config.h.in + - remove defines for ISINF_IN_LIBC and ISNAN_IN_LIBC, no longer used + by snprintf.c + + 4/2 + --- +braces.c + - brace_gobbler: fix to understand double-quoted command substitution, + since the shell understands unquoted comsubs. Fixes bug reported + by Michael Whitten + +lib/readline/display.c + - include on MDOS + - get and set screen size using DJGPP-specific calls on MSDOS + - move cursor up clear screen using DJGPP-specific calls + - don't call tputs on DJGPP; there is no good terminfo support + +lib/readline/terminal.c + - include on MDOS + - get and set screen size using DJGPP-specific calls on MSDOS + - use DJGPP-specific initialization on MSDOS, zeroing all the + _rl_term_* variables + - don't call tputs on DJGPP; there is no good terminfo support + DJGPP support from Eli Zaretskii + + 4/6 + --- + +config-top.h + - change DEFAULT_PATH_VALUE to something more useful and modern + + 4/8 + --- +tests/printf2.sub + - make sure LC_ALL and LC_CTYPE are set so LANG assignment takes effect. + Reported by Cedric Arbogast + + 4/11 + ---- +include/chartypes.h + - fix a couple of dicey defines (though ones that don't cause any + compiler warnings) in IN_CTYPE_DOMAIN + +doc/{bashref.texi,bash.1} + - add note referring to duplicating file descriptors in sections + describing redirecting stdout and stderr and appending to stdout + and stderr. Suggested by Matthew Dinger + +pcomplete.c + - it_init_helptopics: new function to support completing on help topics, + not just builtins + - it_helptopics: new programmable completion list of help topics + - build list of helptopic completions in gen_action_completions on + demand + +pcomplete.h + - new extern declaration for it_helptopics + +builtins/complete.def + - the `helptopic' action now maps to CA_HELPTOPIC intead of CA_BUILTIN, + since there are more help topics than just builtins. Suggested by + Clark Wang + + 4/12 + ---- +print_cmd.c + - fix print_arith_for_command to add a call to PRINT_DEFERRED_HEREDOCS + before ending the body of the command, so heredocs get attached to + the right command instead of to the loop. From gentoo bug 363371 + http://bugs.gentoo.org/show_bug.cgi?id=363371 + +execute_cmd.c + - change coproc_pidchk to unset the appropriate shell variables when + the (currently single) known coproc pid terminates + - cleanup and new functions to fully support multiple coprocesses when + and if I decide to go there + + 4/13 + ---- +print_cmd.c + - fix print_group_command to add a call to PRINT_DEFERRED_HEREDOCS + after call to make_command_string_internal before printing closing + `}' + - fix make_command_string_internal to add a call to + PRINT_DEFERRED_HEREDOCS after recursive call to + make_command_string_internal in case cm_subshell before printing + closing `)' + + 4/14 + ---- +print_cmd.c + - change overlapping strcpy in named_function_string to memmove + +sig.h + - UNBLOCK_SIGNAL: convenience define, same as UNBLOCK_CHILD, just + restores an old signal mask + +trap.c + - set_signal: instead of setting the signal handler to SIG_IGN while + installing the new trap handler, block the signal and unblock it + after the new handler is installed. Fixes bug reported by Roman + Rakus + + 4/15 + ---- +doc/{bash.1,bashref.texi} + - make it clear that enabling monitor mode means that all jobs run in + separate process groups + + 4/18 + ---- +builtins/fc.def + - update fix of 4/15/2010 to not take saved_command_line_count into + account when stepping down the history list to make sure that + last_hist indexes something that is valid. Fixes bug reported by + + + 4/19 + ---- +builtins/fc.def + - fc_gethnum: make sure the calculation to decide the last history + entry is exactly the same as fc_builtin. Fixes bug uncovered by + fix of 4/18 to stop seg fault + + 4/22 + ---- +lib/readline/terminal.c + - change _rl_enable_meta_key to set a flag indicating that it sent the + enable-meta sequence + - _rl_disable_meta_key: new function to turn off meta mode after we + turned it on with _rl_enable_meta_key + +lib/readline/rlprivate.h + - extern declaration for _rl_disable_meta_key + +configure.in + - if not cross-compiling, set CFLAGS_FOR_BUILD from any CFLAGS inherited + from the environment. Fixes HP/UX build problem reported by + "Daniel Richard G." + + 4/26 + ---- +config-top.h + - define MULTIPLE_COPROCS to 0 so the code is still disabled but easy + to enable via configure option or editing this file + + 4/29 + ---- +lib/sh/eaccess.c + - freebsd provides faccessat, with the same misfeature as their eaccess + and access implementations (X_OK returns true for uid==0 regardless + of the actual file permissions), so reorganize code to check the + file permissions as with eaccess. Report and fix from Johan Hattne + + + 5/2 + --- +doc/{bash.1,bashref.texi} + - add forward reference to `Pattern Matching' from `Pathname + Expansion', suggested by Greg Wooledge + + 5/5 + --- +pcomplib.c + - the bash_completion project now distributes over 200 completions + for various programs, with no end in sight, so increase the value + of COMPLETE_HASH_BUCKETS from 32 to 128 + +pathexp.c + - quote_string_for_globbing: make sure CTLESC quoting CTLESC is + translated into \ even if the flags include QGLOB_REGEXP. + We don't want to process the second CTLESC as a quote character. + Fixes bug reported by Shawn Bohrer + + 5/6 + --- +builtins/printf.def + - change PRETURN to not call fflush if ferror(stdout) is true + - if a call to one of the stdio functions or printstr leaves + ferror(stdout) true, and PRETURN is going to be called, let PRETURN + print the error message rather than doubling up the messages. Fixes + problem reported by Roman Rakus + + 5/9 + --- +doc/{bash.1,bashref.texi} + - add note to the effect that lists inside compound command can be + terminated by newlines as well as semicolons. Suggested by + Roman Byshko + + 5/10 + ---- +subst.c + - remove_quoted_nulls: fix problem that caused it to skip over the + character after a CTLNUL, which had the effect of skipping every + other of a series of CTLNULs. Fixes bug reported by + Marten Wikstrom + + 5/11 + ---- +subst.c + - extract_process_subst: add SX_COMMAND flag to call to + extract_delimited_string, since we're expanding the same sort of + command as command substitution. Fixes bug reported in Ubuntu + bug 779848 + + 5/12 + ---- +configure.in + - set the prefer_shared and prefer_static variables appropriately + depending on the value of $opt_static_link + +aclocal.m4 + - AC_LIB_LINKFLAGS_BODY: change to not prefer shared versions of the + libraries it's searching for if the prefer_shared variable is "no". + Fixes problem reported by Cedric Arbogast + + 5/13 + ---- +lib/readline/readline.c + - _rl_internal_teardown: add call to _rl_disable_meta_key to make the + meta key active only for the duration of the call to readline() + - _rl_internal_setup: move call to _rl_enable_meta_key here from + readline_initialize_everything so the meta key is active only for + the duration of the call to readline(). Suggestion from Miroslav + Lichvar + +builtins/help.def + - help_builtin: change strncmp to strcmp so that `help read' no longer + matches `readonly'. Suggested by Clark Wang + +config.h.in + - add define for GLIBC21, checked using jm_GLIBC21 as part of the tests + for libintl + +lib/malloc/malloc.c + - internal_free: don't use the cached value of memtop when deciding + whether or not to adjust the break and give memory back to the kernel + when using the GNU C library, since glibc uses sbrk for its own + internal purposes. From Debian bug 614815, reported by Samuel + Thibault + +aclocal.m4 + - BASH_STRUCT_WEXITSTATUS_OFFSET: change AC_RUN_IFELSE to AC_TRY_RUN + to avoid warning about not using AC_LANG_SOURCE + + 5/14 + ---- +bashline.[ch] + - two new functions, bashline_set_event_hook and bashline_reset_event_hook, + to set rl_event_hook to bash_event_hook and back to NULL, respectively + - don't set rl_event_hook unconditionally + +sig.c + - termsig_sighandler: if the shell is currently interactive and + readline is active, call bashline_set_event_hook to cause + termsig_handler to be called via bash_event_hook when the shell + returns from the signal handler + + 5/15 + ---- +lib/readline/display.c + - _rl_col_width: Mac OS X has a bug in wcwidth: it does not return 0 + for UTF-8 combining characters. Added workaround dependent on + MACOSX. Fixes problem pointed out by Thomas De Contes + + + 5/16 + ---- +lib/readline/rlmbutil.h + - WCWIDTH: wrapper for wcwidth that returns 0 for Unicode combining + characters on systems where wcwidth is broken (e.g., Mac OS X). + +lib/readline/{complete,display,mbutil}.c + - use WCWIDTH instead of wcwidth + + 5/17 + ---- +lib/readline/display.c + - update_line: after computing ofd and nfd, see whether the next + character in ofd is a zero-width combining character. If it is, + back ofd and nfd up one, so the base characters no longer compare + as equivalent. Fixes problem reported by Keith Winstein + + +lib/readline/nls.c + - _rl_utf8locale: new flag variable, set to non-zero if the current + locale is UTF-8 + - utf8locale(): new function, returns 1 if the passed lspec (or the + current locale) indicates that the locale is UTF-8. Called from + _rl_init_eightbit + +lib/readline/rlprivate.h + - extern declaration for _rl_utf8locale + +locale.c + - locale_utf8locale: new flag variable, set to non-zero if the current + locale is UTF-8 (currently unused) + - locale_isutf8(): new function, returns 1 if the passed lspec (or the + current locale) indicates that the locale is UTF-8. Should be called + whenever the locale or LC_CTYPE value is modified + +aclocal.m4 + - BASH_WCWIDTH_BROKEN: new test for whether or not wcwidth returns + zero-width characters like unicode combining characters as having + display length 1; define WCWIDTH_BROKEN in this case + +config.h.in + - WCWIDTH_BROKEN: new define + +lib/readline/rlmbutil.h + - change WCWIDTH macro to use _rl_utf8locale and the full range of + Unicode combining characters (U+0300-U+036F) + + 5/19 + ---- +lib/readline/rlprivate.h + - _rl_search_context: new member, prevc, will hold character read + prior to lastc + +lib/readline/isearch.c + - _rl_isearch_dispatch: if the character causes us to index into + another keymap, save that character in cxt->prevc + - _rl_isearch_dispatch: if we index into another keymap, but don't + find a function that's special to i-search, and the character that + caused us to index into that keymap would have terminated the + search, push back cxt->prevc and cxt->lastc to make it appear as + if `prevc' terminated the search, and execute lastc as a command. + We have to push prevc back so we index into the same keymap before + we read lastc. Fixes bug report from Davor Cubranic + + + 5/20 + ---- +expr.c + - expr_bind_variable: pay attention to the return value from + bind_variable and check whether or not we should error out due to + a readonly or noassign variable. Fixes bug reported by Eric + Blake + + 5/26 + ---- + +lib/readline/search.c + - include histlib.h for ANCHORED_SEARCH defines + - rl_history_search_flags: new variable, holds ANCHORED_SEARCH flag for + the duration of a history search + - rl_history_search_reinit: takes a new flags variable, defines whether + or not the search is anchored; assigned to rl_history_search_flags + - rl_history_serarch_reinit: if ANCHORED_SEARCH flag passed, add ^ to + beginning of search string; otherwise search string is unmodified + - rl_history_search_internal: set rl_point appropriately based on + whether or not rl_history_search_flags includes ANCHORED_SEARCH + - rl_history_substr_search_forward: new function, for non-anchored + substring search forward through history for string of characters + preceding rl_point + - rl_history_substr_search_backward: new function, for non-anchored + substring search backward through history for string of characters + preceding rl_point. Original code from Niraj Kulkarni + + +lib/readline/readline.h + - extern declarations for rl_history_substr_search_{for,back}ward + +lib/readline/funmap.c + - history-substring-search-forward: new bindable command, invokes + rl_history_substr_search_forward + - history-substring-search-backward: new bindable command, invokes + rl_history_substr_search_backward + +lib/readline/doc/{rluser.texi,readline.3} + - document history-substring-search-forward and + history-substring-search-backward + + 5/27 + ---- +{nojobs,jobs}.c + - add support for DONT_REPORT_SIGTERM so that the shell doesn't print + a message when a job exits due to SIGTERM since that's the default + signal sent by the kill builtin. Suggested by Marc Herbert + + +config-top.h + - DONT_REPORT_SIGTERM: new user-modifiable setting. Commented out + by default + + 5/28 + ---- +lib/readline/bind.c + - _rl_skip_to_delim: skip to a closing double quote or other delimiter, + allowing backslash to quote any character, including the delimiter + - rl_parse_and_bind: call _rl_skip_to_delim instead of using inline + code + - rl_parse_and_bind: allow quoted strings as the values of string + variables. Variable values without double quotes have trailing + whitespace removed (which still allows embedded whitespace, for + better or worse). Fixes problem with string variables not matching + in `set' command if values happen to have trailing spaces or tabs + (debian bash bug #602762), but introduces slight incompatibility. + + 5/29 + ---- +doc/{bash.1,bashref.texi} + - clarify unset description to specify that without options, a + variable, then a shell function if there is no variable by that + name, is unset. Fixes discrepancy reported by Mu Qiao + + + 6/4 + ---- +doc/{bash.1,bashref.texi} + - clarify description of LINES and COLUMNS (and checkwinsize shopt + option) to make it clear that only interactive shells set a + handler for SIGWINCH and update LINES and COLUMNS. Original + report submitted by Jonathan Nieder + +arrayfunc.c + - expand_compound_array_assignment: defer expansion of words between + parens when performing compound assignmnt to an associative array + variable + - assign_compound_array_list: perform the same expansions when doing + a compound array assignment to an associative array variable as + when doing a straight array index assignment. The idea is that + foo=( [ind1]=bar [ind2]=quux) + is the same as + foo[ind1]=bar ; foo[ind2]=quux + + This fixes problems with double-expansion and quote removal being + performed on the array indices + + 6/13 + ---- +doc/{bash.1,bashref.texi} + - Add a little text to make it clear that the locale determines how + range expressions in glob patterns are handled. + + + 6/21 + ---- +builtins/read.def + - display a message and return error status if -a is used with an + existing associative array. Fixes bug reported by Curtis Doty + + + 6/24 + ---- +{jobs,nojobs}.c + - non-interactive shells now react to the setting of checkwinsize + and set LINES and COLUMNS after a foreground job exits. From a + suggestion by Leslie Rhorer + +doc/{bash.1,bashref.texi} + - checkwinsize: remove language saying that only interactive shells + check the window size after each command + +lib/readline/histfile.c + - history_backupfile: new file, creates a backup history file name + given a filename (appending `-') + - history_do_write: when overwriting the history file, back it up + before writing. Restore backup file on a write error. Suggested + by chkno@chkno.net + +bashline.c + - find_cmd_name: two new arguments, return the start and end of the + actual text string used to find the command name, without taking + whitespace into account + - attempt_shell_completion: small changes to make sure that completion + attempted at the beginning of a non-empty line does not find a + programmable completion, even if the command name starts at point + - attempt_shell_completion: small change to make sure that completion + does not find a progcomp when in whitespace before the command + name + - attempt_shell_completion: small change to make sure that completion + does not find a progcomp when point is at the first character of a + command name, even when there is leading whitespace (similar to + above). Fixes problems noted by Ville Skytta + +subst.c + - brace_expand_word_list: since the individual strings in the strvec + returned by brace_expand are already allocated, don't copy them to + newly-allocated memory when building the WORD_LIST, just use them + intact + +locale.c + - locale_mb_cur_max: cache value of MB_CUR_MAX when we set or change + the locale to avoid a function call every time we need to read it + +shell.h + - new struct to save shell_input_line and associated variables: + shell_input_line_state_t + - add members of sh_parser_state_t to save and restore token and the + size of the token buffer + +parse.y + - {save,restore}_input_line_state: new functions to save and restore + shell_input_line and associated variables + - {save,restore}_parser_state: add code to save and restore the token + and token buffer size + - xparse_dolparen: call save_ and restore_input_line_state to avoid + problems with overwriting shell_input_line when we recursively + call the parser to parse a command substitution. Fixes bug + reported by Rui Santos + +include/shmbutil.h + - use locale_mb_cur_max instead of MB_CUR_MAX in ADVANCE_CHAR and + similar macros + +lib/glob/smatch.c + - rangecmp,rangecmp_wc: change to take an additional argument, which + forces the use of strcoll/wscoll when non-zero. If it's 0, a new + variable `glob_asciirange' controls whether or not we use strcoll/ + wscoll. If glob_asciirange is non-zero, we use straight + C-locale-like ordering. Suggested by Aharon Robbins + + + 6/30 + ---- +execute_cmd.c + - execute_pipeline: make sure the lastpipe code is protected by + #ifdef JOB_CONTROL. Fixes problem reported by Thomas Cort + + + 7/2 + --- +lib/readline/complete.c + - EXPERIMENTAL: remove setting of _rl_interrupt_immediately around + completion functions that touch the file system. Idea from Jan + Kratochvil and the GDB development + team + +lib/readline/signals.c + - rl_signal_handler: if we're in callback mode, don't interrupt + immediately on a SIGWINCH + + 7/3 + --- +bashline.c + - set_directory_hook: and its siblings are a new set of functions to + set, save, and restore the appropriate directory completion hook + - change callers to use {set,save,restore}_directory_hook instead of + manipulating rl_directory_rewrite_hook directly + - dircomplete_expand: new variable, defaults to 0, if non-zero causes + directory names to be word-expanded during word and filename + completion + - change {set,save,restore}_directory_hook to look at dircomplete_expand + and change rl_directory_completion_hook or rl_directory_rewrite_hook + appropriately + +bashline.h + - extern declaration for set_directory_hook so shopt code can use it + + 7/6 + --- +builtins/shopt.def + - globasciiranges: new settable shopt option, makes glob ranges act + as if in the C locale (so b no longer comes between A and B). + Suggested by Aharon Robbins + + 7/7 + --- +doc/{bash.1,bashref.texi} + - document new `globasciiranges' shopt option + + 7/8 + --- +builtins/shopt.def + - direxpand: new settable option, makes filename completion expand + variables in directory names like bash-4.1 did. + - shopt_set_complete_direxpand: new function, does the work for the + above by calling set_directory_hook + +doc/{bash.1,bashref.texi} + - document new `direxpand' shopt option + + 7/15 + ---- +lib/readline/isearch.c + - _rl_isearch_dispatch: when adding character to search string, use + cxt->lastc (which we use in the switch statement) instead of c, + since lastc can be modified earlier in the function + + 7/18 + ---- +lib/readline/rlprivate.h + - _rl_search_context: add another member to save previous value of + (multibyte) lastc: pmb is to mb as prevc is to lastc + +lib/readline/isearch.c: + - _rl_isearch_dispatch: if a key sequence indexes into a new keymap, + but doesn't find any bound function (k[ind].function == 0) or is + bound to self-insert (k[ind].function == rl_insert), back up and + insert the previous character (the one that caused the index into a + new keymap) and arrange things so the current character is the next + one read, so both of them end up in the search string. Fixes bug + reported by Clark Wang + - _rl_isearch_dispatch: a couple of efficiency improvements when adding + characters to the isearch string + + 7/24 + ---- +lib/readline/isearch.c + - _rl_isearch_dispatch: save and restore cxt->mb and cxt->pmb + appropriately when in a multibyte locale + +doc/{bash.1,bashref.texi} + - correct description of {x}>file (and other redirection operators + that allocate a file descriptor) to note the the fd range is + greater than or equal to 10. Fixes problem reported by + Christian Ullrich + +lib/readline/signals.c + - rl_signal_handler: don't interrupt immediately if in callback mode + +lib/readline/callback.c + - rl_callback_read_char: install signal handlers only when readline + has control in callback mode, so readline's signal handlers aren't + called when the application is active (e.g., between the calls to + rl_callback_handler_install and rl_callback_read_char). If the + readline signal handlers only set a flag, which the application + doesn't know about, the signals will effectively be ignored until + the next time the application calls into the readline callback + interface. Fixes problem of calling unsafe functions from signal + handlers when in callback mode reported by Jan Kratochvil + + +execute_cmd.c + - fix_assignment_words: when in Posix mode, the `command' builtin + doesn't change whether or not the command name it protects is an + assignment builtin. One or more instances of `command' + preceding `export', for instance, doesn't make `export' treat its + assignment statement arguments differently. Posix interpretation + #351 + +doc/{bash.1,bashref.texi} + - document new Posix-mode behavior of `command' when preceding builtins + that take assignment statements as arguments + +builtins/printf.def + - printstr: if fieldwidth or precision are < 0 or > INT_MAX when + supplied explicitly (since we take care of the `-' separately), + clamp at INT_MAX like when using getint(). Fixes issue reported + by Ralph Coredroy + + 7/25 + ---- +lib/readline/chardefs.h + - isxdigit: don't define if compiling with c++; declared as a c++ + template function. Fixes bug reported by Miroslav Lichvar + + +builtins/printf.def + - getint: if garglist == 0, return whatever getintmax returns (0). + Fixes bug reported by Ralph Coredroy + + 7/28 + ---- +doc/{bash.1,bashref.texi} + - minor changes to the descriptions of the cd and pushd builtins + +lib/sh/zread.c + - zsyncfd: change variable holding return value from lseek to + off_t. Bug report and fix from Gregory Margo + + 8/1 + --- +expr.c + - don't check for division by 0 when in a context where no evaluation + is taking place. Fixes bug reported by dnade.ext@orange-ftgroup.com + + 8/6 + --- +execute_cmd.c + - execute_command_internal: the parent branch of the subshell code + (where the child calls execute_in_subshell) should not close all + open FIFOs with unlink_fifo_list if it's part of a shell function + that's still executing. Fixes bug reported by Maarten Billemont + + + 8/9 + --- +builtins/common.c + - get_exitstat: return EX_BADUSAGE (2) on a non-numeric argument + +builtins/return.def + - return_builtin: just call get_exitstat to get the return status, + let it handle proper parsing and handling of arguments. Fixes + issue most recently raised by Linda Walsh . + Reverses change from 9/11/2008 (see above) + + 8/16 + ---- +doc/{bash.1,bashref.texi} + - clean up `set -e' language to make it clearer that any failure of + a compound command will cause the shell to exit, not just subshells + and brace commands + + 8/17 + ---- +configure.in + - make the various XXX_FOR_BUILD variables `precious' to autoconf to + avoid stale data + - change how CC_FOR_BUILD is initialized when cross-compiling and not, + but do not change behavior + - initialize CFLAGS_FOR_BUILD to -g when cross-compiling + - initialize LIBS_FOR_BUILD to $(LIBS) when not cross-compiling, empty + when cross-compiling + - create AUTO_CFLAGS variable to hold basic CFLAGS defaults; used when + CFLAGS not inherited from environment (like effect of old + auto_cflags variable) + - substitute LIBS_FOR_BUILD into output Makefiles + [changes inspired by bug report from Nathan Phillip Brink + -- gentoo bug 378941] + +builtins/Makefile.in + - substitute LIBS_FOR_BUILD from configure, not strictly initialized + to $(LIBS) + + 8/27 + ---- +doc/{bash.1,bashref.texi} + - minor changes to the here string description to clarify the + expansions performed on the word + +support/shobj-conf + - handle compilation on Lion (Mac OS X 10.7/darwin11) with changes + to darwin stanzas. Fixes readline bug reported by Vincent + Sheffer + +lib/sh/strtrans.c + - ansic_wshouldquote: check a string with multi-byte characters for + characters that needs to be backslash-octal escaped for $'...' + - ansic_shouldquote: if is_basic fails for one character, let + ansic_wshouldquote examine the rest of the string and return what + it returns. From a patch sent by Roman Rakus + + 8/30 + ---- +lib/sh/strtrans.c + - ansic_quote: changes to quote (or not) multibyte characters. New + code converts them to wide characters and uses iswprint to check + valid wide chars. From a patch sent by Roman Rakus + + + 9/7 + --- +lib/sh/shquote.c + - sh_backslash_quote: change to be table-driven so we can use a + different table if we want to + - sh_backslash_quote: takes a second char table[256] argument; + +externs.h + - sh_backslash_quote: add second argument to function prototype + +bashline.c,braces.c,parse.y,builtins/printf.def + - change callers of sh_backslash_quote to add second argument + +bashline.c + - filename_bstab: table of characters to pass to sh_backslash_quote; + characters with value 1 will be backslash-quoted + - set_filename_bstab: turn on characters in filename backslash-quote + table according to passed string argument + - call set_filename_bstab every time rl_filename_quote_characters is + assigned a value + - bash_quote_filename: call sh_backslash_quote with filename_bstab + as second argument. This allows other characters in filenames to + be quoted without quoting, for instance, a dollar sign in a shell + variable reference + + 9/8 + --- +bashline.c + - complete_fullquote: new variable, controls table passed to + sh_backslash_quote. If non-zero (the default), the standard set + of shell metacharacters -- as in bash versions up to and including + bash-4.2 -- gets backslash-quoted by the completion code. If zero, + sh_backslash_quote gets the table with the characters in the + variable reference removed, which means they are removed from the + set of characters to be quoted in filenames + + 9/10 + ---- +bashline.c + - bash_filename_stat_hook: new function, designed to expand variable + references in filenames before readline passes them to stat(2) + to determine whether or not they are a directory + + 9/15 + ---- +builtins/declare.def + - if assign_array_element fails due to a bad (or empty) subscript, mark + it as an assignment error and don't attempt any further processing + of that declaration. Fixes segfault bug reported by Diego Augusto + Molina + + 9/19 + ---- +expr.c + - exppower: replace the simple exponentiation algorithm with an + implementation of exponentiation by squaring. Inspired by report + from Nicolas ARGYROU + +bashline.c + - bash_quote_filename: check for rtext being non-null before + dereferencing it + - set_saved_history: operate_and_get_next assumes that the previous + line was added to the history, even when the history is stifled and + at the max number of entries. If it wasn't, make sure the history + number is incremented properly. Partial fix for bug reported by + gregrwm + +doc/{bash.1,bashref.texi},lib/readline/doc/{hsuser,rluser}.texi + - minor editorial changes inspired by suggestions from + Roger Zauner + + 9/20 + ---- +lib/intl/localealias.c + - read_alias_file: close resource leak (fp) when returning on error + + 9/22 + ---- +execute_command.c + - execute_intern_function: implement Posix interpretation 383 by making + it an error to define a function with the same name as a special + builtin when in Posix mode. + http://austingroupbugs.net/view.php?id=383#c692 + + 9/25 + ---- +doc/{bash.1,bashref.texi} + - formatting and some content changes from Benno Schulenberg + + - document new posix-mode behavior from interp 383 change of 9/22 + + 9/30 + ---- +execute_cmd.c + - shell_execve: add strerror to error message about executable file + that shell can't execute as a shell script. From suggestion by + daysleeper + + 10/1 + ---- +bashhist.c + - maybe_add_history: act as if literal_history is set when parser_state + includes PST_HEREDOC, so we save the bodies of here-documents just + as they were entered. Fixes bug reported by Jonathan Wakely + + - bash_add_history: make sure that the second and subsequent lines of + a here document don't have extra newlines or other delimiting + chars added, since they have the trailing newline preserved, when + `lithist' is set and history_delimiting_chars isn't called + +execute_cmd.c + - execute_command_internal: avoid fd exhaustion caused by using + process substitution in loops inside shell functions by using + copy_fifo_list and close_new_fifos (). Fixes debian bash bug + 642504 + +lib/readline/complete.c + - new variable, rl_filename_stat_hook, used by append_to_match. If + filename completion is desired, and rl_filename_stat_hook points + to a function, call that function to expand the filename in an + application-specific way before calling stat. + +bashline.c + - bash_default_completion: if variable completion returns a single + match, use bash_filename_stat_hook and file_isdir to determine + whether or not the variable name expands to a directory. If it + does, set the filename_append_character to `/'. This is not + perfect, so we will see how it works out. Adds functionality + requested by Peter Toft and Patrick Pfeifer + + - rl_filename_stat_hook: assigned bash_filename_stat_hook, so things + like $HOME/Downloads (after completion) have a slash appended. + In general, this causes the stat hook to be called whenever + filename completion is appended. Adds functionality requested by + Patrick Pfeifer + +lib/readline/readline.h + - new extern declaration for rl_filename_stat_hook + +lib/readline/doc/rltech.texi + - rl_directory_rewrite_hook: now documented + - rl_filename_stat_hook: document + +pcomplete.c + - gen_action_completions: in the CA_DIRECTORY case, turn off + rl_filename_completion_desired if it was off before we called + rl_filename_completion_function and we didn't get any matches. + Having it on causes readline to quote the matches as if they + were filenames. Adds functionality requested by many, + including Clark Wang + +assoc.[ch] + - assoc_replace: new function, takes the same arguments as + assoc_insert, but returns the old data instead of freeing it + - assoc_insert: if the object returned by hash_insert doesn't have + the same value for its key as the key passed as an argument, we + are overwriting an existing value. In this case, we can free the + key. Fixes bug reported by David Parks + + 10/5 + ---- +print_cmd.c + - indirection_level_string: small change to only re-enable `x' + option after calling decode_prompt_string if it was on before. In + normal mode, it will be, but John Reiser + has a novel use for that code in conjunction with a pre-loaded + shared library that traces system call usage in shell scripts + + 10/10 + ----- +Makefile.in + - Fix from Mike Frysinger to avoid trying to + build y.tab.c and y.tab.h with two separate runs of yacc if + parse.y changes. Problem with parallel makes + - Fix from Mike Frysinger to avoid subdirectory + builds each trying to make version.h (and all its dependencies) + +lib/sh/Makefile.in + - remove some dependencies on version.h where it doesn't make sense + +variables.c + - initialize_shell_variables: while reading the environment, a shell + running in posix mode now checks for SHELLOPTS being readonly (it + gets set early on in main()) before trying to assign to it. It + saves an error message and the variable gets parsed as it should. + Fixes bug reported by Len Giambrone + + 10/14 + ----- +doc/{bash.1,bashref.texi} + - add to the "duplicating file descriptors" description that >&word + doesn't redirect stdout and stderr if word expands to `-' + - add to the "appending standard output and standard error" + description a note that >&word, where word is a number or `-', + causes other redirection operators to apply for sh and Posix + compatibility reasons. Suggested by Greg Wooledge + + + 10/15 + ----- +pcomplete.c + - change pcomp_filename_completion_function to only run the filename + dequoting function in the cases (as best as it can figure) where + readline won't do it via rl_filename_completion_function. Based + on reports from + + 10/19 + ----- +bashline.c + - attempt_shell_completion: add call to set_directory_hook() to make + sure the rewrite functions are correct. It's cheap and doesn't + hurt + - command_word_completion_function: if completing a command name that + starts with `.' or `..', temporarily suppress the effects of the + `direxpand' option and restore the correct value after calling + rl_filename_completion_function. If it's enabled, the directory + name will be rewritten and no longer match `./' or `../'. Fixes + problem reported by Michael Kalisz + + 10/22 + ----- +builtins/history.def + - push_history: make sure remember_on_history is enabled before we + try to delete the last history entry -- the `history -s' command + might not have been saved. Fixes bug reported by + lester@vmw-les.eng.vmware.com + +lib/readline/complete.c + - rl_callback_read_char: add calls to a macro CALLBACK_READ_RETURN + instead of straight return; add same call at end of function. + Placeholder for future work in deinstalling signal handlers when + readline is not active + + 10/25 + ----- +expr.c + - exp2: catch arithmetic overflow when val1 == INTMAX_MIN and val2 == -1 + for DIV and MOD and avoid SIGFPE. Bug report and pointer to fix + from Jaak Ristioja + - expassign: same changes for arithmetic overflow for DIV and MOD + + 10/28 + ----- +subst.c + - parameter_brace_expand: allow pattern substitution when there is an + expansion of the form ${var/} as a no-op: replacing nothing with + nothing + - parameter_brace_patsub: don't need to check for PATSUB being NULL; + it never is + +flags.c + - if STRICT_POSIX is defined, initialize history_expansion to 0, since + history expansion (and its treatment of ! within double quotes) is + not a conforming posix environment. From austin-group issue 500 + +lib/readline/histexpand.c + - history_expand: when processing a string within double quotes + (DQUOTE == 1), make the closing double quote inhibit history + expansion, as if the word were outside double quotes. In effect, + we assume that the double quote is followed by a character in + history_no_expand_chars. tcsh and csh seem to do this. This + answers a persistent complaint about history expansion + + 10/29 + ----- +make_cmd.c + - make_arith_for_command: use skip_to_delim to find the next `;' + when breaking the string between the double parens into three + separate components instead of a simple character loop. Fixes + bug reported by Dan Douglas + + 11/2 + ---- +Makefile.in + - make libbuiltins.a depend on builtext.h to serialize its creation + and avoid conflict between multiple invocations of mkbuiltins. + Fix from Mike Frysinger + + 11/5 + ---- +findcmd.c + - user_command_matches: if stat(".", ...) returns -1, set st_dev + and st_ino fields in dotinfo to 0 to avoid same_file matches + - find_user_command_in_path: check stat(2) return the same way + +lib/glob/glob.c + - glob_vector: don't call strlen(pat) without checking pat == 0 + - glob_dir_to_array: make sure to free `result' and all allocated + members before returning error due to malloc failure + - glob_vector: make sure to free `nextname' and `npat' on errors + (mostly when setting lose = 1) + - glob_vector: if flags & GX_MATCHDIRS but not GX_ALLDIRS, make + sure we free `subdir' + - glob_filename: when expanding ** (GX_ALLDIRS), make sure we + free temp_results (return value from glob_vector) + +lib/glob/xmbsrtowcs.c + - xdupmbstowcs: fix call to realloc to use sizeof (char *) instead + of sizeof (char **) when assigning idxtmp + +execute_cmd.c + - print_index_and_element: return 0 right away if L == 0 + - is_dirname: fix memory leak by freeing `temp' + - time_command: don't try to deref NULL `command' when assigning + to `posix_time' + - shell_execve: null-terminate `sample' after READ_SAMPLE_BUF so it's + terminated for functions that expect that + +builtins/read.def + - read_builtin: don't call bind_read_variable with a potentially-null + string + +pcomplete.c + - gen_command_matches: don't call dispose_word_desc with a NULL arg + - gen_compspec_completions: fix memory leak by freeing `ret' before + calling gen_action_completions (tcs, ...). happens when + performing directory completion as default and no completions + have been generated + - gen_progcomp_completions: make sure to set foundp to 0 whenever + returning NULL + - it_init_aliases: fix memory leak by freeing alias_list before + returning + +bashline.c + - command_word_completion_function: don't call restore_tilde with a + NULL directory_part argument + - bash_directory_expansion: bugfix: don't throw away results of + rl_directory_rewrite_hook if it's set and returns non-zero + - bind_keyseq_to_unix_command: free `kseq' before returning error + +arrayfunc.c + - assign_array_element_internal: make sure `akey' is freed if non-null + before returning error + - assign_compound_array_list: free `akey' before returning error + - array_value_internal: free `akey' before returning error + - unbind_array_element: free `akey' before returning error + +subst.c + - array_length_reference: free `akey' before returning error in case + of expand_assignment_string_to_string error + - array_length_reference: free `akey' after call to assoc_reference + - skip_to_delim: if skipping process and command substitution, free + return value from extract_process_subst + - parameter_brace_substring: free `val' (vtype == VT_VARIABLE) before + returning if verify_substring_values fails + - parameter_brace_expand: remove two duplicate lines that allocate + ret in parameter_brace_substring case + - parameter_brace_expand: convert `free (name); name = xmalloc (...)' + to use `xrealloc (name, ...)' + - parameter_brace_expand: free `name' before returning when handling + ${!PREFIX*} expansion + - split_at_delims: fix memory leak by freeing `d2' before returning + +redir.c + - redirection_error: free `filename' if the redirection operator is + REDIR_VARASSIGN by assigning allocname + +eval.c + - send_pwd_to_eterm: fix memory leak by freeing value returned by + get_working_directory() + +builtins/cd.def + - change_to_directory: fix memory leak by freeing return value from + resetpwd() + - cd_builtin: fix memory leak by freeing value returned by dirspell() + - cd_builtin: fix memory leak by freeing `directory' if appropriate + before overwriting with return value from resetpwd() + +builtins/type.def + - describe_command: free `full_path' before overwriting it with return + value from sh_makepath + +builtins/complete.def + - compgen_builtin: fix memory leak by calling strlist_dispose (sl) + before overwriting sl with return value from completions_to_stringlist + +builtins/hash.def + - list_hashed_filename_targets: fix memory leak by freeing `target' + +make_cmd.c + - make_arith_for_command: free `init', `test', and `step' before + returning error on parse error + +jobs.c + - initialize_job_control: don't call move_to_high_fd if shell_tty == -1 + +general.c + - check_dev_tty: don't call close with an fd < 0 + - legal_number: deal with NULL `string' argument, return invalid + +lib/sh/fmtulong.c + - fmtulong: if the `base' argument is invalid, make sure we index + buf by `len-1' at maximum + +print_cmd.c + - print_deferred_heredocs: don't try to dereference a NULL `cstring' + - cprintf: make sure to call va_end (args) + +variables.c + - push_dollar_vars: fix call to xrealloc to use sizeof (WORD_LIST *) + instead of sizeof (WORD_LIST **) + +lib/sh/zmapfd.c + - zmapfd: if read returns error, free result and return -1 immediately + instead of trying to reallocate it + + 11/6 + ---- +execute_cmd.c + - cpl_reap: rewrote to avoid using pointer after freeing it; now builds + new coproc list on the fly while traversing the old one and sets the + right values for coproc_list when done + + 11/12 + ----- +builtins/set.def + - if neither -f nor -v supplied, don't allow a readonly function to + be implicitly unset. Fixes bug reported by Jens Schmidt + + +lib/readline/callback.c + - change CALLBACK_READ_RETURN to clear signal handlers before returning + from rl_callback_read_char so readline's signal handlers aren't + installed when readline doesn't have control. Idea from Jan + Kratochvil and the GDB development + team + +pcomplete.h + - COPT_NOQUOTE: new complete/compgen option value + +builtins/complete.def + - noquote: new complete/compgen option; will be used to disable + filename completion quoting + +pcomplete.c + - pcomp_set_readline_variables: pay attention to COPT_NOQUOTE; turns + of rl_filename_quoting_desired if set; turns it on if unset (value + is inverted, since default is on) + +doc/bash.1,lib/readline/doc/rluser.texi + - document new -o noquote option to complete/compgen/compopt + +pathexp.c + - quote_string_for_globbing: if QGLOB_REGEXP, make sure characters + between brackets in an ERE bracket expression are not inappropriately + quoted with backslashes. This is a pretty substantial change, + should be stressed when opening bash up for alpha and beta tests. + Fixes bug pointed out by Stephane Chazleas + + +doc/{bash.1,bashref.texi} + - document that regexp matches can be inconsistent when quoting + characters in bracket expressions, since usual quoting characters + lose their meaning within brackets + - note that regular expression matching when the pattern is stored + in a shell variable which is quoted for expansion causes string + matching + +redir.h + - RX_SAVEFD: new flag value; notes that a redirection denotes an + fd used to save another even if it's not >= SHELL_FD_BASE + +redir.c + - do_redirection_internal: when deciding whether or not to reset the + close-on-exec flag on a restored file descriptor, trust the value + of redirect->flags & RX_SAVCLEXEC even if the fd is < SHELL_FD_BASE + if the RX_SAVEFD flag is set + - add_undo_redirect: set the RX_SAVEFD flag if the file descriptor + limit is such that the shell can't duplicate to a file descriptor + >= 10. Fixes a limitation that tripped a coreutils test reported + by Paul Eggert + + 11/19 + ----- +doc/{bash.1,bashref.texi},lib/readline/doc/hsuser.texi + - make it clear that bash runs HISTFILESIZE=$HISTSIZE after reading + the startup files + - make it clear that bash runs HISTSIZE=500 after reading the + startup files + - make it clear that setting HISTSIZE=0 causes commands to not be + saved in the history list + - make it clear that setting HISTFILESIZE=0 causes the history file + to be truncated to zero size + +variables.c + - sv_histsize: change so setting HISTSIZE to a value less than 0 + causes the history to be `unstifled' + - sv_histsize: change so setting HISTFILESIZE to a value less than 0 + results in no file truncation + - make it clear that numeric values less than 0 for HISTFILESIZE or + HISTSIZE inhibit the usual functions + + 11/23 + ----- +parse.y + - save_input_line_state: add missing `return ls' at the end, since the + function is supposed to return its argument. Pointed out by + Andreas Schwab + +builtins/read.def + - skip over NUL bytes in input, as most modern shells seem to. Bug + report by Matthew Story + +lib/readline/vi_mode.c + - rl_vi_replace: set _rl_vi_last_key_before_insert to invoking key + + 11/25 + ----- +builtins/read.def + - read_builtin: if xrealloc returns same pointer as first argument, + don't bother with the remove_unwind_protect/add_unwind_protect pair + - read_builtin: set a flag (`reading') around calls to zread/zreadc + and readline() + - sigalrm: change to set flag (`sigalrm_seen') and only longjmp if + currently in read(2) (reading != 0) + - CHECK_ALRM: new macro, checks sigalrm_seen and longjmps if non-zero, + behavior of old SIGALRM catching function + - read_builtin: call CHECK_ALRM in appropriate places while reading + line of input. Fixes bug reported by Pierre Gaston + + +lib/readline/vi_mode.c + - rl_vi_replace: initialize characters before printing characters in + vi_replace_keymap to their default values in vi_insertion_keymap, + since we're supposed to be in insert mode replacing characters + - rl_vi_replace: call rl_vi_start_inserting to set last command to + `R' for undo + - rl_vi_replace: set _rl_vi_last_key_before_insert to `R' for future + use by _rl_vi_done_inserting + - vi_save_insert_buffer: new function, broke out code that copies text + into vi_insert_buffer from _rl_vi_save_insert + - _rl_vi_save_replace: new function, saves text modified by + rl_vi_replace (using current point and vi_replace_count to figure + it out) to vi_replace_buffer + - _rl_vi_save_insert: call vi_save_insert_buffer + - _rl_vi_done_inserting: if _rl_vi_last_key_before_insert == 'R', call + _rl_vi_save_replace to save text modified in replace mode (uses + vi_save_insert_buffer) + - _rl_vi_replace_insert: new function, replaces the number of chars + in vi_insert_buffer after rl_point with contents ov vi_insert_buffer + - rl_vi_redo: call _rl_vi_replace_insert if last command == 'R' and + there's something in vi_insert_buffer. Fixes bug with `.' not + redoing the most recent `R' command, reported by Geoff Clare + in readline area on savannah + + 11/26 + ----- +lib/readline/rlprivate.h + - RL_SIG_RECEIVED(): evaluate to non-zero if there is a pending signal + to be handled + - RL_SIGINT_RECEIVED(): evaluate to non-zero if there is a pending + SIGINT to be handled + +lib/readline/complete.c + - remove all mention of _rl_interrupt_immediately + - rl_completion_matches: check RL_SIG_RECEIVED after each call to + the entry function, call RL_CHECK_SIGNALS if true to handle the + signal + - rl_completion_matches: if RL_SIG_RECEIVED evaluates to true, free + and zero out the match_list this function allocated + - rl_completion_matches: if the completion entry function is + rl_filename_completion_function, free the contents of match_list, + because that function does not keep state and will not free the + entries; avoids possible memory leak pointed out by + Garrett Cooper + - gen_completion_matches: if RL_SIG_RECEIVED evalutes to true after + calling rl_attempted_completion_function, free the returned match + list and handle the signal with RL_CHECK_SIGNALS; avoids + possible memory leak pointed out by Garrett Cooper + + - gen_completion_matches: if RL_SIG_RECEIVED evaluates to true after + calling rl_completion_matches, free the returned match list and + handle the signal with RL_CHECK_SIGNALS + +lib/readline/util.c + - rl_settracefp: new utility function to set the tracing FILE * + +lib/readline/signals.c + - _rl_sigcleanup: pointer to a function that will be called with the + signal and a void * argument from _rl_handle_signal + - _rl_sigcleanarg: void * that the rest of the code can set to have + passed to the signal cleanup function + - _rl_handle_signal: if _rl_sigcleanup set, call as + (*_rl_sigcleanup) (sig, _rl_sigcleanarg) + +lib/readline/rlprivate.h + - extern declarations for _rl_sigcleanup and _rl_sigcleanarg + +lib/readline/complete.c + - _rl_complete_sigcleanup: signal cleanup function for completion code; + calls _rl_free_match_list on _rl_sigcleanarg if signal == SIGINT + - rl_complete_internal: before calling display_matches if what_to_do + == `?', set _rl_sigcleanup to _rl_complete_sigcleanup so the match + list gets freed on SIGINT; avoids possible memory leak pointed out + by Garrett Cooper + - rl_complete_internal: in default switch case, call _rl_free_match_list + before returning to avoid memory leak + +doc/bashref.texi + - start at a set of examples for the =~ regular expression matching + operator, touching on keeping the pattern in a shell variable and + quoting portions of the pattern to remove their special meaning + + 12/1 + ---- +lib/glob/gmisc.c + - extglob_pattern: new function, returns 1 if pattern passed as an + argument looks like an extended globbing pattern + +lib/glob/glob.c + - skipname: return 0 immediately if extglob_pattern returns non-zero, + let the extended globbing code do the right thing with skipping + names beginning with a `.' + - mbskipname: return 0 immediately if extglob_pattern returns non-zero, + let the extended globbing code do the right thing with skipping + names beginning with a `.'. Fixes bug reported by Yongzhi Pan + + + 12/2 + ---- +lib/glob/smatch.c + - patscan, patscan_wc: no longer static so other parts of the glob + library can use them, renamed to glob_patscan, glob_patscan_wc + +lib/glob/glob.c + - extern declarations for glob_patscan, glob_patscan_wc + - wchkname: new function, does skipname on wchar_t pattern and dname, + old body of mbskipname after converting to wide chars + - extglob_skipname: new function, checks all subpatterns in an extglob + pattern to determine whether or not a filename should be skipped. + Calls skipname for each subpattern. Dname is only skipped if all + subpatterns indicate it should be. Better fix for bug reported by + Yongzhi Pan + - wextglob_skipname: wide-char version of extglob_skipname, calls + wchkname instead of calling back into mbskipname for each + subpattern to avoid problems with char/wchar_t mismatch + - skipname: call extglob_skipname if extglob_pattern returns non-zero + - mbskipname: call wextglob_skipname if extglob_pattern returns non-zero + - mbskipname: short-circuit immediately if no multibyte chars in + pattern or filename + +execute_cmd.c + - execute_cond_node: added parens to patmatch assignment statement to + make intent clearer + + 12/3 + ---- +configure.in,config.h.in + - check for imaxdiv, define HAVE_IMAXDIV if present + +expr.c + - expassign, exp2: use imaxdiv if available. Doesn't help with checks + for overflow from 10/25 + + 12/6 + ---- +lib/readline/complete.c + - compute_lcd_of_matches: if we're ignoring case in the matches, only + use what the user typed as the lcd if it matches the first match + (after sorting) up to the length of what was typed (if what the + user typed is longer than the shortest of the possible matches, use + the shortest common length of the matches instead). If it doesn't + match, use the first of the list of matches, as if case were not + being ignored. Fixes bug reported by Clark Wang + + + 12/7 + ---- +builtins/cd.def + - cd_builtin: add code to return error in case cd has more than one + non-option argument, conditional on CD_COMPLAINS define (which is + not defined anywhere) + +doc/{bash.1,bashref.texi} + - note that additional arguments to cd following the directory name + are ignored. Suggested by Vaclav Hanzl + + 12/10 + ----- +lib/readline/input.c + - rl_read_key: don't need to increment key sequence length here; doing + it leads to an off-by-one error + +lib/readline/macro.c + - rl_end_kbd_macro: after off-by-one error with rl_key_sequence_length + fixed, can decrement current_macro_index by rl_key_sequence_length + (length of key sequence that closes keyboard macro) + +lib/readline/readline.c + - _rl_dispatch_subseq: fix extra increment of rl_key_sequence_length + when ESC maps to a new keymap and we're converting meta characters + to ESC+key + - _rl_dispatch_subseq: better increment of rl_key_sequence_length + before we dispatch to a function in the ISFUNC case (where the + second increment above should have happened) + - rl_executing_keyseq: the full key sequence that ended up executing + a readline command. Available to the calling application, maintained + by _rl_dispatch_subseq, indexed by rl_key_sequence_length + - rl_executing_key: the key that was bound to the currently-executing + readline command. Same as the `key' argument to the function + +lib/readline/readline.h + - rl_executing_keyseq: extern declaration + - rl_executing_key: extern declaration + - rl_key_sequence_length: declaration moved here from rlprivate.h, + now part of public interface + +lib/readline/rlprivate.h + - new extern declaration for _rl_executing_keyseq_size, buffer size + for rl_executing_keyseq + +lib/readline/doc/rltech.texi + - documented new variables: rl_executing_key, rl_executing_keyseq, + rl_key_sequence_length + + 12/13 + ----- +bashline.c + - bash_execute_unix_command: replace ad-hoc code that searches + cmd_xmap for correct command with call to rl_function_of_keyseq + using rl_executing_keyseq; now supports key sequences longer + than two characters. Fixes bug reported by Michael Kazior + + + 12/15 + ----- +make_cmd.c + - make_function_def: don't null out source_file before calling + make_command so it can be used later on when the function definition + is executed + +execute_cmd.c + - execute_intern_function: second argument is now FUNCTION_DEF * + instead of COMMAND * + - execute_command_internal: call execute_intern_function with the + new second argument (the entire FUNCTION_DEF instead of just the + command member) + - execute_intern_function: if DEBUGGER is defined, call + bind_function_def before calling bind_function, just like + make_function_def does (might be able to take out the call in + make_function_def depending on what the debugger does with it). + Fixes bug reported by + +expr.c + - more minor changes to cases of INTMAX_MIN % -1 and INTMAX_MIN / 1; + fix typos and logic errors + + 12/16 + ----- +bashline.c + - find_cmd_start: change flags to remove SD_NOSKIPCMD so it skips over + command substitutions and doesn't treat them as command separators + - attempt_shell_completion: instead of taking first return from + find_cmd_name as command name to use for programmable completion, + use loop to skip over assignment statements. Fixes problem reported + by Raphael Droz + - attempt_shell_completion: if we don't find a command name but the + command line is non-empty, assume the other words are all assignment + statements and flag that point is in a command position so we can + do command name completion + - attempt_shell_completion: if the word being completed is the first + word following a series of assignment statements, and the + command line is non-empty, flag that point is in a command position + so we can do command name completion + +lib/readline/history.c + - history_get_time: atol -> strtol + + 12/18 + ----- +parse.y + - parser_in_command_position: external interface to the + command_token_position macro for use by other parts of the shell, + like the completion mechanism + +externs.h + - extern declaration for parser_in_command_position + + 12/19 + ----- + +builtins/read.def + - read_builtin: make sure all calls to bind_read_variable are passed + a non-null string. Fixes bug reported by Dan Douglas + + +bashline.c + - attempt_shell_completion: mark that we're in a command position if + we're at the start of the line and the parser is ready to accept + a reserved word or command name. Feature most recently suggested + by Peng Yu + + 12/21 + ----- +lib/readline/bind.c + - _rl_escchar: return the character that would be backslash-escaped + to denote the control character passed as an argument ('\n' -> 'n') + - _rl_isescape: return 1 if character passed is one that has a + backslash escape + - _rl_untranslate_macro_value: new second argument: use_escapes, if + non-zero translate to backslash escapes where possible instead of + using straight \C-x for control character `x'. Change callers + - _rl_untranslate_macro_value: now global + +lib/readline/rlprivate.h + - _rl_untranslate_macro_value: extern declaration + +lib/readline/{macro.c,readline.h} + - rl_print_last_kbd_macro: new bindable function, inspired by patch + from Mitchel Humpherys + +lib/readline/funmap.c + - print-last-kbd-macro: new bindable command, bound to + rl_print_last_kbd_macro + +lib/readline/doc/{rluser.texi,readline.3},doc/bash.1 + - print-last-kbd-macro: document. + +lib/readline/text.c + - _rl_insert_next: if we're defining a macro, make sure the key gets + added to the macro text (should really audit calls to rl_read_key() + and make sure the right thing is happening for all of them) + +bashline.[ch] + - print_unix_command_map: new function, prints all bound commands in + cmd_xmap using rl_macro_dumper in a reusable format + +builtins/bind.def + - new -X option: print all keysequences bound to Unix commands using + print_unix_command_map. Feature suggested by Dennis Williamson + (2/2011) + +doc/{bash.1,bashref.texi} + - document new `bind -X' option + + 12/24 + ----- + +doc/{bash.1,bashref.texi} + - add a couple of sentences to the description of the case modification + operators making it clearer that each character of parameter is + tested against the pattern, and that the pattern should only attempt + to match a single character. Suggested by Bill Gradwohl + + + 12/28 + ----- +shell.c + - init_noninteractive: instead of calling set_job_control(0) to + unconditionally turn off job control, turn on job control if + forced_interactive or jobs_m_flag is set + - shell_initialize: call initialize_job_control with jobs_m_flag as + argument so `bash -m script' enables job control while running the + script + +jobs.c + - initialize_job_control: if the `force' argument is non-zero, turn on + job control even if the shell is not currently interactive + (interactive == 0) + + 12/29 + ----- + +flags.h + - new extern declaration for jobs_m_flag + +builtins/{cd,set}.def,doc/{bash.1,bashref.texi} + - added text clarifying the descriptions of cd -L and -P, suggested by + Padraig Brady + - slight change to the description of `set -P' about resolving symbolic + links + +lib/readline/doc/rluser.texi + - Added an example to the programmable completion section: _comp_cd, + a completion function for cd, with additional verbiage. Text + includes a reference to the bash_completion project + + 1/1/2012 + -------- +jobs.c + - set_job_status_and_cleanup: note that a job is stopped due to + SIGTSTP (any_tstped) if job_control is set; there's no need to + test interactive + + 1/5 + --- +quit.h + - LASTSIG(): new macro, expands to signal number of last terminating + signal received (terminating_signal or SIGINT) + +trap.c + - first_pending_trap: returns lowest signal number with a trap pending + - trapped_signal_received: set to the last trapped signal the shell + received in trap_handler(); reset to 0 in run_pending_traps + +builtins/read.def + - read_builtin: changes to posix-mode (posixly_correct != 0) to make + `read' interruptible by a trapped signal. After the trap runs, + read returns 128+sig and does not assign the partially-read line + to the named variable(s). From an austin-group discussion started + by David Korn + + 1/11 + ---- +doc/{bash.1,bashref.texi} + - slight changes to the descriptions of the compat32 and compat40 shell + options to clarify their meaning + + 1/12 + ---- +lib/readline/{colors.[ch],parse-colors.[ch]} + - new files, part of color infrastructure support + +Makefile.in,lib/readline/Makefile.in + - arrange to have colors.o and parse-colors.o added to readline + library + +{configure,config.h}.in + - check for stdbool.h, define HAVE_STDBOOL_H if found + + 1/14 + ---- +lib/readline/bind.c + - colored_stats: new bindable variable, enables using colors to + indicate file type when listing completions + +lib/readline/complete.c + - _rl_colored_stats: new variable, controlled by colored-stats bindable + variable + - colored_stat_start, colored_stat_end: new functions to set and reset + the terminal color appropriately depending on the type of the + filename to be printed + - print_filename: changes to print colors if `colored-stats' variable + set. Changes contributed by Raphael Droz + + +lib/readline/readline.c + - rl_initialize_everything: add call to _rl_parse_colors to parse + color values out of $LS_COLORS. May have to add to rl_initialize + to make more dynamic if LS_COLORS changes (which doesn't happen + very often, if at all) + +lib/readline/rlprivate.h + - _rl_colored_stats: new extern declaration + +lib/readline/doc/{readline.3,rluser.texi},doc/bash.1 + - colored-stats: document new bindable readline variable + +lib/readline/colors.c + - _rl_print_color_indicator: call rl_filename_stat_hook before calling + lstat/stat so we can get color indicators for stuff like + $HOME/Applications + +lib/readline/complete.c + - stat_char: call rl_filename_stat_hook before calling lstat/stat + +findcmd.[ch],execute_cmd.c + - search_for_command: now takes a second `flags' argument; changed + header function prototype and callers + - search_for_command: if (flags & 1), put the command found in $PATH + into the command hash table (previous default behavior) + +execute_cmd.c + - is_dirname: call search_for_command with flags argument of 0 so it + doesn't try to put something in the command hash table + +bashline.c + - bash_command_name_stat_hook: a hook function for readline's + filename_stat_hook that does $PATH searching the same way that + execute_cmd.c:execute_disk_command() does it, and rewrites the + passed filename if found. Does not put names into command hash + table. This allows command name completion to take advantage + of `visible-stats' and `colored-stats' settings. + - executable_completion: new function, calls the directory completion + hook to expand the filename before calling executable_file or + executable_or_directory; change command_word_completion_function to + call executable_completion. This allows $HOME/bin/[TAB] to do + command completion and display alternatives + + 1/17 + ---- +pcomplete.c + - gen_command_matches: now takes a new second argument: the command + name as deciphered by the programmable completion code and used + to look up the compspec; changed callers (gen_compspec_completions) + - gen_shell_function_matches: now takes a new second argument: the + command that originally caused the completion function to be + invoked; changed callers (gen_compspec_completions)) + - build_arg_list: now takes a new second argument: the command name + corresponding to the current compspec; changed callers + (gen_command_matches, gen_shell_function_matches) + - build_arg_list: now uses `cmd' argument to create $1 passed to + invoked command or shell function + - gen_compspec_completions: if we skipped a null command at the + beginning of the line (e.g., for completing `>'), add a new word for + it at the beginning of the word list and increment nw and cw + appropriately. This is all a partial fix for the shortcoming + pointed out by Sung Pae + + 1/18 + ---- + +{configure,config.h}.in + - new check: check for AUDIT_USER_TTY defined in , + define HAVE_DECL_AUDIT_USER_TTY if both are found + +lib/readline/rlconf.h + - ENABLE_TTY_AUDIT_SUPPORT: new define, allows use of the Linux kernel + tty auditing system if it's available and enabled + +lib/readline/util.c + - _rl_audit_tty: new function, send a string to the kernel tty audit + system + +lib/readline/rlprivate.h + - _rl_audit_tty: new extern declaration + +lib/readline/readline.c + - readline: call _rl_audit_tty with line to be returned before returning + it if the Linux tty audit system is available and it's been enabled + in rlconf.h Original patch from Miroslav Trmac; recent request + from Miroslav Lichvar + + 1/21 + ---- + +lib/readline/readline.c: + - _rl_dispatch_subseq: add an inter-character timeout for multi-char + key sequences. Suggested by . Still needs + work to make a user-settable variable + +parse.y + - shell_getc: make code that uses the pop_alias dependent on ALIAS + define + +variables.h + - sv_tz: extern define should only depend on HAVE_TZSET + +expr.c + - expr_streval: if ARRAY_VARS is not defined, set lvalue->ind to -1; + move assignment to `ind' inside define + - expr_bind_array_element: declaration and uses need to be #ifdef + ARRAY_VARS + +arrayfunc.h + - AV_ALLOWALL, AV_QUOTED, AV_USEIND: define to 0 if ARRAY_VARS not + defined; used in subst.c unconditionally + +sig.h + - make the signal blocking functions not dependent on JOB_CONTROL + +sig.c + - sigprocmask: make the replacement definition not dependent on + JOB_CONTROL + +trap.c + - use BLOCK_SIGNAL/UNBLOCK_SIGNAL instead of code dependent on + HAVE_POSIX_SIGNALS and BSD signals + + 1/24 + ---- + +print_cmd.c + - print_redirection_list: change the conditions under which + r_duplicating_output_word is mapped to r_err_and_out to more or + less match those used in redir.c. Fixes bug pointed out by + Dan Douglas + + + 1/29 + ---- +lib/readline/signals.c + - _rl_block_sigwinch,_rl_release_sigwinch: don't compile in bodies + unless SIGWINCH is defined. Fixes bug reported by Pierre Muller + + +doc/{bash.1,bashref.texi} + - small modifications to the introduction to the REDIRECTION section + to describe how redirections can modify file handles + - small modification to the section describing base#n to make it + clearer that n can be denoted using non-numerics. From a posting + by Linda Walsh + + 2/2 + --- +builtins/printf.def + - printf_builtin: make sure vbuf is intialized and non-null when -v + is supplied, since other parts of the code assume that it's not + null (e.g., bind_printf_variable()). Fixes bug reported by Jim + Avera + + 2/4 + --- +lib/readline/undo.c + - _rl_free_undo_list: new function, old body of rl_free_undo_list, + frees undo entries in UNDO_LIST * passed as argument + - rl_free_undo_list: call _rl_free_undo_list + +lib/readline/rlprivate.h + - _rl_free_undo_list: new extern declaration + - _rl_keyseq_timeout: new extern declaration (see below) + +lib/readline/misc.c + - rl_clear_history: new function. Clears the history list and frees + all associated data similar to history.c:clear_history(), but + takes rl_undo_list into account and frees and UNDO_LISTs saved as + `data' members of a history list entry + +lib/readline/doc/rltech.texi + - rl_clear_history: documented + +lib/readline/readline.c + - _rl_keyseq_timeout: new variable to hold intra-key timeout value + from 1/21 fix; specified in milliseconds. Default value is 500 + - _rl_dispatch_subseq: change to use _rl_keyseq_timeout as intra-key + timeout if it's greater than 0; no timeout if <= 0 + - _rl_dispatch_subseq: don't check for queued keyboard input if we have + pushed or pending input, or if we're reading input from a macro + +lib/readline/bind.c + - keyseq-timeout: new bindable variable, shadows _rl_keyseq_timeout + - string_varlist: add keyseq-timeout + - sv_seqtimeout: new function to modify value of _rl_keyseq_timeout; + clamps negative values at 0 for now + - _rl_get_string_variable_value: return value for keyseq-timeout + +doc/bash.1,lib/readline/doc/{rluser.texi,readline.3} + - keyseq-timeout: documented + +lib/readline/isearch.c + - _rl_isearch_dispatch: modification to fix from 7/18 to not use + cxt->keymap and cxt->okeymap, since by the time this code is + executed, they are equal. Use `f' to check for rl_insert or + unbound func + - _rl_isearch_dispatch: if we're switching keymaps, not in + callback mode, and don't have pending or pushed input, use + _rl_input_queued to resolve a potentially ambiguous key sequence. + Suggested by Roger Zauner + - _rl_isearch_dispatch: if we have changed keymaps and resolved to + an editing function (not self-insert), make sure we stuff the + right characters back onto the input after changing the keymap + back so the right editing function is executed after the search + is terminated. Rest of fix for bug reported by Roger Zauner + + + 2/5 + --- +builtins/gen-helpfiles.c + - new file: reads struct builtin and writes the long docs to files + in the `helpdirs' subdirectory. The filename is given in the + previously-unused `handle' member of the struct builtin. Links + with `tmpbuiltins.o', which is created by Makefile to have the + right long documentation. When not cross-compiling, gets the + right #defines based on configuration options from config.h instead + of trying to parse conditional parts of def files. Fixes + shortcoming pointed out by Andreas Schwab + +builtins/Makefile.in + - tmpbuiltins.c: new generated file, created to enable creation of + separate helpfiles based on correct #defines instead of trying to + parse conditional parts of def files + - gen-helpfiles: new program to generate helpfiles, links with + tmpbuiltins.o + - HELPFILES_TARGET: new target, substituted by configure to `helpdoc' + if separate helpfiles requested + - targets: new target, libbuiltins.a and $(HELPFILES_TARGET) + - CREATED_OBJECTS: new variable, holds created object files for + make clean; changed make clean to remove created objects + - helpdoc: changed to call gen-helpfiles instead of mkbuiltins + +Makefile.in + - when building libbuiltins.a, recursively call make with `targets' + argument to make sure separate helpfiles get built + +configure.in + - substitute `helpdoc' as value of HELPFILES_TARGET if + --enable-separate-helpfiles supplied as configure argument + +builtins/mkbuiltins.c + - `-nofunctions': new argument, causes mkbuiltins to not write value + for function implementing a particular builtin to struct builtin + and to write document file name to `handle' member of struct builtin + - no longer writes separate helpfiles; that is left to gen-helpfiles + + 2/8 + --- +subst.c + - make sure last_command_exit_value is set to a non-zero value before + any calls to report_error, since `-e' set will short-circuit + report_error. Fixes bug reported by Ewan Mellor + + +variables.c + - make_local_array_variable: added second argument; if non-zero, + function will return an existing local associative array variable + instead of insisting on an indexed array + +variable.h,subst.c + - make_local_array_variable: changed prototype and caller + +builtins/declare.def + - declare_internal: add second arg to call to make_local_array_variable; + making_array_special, which indicates we're processing an + assignment like declare a[b]=c. Fixes seg fault resulting from + a being an already-declared local associative array variable in a + function. Ubuntu bash bug 928900. + + 2/14 + ---- + +execute_cmd.c + - execute_command_internal: if redirections into or out of a loop fail, + don't try to free ofifo_list unless saved_fifo is non-zero. It's + only valid if saved_fifo is set + + 2/15 + ---- +{arrayfunc,braces,variables}.c + - last_command_exit_value: make sure it's set before any calls to + report_error, since -e will cause that to exit the shell + +builtins/common.c + - get_job_by_name: call internal_error instead of report_error so this + doesn't exit the shell + + 2/18 + ---- +builtins/evalstring.c + - parse_and_execute: make sure the file descriptor to be redirected to + is 1 before calling cat_file. One fix for bug reported by Dan Douglas + + +parse.y + - read_token_word: don't return NUMBER if a string of all digits + resolves to a number that overflows the bounds of an intmax_t. + Other fix for bug reported by Dan Douglas + + 2/19 + ---- +lib/sh/strtrans.c + - ansicstr: use 0x7f as the boundary for characters that translate + directly from ASCII to unicode (\u and \U escapes) instead of + UCHAR_MAX, since everything >= 0x80 requires more than one byte. + Bug and fix from John Kearney + +builtins/printf.def + - tescape: ditto for printf \u and \U escape sequences + + 2/20 + ---- +lib/sh/unicode.c + - u32toutf8: fix to handle encodings up to six bytes long correctly + (though technically UTF-8 only has characters up to 4 bytes long). + Report and fix from John Kearney + - u32toutf8: first argument is now an unsigned 32-bit quantity, + changed callers (u32cconv) to pass c instead of wc + - u32reset: new function, resets local static state to uninitialized + (locale information, currently) + +locale.c + - call u32reset whenever LC_CTYPE/LC_ALL/LANG is changed to reset the + cached locale information used by u32cconv. From a report from + John Kearney + + 2/21 + ---- +doc/{bash,builtins}.1 + - minor changes from Bjarni Ingi Gislason + +lib/sh/unicode.c + - u32cconv: only assume you can directly call wctomb on the passed + value if __STDC_ISO_10646__ is defined and the value is <= + 0x7fffffff + - stub_charset: return locale as default instead of "ASCII", let + rest of code decide what to do with it + +lib/readline/parens.c + - _rl_enable_paren_matching: make paren matching work in vi insert + mode. Bug report from + + 2/22 + ---- +lib/sh/shquote.c + - sh_backslash_quote: quote tilde in places where it would be + expanded. From a report from John Kearney + + 2/23 + ---- +execute_cmd.c + - execute_pipeline: wrap the discard_unwind_frame call in #ifdef + JOB_CONTROL, since the frame is only created if JOB_CONTROL is + defined. Bug and fix from Doug Kehn + + 2/25 + ---- +error.c + - report_error: make sure last_command_exit_value is non-zero before + we call exit_shell, since the exit trap may reference it. Call + exit_shell with last_command_exit_value to allow exit statuses + other than 1 + +unicode.c + - stub_charset: use local static buffer to hold charset, don't change + value returned by get_locale_var. Based on idea and code from + John Kearney + - u32toutf16: function to convert unsigned 32-bit value (unicode) to + UTF-16. From John Kearney + - u32cconv: call u32toutf16 if __STDC_ISO_10646__ defined and wchar_t + is two bytes, send result to wcstombs, return if not encoding error. + From John Kearney + - u32cconv: return UTF-8 conversion if iconv conversion to local + charset is unsupported + + 3/2 + --- +lib/readline/complete.c + - print_filename: if there is no directory hook, but there is a stat + hook, and we want to append a slash to directories, call the stat + hook before calling path_isdir on the expanded directory name. + Report and pointer to fix from Steve Rago + + 3/3 + --- +builtins/evalstring.c + - parse_and_execute: fix to change of 2/18: make sure the file + descriptor being redirected to is 0 before calling cat_file when + we see something like $(< file). Real fix for bug reported by + Dan Douglas + +subst.c + - parameter_brace_patsub: run the replacement string through quote + removal even if the expansion is within double quotes, because + the parser and string extract functions treat the quotes and + backslashes as special. If they're treated as special, quote + removal should remove them (this is the Posix position and + compatible with ksh93). THIS IS NOT BACKWARDS COMPATIBLE. + + 3/4 + --- +lib/readline/complete.c + - rl_menu_complete: fix to make show-all-if-ambiguous and + menu-complete-display-prefix work together if both are set. Fix + from Sami Pietila + + 3/5 + --- +bashline.c + - dircomplete_expand_relpath: new variable, if non-zero, means that + `shopt -s direxpand' should expand relative pathnames. Zero by + default, not user-settable yet + - bash_directory_completion_hook: if we have a relative pathname that + isn't changed by canonicalization or spell checking after being + appended to $PWD, then don't change what the user typed. Controlled + by dircomplete_expand_relpath + + 3/7 + --- +m4/timespec.m4 + - new macros, cribbed from gnulib and coreutils: find out whether we + have `struct timespec' and what file includes it + +m4/stat-time.m4 + - new macros, cribbed from gnulib and coreutils: find out whether the + mtime/atime/ctime/etctime fields of struct stat are of type + struct timespec, and what the name is + +include/stat-time.h + - new file, cribbed from gnulib, with additions from coreutils: include + the right file to get the struct timespec define, or provide our own + replacement. Provides a bunch of inline functions to turn the + appropriate members of struct stat into `struct timespec' values, + zeroing out the tv_nsec field if necessary + +test.c + - include "stat-time.h" for the nanosecond timestamp resolution stuff + - stat_mtime: new function, returns struct stat and the mod time + normalized into a `struct timespec' for the filename passed as the + first argument + - filecomp: call stat_mtime instead of sh_stat for each filename + argument to get the mtime as a struct timespec + - filecomp: call timespec_cmp instead of using a straight arithmetic + comparison for the -nt and -ot operators, using timespec returned by + stat_mtime. Added functionality requested by by Werner Fink + for systems that can support it + + 3/10 + ---- +include/posixdir.h + - REAL_DIR_ENTRY: remove dependency on _POSIX_SOURCE, only use feature + test macros to decide whether dirent.d_ino is present and usable; + define D_INO_AVAILABLE. Report and fix from Fabrizion Gennari + + - D_FILENO_AVAILABLE: define if we can use dirent.d_fileno + +lib/sh/getcwd.c + - use D_FILENO_AVAILABLE to decide whether or not to compile in + _path_checkino and whether or not to call it. Report and initial + fix from Fabrizion Gennari + +lib/readline/signals.c + - make sure all occurrences of SIGWINCH are protected by #ifdef + +sig.c + - make sure all occurrences of SIGCHLD are protected by #ifdef + +nojobs.c + - make sure SA_RESTART is defined to 0 if the OS doesn't define it + +version.c + - show_shell_version: don't use string literals in printf, use %s. + Has added benefit of removing newline from string to be translated + +trap.c + - queue_sigchld_trap: new function, increments the number of pending + SIGCHLD signals by the argument, which is by convention the number + of children reaped in a call to waitchld() + +trap.h + - queue_sigchld_trap: new extern declaration + +jobs.c + - waitchld: if called from the SIGCHLD signal handler (sigchld > 0), + then call queue_sigchld_trap to avoid running the trap in a signal + handler context. Report and original fix from Siddhesh Poyarekar + + +lib/sh/unicode.c + - u32tocesc: take an unsigned 32-bit quantity and encode it using + ISO C99 string notation (\u/\U) + - u32cconv: call u32tocesc as a fallback instead of u32cchar + - u32cconv: call u32tocesc if iconv cannot convert the character. + Maybe do the same thing if iconv_open fails + - u32reset: call iconv_close on localconv if u32init == 1 + + 3/11 + ---- +config-top.h + - CHECKWINSIZE_DEFAULT: new define, set to initial value of + check_window_size (shopt checkwinsize): 0 for off, 1 for on. + Default is 0 + +{jobs,nojobs}.c + - check_window_size: default initial value to CHECKWINSIZE_DEFAULT + + 3/13 + ---- +doc/bashref.texi + - change text referring to the copying restrictions to that + recommended by the FSF (no Front-Cover Texts and no Back-Cover + Texts) + +lib/readline/doc/{history,rlman,rluserman}.texi + - change text referring to the copying restrictions to that + recommended by the FSF (no Front-Cover Texts and no Back-Cover + Texts) + + 3/15 + ---- +array.c + - LASTREF_START: new macro to set the starting position for an array + traversal to `lastref' if that's valid, and to the start of the array + if not. Used in array_reference, array_insert, array_remove + - array_remove: try to be a little smarter with lastref instead of + unconditionally invalidating it + + 3/16 + ---- +array.c + - array_insert: fix memory leak by deleting element to be added in the + case of an error + + 3/18 + ---- +lib/sh/mbschr.c + - mbschr: don't call mbrlen unless is_basic is false; devolves to a + straight character-by-character run through the string + + 3/19 + ---- +stringlib.c + - substring: use memcpy instead of strncpy, since we know the length + and are going to add our own NUL terminator + + 3/20 + ---- +subst.c + - parameter_brace_expand_rhs: if expand_string_for_rhs returns a quoted + null string (a list with one element for which + QUOTED_NULL(list->word->word) returns true), return the quoted null + and set the flags in the returned word to indicate it. Fixes bug + reported by Mark Edgar + +lib/sh/tmpfile.c + - use random(3) instead of get_random_number to avoid perturbing the + random sequence you get using $RANDOM. Bug report and fix from + Jurij Mihelic + + 3/21 + ---- +config-top.h + - OPTIMIZE_SEQUENTIAL_ARRAY_ASSIGNMENT: define to 1 to optimize + sequential indexed array assignment patterns. Defined to 1 by + default + +array.c + - array_insert: if OPTIMIZE_SEQUENTIAL_ARRAY_ASSIGNMENT is defined, + start the search at lastref (see change from 3/15) + + 3/27 + ---- +print_cmd.c + - debug_print_word_list: new debugging function, prints a word list + preceded by an optional string and using a caller-specified + separator + + 4/1 + --- +command.h + - W_ASSNGLOBAL: new flag, set to indicate declare -g + +execute_cmd.c + - fix_assignment_words: note that we have a -g argument to an assignment + builtin and set the W_ASSNGLOBAL flag in the variable word + +subst.c + - dump_word_flags: print out W_ASSNGLOBAL if present + - do_assignment_internal: only set ASS_MKLOCAL if W_ASSIGNARG is set + and W_ASSNGLOBAL is not. Don't want to create a local variable even + if variable_context is non-zero if ASSNGLOBAL is set. Fixes bug + reported by Bill Gradwohl + + 4/7 + --- +lib/readline/readline.c + - _rl_dispatch_subseq: make the `keyseq-timeout' variable apply to + ESC processing when in vi mode. After hitting ESC, readline will + wait up to _rl_keyseq_timeout*1000 microseconds (if set) for + additional input before dispatching on the ESC and switching to + command/movement mode. Completes timeout work suggested by + ; this prompted by report from Barry Downes + + +lib/sh/shmbchar.c + - sh_mbsnlen: new function, returns the number of (possibly multibyte) + characters in a passed string with a passed length, examining at most + maxlen (third argument) bytes + +externs.h + - sh_mbsnlen: extern declaration for new function + +shell.c + - exit_shell: call maybe_save_shell_history if remember_on_history is + set, not just in interactive shells. That means the history is + saved if history is enabled, regardless of whether or not the shell + is interactive + +doc/{bash.1,bashref.texi} + - TMOUT: fix description to make it explicit that TMOUT is the timeout + period for a complete line of input, not just any input. Fixes + problem reported in Ubuntu bug 957303: + https://bugs.launchpad.net/ubuntu/+source/bash/+bug/957303 + - HISTFILE: document change to write history list to history file in + any shell with history enabled, not just interactive shells. This + seems to be more logical behavior. Suggested by Greg Wooledge + + + 4/12 + ---- +lib/readline/colors.h + - only include stdbool.h if HAVE_STDBOOL_H is defined + - if HAVE_STDBOOL_H is not defined, provide enough definition for the + library to use `bool', `true', and `false' + +lib/readline/parse-colors.[ch] + - don't try to include at all; rely on colors.h to do it + +lib/sh/snprintf.c + - vsnprintf_internal: only treat '0' as a flag to indicate zero padding + if `.' hasn't been encountered ((flags&PF_DOT) == 0); otherwise treat + it as the first digit of a precision specifier. Fixes bug reported + by Petr Sumbera + + 4/15 + ---- +lib/sh/snprintf.c + - vsnprintf_internal: if the '0' and '-' flags both occur, the '0' + flag is ignored -- Posix. Start of a series of fixes based on + tests and patches from Petr Sumbera + - PUT_PLUS: make sure PF_PLUS flag is specified before putting the `+' + - vsnprintf_internal: when '+' is read as a flag, don't set right- + justify flag if the LADJUST (`-') flag has already been supplied + - floating: make sure to output space padding before the `+', zero + padding after + - exponent: make sure to output space padding before the `+', zero + padding after + - exponent: only subtract one from the width for the decimal point + if we're really going to print one + - floating: use presence of PF_PLUS flag to decide whether to account + for the `+' in the padded field width. Ditto for exponent() + + 4/16 + ---- +lib/sh/snprintf.c + - vsnprint_internal: only reduce precision by 1 when processing the `g' + format if it's > 0. A precision of 0 should stay 0; otherwise it + gets set to -1 (NOT_FOUND) and converted to the default + - number, lnumber: if an explicit precision is supplied, turn off the + zero-padding flag and set the pad character back to space + - number, lnumber: only account for a `+' when performing the field + width calculation if the coversion is base 10; we don't add a `+' + for other bases + + 4/18 + ---- +tests/printf3.sub + - try using "perl -e 'print time'" to get the current time in seconds + since the epoch if "date +%s" is not available (solaris 8-10) + + 4/19 + ---- +tests/run-printf + - use cat -v instead of relying on diff -a being available to convert + control characters to ascii and avoid the dreaded "Binary files + /tmp/xx and printf.right differ" + + 4/20 + ---- +lib/sh/strftime.c + - incoporated new version from Aharon Robbins + + 4/22 + ---- +doc/{bash.1,bashref.texi} + - slight change to the description of /dev/tcp and /dev/udp + +subst.c + - match_wpattern: logic fix to the calculation of `simple' (was |=, + needs to be &=). Bug report from Mike Frysinger , + fix from Andreas Schwab + +bashline.c + - bash_filename_stat_hook: add code from bash_directory_completion_hook + that performs pathname canonicalization in the same way that cd and + other builtins will do + + 4/25 + ---- +execute_cmd.c + - execute_pipeline: change the call to move_to_high_fd to make it use + getdtablesize() and to not stomp on existing open file descriptors, + like the fd the shell is using to read a script. Bug report from + Greg Wooledge + + 5/6 + --- +subst.c + - expand_word_internal: case '$': after calling param_expand and + setting had_quoted_null, set TEMP to null. The code that builds the + returned string at the end of the function will take care of making + and returning a quoted null string if there's nothing else in + ISTRING. If there is, the quoted null should just go away. Part of + fix for bug reported by Ruediger Kuhlmann + - expand_word_internal: when processing ISTRING to build return value, + only set W_HASQUOTEDNULL in the returned word flags if the word is + a quoted null string AND had_quoted_null is set. Rest of fix + + 5/9 + --- +variables.c + - bind_variable_internal: if we get an array variable here (implicit + assignment to index 0), call make_array_variable_value, which + dummies up a fake SHELL_VAR * from array[0]. This matters when + we're appending and have to use the current value + - bind_variable_internal: after computing the new value, treat assoc + variables with higher precedence than simple array variables; it + might be that a variable has both attributes set + +arrayfunc.c + - bind_array_var_internal: break code out that handles creating the + new value to be assigned to an array variable index into a new + function, make_array_variable_value. This handles creating a + dummy SHELL_VAR * for implicit array[0] assignment. Fixes bug + reported by Dan Douglas + +arrayfunc.h + - make_array_variable_value: new extern declaration + + 5/19 + ---- +variables.c + - bind_int_variable: if an assignment statement like x=y comes in + from the expression evaluator, and x is an array, handle it like + x[0]=y. Fixes bug reported by Dan Douglas + + 5/24 + ---- + +braces.c + - mkseq: handle possible overflow and break the sequence generating + loop if it occurs. Fixes OpenSUSE bug 763591: + https://bugzilla.novell.com/show_bug.cgi?id=763591 + + 5/25 + ---- +Makefile.in + - LDFLAGS_FOR_BUILD: add to compilation recipes for build tools + buildversion, mksignames, mksyntax + - LDFLAGS_FOR_BUILD: add to compilation recipes for test tools + recho, zecho, printenv, xcase + +builtins/Makefile.in + - LDFLAGS_FOR_BUILD: add to compilation recipes for build tools + gen-helpfiles, psize.aux + +variables.c + - bind_int_variable: if LHS is a simple variable name without an array + reference, but resolves to an array variable, call + bind_array_variable with index 0 to make x=1 equivalent to x[0]=1. + Fixes bug reported by Dan Douglas + + 5/27 + ---- +subst.c + - expand_word_internal: make sure has_dollar_at doesn't get reset before + recursive calls to param_expand or expand_word_internal, since it has + to save state of what came before. Use temp variable and make sure + has_dollar_at is incremented if recursive call processes "$@". + Fixes bug reported by gregrwm and + supplemented by Dan Douglas + +doc/{bash.1,bashref.texi} + - changes to the description of substring expansion inspired by + suggestions from Bill Gradwohl + +doc/bashref.texi + - added substring expansion examples inspired by suggestions from + Bill Gradwohl + +variables.c + - find_shell_variable: search for a variable in the list of shell + contexts, ignore the temporary environment + - find_variable_tempenv: search for a variable in the list of shell + contexts, force search of the temporary environment + - find_variable_notempenv: search for a variable in the list of shell + contexts, don't force search of the temporary environment + +variables.h + - find_shell_variable: extern declaration + - find_variable_tempenv: extern declaration + - find_variable_notempenv: extern declaration + +arrayfunc.c + - bind_array_variable: call find_shell_variable instead of calling + var_lookup directly + +findcmd.c + - search_for_command: call find_variable_tempenv instead of + find_variable_internal directly + - _find_user_command_internal: call find_variable_tempenv instead of + find_variable_internal directly + +builtins/setattr.def + - set_var_attribute: call find_variable_notempenv instead of + find_variable_internal directly + - show_name_attributes: call find_variable_tempenv instead of + find_variable_internal directly + + 6/1 + --- +sig.c + - termsig_handler: don't try to save the shell history on a terminating + signal any more, since it just causes too many problems on Linux + systems using glibc and glibc malloc + +lib/readline/vi_mode.c + - rl_vi_change_to: change to correctly redo `cc', since `c' is not a vi + motion character. From Red Hat bug 813289 + - rl_vi_delete_to: change to correctly redo `dd', since `d' is not a vi + motion character + - rl_vi_yank_to: change to correctly redo `yy', since `y' is not a vi + motion character + + 6/4 + --- +lib/sh/mktime.c + - current versions of VMS do not need to include . Fix from + John E. Malmberg + + 6/5 + --- +lib/sh/eaccess.c + - sh_stat: instead of using a static buffer to do the DEV_FD_PREFIX + translation, use a dynamically-allocated buffer that we keep + resizing. Fixes potential security hole reported by David Leverton + + + 6/5 + --- +braces.c + - expand_seqterm: check errno == ERANGE after calling strtoimax for + rhs and incr. Part of a set of fixes from Scott McMillan + + - expand_seqterm: incr now of type `intmax_t', which changes + arguments to mkseq + - mkseq: a better fix for detecting overflow and underflow since it's + undefined in C and compilers `optimize' out overflow checks. Uses + ADDOVERFLOW and SUBOVERFLOW macros + - mkseq: use sh_imaxabs (new macro) instead of abs() for intmax_t + variables + - mkseq: don't allow incr to be converted to -INTMAX_MIN + - mkseq: make sure that strvec_create isn't called with a size argument + greater than INT_MAX, since it only takes an int + + 6/6 + --- +braces.c + - mkseq: try and be smarter about not overallocating elements in + the return array if the increment is not 1 or -1 + + 6/7 + --- +parse.y + - history_delimiting_chars: if the parser says we're in the middle of + a compound assignment (PST_COMPASSIGN), just return a space to avoid + adding a stray semicolon to the history entry. Fixes bug reported + by "Davide Brini" + + 6/8 + --- +bashline.c + - bash_directory_completion_hook: don't attempt spelling correction + on the directory name unless the direxpand option is set and we are + going to replace the directory name with the corrected one in the + readline line. Suggested by Linda Walsh + +lib/sh/shquote.c + - sh_backslash_quote: now takes a third argument: flags. If non-zero, + tildes are not backslash-escaped. Have to handle both printf %q, + where they should be escaped, and filename completion, where they + should not when used as usernames + +externs.h + - sh_backslash_quote: declaration now takes a third argument + +builtins/printf.def + - printf_builtin: call sh_backslash_quote with 1 as third argument + so tildes get escaped + +{bashline,bracecomp}.c + - call sh_backslash_quote with 0 as third argument so tildes are not + escaped in completed words + +doc/bash.1 + - add `coproc' to the list of reserved words. From a report by + Jens Schweikhardt + + 6/10 + ---- +execute_cmd.c + - line_number_for_err_trap: now global, so parse_and_execute can save + and restore it with unwind-protect + +builtins/evalstring.c + - parse_prologue: save and restore line_number_for_err_trap along + with line_number + - restore_lastcom: new function, unwind-protect to restore + the_printed_command_except_trap + - parse_prologue: use restore_lastcom to save and restore the value + of the_printed_command_except_trap around calls to parse_and_execute + (eval/source/.) + + 6/15 + ---- +lib/readline/complete.c + - complete_fncmp: change filename comparison code to understand + multibyte characters, even when doing case-sensitive or case-mapping + comparisons. Fixes problem reported by Nikolay Shirokovskiy + + + 6/20 + ---- +builtins/mapfile.def + - mapfile: move the line count increment and check for having read + the specified number of lines to the end of the loop to avoid + reading an additional line with zgetline. Fixes bug reported by + Dan Douglas + + 6/21 + ---- + +execute_cmd.c + - execute_pipeline: make sure `lastpipe_flag' is initialized to 0 on + all systems, since it's tested later in the function. Fixes bug + reported by John E. Malmberg + + 6/22 + ---- +mailcheck.c + - file_mod_date_changed: return 0 right away if mailstat() does not + return success. Fixes bug with using uninitialized values reported + by szymon.kalasz@uj.edu.pl + +builtins/set.def + - the `monitor' option is not available when the shell is compiled + without job control, since the underlying `m' flag is not available + +nojobs.c + - job_control: now declared as int variable, initialized to 0, never + modified + +jobs.h + - job_control: extern declaration no longer dependent on JOB_CONTROL + +execute_cmd.c + - execute_pipeline: made necessary changes so `lastpipe' shell option + is now available in all shells, even those compiled without + JOB_CONTROL defined + + 6/23 + ---- +lib/glob/glob.c + - glob_filename: check for interrupts before returning if glob_vector + returns NULL or an error. Bug reported by Serge van den Boom + , fix from Andreas Schwab + - call run_pending_traps after each call to QUIT or test of + interrupt_state, like we do in mainline shell code + - glob_vector: don't call QUIT; in `if (lose)' code block; just free + memory, return NULL, and let callers deal with interrupt_state or + other signals and traps + + 6/25 + ---- +lib/readline/input.c + - rl_read_key: restructure the loop that calls the event hook a little, + so that the hook is called only after rl_gather_tyi returns no input, + and any pending input is returned first. This results in better + efficiency for processing pending input without calling the hook + on every input character as bash-4.1 did. From a report from + Max Horn + + 6/26 + ---- +trap.c + - signal_is_pending: return TRUE if SIG argument has been received and + a trap is waiting to execute + +trap.h + - signal_is_pending: extern declaration + +lib/glob/glob.c + - glob_vector: check for pending SIGINT trap each time through the loop, + just like we check for interrupt_state or terminating_signal, and + set `lose = 1' so we clean up after ourselves and interrupt the + operation before running the trap. This may require a change later, + maybe call run_pending_traps and do that if run_pending_traps returns? + +variables.c + - sv_histtimefmt: set history_comment_character to default (`#') if + it's 0 when we're turning on history timestamps. The history code + uses the history comment character to prefix timestamps, and + leaving it at 0 effectively removes them from the history. From a + report to help-bash by Dennis Williamson + + 6/27 + ---- +lib/readline/signals.c + - rl_maybe_restore_sighandler: new function, sets handler for SIG to + HANDLER->sa_handler only if it's not SIG_IGN. Needs to be called + on same signals set using rl_maybe_set_sighandler, which does not + override an existing SIG_IGN handler (SIGALRM is ok since it does + the check inline; doesn't mess with SIGWINCH) + + 6/30 + ---- +variables.h + - additional defines for the new `nameref' variable attribute + (att_nameref): nameref_p, nameref_cell, var_setref + +variables.c + - find_variable_nameref: resolve SHELL_VAR V through chain of namerefs + - find_variable_last_nameref: resolve variable NAME until last in a + chain of possibly more than one nameref starting at shell_variables + - find_global_variable_last_nameref: resolve variable NAME until last + in a chain of possibly more than one nameref starting at + global_variables + - find_nameref_at_context: resolve SHELL_VAR V through chain of namerefs + in a specific variable context (usually a local variable hash table) + - find_variable_nameref_context: resolve SHELL_VAR V through chain of + namerefs following a chain of varible contexts + - find_variable_last_nameref_context: resolve SHELL_VAR V as in + find_variable_last_context, but return the final nameref instead of + what the final nameref resolves to + - find_variable_tempenv, find_variable_notempenv, find_global_variable, + find_shell_variable, find_variable: modified to follow namerefs + - find_global_variable_noref: look up a global variable without following + any namerefs + - find_variable_noref: look up a shell variable without following any + namerefs + - bind_variable_internal: modify to follow a chain of namerefs in the + global variables table; change to handle assignments to a nameref by + following nameref chain + - bind_variable: modify to follow chain of namerefs when binding to a + local variable + - unbind_variable: changes to unset nameref variables (unsets both + nameref and variable it resolves to) + +subst.c + - parameter_brace_expand_word: change to handle expanding nameref whose + value is x[n] + - parameter_brace_expand_indir: change to expand in ksh93-compatible + way if variable to be indirected is nameref and a simple (non-array) + expansion + - param_expand: change to expand $foo where foo is a nameref whose value + is x[n] + +execute_cmd.c + - execute_for_command: changes to implement ksh93 semantics when index + variable is a nameref + +builtins/setattr.def + - show_var_attributes: change to add `n' to flags list if att_nameref + is set + +builtins/set.def + - unset_builtin: changes to error messages to follow nameref variables + +builtins/declare.def + - document new -n option + - declare_internal: new `-n' and `+n' options + - declare_internal: handle declare -n var[=value] and + declare +n var[=value] for existing and non-existant variables. + Enforce restriction that nameref variables cannot be arrays. + Implement semi-peculiar ksh93 semantics for typeset +n ref=value + + 7/5 + --- +variables.c + - unbind_variable: unset whatever a nameref resolves to, leaving the + nameref variable itself alone + - unbind_nameref: new function, unsets a nameref variable, not the + variable it references + +variables.h + - unbind_nameref: extern declaration + +builtins/set.def + - unset_builtin: modify to add -n option, which calls unbind_nameref + leaving unbind_variable for the usual case. This required slight + changes and additions to the test suite + +doc/{bash.1,bashref.texi} + - document namerefs and typeset/declare/local/unset -n + + 7/13 + ---- +lib/sh/casemod.c + - include shmbchar.h for is_basic and supporting pieces + - sh_casemod: use _to_wupper and _to_wlower to convert wide character + case instead of TOUPPER and TOLOWER. Fixes bug reported by + Dennis Williamson , fix from + Andreas Schwab + - cval: short-circuit and return ascii value if is_basic tests true + - sh_casemod: short-circuit and use non-multibyte case modification + and toggling code if is_basic tests true + +lib/readline/signals.c + - _rl_{block,release}_sigint: remove the code that actually blocks and + releases the signals, since we defer signal handling until calls to + RL_CHECK_SIGNALS() + +lib/readline/{callback,readline,util}.c + - if HAVE_POSIX_SIGSETJMP is defined, use sigsetjmp/siglongjmp without + saving and restoring the signal mask instead of setjmp/longjmp + +lib/readline/rltty.c + - prepare_terminal_settings: don't mess with IXOFF setting if + USE_XON_XOFF defined + +doc/{bash.1,bashref.texi} + - add some text to the description of set -e clarifying its effect + on shell functions and shell function execution. Suggested by + Rainer Blome + +bashline.c + - edit_and_execute_command: increment current_command_line_count before + adding partial line to command history (for command-oriented-history + because of rl_newline at beginning of function), then reset it to 0 + before adding the dummy history entry to make sure the dummy entry + doesn't get added to previous incomplete command. Partial fix for + problem reported by Peng Yu + + 7/24 + ---- +configure.in + - interix: define RECYCLES_PIDS. Based on a report from Michael + Haubenwallner + + 7/26 + ---- +jobs.c + - make_child: call bgp_delete on the newly-created pid unconditionally. + Some systems reuse pids before cycling through an entire set of + CHILD_MAX/_SC_CHILD_MAX unique pids. This is no longer dependent + on RECYCLES_PIDS. Based on a report from Michael Haubenwallner + + +support/shobj-conf + - Mac OS X: drop MACOSX_DEPLOYMENT_TARGET=10.3 from the LDFLAGS. We + can finally kill Panther + + 7/28 + ---- +subst.c + - command_substitute: make sure last_made_pid gets reset if make_child + fails + +execute_cmd.c + - execute_command_internal: case cm_simple: decide whether or not to + wait_for a child if already_making_children is non-zero, indicates + that there is an unwaited-for child. More of fix for bug report + from Michael Haubenwallner + +jobs.c + - make_child: call delete_old_job (new_pid) unconditionally, don't + bother to check whether or not pid wrap occurred. Rest of fix for + bug report from Michael Haubenwallner + + + 7/29 + ---- +shell.c + - subshell_exit: new function, exits the shell (via call to sh_exit()) + after calling any defined exit trap + +externs.h + - subshell_exit: new extern declaration + +execute_cmd.c + - execute_command_internal: make sure to call subshell_exit for + {} group commands executed asynchronously (&). Part of fix for + EXIT trap bug reported by Maarten Billemont + +sig.c + - reset_terminating_signals: make sure to set termsigs_initialized back + to 0, so a subsequent call to initialize_terminating_signals works + right. Rest of fix for bug reported by Maarten Billemont + + +{execute_cmd,general,jobs,mailcheck,mksyntax,test}.c +builtins/{cd,fc,pushd,ulimit}.def +lib/malloc/getpagesize.h +lib/sh/{clktck,fpurge,inet_aton,mailstat,oslib,pathcanon,pathphys,spell,strerror}.c + - make inclusion of dependent on HAVE_SYS_PARAM_H + consistently + + 8/6 + --- +lib/readline/histexpand.c + - history_expand_internal: now takes an additional argument saying + whether the history expansion occurs within a quoted string, set to + the open quote character + - history_expand_internal: use new argument instead of checking prev + char and initializing quoted_search_delimiter, pass qc directly to + get_history_event, where it allows a matching quote to terminate a + string defining an event + - history_expand: change single-quote handling code so that if + history_quotes_inhibit_expansion is 0, single quotes are treated + like double quotes + - history_expand: change call to history_expand_internal to pass new + argument of `"' if double-quoted string, `'' if single-quoted string; + this lets history_expand decide what is a quoted string and what + is not + + 8/7 + --- +configure.in + - AC_CANONICAL_BUILD: invoke for later use + +lib/readline/macro.c + - _rl_prev_macro_key: new function, inverse of _rl_next_macro_key: + backs up the index into the current macro by 1 + +lib/readline/rlprivate.h + - _rl_prev_macro_key: extern declaration + + +lib/readline/readline.c + - _rl_dispatch_subseq, _rl_subseq_result: don't call _rl_unget_char + if we're currently reading from a macro; call _rl_prev_macro_key + instead. Fixes bug reported by Clark Wang + + 8/13 + ---- +builtins/evalstring.c + - evalstring(): new function, wrapper around parse_and_execute. + make sure we handle cases where parse_and_execute can call `return' + and short-circuit without cleaning up properly. We call + parse_and_execute_cleanup() then jump to the previous-saved return + location + +builtins/common.h + - extern declaration for evalstring() + +builtins/eval.def + - eval_builtin: make sure we handle `eval " ... return"' in contexts + where `return' is valid by calling evalstring(). Fixes bug with + `eval return' in sourced files reported by Clark Wang + + +trap.c + - run_pending_traps: call evalstring instead of parse_and_execute. + XXX - still needs to handle saving and restoring token state in the + presence of `return'; could use unwind_protects for that + +builtins/mapfile.def + - run_callback: call evalstring instead of parse_and_execute + + 8/15 + ---- +bashline.c + - bash_filename_stat_hook: make sure we don't free local_dirname + before using it to canonicalize any expanded filename. Make sure + it always points to *dirname and only free it if we're replacing + it. + +lib/readline/complete.c + - append_to_match: make sure we call rl_filename_stat_hook with + newly-allocated memory to avoid problems with freeing it twice + + 8/17 + ---- +variables.c,config-top.h + - if ARRAY_EXPORT is defined to 1 when variables.c is compiled, the + code that allows indexed arrays to be exported is enabled and + included + + 8/19 + ---- +shell.c + - call start_debugger from main() only if dollar_vars[1] != 0 (close + enough to a non-interactive shell, since we can be interactive with + -i while running a shell script). Fixes oddity reported by + Techlive Zheng + + 8/20 + ---- +arrayfunc.c + - quote_array_assignment_chars: don't bother quoting if the word has + not been marked as an assignment (W_ASSIGNMENT) + - quote_array_assignment_chars: turn on W_NOGLOB in the word flags + so assignment statements don't undergo globbing. Partial fix for + problems reported by Dan Douglas + + 8/21 + ---- +command.h + - W_NOBRACE: new word flag that means to inhibit brace expansion + +subst.c + - brace_expand_word_list: suppress brace expansion for words with + W_NOBRACE flag + + 8/22 + ---- +builtins/read.def + - read_builtin: don't call dequote_string on what we've read, even if + we saw an escape character, unless (input_string && *input_string). + We may have escaped an IFS whitespace character. Fixes seg fault + reported by + +execute_cmd.c + - execute_command_internal: set the_printed_command_except trap when + about to execute a ( ... ) user subshell. For now, set it only if + ERR is trapped; can relax that later. Fixes bug reported by + Mike Frysinger + + 8/23 + ---- +jobs.c + - remove references to first_pid and pid_wrap, since we're not using + them for anything anymore + + 8/24 + ---- +subst.c + - changes for W_NOBRACE everywhere appropriate: so it can be displayed + for debugging, and passed out of expand_word_internal + +doc/{bash.1,bashref.texi} + - small changes to make it clearer that the = and == operators are + equivalent, and will cause pattern matching when used with [[. + From a question from Michal Soltys + +doc/bashref.texi + - some small formatting changes from Karl Berry + + 8/27 + ---- +lib/readline/doc/{history,rlman,rluserman}.texi + - some small formatting changes from Karl Berry + +arrayfunc.c + - assign_array_element_internal, assign_compound_array_list, + unbind_array_element, array_value_internal: changes to make + assignment statements to negative indices (a[-1]=2) and unsetting + array elements using negative indices (unset 'a[-1]') work. + From suggestions by Dennis Williamson + and Chris F. A. Johnson + +subst.c + - array_length_reference: changes to make length references to array + elements using negative indices (${#a[-1]}) work + + 8/28 + ---- +doc/{bash.1,bashref.texi} + - document new treatment of negative indices to indexed arrays when + assigning, referencing, calculating length, and unsetting + + 8/29 + ---- +shell.c + - show_shell_usage: add -l to list of shell invocation options (short + for --login). From Red Hat bug 852469 + +configure.ac + - renamed from configure.in, as latest autoconf versions want. Patches + Stefano Lattarini + +MANIFEST,Makefile.in,doc/bashref.texi,support/mkconffiles + - configure.in -> configure.ac + + 9/1 + --- + +parse.y + - read_token_word: allow words like {array[ind]} to be valid redirection + words for constructs like {x} + +lib/readline/display.c + - update_line: if the first difference between the old and new lines + is completely before any invisible characters in the prompt, we + should not adjust _rl_last_c_pos, since it's before any invisible + characters. Fixed in two places + - prompt_modechar: return a character indicating the editing mode: + emacs (@), vi command (:), or vi insert (+) + - _rl_reset_prompt: new function, just calls rl_expand_prompt. Will be + inlined, placeholder for more changes + - expand_prompt: if show-mode-in-prompt is enabled, add a character to + the front of the prompt indicating the editing mode, adjusting the + various variables as appropriate to keep track of the number of + visible characters and number of screen positions + +lib/readline/bind.c + - show-mode-in-prompt: new bindable boolean variable, shadowed by + _rl_show_mode_in_prompt variable + - hack_special_boolean_var: call _rl_reset_prompt when toggling or + setting show-mode-in-prompt + +lib/readline/readline.c + - readline_internal_setup: make sure the correct vi mode keymap is set + before expanding the prompt string for the first time + +lib/readline/misc.c + - rl_emacs_editing_mode: make sure to call _rl_reset_prompt if we're + showing the editing mode in the prompt + +lib/readline/rlprivate.h + - _rl_reset_prompt, _rl_show_mode_in_prompt: extern declarations + +lib/readline/vi_mode.c + - rl_vi_insertion_mode: call _rl_reset_prompt + - rl_vi_movement_mode: call _rl_reset_prompt. Finishes changes for + showing mode in prompt string, originally requested by Miroslav + Koskar and most recently by Jordan Michael + Ziegler + +doc/bash.1,lib/readline/doc/{readline.3,rluser.texi} + - document new show-mode-in-prompt variable, off by default + + 9/3 + --- + +jobs.c + - set_childmax: new function, external mechanism for other parts of + the shell to set js.c_childmax, the number of saved exited child + statuses to remember +jobs.h + - set_childmax: extern declaration + +variables.c + - CHILD_MAX: new special variable, with sv_childmax function to + run when it changes. Setting CHILD_MAX to a value greater than + zero but less than some maximum (currently 8192) sets the number of + exited child statuses to remember. set_childmax (jobs.c) ensures + that the number does not drop below the posix-mandated minimum + (CHILD_MAX) + +doc/{bash.1,bashref.texi} + - CHILD_MAX: document new meaning and action when variable is set + + 9/5 + --- +redir.c + - redir_varassign: call stupidly_hack_special_variables after + assigning fd number to specified variable, so we can use constructs + like {BASH_XTRACEFD}>foo. Suggested by Pierre Gaston + + + 9/8 + --- +expr.c + - readtok: invalidate previous contents of `curlval' before freeing + and reallocating tokstr (which, chances are, will get the same + pointer as before and render curlval inconsistent). Fixes other + bug reported by Dan Douglas + + 9/9 + --- +lib/readline/complete.c + - rl_username_completion_function: protect call to setpwent() with + #ifdef (HAVE_GETPWENT)/#endif. Fixes bug reported by + Gerd Hofmann + +lib/readline/display.c + - rl_message: second and subsequent calls to rl_message can result in + local_prompt being overwritten with new values (e.g., from the + successive calls displaying the incremental search string). Need + to free before overwriting if it's not the same as the value saved + in saved_local_prompt. Fixes memory leak reported by + Wouter Vermaelen + +lib/readline/{terminal.c,rlprivate.h} + - move CUSTOM_REDISPLAY_FUNC and CUSTOM_INPUT_FUNC defines from + terminal.c to rlprivate.h so other files can use them + +expr.c + - expr_streval: if noeval is non-zero, just return 0 right away, + short-circuiting evaluation completely. readtok will leave curtok + set correctly without re-entering the evaluator at all. Rest of + fix for bug reported by Dan Douglas + + 9/11 + ---- + +parse.y + - parse_comsub: make sure the `reserved word ok in this context' flag + is preserved after we read `do' followed by whitespace. Fixes bug + reported by Benoit Vaugon + + 9/13 + ---- +configure.ac,config.h.in + - enable-direxpand-default: new configure option, turns the `direxpand' + shell option on by default + +bashline.c + - dircomplete_expand, dircomplete_expand_relpath: initialize to 1 if + DIRCOMPLETE_EXPAND_DEFAULT is defined and non-zero + +doc/bashref.texi + - enable-direxpand-default: document new configure option + + 9/14 + ---- +shell.c + - --protected: make option valid only when wordexp is compiled into + the shell. Fix from Roman Rakus + +configure.ac + - HP NonStop (*-nsk*): compile --without-bash-malloc. Change from + Joachim Schmitz + + 9/16 + ---- +subst.c,execute_cmd.c,lib/glob/sm_loop.c,lib/sh/shquote.c + - minor code cleanups from Joachim Schmitz + +lib/readline/colors.h + - workaround for HP NonStop compiler issue with from + Joachim Schmitz + + 9/17 + ---- +builtins/printf.def + - printf_builtin: handle localtime returning NULL, as can happen when + encountering overflow. Bug report and initial fix from + Eduardo A. Bustamante López + +doc/{bash.1,bashref.texi} + - emphasize that brace expansion using character ranges ({a..c}) acts + as if the C locale were in use. Prompted by message from + Marcel Giannelia + + 9/20 + ---- +lib/sh/wcsnwidth.c + - wcsnwidth: new function, variant of wcwidth, returns the number of + wide characters from a string that will be displayed to not exceed + a specified max column position + + 9/21 + ---- +builtins/help.def + - show_builtin_command_help: break code that displays the short-doc + for each builtin in two columns into a new function: dispcolumn + - wdispcolumn: multibyte-char version of dispcolumn; uses wide + chars and printf "%ls" format. Fixes problem reported by + Nguyá»n Thái Ngá»c Duy + + 9/22 + ---- +execute_cmd.c + - execute_disk_command: before running the command-not-found hook, + call kill_current_pipeline() to make sure we don't add processes + to an existing pipeline or wait for processes erroneously + + 9/23 + ---- +lib/readline/input.c + - rl_input_available_hook: new hook function, called from + _rl_input_available (or _rl_input_queued) to return whether or not + input is available wherever the input source is + +lib/readline/doc/rltech.texi + - rl_input_available_hook: document + + 9/27 + ---- +lib/glob/sm_loop.c: + - GMATCH: after one or more `*', an instance of ?(x) can match zero or + 1 times (unlike ?, which has to match one character). The old code + failed if it didn't match at least once. Fixes `a*?(x)' bug. + - GMATCH: if we hit the end of the search string, but not the end of + the pattern, and the rest of the pattern is something that can + match the NUL at the end of the search string, we should successfully + match. Fixes `a*!(x)' bug reported by + + 10/2 + ---- +command.h + - add c_lock member to coproc structure for future use to tell who is + manipulating it + +execute_cmd.c + - execute_coproc: block SIGCHLD while parent is forking coproc + process and adding pid to sh_coproc struct to avoid race condition + where child is reaped before the pid is assigned and the coproc is + never marked as having died. Fixes race condition identified by + Davide Baldini + - add assignments to c_lock member of struct coproc in various + functions that manipulate it; was used to identify race condition + - coproc_pidchk: don't call coproc_dispose to avoid using malloc and + other functions in a signal handler context + - coproc_dispose: call BLOCK_SIGNAL/UNBLOCK_SIGNAL for SIGCHLD while + manipulating the sh_coproc struct + + 10/6 + ---- +lib/readline/complete.c + - rl_display_match_list: if printing completions horizontally, don't + bother with spacing calculations if limit == 1, which means we are + printing one completion per line no matter what. Fixes bug + reported by David Kaasen + + 10/7 + ---- +builtins/declare.def + - declare_internal: add error checking for nameref attribute and + variable assignments: self-references, attempts to make an array + variable a nameref + +subst.c + - parameter_brace_expand: handle parameter_brace_expand_word returning + &expand_param_fatal or &expand_param_error and return the appropriate + error value + - parameter_brace_expand_word: if a nameref variable's value is not a + valid identifier, return an error + - param_expand: if a nameref variable's value is not a valid identifier, + return an error + +test.c + - unary_operator: add new -R variable, returns true if variable is set + and has the nameref attribute. From ksh93 + +builtins/test.def + - add -R to description of conditional commands for help test + +doc/{bash.1,bashref.texi} + - document new -R unary conditional operator + + 10/13 + ----- +trap.c + - check_signals_and_traps: new function, convenience function for the + rest of the shell to check for pending terminating and interrupt + signals, and to check for and process any pending traps + - any_signals_trapped: new function, returns non-zero if any signals + are trapped and -1 if not + +trap.h + - extern declaration for check_signals_and_traps + +bashline.c + - bashline_reset: make sure we reset the event hook + - bash_event_hook: call check_signals_and_traps instead of just + checking for terminating signals so we can run pending traps and + react to interrupts, and reset the event hook when we're done + + + 10/14 + ----- +trap.c + - trap_handler: if executing in a readline signal handler context, + call bashline_set_event_hook to install bash_event_hook to process + the signal (if bash cares about it) + +sig.c + - sigint_sighandler: call bashline_set_event_hook to set the event + hook if we're executing in a readline signal handler context + +lib/readline/input.c + - rl_getc: call RL_CHECK_SIGNALS if read returns -1/EINTR and the caught + signal is SIGINT or SIGQUIT rather than waiting until the next time + around the loop + - rl_getc: call rl_event_hook after calling RL_CHECK_SIGNALS to allow + an application signal handler to set the event hook in its own + signal handler (e.g., like bash trap_handler or sigint_sighandler) + + +parse.y + - yy_readline_get: don't set interrupt_immediately before we call + readline(). Inspired by report from lanshun zhou + + +input.c + - getc_with_restart: add call to run_pending_traps after call to + CHECK_TERMSIG + +lib/sh/zread.c + - zread: call check_signals_and_traps if read() returns -1/EINTR + instead of just ignoring the EINTR and deferring handling any + signal that generated it + +builtins/mapfile.def + - mapfile: don't set interrupt_immediately before calling zgetline() + (which uses zread internally) + +builtins/read.def + - read_builtin: don't set interrupt_immediately before calling zread + (moved code around so that it was only being set right around calls + to zread to avoid signal handler conflicts). Inspired by report + from lanshun zhou + - edit_line: don't set interrupt_immediately around call to readline() + - include shmbutil.h + - read_builtin: don't call read_mbchar unless is_basic(c) returns + false for the character we just read + + 10/15 + ----- +sig.c + - throw_to_top_level: if interrupt_state is non-zero, make sure that + last_command_exit_value reflects 128+SIGINT if it's not already + greater than 128 + + 10/20 + ----- +builtins/wait.def + - WAIT_RETURN: set wait_signal_received back to 0 for the potential + next call to wait + +quit.h + - CHECK_WAIT_INTR: macro to check whether trap_handler handled a + signal and set wait_signal_received; longjmp to wait_intr_buf in + that case + +jobs.c + - wait_for, waitchld: call CHECK_WAIT_INTR at the same places we call + CHECK_TERMSIG to check for terminating signals + - wait_sigint_handler: don't longjmp out of the wait builtin unless + interrupt_immediately is set; otherwise just SIGRETURN from the + handler + - wait_sigint_handler: if interrupt_immediately not set, but we are + executing in the wait builtin and SIGINT is not trapped, treat it + as a `normally received' SIGINT: restore the signal handler and + send SIGINT to ourselves + - waitchld: when in posix mode and running SIGCHLD traps, don't longjmp + to wait_intr_buf (and let wait be interrupted) if we're running from + a signal handler. Wait for CHECK_WAIT_INTR to do the longjmp. + run_pending_traps will run the SIGCHLD trap later + +nojobs.c + - reap_zombie_children, wait_for_single_pid, wait_for: call + CHECK_WAIT_INTR where we call CHECK_TERMSIG + - wait_sigint_handler: don't longjmp out of the wait builtin unless + interrupt_immediately is set; otherwise just SIGRETURN from the + handler + +trap.c + - trap_handler: make sure wait_signal_received is set if the wait + builtin is executing, and only longjmp if interrupt_immediately is + set. This whole set of fixes was prompted by report from + lanshun zhou + + 10/24 + ----- +lib/glob/glob.c + - glob_filename: only check directory_name for globbing chars if + it's of non-zero length + +lib/sh/strchrnul.c + - new simpler implementation + +subst.c + - command_substitute: call set_shellopts after turning off errexit + in subshells so it's reflected in $SHELLOPTS + + 11/7 + ---- +builtins/evalstring.c + - parse_and_execute: treat ERREXIT case like reader_loop does: set + variable_context to 0 before longjmping back to top_level. Don't + run the unwind-protect context to avoid side effects from popping + function contexts. Part of fix for problem reported by Nikolai + Kondrashov + +execute_cmd.c + - execute_simple_command: call unlink_fifo_list only if this is the + last element of a pipeline (or not in a pipeline), rather than for + every child. Fixes difference in behavior between /dev/fd and + FIFOs reported by Zev Weiss + - execute_null_command: do the same thing in the parent branch after + make_child + + 11/14 + ----- +subst.c + - parameter_brace_expand: a variable is null if it's special ($@, $*), + the expansion occurs within double quotes, and the expansion turns + into a quoted null. Fixes debian bug 692447 reported by + Matrosov Dmitriy + +jobs.c + - run_sigchld_trap: make sure `running_trap' sentinel is set + appropriately + - waitchld: only run the sigchld trap if we're not in a signal + handler, not running a trap, and executing the wait builtin. + Otherwise, queue for later handling. We still run one instance + of the trap handler per exited child. Bulk of fix for bug + reported by Elliott Forney + +trap.c + - queue_sigchld_trap: set catch_flag so run_pending_traps notices, + and set trapped_signal_received for completeness. Rest of fix + for bug reported by Elliott Forney + +lib/malloc/malloc.c + - block_signals: renamed to _malloc_block_signals, made public + - unblock_signals: renamed to _malloc_unblock_signals, made public + +lib/malloc/imalloc.h + - extern declarations for _malloc_{un,}block_signals + +lib/malloc/table.c + - mregister_alloc, mregister_free: block signals around table + manipulation + + 11/15 + ----- +trap.c + - run_pending_traps: set SIG_INPROGRESS flag around calls to + run_sigchld_handler so other parts of the shell know that the + SIGCHLD trap handler is executing + - run_pending_traps: if we get a situation where we are looking at + running a SIGCHLD trap but the trap string is IMPOSSIBLE_TRAP_HANDLER + and the SIG_INPROGRESS flag is set, just skip it. This is possible + if run_pending_traps is called from a SIGCHLD trap handler run by + run_sigchld_trap + +doc/bash.1,lib/readline/doc/{rluser.texi,readline.3} + - corrected description of the effect of `set history-size 0'. Report + from Vesa-Matti J Kari + +include/stdc.h + - CPP_STRING: new define, replaces __STRING + +lib/malloc/{malloc.c,imalloc.h} + - replace __STRING with CPP_STRING + + 11/16 + ----- +lib/readline/bind.c + - sv_histsize: if argument evaluates to a value < 0, unstifle the + history + + 11/22 + ----- +redir.c + - do_redirection_internal: if we have REDIR_VARASSIGN set in the + redirection flags and we set up `redirector' using fcntl or dup2, + don't add a redirect to make sure it stays open. Let the + script programmer manage the file handle. Fixes bug reported by + Sam Liddicott + + 11/24 + ----- +jobs.c + - wait_for_any_job: new function, waits for an unspecified background + job to exit and returns its exit status. Returns -1 on no background + jobs or no children or other errors. Calls wait_for with new + sentinel value ANY_PID + - wait_for: changes to handle argument of ANY_PID: don't look up or + try to modify the child struct, only go through the wait loop once. + Return -1 if waitpid returns no children + +jobs.h + - ANY_PID: new define + +builtins/wait.def + - new option: -n. Means to wait for the next job and return its exit + status. Returns 127 if there are no background jobs (or no + children). Feature most recently requested by Elliott Forney + + +doc/{bash.1,bashref.texi} + - document new `wait -n' option + +execute_cmd.c + - execute_command_internal: save make_command_string () result in a + temp variable before calling savestring() on it; avoids evaluating + make_command_string() result twice. Fix from John E. Malmberg + + + 11/28 + ----- + +builtins/declare.def + - declare_internal: if an array variable is declared using `declare -a' + or `declare -A', but not assigned a value, set the `invisible' + attribute so the variable does not show up as set. Fix for bug + about variable initialization reported by Tim Friske + +builtins/{mapfile,read}.def + - after calling find_or_make_array_variable, make sure the invisible + flag is turned off, in case the variable was declared previously + using `declare -a' or `declare -A'. Side effect of above change to + declare_internal + +subst.c + - shell_expand_word_list: handle the W_ASSNGLOBAL flag and put -g into + the list of options passed to make_internal_declare as appropriate. + Fix for bug reported by Tim Friske + + 11/30 + ----- +test.c + - unary_op: make sure -v and -n check that the variable is not marked + as invisible before calling var_isset. Fix for bug reported by Tim + Friske + + 12/2 + ---- +subst.c + - process_substitute: turn off the `expanding_redir' flag, which + controls whether or not variables.c:find_variable_internal uses the + temporary environment to find variables. We want to use the + temp environment, since we don't have to worry about order of + evaluation in a subshell. Fixes bug reported by Andrey Borzenkov + + + 12/4 + ---- +lib/glob/glob.c + - glob_filename: changes to avoid null filenames and multiple entries + returned for patterns like **/** (globstar enabled). Fixes bug + reported by Ulf Magnusson + + 12/10 + ----- +lib/glob/glob.c + - glob_filename: finish up a series of changes to make globstar-style + globbing more efficient, avoid more duplicate filenames, and be more + compatible with other shells that implement it + o collapse a sequence of **/**/** to one ** + o note when the directory name is all ** or ends in ** so we + can treat it specially when the filename is ** + All inspired by report from Andrey Borzenkov + +lib/sh/zread.c + - zreadn: new function, like zread, but takes an additional argument + saying how many bytes to read into the local buffer. Can be used to + implement `read -N' without so many one-byte calls to zreadc. Code + from Mike Frysinger + + 12/12 + ----- +lib/glob/sm_loop.c + - PATSCAN (glob_patscan): if passed string already points to end of + pattern, return NULL immediately. Fixes problem with + extglob_skipname reported by Raphaël Droz + + 12/13 + ----- +execute_cmd.c + - execute_coproc: handle the command's exit status being inverted + (an oversight). Fixes bug reported by DJ Mills + and Andreas Schwab + + 12/14 + ----- +lib/readline/readline.c + - bind_arrow_keys_internal: add MINGW key bindings for Home, End, + Delete, and Insert keys. Fix from Pierre Muller + + +builtins/printf.def + - printf_builtin: '%()T' conversion: if there is no argument supplied, + behave as if -1 had been supplied (current time). ksh93-like feature + suggested by Clark Wang + +doc/{bash.1,bashref.texi} + - document new printf %()T default argument behavior + + 12/15 + ----- +lib/readline/display.c + - displaying_prompt_first_line: new variable, indicates whether or + not the first line of output is displaying the prompt. Always true + in normal mode, sometimes false in horizontal scrolling mode + - rl_redisplay: set displaying_prompt_first_line to true unless we + are in horizontal mode; set to false in horizontal mode if the left + margin of the displayed line is greater than the end of the prompt + string + - rl_redisplay: when in horizontal scroll mode, don't adjust + _rl_last_c_pos by the wrap offset unless the line is displaying + a prompt containing invisible chars + - update line: don't adjust _rl_last_c_pos by the wrap offset unless + the line is displaying a prompt containing invisible chars + - update_line: if shrinking the line by reducing the number of + displayed characters, but we have already moved the cursor to the + beginning of the line where the first difference starts, don't + try to delete characters + +builtins/read.def + - unbuffered_read: set to 2 if invoked as `read -N' + - if unbuffered_read is set to 2, compute the number of chars we + need to read and read that many with zreadn. Posix mode still + uses zreadintr. Code from Mike Frysinger + +doc/{bash.1,bashref.texi} + - read: make it clear that if read times out, it saves any input + read to that point into the variable arguments. Report from + Fiedler Roman + +subst.c + - command_substitute: change direct assignment of exit_immediately_on_error + to use change_flag ('e', FLAG_OFF) instead + +flags.c + - use errexit_flag as the variable modified by changes to the -e + option, reflect those changes to exit_immediately_on_error + +execute_cmd.c + - execute_builtin: new global variable, builtin_ignoring_errexit, set + to 0 by default and set to 1 if eval/source/command executing in a + context where -e should be ignored + - execute_builtin: set exit_immediately_on_error to errextit_flag + after executing eval/source/command in a context where -e should + be ignored + +flags.c + - if builtin_ignoring_errexit is set, changes to errexit_flag are + not reflected in the setting of exit_immediately_on_error. Fixes + bug reported by Robert Schiele + + 12/23 + ----- +include/posixjmp.h + - setjmp_nosigs: new define, call setjmp in such a way that it will + not manipulate the signal mask + +{expr,test,trap}.c + - setjmp_nosigs: call instead of setjmp; don't need to manipulate + signal mask + +builtins/read.def + - read_builtin: setjmp_nosigs: call instead of setjmp; don't need + to manipulate signal mask + +builtins/evalstring.c: + - parse_and_execute: setjmp_nosigs: call instead of setjmp; don't need + to manipulate signal mask + - parse_string: setjmp_nosigs: call instead of setjmp; don't need + to manipulate signal mask + - parse_and_execute: save and restore the signal mask if we get a + longjmp that doesn't cause us to return or exit (case DISCARD) + + 12/24 + ----- +general.c + - bash_tilde_expand: only set interrupt_immediately if there are no + signals trapped; we want to jump to top level if interrupted but + not run any trap commands + + 12/25 + ----- +jobs.c + - run_sigchld_trap: no longer set interrupt_immediately before calling + parse_and_execute, even if this is no longer run in a signal handler + context + +input.c + - getc_with_restart: add call to QUIT instead of CHECK_TERMSIG + +parse.y + - yy_stream_get: now that getc_with_restart calls QUIT, don't need to + set interrupt_immediately (already had call to run_pending_traps) + +execute_cmd.c + - execute_subshell_builtin_or_function,execute_function,execute_in_subshell: + setjmp_nosigs: call instead of setjmp when saving return_catch; don't + need to manipulate signal mask + - execute_subshell_builtin_or_function,execute_in_subshell: + setjmp_nosigs: call instead of setjmp where appropriate when saving + top_level; don't need to manipulate signal mask if we're going to + exit right away + +subst.c + - command_substitute: setjmp_nosigs: call instead of setjmp when saving + return_catch; don't need to manipulate signal mask + - command_substitute: setjmp_nosigs: call instead of setjmp where + appropriate when saving top_level; don't need to manipulate signal + mask if we're going to exit right away + +trap.c + - run_exit_trap: setjmp_nosigs: call instead of setjmp when saving + return_catch; don't need to manipulate signal mask + - run_exit_trap: setjmp_nosigs: call instead of setjmp where + appropriate when saving top_level; don't need to manipulate signal + mask if we're going to exit right away + - _run_trap_internal: setjmp_nosigs: call instead of setjmp when saving + return_catch; don't need to manipulate signal mask + +builtins/evalfile.c + - _evalfile: setjmp_nosigs: call instead of setjmp when saving + return_catch; don't need to manipulate signal mask + +builtins/evalstring.c + - evalstring: setjmp_nosigs: call instead of setjmp when saving + return_catch; don't need to manipulate signal mask + +shell.c + - main: setjmp_nosigs: call instead of setjmp where appropriate when + saving top_level; don't need to manipulate signal mask if we're + going to exit right away + - run_one_command: setjmp_nosigs: call instead of setjmp where + appropriate when saving top_level; don't need to manipulate signal + mask if we're going to exit right away + - run_wordexp: setjmp_nosigs: call instead of setjmp where + appropriate when saving top_level; don't need to manipulate signal + mask if we're going to exit right away + +eval.c + - reader_loop: save and restore the signal mask if we get a longjmp + that doesn't cause us to return or exit (case DISCARD) + + 12/26 + ----- +parse.y + - shell_input_line_{index,size,len}: now of type size_t; in some cases + the unsigned property makes a difference + - STRING_SAVER: saved_line_{size,index} now of type size_t + - shell_getc: don't allow shell_input_line to grow larger than SIZE_MAX; + lines longer than that are truncated until read sees a newline; + addresses theoretical buffer overflow described by Paul Eggert + + - set_line_mbstate: size_t changes like shell_getc + - shell_getc: if shell_input_line is larger than 32K, free it and + start over to avoid large memory allocations sticking around + +variables.c + - bind_global_variable: new function, binds value to a variable in + the global shell_variables table + +variables.h + - bind_global_variable: new extern declaration + +builtins/declare.def + - declare_internal: if -g given with name=value, but variable is not + found in the global variable table, make sure to call + bind_global_variable so the variable is created and modified at + global scope. Fixes a bug where declare -g x=y could modify `x' + at a previous function scope + +command.h + - W_ASSIGNARRAY: new word flag, compound indexed array assignment + +subst.h + - ASS_MKGLOBAL: new assignment flag, forcing global assignment even in + a function context, used by declare -g + +execute_cmd.c + - fix_assignment_words: set W_ASSIGNARRAY flag if -a option given to + declaration builtin + +subst.c + - do_assignment_internal: explicitly handle case where we are + executing in a function and we want to create a global array or + assoc variable + - shell_expand_word_list: call make_internal_declare if -a option + given to declaration builtin (W_ASSIGNARRAY); handle -g option with + it (W_ASSNGLOBAL). Fixes inconsistency noticed by Vicente Couce + Diaz , where declare -ag foo=(bar) could modify + array variable foo at previous function scope, not global scope + + 12/27 + ----- +bashline.c + - Minix needs the third argument to tputs to be a void funtion taking + an int argument, not an int-returning function. Fix from + John E. Malmberg as part of VMS bash port + + 12/29 + ----- +configure.ac,version.c,patchlevel.h + - bash-4.3-devel: new version, new shell compatibility level (43) + +subst.c + - parameter_brace_patsub: put the bash-4.2 code back in from the + change of 3/3 that runs the replacement string through quote + removal, make it dependent on shell_compatibility_level <= 42 + +builtins/shopt.def + - compat42: new shopt option + - set_compatibility_level: change logic to set and unset various + compat variables and shell_compatibility_level + +COMPAT + - new documentation for bash-4.3 compatibility changes + +doc/{bash.1,bashref.texi} + - compat42: document new shopt option + +builtins/shopt.def + - set_compatibility_opts: new function, sets the various shopt + compat variables based on the value of shell_compatibility_level + +builtins/common.h + - set_compatibility_opts: new extern declaration + +variables.c + - BASH_COMPAT: new special variable; sets the shell compatibility + level. Accepts values in decimal (4.2) or integer (42) form; + Unsetting variable, setting it to empty string, or setting it to + out-of-range value sets the shell's compatibility level to the + default for the current version. Valid values are 3.1/31 through + the current version + - sv_shcompat: new function implementing logic for BASH_COMPAT + +variables.h + - sv_shcompat: new extern declaration + +doc/{bash.1,bashref.texi} + - BASH_COMPAT: description of new variable + +lib/readline/complete.c + - _rl_colored_stats: default back to 0 for 4.3 release branch + + 1/5/2013 + -------- +quit.h + - remove spurious call to itrace in CHECK_WAIT_INTR + +bashline.c + - bash_event_hook: if we're going to jump to top_level, make sure we + clean up after readline() by calling rl_cleanup_after_signal(). + Fixes bug reported against devel branch by Raphaël Droz + + - bash_event_hook: reset the event hook before checking for signals + or traps in case we longjmp + +doc/{bash.1,bashref.texi} + - small additions to the set -e section to make it more clear that + contexts where -e is ignored extend to compound commands as well + as shell functions + +lib/readline/readline.h + - rl_signal_event_hook: new extern declaration + +lib/readline/input.c + - rl_signal_event_hook: new variable, hook function to call when a + function (currently just read(2)) is interrupted by a signal and + not restarted + - rl_getc: call rl_signal_event_hook instead of rl_event_hook + +lib/readline/doc/rltech.texi + - rl_signal_event_hook: document new function + +bashline.c + - changes to set rl_signal_event_hook instead of rl_event_hook + +lib/readline/readline.h + - change readline version numbers to 6.3 + + 1/6 + --- +doc/{bash.1,bashref.texi} + - a couple of changes to the descriptions of the ERR trap and its + effects based on a message from Rob Nagler + + 1/9 + --- +expr.c + - expassign: invalidate curlval before freeing and NULLing tokstr to + avoid aliasing issues. Fixes bug reported by Eduardo A. Bustamante + López and Dan Douglas + +braces.c + - array_concat: don't be so aggressive in trying to short-circuit. We + can only short-circuit if we have a single-element array where the + element is an empty string (array[0] == "" array[1] = 0x0). Existing + practice requires us to replicate arrays and prefix or append empty + strings. Fixes bug reported by Eduardo A. Bustamante López + + + 1/11 + ---- +execute_cmd.c + - execute_builtin: since mapfile uses evalstring() to run its callbacks + internally, just like eval, so it needs to handle the case where the + temp environment given to mapfile persists throughout the entire + set of callback commands. This might be a problem with trap also, but + trap isn't run in the same way. Fixes bug reported by Dan Douglas + + + 1/13 + ---- +redir.c + - redirection_error: before expanding the redirection word (if + expandable_redirection_filename returns true), disable command + substitution during expansion. Fixes bug reported by Dan Douglas + + +subst.c + - expand_word_internal: case '\\': if the next character is an IFS + character, and the expansion occurs within double quotes, and the + character is not one for which backslash retains its meaning, add + the (escaped) '\' and the (escaped) character. Fixes bug reported + by Dan Douglas + + 1/15 + ---- +builtins/cd.def + - cd_builtin: make sure call to internal_getopt handles -e option. + Fixes bug reported by + + 1/17 + ---- +subst.c + - expand_word_list_internal: make sure tempenv_assign_error is + initialized to 0 + +execute_cmd.c + - execute_simple_command: make sure tempenv_assign_error is reset to 0 + after it's tested to see if an error should force the shell to exit. + Fixes problem where a the failure of a tempenv assignment preceding + a non-special builtin `sticks' and causes the next special builtin + to exit the shell. From a discussion on bug-bash started by + douxin + + 1/20 + ---- +subst.c + - parameter_brace_expand_rhs: call stupidly_hack_special_variables + after assigning with ${param[:]=word} even if IFS is changing. + Suggested by Dan Douglas [TENTATIVE, needs work + on IFS side effects] + +command.h + - W_GLOBEXP (which was unused) is now W_SPLITSPACE (which isn't used + yet) + +{execute_cmd,subst,variables}.c + - removed all code that mentioned W_GLOBEXP + - removed mention of gnu_argv_flags and code that set it + + 1/22 + ---- +subst.c + - param_expand: set W_SPLITSPACE if we expand (unquoted) $* and + IFS is unset or null so we can be sure to split this on spaces + no matter what happens with IFS later + - expand_word_internal: note that param_expand returns W_SPLITSPACE + in the returned word flags and keep track of that state with + `split_on_spaces' + + 1/23 + ---- +subst.c + - expand_word_internal: if split_on_spaces is non-zero, make sure + we split `istring' on spaces and return the resultant word. The + previous expansions should have quoted spaces in the positional + parameters where necessary. Suggested by Dan Douglas + + +execute_cmd.c + - execute_command_internal: make sure any subshell forked to run a + group command or user subshell at the end of a pipeline runs any + EXIT trap it sets. Fixes debian bash bug 698411 + http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=698411 + +subst.c + - shell_expand_word_list: fix code that creates args for and calls + make_internal_declare to avoid calling it twice (missing `else' + in 12/26 change) + - do_assignment_internal: fix code from 12/26 change to fix problem + where an existing assoc variable could be converted to an array + without checking `mkassoc' + + 1/24 + ---- +builtins/evalfile.c + - _evalfile: add missing `close (fd)' calls before returning to + avoid fd leaks. Bug and fix from Roman Rakus + + 1/25 + ---- +builtins/read.def + - read_builtin: don't try to play tricks with the top of the unwind- + protect stack after read gets a SIGALRM; save input_string to new + memory, run the stack, then restore input_string and assign the + variables. Part of fix for bug reported by konsolebox + ; the rest of the fix is with the changes in + trap and signal handling and doing away with interrupt_immediately + + 1/26 + ---- +redir.c + - redirection_expand, write_here_string, write_here_document: before + calling any of the word expansion functions, after setting + expanding_redir to 1 (which bypasses the temp environment in the + variable lookup functions), call sv_ifs to reset the cached IFS- + related variables set by subst.c:setifs(). This ensures that + redirections will not get any IFS values that are set in the + temporary environment, as Posix specifies. Then, after the word + expansions, after resetting expanding_redir to 0, call sv_ifs + again to make sure the cached IFS values are set from any + assignments in the temporary environment. We force executing_builtin + to 1 to `fool' the variable lookup functions into using any temp + environment, then reset it to its old value after sv_ifs returns. + This is what allows read() to use the (cached) IFS variables set + in the temp environment. Fixes inconsistency reported by Dan Douglas + + + 1/29 + ---- +lib/readline/display.c + - update_line: fix off-by-one error when updating vis_lbreaks array + in a multibyte locale that occurs when moving multibyte chars from + one line down to another. Bug report and fix from Egmont + Koblinger + + 1/30 + ---- +configure.ac + - changed version to 4.3-alpha + +redir.c + - redir_open: handle open returning -1/EINTR, which seems to happen + a lot with FIFOs and SIGCHLD, and call QUIT to handle other + signals that can interrupt open(2). Bug report and initial fix + from Mike Frysinger + + 1/31 + ---- +subst.c + - parameter_brace_expand: make sure to propagate the PF_ASSIGNRHS flag + to parameter_brace_expand_word + - parameter_brace_expand_word: make sure that if the PF_ASSIGNRHS flag + is set and we are expanding ${a[@]} or ${a[*]} we set quoted to + include Q_DOUBLE_QUOTES before calling array_value_internal, mirroring + what we do for $@ and $*. Fixes inconsistency reported by Dan + Douglas + +configure.ac + - use AC_CHECK_TOOL instead of AC_CHECK_PROG to check for ar, since it + will find $host-prefixed versions of utilities. Report and fix from + Mike Frysinger + +builtins/setattr.def + - set_var_attribute: check whether bind_variable (called when the + variable whose attributes are being modified is found in the temp + environment) just modified a read-only global variable, and don't + bother marking the temporary variable for propagation if so. The + propagation is superfluous and will result in a strange error + message + + 2/2 + --- +variables.c + - initialize_shell_variables: don't try to import function definitions + with invalid names from the environment if already in posix mode, + but create them as (invisible) exported variables so they pass + through the environment. Print an error message so user knows + what's wrong. Fixes bug reported by Tomas Trnka + + 2/9 + --- + +builtins/read.def + - sigalrm_seen, alrmbuf: now global so the rest of the shell (trap.c) + can use them + - sigalrm: just sets flag, no longer longjmps to alrmbuf; problem was + longjmp without manipulating signal mask, leaving SIGALRM blocked + +quit.h + - move CHECK_ALRM macro here from builtins/read.def so trap.c: + check_signals() can call it + +trap.c + - check_signals: add call to CHECK_ALRM before QUIT + - check_signals_and_traps: call check_signals() instead of including + CHECK_ALRM and QUIT inline. Integrating check for read builtin's + SIGALRM (where zread call to check_signals_and_traps can see it) + fixes problem reported by Mike Frysinger + + 2/12 + ---- +lib/glob/xmbsrtowcs.c + - xdupmbstowcs2: fixed but where end of string was not handled + correctly, causing loop to go past end of string in a bunch of cases. + Fixes bug reported by "Dashing" + + + 2/13 + ---- +builtins/pushd.def + - popd_builtin: treat any argument that isn't -n or of the form + [-+][[:digit:]]* as an error. Fixes problem reported by Bruce + Korb + + 2/14 + ---- +configure.ac + - add check for sig_atomic_t; already a placeholder for it in + config.h.in + + 2/15 + ---- +subst.c + - do_compound_assignment: don't call assign_compound_array_list with + a NULL variable in case make_local_xxx_variable returns NULL + (it will if you try to shadow a readonly or noassign variable). + Fixes bug reported by Richard Tollerton + + 2/16 + ---- +variables.c + - make_local_variable: print error messager if an attempt is made to + create a local variable shadowing a `noassign' variable. Previously + we just silently refused to do it + +trap.[ch] + - get_original_signal: now global so rest of the shell can use it + +sig.c + - initialize_shell_signals: install a signal handler for SIGTERM + that does nothing except set a sigterm_received flag instead of + ignoring it with SIG_IGN, as long as SIGTERM is not ignored when + the shell is started. Use get_original_signal early to get the + original handler, since we will do that later anyway + - set_signal_handler: if installing sigterm_sighandler as the SIGTERM + handler, make sure to add SA_RESTART flag to make it as close to + SIG_IGN as possible + +sig.h + - sigterm_sighandler: new extern declaration + +quit.h + - RESET_SIGTERM: set sigterm_receved to 0 + - CHECK_SIGTERM: check sigterm_received; if it's non-zero, treat it + as a fatal signal and call termsig_handler to exit the shell + +jobs.c + - make_child: call RESET_SIGTERM just before fork() so we can detect + if the child process received a SIGTERM before it's able to change + the signal handler back to what it was when the shell started + (presumably SIG_DFL). Only has effect if the shell installed + sigterm_sighandler for SIGTERM, interactive shells that were not + started with SIG_IGN as the SIGTERM handler + - make_child: call RESET_SIGTERM in the parent after fork() so the + rest of the shell won't react to it + +execute_cmd.c + - execute_simple_command: call CHECK_SIGTERM after make_child in child + to catch SIGTERM received after fork() and before restoring old + signal handlers + - execute_disk_command: call CHECK_SIGTERM after make_child in child + process after restoring old signal handlers and again just before + calling shell_execve. Fixes race condition observed by + Padraig Brady when testing with his `timeout' + program + +lib/readline/display.c + - open_some_spaces: new function, subset of insert_some_chars that just + opens up a specified number of spaces to be overwritten + - insert_some_spaces: now just calls to open_some_spaces followed by + _rl_output_some_chars + - update_line: use col_temp instead of recalculating it using + _rl_col_width in the case where we use more columns with fewer bytes + - update_line: use open_some_spaces and then output the right number + of chars instead of trying to print new characters then overwrite + existing characters in two separate calls. This includes removing + some dodgy code and making things simpler. Fix from Egmont + Koblinger + - use new variable `bytes_to_insert' instead of overloading temp in + some code blocks (nls - nfd, bytes that comprise the characters + different in the new line from the old) + + 2/18 + ---- +redir.c + - do_redirection_internal: add undoable redirection for the implicit + close performed by the <&n- and >&n- redirections. Fixes bug + reported by Stephane Chazelas + + 2/19 + ---- +sig.c + - termsig_handler: an interactive shell killed by SIGHUP and keeping + command history will try to save the shell history before exiting. + This is an attempt to preserve the save-history-when-the-terminal- + window-is-closed behavior + + 2/21 + ---- +braces.c + - brace_expand: if a sequence expansion fails (e.g. because the + integers overflow), treat that expansion as a simple string, including + the braces, and try to process any remainder of the string. The + remainder may include brace expansions. Derived from SuSE bug + 804551 example (https://bugzilla.novell.com/show_bug.cgi?id=804551) + + 2/23 + ---- +{quit,sig}.h,sig.c + - sigterm_received declaration now in sig.h; type is sig_atomic_t + - sigwinch_received type now sig_atomic_t + - sig.h includes bashtypes.h and if SIG_DFL not defined + (same logic as trap.h) to pick up sig_atomic_t + +unwind_prot.c + - include sig.h before quit.h (reverse order) + + 2/27 + ---- +builtins/shopt.def + - reset_shopt_options: make sure check_window_size is reset to the + default from config.h, not unconditionally to 0 + +jobs.[ch] + - last_made_pid, last_asynchronous_pid: now volatile. Change from SuSE + +jobs.c + - wait_for: if we're using sigaction to install a handler for SIGCHLD, + make sure we specify SA_RESTART + +lib/{tilde,readline}/shell.c + - get_home_dir: instead of looking in the password file every time, + look once and cache the result + +sig.[ch] + - sigwinch_received, sigterm_received: now `volatile' qualified + +sig.c,quit.h + - interrupt_state,terminating_signal: now sig_atomic_t + + 3/1 + --- +MANIFEST,examples/* + - removed around 120 files without FSF copyrights; requested by + Karl Berry in early January + + 3/2 + --- +lib/malloc/malloc.c + - morecore: only check whether SIGCHLD is trapped if SIGCHLD is defined + +doc/bashref.texi + - Fixed most of the examples in the GNU Parallel section to use better + shell idioms following complaints on bug-bash; added a couple of + examples and smoothed out the text + +quit.h + - include "sig.h" for sig_atomic_t + +lib/readline/display.c + - update_line: when inserting one or more characters at the end of + the display line in a non-multibyte environment, just write from the + first difference to the end of the line and return. We don't have + to adjust _rl_last_c_pos. This is needed to adjust from the old + two-part copy to a single call to _rl_output_some_chars (change of + 2/16) + + 3/4 + --- +Makefile.in,doc/Makefile.in + - PACKAGE_TARNAME, docdir: new variables substituted by autoconf + - OTHER_DOCS,OTHER_INSTALLED_DOCS: new variables with auxiliary + documentation files to be installed into $(docdir) + - install: add new rule to install $(OTHER_DOCS) + - uninstall: add new rule to uninstall $(docdir)/$(OTHER_INSTALLED_DOCS) + +doc/bash.1 + - add URL to `POSIX' file in `SEE ALSO' section; put pointer to that + section in --posix and set -o posix descriptions + +examples/ + - removed around 110 examples at the request of the FSF due to copyright + issues + + 3/5 + --- +builtins/setattr.def + - readonly: modified help text slightly to make it clearer that + functions aren't changed or displayed unless the -f option is given. + Report from + + 3/9 + --- +include/typemax.h + - SIZE_MAX: define to 65535 (Posix minimum maximum) if not defined + +parse.y + - include "typemax.h" for possible SIZE_MAX definition, make sure we + include it after shell.h + +{braces,expr}.c + - include "typemax.h" for possible INTMAX_MIN and INTMAX_MAX definitions + + 3/10 + ---- +bashline.c + - bash_default_completion: make sure completion type of `!' (same as + TAB but with show-all-if-ambiguous set) and glob-word-completion + sets rl_filename_completion_desired to 0 so extra backslashes don't + get inserted by `quoting' the completion. We can't kill all the + matches because show-all-if-ambiguous needs them. Bug report from + Marcel (Felix) Giannelia + +[bash-4.3-alpha frozen] + + 3/14 + ---- +general.c + - trim_pathname: use memmove instead of memcpy since the source and + destination pathnames may overlap. Report and fix from Matthew + Riley + + 3/18 + ---- +configure.ac + - socklen_t is defined as `unsigned int' if configure can't find it + + 3/20 + ---- +lib/readline/complete.c + - S_ISVTX: since it's not defined on all platforms (Minix), make sure + its use is protected with #ifdef + + 3/21 + ---- +doc/{bash.1,bashref.texi} + - Added mention of ${!name[@]} and ${!name[*]} expansions to get all + indices of an array. Suggested by Jonathan Leffler + + + 3/24 + ---- +subst.h + - SD_IGNOREQUOTE: new define for skip_to_delim; if set, means that + single quotes (for now) will be treated as ordinary characters + +subst.c + - skip_to_delim: handle SD_IGNOREQUOTE. no callers use it for now + + 3/25 + ---- +support/config.{guess,sub} + - updated to versions from autoconf-2.69 + + 3/31 + ---- +lib/sh/shquote.c + - sh_single_quote: short-circuit quoting a single "'" instead of + creating a long string with empty single-quoted strings + +parser.h + - DOLBRACE_QUOTE2: new define, like DOLBRACE_QUOTE, but need to single- + quote results of $'...' expansion because quote removal will be + done later. Right now this is only done for ${word/pat/rep} + +parse.y + - parse_matched_pair: set state to DOLBRACE_QUOTE2 for pattern + substitution word expansion so we don't treat single quote specially + in the pattern or replacement string + - parse_matched_pair: if we're parsing a dollar-brace word expansion + (${...}) and we're not treating single quote specially within + double quotes, single-quote the translation of $'...' ansi-c + escaped strings. Original report and fix from Eduardo A. + Bustamante López + +subst.c + - extract_dollar_brace_string: ${word/pat/rep} scanning now sets the + DOLBRACE_QUOTE2 flag instead of DOLBRACE_QUOTE so we don't treat + single quotes specially within a double-quoted string + +execute_cmd.c + - fix_assignment_words: skip over assignment statements preceding a + command word before trying to figure out whether or not assignment + statements following a possible declaration command should be + treated specially. Fixes bug reported by Dan Douglas + + + 4/4 + --- +lib/readline/readline.c + - _rl_dispatch_subseq: only call _rl_vi_set_last (and check whether + the key is a text modification command) if the key sequence length + is 1. That keeps the arrow keys from setting the last command + when called in vi command mode. Fixes bug reported by Ian A. + Watson + + 4/6 + --- +lib/readline/bind.c + - rl_parse_and_bind: when parsing a double-quoted string as the value + of a variable, make sure we skip past the leading double quote. + Fix from Andreas Schwab + +variables.c + - hash_lookup: set new local variable last_table_searched to the table + a successful lookup appears in; tested in make_local_variable to + solve the problem below + - make_local_variable: if we find a variable with the tempenv flag + set at the same `level' as variable_context', but not found in the + temporary_env (temp environment preceding the builtin), return it. + The temp environment preceding the function call has already been + merged (in execute_function) into the list of variable contexts the + function sees as shell_variables by the time this is called. Fixes + inconsistency pointed out by Dan Douglas + +subst.c + - expand_arith_string: expanded out contents of expand_string, + expand_string_internal, expand_string_if_necessary to create a + WORD_DESC and call call_expand_word_internal() on it directly. + We don't want process substitution to be performed ( 1<(2) ) should + mean something different in an arithmetic expression context. + It doesn't work to just turn on the DQUOTE flag, since that means + that things like ${x["expression"]} are not expanded correctly. + Fixes problem pointed out by Dan Douglas + + 4/13 + ---- +subst.c + - process_substitute: run the EXIT trap before exiting, as other + shells seem to. Fixes problem pointed out by Dan Douglas + + +lib/readline/readline.c + - readline_internal_setup: call rl_vi_insertion_mode to enter vi + mode instead of rl_vi_insert_mode to avoid resetting the saved last + command information. Posix says that `.' can repeat a command + that was entered on a previous line so we need to save the info. + Fixes bug reported by Ian A. Watson + + 4/14 + ---- +lib/readline/complete.c + - rl_completion_matches: make sure xrealloc returns something non-null + (can happen when interrupted by a signal) before trying to add + matches to match_list + +subst.c + - array_remove_pattern: return NULL right away if array_variable_part + returns an invisible variable + - array_length_reference: handle array_variable_part returning an + invisible variable + - get_var_and_type: handle array_variable_part returning an invisible + variable + + 4/15 + ---- +execute_cmd.c + - execute_command_internal: make sure to run the EXIT trap for group + commands anywhere in pipelines, not just at the end. From a point + raised by Andreas Schwab + +variables.c + - bind_int_variable: make sure invisible flag is unset. Fixes problems + like "declare -ai a; : $(( a[4]=4 ));" + +arrayfunc.c + - array_variable_part: return variable even if invisible flag set, + callers must handle invisible vars + + 4/18 + ---- +builtins/set.def + - unset_builtin: if -n flag given, call unset_nameref instead of + unset_variable + +variables.c + - find_variable_nameref: print warning message if nameref circular + reference detected, return NULL and let caller deal with it + +builtins/declare.def + - declare_builtin: only disallow global references at this point if + we are at the global scope + + 5/16 + ---- +configure.ac + - update release status to beta + + 5/23 + ---- +trap.c + - run_pending_traps: save and restore pipeline around calls to + evalstring() in case we get a trap while running a trap. Have to + figure out the recursive running traps issue elsewhere. Fixes + bug reported by Roman Rakus + - run_pending_traps: make sure to set running_trap to the appropriate + signal value when running a trap command + - run_pending_traps: short-circuit immediately if running_trap set + when invoked. Could change this later to only skip if it would + run the same trap as currently being run (running_trap == sig + 1) + +configure.ac + - add warning if bison not found + +lib/readline/doc/rltech.texi + - new section with an example program illustrating the callback + interface. Suggested by Peng Yu + +examples/loadables/Makefile.in + - remove references to `cut' and `getconf', which were removed in + early March + + 5/28 + ---- +lib/sh/pathphys.c + - sh_realpath: correct inverted two arguments to call to sh_makepath. + Report and fix from Julien Thomas + + 6/7 + --- +execute_cmd.c + - executing_line_number: the else clauses that are conditional on + various options being defined can simply be if clauses -- they are + mutually exclusive and all have `return' in the body. Fixes bug + reported by Flavio Medeiros + + 6/25 + ---- +lib/readline/readline.c + - readline_internal_setup: only sent the meta-key enable string to the + terminal if we've been told to use one and the terminal has been + successfully initialized (RL_ISSTATE (RL_STATE_TERMPREPPED) != 0). + Suggested by Dan Mick + +lib/readline/signals.c + - _rl_signal_handler: call any defined signal hook after calling + rl_resize_terminal when handling a SIGWINCH. We already have called + the original SIGWINCH handler but will not be resending the signal + to ourselves + + 6/27 + ---- +lib/readline/doc/history.3, doc/bash.1 + - fix description of the `$' modifier to note that it expands to the + last *word*, which is not always the last argument. Report from + ariyetz@gmail.com via gnu.org RT + + 6/29 + ---- +lib/glob/smatch.c + - glob_asciiranges: initialize to value of GLOBASCII_DEFAULT instead + of 0 (0 if not defined) + +configure.ac,config.h.in + - --enable-glob-asciiranges-default: new option, controls the value of + GLOBASCII_DEFAULT; use it to turn globasciiranges shopt option on + by default + +doc/bashref.texi + - document new --enable-glob-asciiranges-default configure option + +variables.c + - assign_in_env: implement += value appending semantics for assignments + preceding command names + + 7/4 + --- +expr.c + - set lasttok = NUM in all of the functions that result in a number, + even if it's a boolean, to avoid errors with constructs like + 1 * x = 1, which should be an asignment error. Fixes problem + pointed out by Dan Douglas + +parse.y + - decode_prompt_string: don't bother to call strcpy if + polite_directory_format returns its argument unchanged. It's not + necessary and Mac OS X 10.9 aborts because of a supposed overlapping + string copy. Bug and fix from simon@hitzemann.org + +subst.c + - parameter_brace_find_indir: new function, code from + parameter_brace_expand_indir that looks up the indirectly-referenced + variable, but does not expand it + - parameter_brace_expand_indir: call parameter_brace_find_indir to + look up indirected variable reference + - get_var_and_type: call parameter_brace_find_indir if it looks like we + are trying to manipulate an indirect variable reference like + ${!b%%foo}. This makes a difference if !b references an array + variable. Bug report from Dan Douglas + + 7/6 + --- +lib/sh/casemod.c + - sh_modcase: make sure argument passed to is_basic is <= UCHAR_MAX, + since cval can convert something to a wchar_t greater than UCHAR_MAX. + Fixes bug reported by Tomasz Tomasik + + 7/8 + --- +lib/readline/history.c + - add_history_time: if history_length == 0, referencing history_length + - 1 will result in an array bounds error, so make history_length be + at least 1 before going on. Fixes bug reported by Geng Sheng Liu + + +builtins/setattr.def + - show_func_attributes: display definition (if NODEFS argument is 0) and + attributes for a particular function; used by `declare -fp name' + +builtins/declare.def + - declare_internal: call show_func_attributes if -f supplied with -p. + Fixes inconsistency observed by Linda Walsh + +builtins/common.h + - new extern declaration for show_func_attributes + +builtins/read.def + - read_builtin: check the first supplied variable name for validity + before attempting to read any input, since we know we will have to + at least use that one. Don't check any other names yet. Suggested + by jidanni@jidanni.org + + 7/10 + ---- +redir.c + - do_redirection_internal: when closing a file descriptor with + r_close_this ([n]<&-) count close errors as redirection errors if + errno ends up as EIO or ENOSPC. Originally reported back in April + 2012 by Andrey Zaitsev + + 7/11 + ---- +redir.c + - do_redirection_internal: before calling check_bash_input, make sure + that we don't call check_bash_input for an asynchronous process that + is replacing stdin with something else. The seek backwards affects + the parent process as well, since parents and children share the + file pointer. Fixes problem originally reported in March 2013 by + Martin Jackson + + 7/13 + ---- +doc/{bash.1,bashref.texi} + - slight change to add a description of `shopt -o' suggested by Bruce + Korb + + 7/19 + ---- +lib/readline/histfile.c + - history_do_write: if close returns < 0, make sure we restore the + backup history file and return a non-zero value + - history_truncate_file: if write or close return < 0, make sure we + return a non-zero value + +[bash-4.3-beta frozen] + + 7/21 + ---- +lib/readline/isearch.c + - rl_display_search: now takes an entire search context flags word as + the second argument, instead of just reverse flag; changed callers + - rl_display_search: if the search has failed, add `failed ' to the + beginning of the search prompt + - _rl_isearch_dispatch: if the search has failed, display the entire + search string with an indication that the search failed but with the + last matching line. Suggested by jidanni@jidanni.org + +command.h + - W_ASSIGNINT: new word flag; used internally for make_internal_declare + and set by fix_assignment_words + +execute_cmd.c + - fix_assignment_words: set W_ASSIGNINT if compound assignment and -i + given as option. We don't do anything with the value yet + +subst.c + - shell_expand_word_list: rework the way the option list that is + passed to make_internal_declare is created + + 8/1 + --- +doc/{bash.1,bashref.texi} + - minor changes to description of $! based on a report from Chris + Down + +arrayfunc.c + - assign_array_element_internal: before trying to get an array's max + index to process a negative subscript, make sure the array exists. + Bug report from Geir Hauge + + 8/2 + --- +arrayfunc.c + - assign_array_element_internal: before using array_max_index() when + processing a negative subscript, make sure the variable is an array. + if it's not, use 0 as array_max_index assuming it's a string. + Fixes bug report from Geir Hauge + + 8/3 + --- +Makefile.in + - pcomplete.o: add dependency on $(DEFDIR)/builtext.h. Suggested by + Curtis Doty + + 8/5 + --- +lib/glob/sm_loop.c + - strcompare: short-circuit and return FNM_NOMATCH if the lengths of the + pattern and string (pe - p and se - s, respectively) are not equal + - strcompare: don't bother trying to set *pe or *se to '\0' if that's + what they already are. Fixes bug reported by Geir Hauge + + + 8/6 + --- +doc/{bash.1,bashref.texi},builtins/hash.def,lib/readline/doc/rluser.texi + - minor typo changes from Geir Hauge + +bultins/help.def + - show_longdoc: avoid trying to translate the empty string because it + often translates to some boilerplate about the project and + translation. Report and fix from Geir Hauge + + 8/8 + --- +builtins/help.def + - help_builtin: try two passes through the list of help topics for each + argument: one doing exact string matching and one, if the first pass + fails to find a match, doing string prefix matching like previous + versions. This prevents `help read' from matching both `read' and + `readonly', but allows `help r' to match everything beginning with + `r'. Inspired by report from Geir Hauge + + 8/13 + ---- +builtins/fc.def + - fc_builtin,fc_gethnum: calculate `real' end of the history list and + use it if -0 is specified as the beginning or end of the history + range to list. Doesn't work for fc -e or fc -s by design. Feature + requested by Mike Fied + + 8/16 + ---- +trap.c + - _run_trap_internal: use {save,restore}_parser_state instead of + {save,restore}_token_state. It's more comprehensive + + 8/23 + ---- +doc/bash.1 + - disown: remove repeated text. Report and fix from Thomas Hood + + + 8/25 + ---- +lib/readline/rltty.c + - set_special_char: fix prototype (last arg is rl_command_func_t *) + +sig.c + - set_signal_handler: return oact.sa_handler only if sigaction + succeeds; if it doesn't, return SIG_DFL (reasonable default). From + https://bugzilla.redhat.com/show_bug.cgi?id=911404 + +bashline.c + - attempt_shell_completion: fix to skip assignment statements preceding + command name even if there are no programmable completions defined. + From https://bugzilla.redhat.com/show_bug.cgi?id=994659 + - attempt_shell_completion: if still completing command word following + assignment statements, do command completion even if programmable + completion defined for partial command name entered so far + + 8/26 + ---- +pcomplete.c + - pcomp_filename_completion_function: make sure rl_filename_dequoting_function + is non-NULL before trying to call it. Bug and fix from + Andreas Schwab + +bashline.c + - bash_command_name_stat_hook: if *name is not something we're going + to look up in $PATH (absolute_program(*name) != 0), just call the + usual bash_filename_stat_hook and return those results. This makes + completions like $PWD/exam[TAB] add a trailing slash + + 9/2 + --- +builtins/read.def + - read_builtin: before comparing what we read to the delim, make sure + we are not supposed to be ignoring the delimiter (read -N). We + set the delim to -1, but it's possible to read a character whose + int value ends up being between -1 and -128. Fixes bug + reported by Stephane Chazelas + +doc/{bash.1,bashref.texi} + - word splitting: crib some language from Posix to make it clear that + characters in IFS are treated as field *terminators*, not field + *separators*. Addresses issue raised by DJ Mills + + +lib/readline/{util.c,rldefs.h} + - _rl_stricmp,_rl_strnicmp: now take const char * string arguments; + changed prototype declarations + + 9/5 + --- +doc/{bash.1,bashref.texi} + - [[: modify description of pattern matching to make it clear that the + match is performed as if the extglob option were enabled. From Red + Hat bug https://bugzilla.redhat.com/show_bug.cgi?id=1002078 + + 9/12 + ---- +lib/readline/isearch.c + - _rl_isearch_dispatch: if we read an ESC and it's supposed to + terminate the search, make sure we check for typeahead with + _rl_pushed_input_available, since installing a hook function causes + typeahead to be collected in `ibuffer' (input.c). If there is any, + make sure we still use the ESC as a prefix character. Bug and fix + from Mike Miller + + 9/16 + ---- +builtins/{caller,cd,kill,pushd,wait}.def + - builtin_usage(): make sure call to this sets return status to + EX_USAGE + + 9/18 + ---- +terminal.c + - rl_change_environment: new application-settable variable; if non- + zero (the default), readline will modify LINES and COLUMNS in the + environment when it handles SIGWINCH + - _rl_get_screen_size: if rl_change_environment is non-zero, use setenv + to modify LINES and COLUMNS environment variables + +readline.h + - rl_change_environment: new extern declaration for applications + + 9/22 + ---- +configure.ac + - relstatus: bumped version to bash-4.3-beta2 + + 9/24 + ---- + +lib/readline/readline.c + - bind_arrow_keys_internal: added more key bindings for the numeric key + pad arrow keys on mingw32. Patch from Pierre Muller + + + 10/19 + ----- + +bashline.c + - maybe_restore_tilde: version of restore_tilde that honors `direxpand'; + calls restore_tilde after saving directory expansion hook if + necessary. Report from Andreas Schwab + +builtins/cd.def + - -@: new option, allows cd to use `extended attributes' present in + NFSv4, ZFS; idea taken from ksh93. Attributes associated with a + file are presented as a directory containing the attributes as + individual files. Original patch contributed by Cedric Blancher + + + 10/20 + ----- +aclocal.m4 + - BASH_CHECK_MULTIBYTE: check for wcwidth being broken with unicode + combining characters needs a value to use when cross-compiling. + Bug report from Bert Sutherland + +doc/{bash.1,bashref.texi} + - document new -@ option to cd builtin + + 10/28 + ----- +lib/glob/{{gmisc,glob}.c,glob.h} + - extglob_pattern renamed to extglob_pattern_p, declared in glob.h + +subst.c + - expand_word_internal: typo fix: case to fix " $@\ " bug in bash-4.2 + had a typo (& isexp instead of &&) + + 10/29 + ----- +input.c + - getc_with_restart: make sure local_index and local_bufused are + reset to 0 before returning EOF, in case we are running an interactive + shell without line editing and ignoreeof is set. Report and fix + from Yong Zhang + +lib/readline/search.c + - _rl_nsearch_init: take out extra third argument to rl_message; it + only matches prototype (and maybe format) in cases where + PREFER_STDARG and USE_VARARGS are both undefined, which is rare + + 10/31 + ----- +subst.c + - process_substitute: when opening the named pipe in the child, open + without O_NONBLOCK to avoid race conditions. Happens often on AIX. + Bug report and fix from Michael Haubenwallner + + +builtins/ulimit.def + - RLIMIT_NTHR: if RLIMIT_PTHREAD is not defined, but RLIMIT_NTHR is, + use RLIMIT_NTHR (NetBSD) + + 11/5 + ---- +locale.c + - set_default_locale_vars,set_locale_var: if TEXTDOMAINDIR has been + set, and default_dir has a non-null value, call bindtextdomain(3) + when TEXTDOMAIN is assigned a value. Fixes problem reported by + Michael Arlt + + 11/6 + ---- +builtins/cd.def + - cdxattr: only create synthetic pathname in `buf' if NDIRP argument + is non-null + - change_to_directory: if we have specified -@ and cdxattr returns + failure, fail immediately. Fixes bug reported by Joshuah Hurst + + + 11/12 + ----- +redir.c + - print_redirection: change r_err_and_out (&>) and its append form, + r_append_err_and_out (&>>) cases to separate redirection operator + from filename by a space, in case we have a process substitution. + Fixes bug reported by admn ombres + + 11/15 + ----- +execute_cmd.c + - execute_simple_command: don't close process substitution fds until + we are finished executing any current shell function. Partial fix + for bug reported by John Dawson + +support/shobj-conf + - add support for Darwin 13 (Mac OS X 10.9, Mavericks). Based on a + report by Ludwig Schwardt + + 11/20 + ----- +[bash-4.3-rc1 frozen] + + 11/24 + ----- +builtins/printf.def + - bind_printf_variable: make sure that the variable assigned to is + no longer marked as invisible. Fixes bug reported by NBaH + + + 11/28 + ----- +jobs.c + - delete_old_job: fix off-by-one error in job index in call to + internal_warning. Bug report from Peter Cordes + + 11/30 + ----- +doc/bashref.texi + - add string to description of special parameters with name of + special parameter prefixed by a $, so you can search for $#, + for instance + + 12/2 + ---- +lib/readline/{histexpand.c + - get_history_event: account for current_history() possibly returning + NULL. Report and fix from Pankaj Sharma + + + 12/11 + ----- + +lib/readline/parse-colors.c + - get_funky_string: don't call abort if we see something we can't + parse; just return an error + - _rl_parse_colors: if we encounter an error while parsing $LS_COLORS + we need to leave _rl_color_ext_list as NULL after freeing its + elements, then turn off _rl_colored_stats. Report and fix from Martin + Wesdorp + + 12/13 + ----- + +lib/readline/parse-colors.c + - _rl_parse_colors: if we encounter an unrecognized prefix, throw an + error but try to recover and go on to the next specification + +variables.c + - make_local_variable: for new variables this function creates, set + the att_invisible attribute. All callers from declare_internal. + Indirectly, this is a fix for bug with `declare -n var; var=foo;' + reported by Pierre Gaston + - bind_variable: if assigning to nameref variable that doesn't have + a value yet (e.g., with `declare -n var; var=foo'), don't try to + use the unset name. Fixes a segfault reported by Pierre Gaston + + +execute_cmd.c + - execute_command_internal: make sure last_command_exit_value is set + to 0 after any command executed in the background. Fixes bug + reported by Martin Kealey + + 12/17 + ----- +support/config.{guess,sub} + - updated to latest versions from git + + 12/19 + ----- +parse.y + - struct STRING_SAVER: now has a new `flags' element, to identify the + caller: alias expansion, double-paren parsing, or parse_and_execute + - push_string: now sets flags to PSH_ALIAS if `ap' argument is non-NULL + - push_string: now doesn't attempt to call strlen on a NULL string to + set shell_input_line_size + - parser_expanding_alias, parser_save_alias, parser_restore_alias: new + functions to provide an external interface to push_string and + pop_string; parser_save_alias sets flags element to PSH_SOURCE (could + be renamed PSH_EXTERN someday) + - shell_getc: when yy_getc returns '\0', instead of just testing + whether the pushed_string_list is not-empty before popping it, don't + pop if if the saved string has flags PSH_SOURCE, indicating that + parse_and_execute set it before setting bash_input to the string. + We should continue reading to the end of that string before popping + back to a potential alias. Partial solution for the problem of aliases + with embedded newlines containing `.' commands being executed out of + order reported by Andrew Martin + - shell_getc: when yy_getc returns '\0' and there is a saved string of + type PSH_SOURCE, restart the read without popping the string stack + if we have not read to the end of bash_input.location.string. Rest + of fix for out-of-order execution problem + +externs.h + - parser_expanding_alias, parser_save_alias, parser_restore_alias: new + extern function declarations + +builtins/evalstring.c + - pe_prologue: if the parser is expanding an alias, make sure to add + an unwind-protect to restore the alias; undoes the work that will be + performed by parse_and_execute/parse_string + - parse_and_execute,parse_string: after calling push_stream to save + bash_input, check whether or not the parser is currently expanding + an alias (parser_expanding_alias() != 0). If it is, we want to save + that string in the pushed_string_list, which we do with + parser_save_alias. + + 12/23 + ----- +execute_cmd.c + - execute_for_command: make sure to set line_number before expanding + the word list, so expansion errors have the right line number. + From a report from Ben Okopnik + +expr.c + - exp2: save token pointer before calling readtok(), arrange to use + saved token pointer when printing error token on a division by 0 + error + + 12/27 + ----- +lib/readline/display.c + - rl_redisplay: when calculating effects of invisible characters in a + prompt that is split across physical screen lines to set the indices + of linebreaks, don't bother testing local_prompt_prefix (line 751). + That prefix doesn't matter when calculating prompt visible and + invisible characters. Fixes problem reported by Jinesh Choksi + + +Makefile.in + - install: make sure to use $(DESTDIR) when installing OTHER_DOCS. + Report and fix from Matthias Klose + +doc/texinfo.tex + - updated to version of 2013-09-11 + + 12/28 + ----- +lib/readline/undo.c + - rl_do_undo: if we are undoing from a history entry (rl_undo_list == + current_history()->data), make sure the change to rl_line_buffer is + reflected in the history entry. We use the guts of + rl_maybe_replace_line to do the work. Fixes problem reported by + gregrwm + + 12/30 + ----- +sig.c + - sigint_sighandler: if we get a SIGINT (and this signal handler is + installed) while the wait builtin is running, note that we received + it in the same way as jobs.c:wait_sigint_handler and return. The + various wait_for functions will look for that with CHECK_WAIT_INTR. + This fixes the wait builtin not being interruptible in an interactive + job control shell + + 12/31 + ----- +trap.c + - set_signal_hard_ignored: rename set_signal_ignored to this, since it + both sets original_signals[sig] and sets the HARD_IGNORE flag + - set_signal_ignored: new function, now just sets original_signals[sig] + +trap.h + - set_signal_hard_ignored: new external declaration + +sig.c + - initialize_terminating_signals: call set_signal_hard_ignored instead + of set_signal_ignored for signals with disposition SIG_IGN when the + shell starts + +execute_cmd.c + - setup_async_signals: make sure we get the original dispositions for + SIGINT and SIGQUIT before starting the subshell, and don't call + set_signal_ignored because that sets original_signals[sig]. If we + don't, subsequent attempts to reset handling using trap will fail + because it thinks the original dispositions were SIG_IGN. Posix + interpretation 751 (http://austingroupbugs.net/view.php?id=751) + + 1/2/2014 + -------- +lib/sh/stringvec.c + - strvec_mcreate, strvec_mresize: versions of create and resize that + use malloc and realloc, respectively, instead of xmalloc/xrealloc + +braces.c + - expand_amble,mkseq: use strvec_mcreate/strvec_mresize so we can + catch and handle memory allocation failures instead of aborting + with the xmalloc/xrealloc interface + +lib/sh/strdup.c + - strdup replacement function for ancient systems that don't have it + +lib/sh/itos.c + - mitos: new function, itos that uses strdup instead of savestring + +externs.h + - strvec_mcreate/strvec_mresize: new extern declarations + - mitos: new extern declaration + +configure.ac + - bash version moved to 4.3-rc2 + + 1/6 + --- +doc/bash.1,lib/readline/doc/{rluser.texi,readline.3} + - separate the description of what happens when readline reads the + tty EOF character from the description of delete-char, leaving a + note in the delete-char description about common binding for ^D. + From suggestion by Parke + +lib/readline/doc/{version.texi,history.3,*.texi} + - updated email addresses and copyright dates + + 1/7 + --- +variables.c + - delete_var: new function, just removes a variable from a hash table + and frees it, without doing anything else + - make_variable_value: if we are trying to assign to a nameref variable, + return NULL if the value is null or the empty string or not a valid + identifier + +variables.h + - delete_var: new extern declaration + +subst.h + - ASS_NAMEREF: new define for assignments, means assigning to a nameref + variable + +builtins/declare.def + - declare_internal: if we are creating and assigning to a nameref + variable, make sure the value is a valid variable name (checks done + by make_variable_value via bind_variable_value) and display an + error message, deleting the variable we just created, if it is not. + Fixes bug reported by Peggy Russell + + 1/9 + --- +builtins/declare.def + - declare_internal: turning on nameref attribute for an existing + variable turns off -i/-l/-u/-c attributes (essentially the ones + that cause evaluation at assignment time) for ksh93 compat + +builtins/setattr.def + - show_name_attributes: if asked to display attributes and values for + a nameref variable, don't follow the nameref chain to the end. More + ksh93 compat + + 1/10 + ---- +trap.c + - _run_trap_internal: use {save,restore}_parser_state instead of + {save,restore}_token_state, like in run_pending_traps(); don't + need to save and restore last_command_exit_value as a result + - _run_trap_internal: call {save,restore}_pipeline like in + run_pending_traps() + - run_pending_traps: since we no longer run traps in a signal handler + context, do not block and unblock the trapped signal while the + trap is executing + - run_pending_traps: allow recursive invocations (basically, running + traps from a trap handler) with only a warning if the shell is + compiled in debug mode. If a caller doesn't want this to happen, + it should test running_trap > 0. signal_in_progress (sig) only works + for the signals the shell handles specially + +bashline.c + - bash_event_hook: make sure we clean up readline if interrupt_state + is set, not only when SIGINT is not trapped. check_signals_and_traps + will call check_signals, which calls QUIT, which will longjmp back + to top_level, running the interrupt trap along the way. Fixes the + problem of signal handlers being reset out from under readline, and + not being set properly the next time readline is called, because + signals_set_flag is still set to 1. XXX - might need to do this + for other signals too? + + 1/11 + ---- +subst.h + - SD_GLOB: new define for skip_to_delim; means we are scanning a + glob pattern. + +subst.c + - skip_to_delim: if flags include SD_GLOB, assume we are scanning a + glob pattern. Currently only used to skip bracket expressions + which may contain one of the delimiters + + 1/12 + ---- +subst.c + - parameter_brace_expand: when expanding $@ as part of substring + expansion, pattern substitution, or case modification, don't turn + on the QUOTED_NULL flag. The code that constructs the word to be + returned from expand_word_internal expects a different code path + when $@ is being expanded. Fixes bug reported by Theodoros + V. Kalamatianos + + 1/19 + ---- +subst.c + - list_dequote_escapes: new function; analogue of list_quote_escapes + +pathexp.c + - quote_string_for_globbing: fix case where unescaped ^A is last char + in string; need to pass it through unaltered instead of turning it + into a bare backslash + - quote_string_for_globbing: when quoting for regexp matching in [[, + don't treat backslash as a quote character; quote the backslash as + any other character. Part of investigation into reports from + Eduardo A. Bustamante López + + 1/25 + ---- +builtins/gen-helpfiles.c + - write_helpfiles: add prototype + - make sure to #undef xmalloc/xfree/xrealloc/free if USING_BASH_MALLOC + is defined. the code does not use them, and we don't link against + xmalloc.o. Report from Linda Walsh + +Makefile.in + - variables.o: add dependency on builtins/builtext.h; helps with + parallel builds. Report from Linda Walsh + +support/shobj-conf + - darwin: combine the stanzas into one that will not require them to + be updated on each Mac OS X release. Report and fix from Max Horn + + + 1/27 + ---- +support/shobj-conf + - darwin: changed the install_name embedded into the shared library + to contain only the major version number, not the minor one. The + idea is that the minor versions should all be API/ABI compatible, + and it is better to link automatically with the latest one. Idea + from Max Horn + + 1/29 + ---- +[bash-4.3-rc2 released] + + 1/30 + ---- +lib/readline/readline.h + - rl_clear_history, rl_free_keymap: add extern declarations. Report + from Hiroo Hayashi + +general.c + - include trap.h for any_signals_trapped() prototype + +lib/sh/unicode.c + - include for sprintf prototype + + 1/31 + ---- +execute_cmd.c + - execute_simple_command: only posix-mode shells should exit on an + assignment failure in the temporary environment preceding a special + builtin. This is what the documentation and code comments have + always said + - execute_simple_command: make sure redirection errors, word expansion + errors, and assignment errors to Posix special builtins cause a + non-interactive posix mode shell to exit. Previously the shell + would not exit if the failed special builtin was on the LHS of || + or && + +pathexp.c + - quote_string_for_globbing: when quoting a regular expression + (QGLOB_REGEXP), allow an unquoted backslash to pass through + unaltered. Don't use it as a quote character or quote it. More + investigation from 1/24 and report by Mike Frysinger + + - quote_string_for_globbing: when quoting a regular expression + (QGLOB_REGEXP), turn CTLESC CTLESC into CTLESC without adding a + backslash to quote it. We should not have to quote it because it is + not a character special to EREs. More investigation from 1/24 + +lib/glob/glob.c + - glob_testdir: now takes a second flags argument (currently unused); + changed prototype and callers + + 2/1 + --- +lib/glob/glob.c + - glob_testdir: if flags argument includes GX_ALLDIRS (globstar), use + lstat so we skip symlinks when traversing the directory tree. + Originally reported by Chris Down + + 2/2 + --- +lib/readline/undo.c + - rl_do_undo: make sure CUR is non-zero before dereferencing it to + check cur->data against rl_undo_list. Report and fix from + Andreas Schwab + +doc/{bash.1,bashref.texi} + - added slight clarifying language to the description of $*, + describing what happens when the expansion is not within double + quotes + + 2/4 + --- +test.c + - unary_test: add code to -v case so that it interprets `bare' array + references (foo[1]) and returns true if that index has a value + + 2/5 + --- +trap.c + - restore_default_signal: fix SIGCHLD special case for SIG_TRAPPED flag + off but SIG_INPROGRESS mode set and handler IMPOSSIBLE_TRAP_HANDLER; + continue with resetting handler in this case. maybe_set_sigchld_trap + will check these things before resetting sigchld trap from + run_sigchld_trap. Fixes (apparently long-standing?) problem reported + by Alexandru Damian + + 2/6 + --- +lib/sh/strtrans.c + - ansic_quote: fixed a bug when copying a printable character that + consumes more than one byte; byte counter was not being incremented. + Bug report from jidanni@jidanni.org + + 2/7 + --- +input.c + - getc_with_restart: if read(2) returns -1/EINTR and interrupt_state or + terminating_signal is set (which means QUIT; will longjmp out of this + function), make sure the local buffer variables are zeroed out to + avoid reading past the end of the buffer on the next call. Bug report + from Dan Jacobson + + 2/9 + --- +bashline.c + - command_word_completion_function: if a directory in $PATH contains + quote characters, we need to quote them before passing the candidate + path to rl_filename_completion_function, which performs dequoting on + the pathname it's passed. Fixes bug reported by Ilyushkin Nikita + + + 2/11 + ---- +parse.y + - xparse_dolparen: save and restore shell_eof_token around call to + parse_string, intead of just leaving it set to ')' + - shell_getc: when -v is set, only print the command line when + shell_eof_token is 0, so we don't print it multiple times when + recursively entering the parser to parse $(...) commands. Fixes + bug reported by Greg Wooledge + +[changed release status to 4.3-release] + + 2/13 + ---- +lib/sh/strtrans.c + - ansic_quote: handle case where mbrtowc reports that the multibyte + sequence is incomplete or invalid. Fixes bug reported by + Eduardo A. Bustamante López + + 2/14 + ---- +variables.c + - find_variable_nameref_context: fix a problem that caused the loop + to go one context too close to the global context. In some cases, + simple variable assignment would set a variable in the global + context instead of a local context. Bug report from + Geir Hauge + + 2/26 + ---- +[bash-4.3 released] + + 2/27 + ---- +aclocal.m4 + - broken wcwidth check: fix typo reported by David Michael + + + 2/28 + ---- +support/bashbug.sh + - add ${BUGADDR} to error message printed if sending mail fails + +trap.c + - _run_trap_internal: don't call {save,restore}_pipeline if running + DEBUG trap; run_debug_trap calls them itself. Fixes bug reported + by Moe Tunes + +test.c + - unary_test: fix 'R' case by using find_variable_noref instead of + find_variable + - test_unop: add back missing 'R' case. Fixes bug reported by + NBaH + + 3/2 + --- +jobs.c + - end_job_control: if job control is active, we changed the terminal's + process group, so make sure we restore it. Fixes bug reported by + Eduardo A. Bustamante López + + 3/7 + --- +pcomplete.c + - pcomp_curtxt: new variable, holds the original text to be completed + as passed to the programmable completion code + - pcomp_filename_completion_function: if we are running compgen + (presumably in a shell function completion) and performing readline + completion, check the word being completed. If it's not empty, but + the original word passed to the programmable completion code is an + empty string (""), call a dequoting function if one is available. + This compensates for an assumption in bash-completion. Reported by + Albert Shih + +lib/readline/readline.c + - _rl_dispatch_subseq: when deciding whether or not to set vi mode's + idea of the last command, use whether or not the dispatching keymap + is vi_movement_keymap instead of the key sequence length. The `c', + `d', and `y' commands all take motion commands as `arguments' and + will produce key sequences longer than 1 character. The arrow keys + will end up dispatching out of a different keymap, so the test will + prevent arrow keys from setting the last command (the problem in + bash-4.2). Bug report from Daan van Rossum + +lib/readline/vi_mode.c + - _rl_vi_motion_command: convenience function to test whether a key is + a vi-mode motion command + +lib/readline/rlprivate.h + - _rl_vi_motion_command: extern declaration + +parse.y + - parse_matched_pair: we should not skip processing single quotes in + posix mode if dolbrace_state == DOLBRACE_QUOTE2 (pattern + substitution). Fixes bug reported by David Sines + + + 3/10 + ---- +lib/readline/readline.c + - _rl_dispatch_callback: treat a return value of -1 as the end of + a command dispatch sequence if the current context doesn't + indicate that we're reading a multi-key sequence + ((cxt->flags & KSEQ_SUBSEQ) == 0). Turn off the multikey flag + and free the context chain in this case. Fixes one bug reported + by Felix Yan to bug-readline list + - _rl_dispatch_callback: treat a return value of > 0 the same as 0 + and return from the function, since only values < 0 cause us to + simulate recursion. Rest of fix for bug tracked down by + Anatol Pomozov + + 3/11 + ---- + +execute_cmd.c + - execute_in_subshell: if a longjmp occurs, set result to + EXECUTION_FAILURE only if last_command_exit_value == EXECUTION_SUCCESS; + use value of last_command_exit_value otherwise. Fixes cosmetic + issue reported by Dennis Lambe Jr. + +doc/bash.1 + - shell-kill-word and shell-backward-kill-word should be documented + as unbound by default. Report from Oliver Hartley + + +trap.c + - run_pending_traps: save value of $? before running trap commands in + trap_saved_exit_value, like run_exit_trap + - _run_trap_internal: save value of $? before running trap commands in + trap_saved_exit_value, like run_exit_trap + +builtins/common.c + - get_exitstat: when running `return' in a trap action, and it is not + supplied an argument, use the saved exit status in + trap_saved_exit_value. Fixes Posix problem reported by + Eduardo A. Bustamante López + + 3/13 + ---- +lib/sh/shquote.c + - sh_contains_quotes: new function, returns true if a given string + contains any of the shell quote characters (single quote, double + quote, or backslash) + +externs.h + - sh_contains_quotes: new extern declaration + +pcomplete.c + - pcomp_filename_completion_function: more changes for the benefit of + bash-completion: if the argument is not the same as the original + argument passed to the programmable completion code (pcomp_curtxt), + and we are being run by compgen as part of a completion, dequote the + argument as bash-completion expects. Fix for the complete-word- + with-quoted-special-chars problem with bash-completion + + 3/17 + ---- +execute_cmd.c + - execute_intern_function: when in posix mode, make defining a function + with the same name as a special builtin a fatal error only when the + shell is not interactive. Interactive shells display an error + message and go on. From a discussion with Doug McIlroy + + + 3/18 + ---- +arrayfunc.c + - assign_compound_array_list: when using expand_assignment_string_to_string + to expand the value in a ( [x]=y ) compound assignment, make sure + that we convert 0x0 to "" when expanding [x]= so it doesn't appear as + if the index is unset. Fixes bug reported by Geir Hauge + + +builtins/common.c + - get_exitstat: update fix of 3/11 to allow the DEBUG trap to use the + current value of $? instead of the value it had before the trap + action was run. This is one reason the DEBUG trap exists, and + extended debug mode uses it. Might want to do this only in Posix + mode + +doc/{bash.1,bashref.texi} + - return: add language cribbed from Posix saying what happens when + return is run without an argument from a trap, including the DEBUG + trap exception + + 3/19 + ---- +lib/glob/gmisc.c + - extglob_pattern_p: make sure ?(patlist) is flagged as an extglob + pattern + +lib/glob/glob.c + - extglob_skipname: rewrite to handle patterns that begin but do not + end with an extglob pattern; change test for easy case and loop + through patterns accordingly. Fixes problem with matching filenames + with a leading dot reported by Stephane Chazelas + + - wextglob_skipname: make analogous changes + + 3/20 + ---- +Makefile.in + - pass -DDEBUG down to builds in readline and history directories + +lib/readline/util.c + - _rl_trace and related functions are now only compiled in if DEBUG + is defined + +lib/readline/Makefile.in + - substitute @DEBUG@ and pass -DDEBUG, if necessary, to compilation + in LOCAL_CFLAGS + + 3/21 + ---- +parse.y + - shell_getc: when checking whether or not to reallocate + shell_input_line to add trailing newline, don't try to subtract from + shell_input_line_size. size_t is unsigned, so if its value is less + than 3 (like, say, 2), size-3 is a very large number and the string + will not be reallocated. Use len+3 > size instead of len > size-3. + Fixes bug reported in + https://bugs.launchpad.net/ubuntu/+source/bash/+bug/1295467 + + 3/27 + ---- +lib/readline/display.c + - _rl_clean_up_for_exit: don't bother to call _rl_move_vert to whatever + readline thinks the last displayed line is if it's 0. Two reasons: a + minor optimization, and it protects against unwanted moving if this + function is called twice, as it is when ^C is pressed. Fixes bug + reported by Egmont Koblinger + + 3/28 + ---- +bashline.c + - invalid_completion: new function, used to identify attempts to + complete words that are syntax errors + - attempt_shell_completion: if invalid_completion returns true for a + word in a command position, punt on all completions. Fixes cosmetic + issue reported by Uwe Storbeck + - attempt_shell_completion: add clause so that in_command_position + remains set to 1 for an empty word following a command separator like + (, &, or | + +lib/readline/kill.c + - rl_yank, rl_yank_nth_arg_internal: don't return -1 from bindable + functions, return 1 instead + +lib/readline/text.c + - rl_rubout, _rl_rubout_char, rl_delete, rl_change_case, + rl_transpose_chars, rl_transpose_words, _rl_set_mark_at_pos, + rl_exchange_point_and_mark, _rl_insert_next, _rl_char_search, + _rl_char_search_internal: + don't return -1 from bindable functions, return 1 instead + +lib/readline/vi_mode.c + - rl_vi_end_word, rl_vi_rubout, rl_vi_delete, rl_vi_char_search, + rl_vi_match, _rl_vi_set_mark, _rl_vi_goto_mark: + don't return -1 from bindable functions, return 1 instead + +lib/readline/macro.c + - rl_start_kbd_macro, rl_end_kbd_macro: + don't return -1 from bindable functions, return 1 instead + +builtins/setattr.def + - set_var_attribute: honor setting of no_invisible_vars when setting + att_invisible on a variable + - include "../flags.h" for no_invisible_vars + +builtins/declare.def + - declare_internal: honor setting of no_invisible_vars when setting + att_invisible on a variable + - include "../flags.h" for no_invisible_vars + +Makefile.in,builtins/Makefile.in + - make sure declare.o and setattr.o depend on flags.h + +execute_cmd.c + - decpoint: new function, returns locale's decimal point or `.' default + - mkfmt: use decpoint() to get decimal point instead of unconditionally + using `.'. Fixes bug reported by Andrey Tataranovich + in debian bug 741669 + + 4/10 + ---- +lib/readline/rltypedefs.h + - add back old Function/VFunction/etc typedefs, since other packages + (python, samba) use them. Mark as deprecated using gcc and clang + attributes. Report and fix from Max Horn + + 4/14 + ---- +jobs.c + - run_sigchld_trap: unwind-protect value of this_shell_builtin, since + it matters in some cases whether or not we are running `wait' or + `eval'. Fixes bug reported by Eduardo A. Bustamante López + + + 4/18 + ---- +shell.h + - sh_parser_state_t: add `need_here_doc' flags member, since + xparse_dolparen (via parse_command) sets it to 0 + +parse.y + - gather_here_documents: make sure need_here_doc is > 0, since we + don't want to just decrement it forever if it ends up < 0. Partial + fix for bug reported by Jared Yanovich + - {save,restore}_parser_state: save and restore need_here_doc flag. + Rest of fix for bug reported by Jared Yanovich + + 4/19 + ---- +subst.c + - cond_expand_word: since we are not supposed to be performing word + splitting here, set expand_no_split_dollar_star to 1 in addition to + setting W_NOSPLIT2 + - expand_word_internal: if we have a case where we have an unquoted + $@ but we are in a case where we don't want to split (W_NOSPLIT2), + make sure we return a list consisting of a single word with the + arguments separated by spaces and don't do word splitting. Fixes + bug reported by Greg Wooledge from an IRC + discussion + +builtins/hash.def + - print_portable_hash_info: single-quote pathnames and hashed filenames + that contain shell metacharacters. Fixes bug reported by + in debian bash bug #739853 + + 4/20 + ---- +lib/readline/display.c + - When using horizontal scrolling, the redisplay code erases too much + of the line containing successful results, so make sure we only + erase to the end of the line after making sure we move the cursor + to the end. Fixes bug reported by + + 4/23 + ---- +{bashhist,bashline}.c +builtins{bind,help,type}.def +lib/glob/glob.c, lib/intl/{loadmsgcat,localealias}.c,lib/sh/mktime.c + - fixes to memory leaks uncovered by coverity scan + + 4/24 + ---- +{bashhist,subst,redir,assoc,jobs,array,trap}.c +lib/intl/l10flist.c +builtins/complete.def + - fixes to memory leaks and other resource usage problems uncovered by + coverity scan + +redir.c + - do_redirection_internal: if dup2 fails (presumably because of a + resource limit), close the file descriptor we opened before returning + error + + 4/25 + ---- +config-top.h + - DEFAULT_BASHRC: new define with the name of the default shell + startup file + +bashline.c + - bash_directory_completion_matches: don't dequote the directory name. + If rl_completion_found_quote is non-zero, readline will dequote the + filename itself. Fixes bug reported by Clark Wang + + + 4/27 + ---- +subst.c + - parameter_brace_expand_rhs: if parameter_brace_find_indir returns + NULL or "", or if it returns something that is not a valid identifier, + report an error and return &expand_wdesc_error so the error can + propagate up. Fixes bug reported by Andre Holzhey + + + 4/29 + ---- +subst.c + - parameter_brace_substring: don't short-circuit right away if the + value is NULL but we are looking at the positional parameters. Part + of fix for bug reported by Pierre Gaston + - pos_params: if there are no positional parameters, only short-circuit + if we are looking for $1 and above. Rest of fix for bug reported + by Pierre Gaston + +subst.h + - SD_NOPROCSUB: new flag for skip_to_delim, means to not allow any + process subsitutions (should not have overloaded SD_NOSKIPCMD) + +subst.c + - skip_to_delim: honor SD_NOPROCSUB flag + +make_cmd.c + - make_arith_for_expr: set W_NOPROCSUB flag in the created word + - make_arith_for_command: set SD_NOPROCSUB in the flags argument to + skip_to_delim so we don't treat <( or >( as a process substitution + (we won't evaluate them in eval_arith_for_expr anyway). Fixes + bug reported by Pierre Gaston + + 5/1 + --- +lib/glob/gmisc.c + - glob_dirscan: new function, takes a pattern and a directory separator + argument and advances the pattern to the last occurrence of the + separator. Like strrchr, but understands extended glob patterns and + uses glob_patscan to skip over them + +lib/glob/glob.c + - extglob_skipname: if the extended globbing pattern is invalid, don't + skip the name + - glob_filename: if there is a slash in the pattern to be matched, and + extglob is enabled, use glob_dirscan to find the real last occurrence + of `/' to avoid being confused by slashes in extglob patterns. Fix + for bug reported by Pierre Gaston + + 5/6 + --- +variables.c + - make_local_variable: only set the att_invisible attribute if + no_invisible_vars isn't set + - find_variable_for_assignment: new function, intended to be called by + code that eventually wants to assign a value to the variable; will not + skip invisible variables; currently identical to find_variable + - find_variable_no_invisible: new function, finds the first visible + instance of variable with a given name in the variable context chain; + eventually will be used to replace find_variable; separate right now + for testing + +variables.h + - find_variable_for_assignment: extern declaration + - find_variable_no_invisible: extern declaration + + 5/7 + --- +variables.c + - make_local_variable: don't clear `invisible' attribute if we are + returning an existing local variable at the right context. Let the + upper layers do that. Fixes bug reported by Dan Douglas + + + 5/8 + --- +lib/readline/input.c + - rl_getc: call RL_CHECK_SIGNALS if a read(2) is interrupted (-1/EINTR) + by SIGALRM or SIGVTALRM (placeholder for non-keyboard-generated + signals of interest) + +builtins/read.def + - edit_line: call bashline_set_event_hook and + bashline_reset_event_hook around call to readline(), so the right + signal handling happens + - read_builtin: make sure we add an unwind_protect call to + bashline_reset_event_hook. These changes fix bug reported in + https://bugs.launchpad.net/ubuntu/+source/bash/+bug/1317476 + +bashline.c + - bash_event_hook: make sure we clean up the readline state by calling + rl_cleanup_after_signal if sigalrm_seen is non-zero. The read builtin + sets this when it times out + + 5/12 + ---- +doc/{bash.1,bashref.texi} + - clarify language to make it clear that changing attributes of a + nameref variable (e.g., export), actually changes the attributes of + the referenced variable. Fixes omission noted by Jeff Haemer + + +arrayfunc.c + - bind_array_var_internal: make sure ENTRY no longer has invisible + attribute before returning. Fixes bug reported by Geir Hauge + + + 5/22 + ---- +execute_cmd.c + - shell_execve: if execve fails and we return 127 or 126, make sure to + set last_command_exit_value if a call to file_error or report_error + causes the shell to exit. This ensures that the shell exits with + the right value. + + 6/6 + --- +shell.c + - drop_priv_mode: print an error message on setuid() failure, optionally + exit if errno == EAGAIN, as it can be on Linux when RLIMIT_NPROC for + the target user is exceeded. + +config-top.h + - EXIT_ON_SETUID_FAILURE: new settable define, will cause the shell to + exit if setuid fails with errno == EAGAIN + + 6/10 + ---- +parse.y + - time_command_acceptable: fix so time is accepted everywhere the + grammar is looking for a `compound_list'. Fixes bug reported by + Dale Worley + + 6/12 + ---- +subst.c + - clear_fifo_list: new function, clears FDs associated with open pipes + in current FIFO list without closing the file descriptors. Can + possibly be used when shell_execve fails and the shell jumps back + to top_level and we don't want the shell to close the open FIFOs + each time through the read-execute loop. Bug reported by Harald + Koenig + + + 6/16 + ---- +builtins/shopt.def + - compat42: make sure the `compat42' option sets the correct variable + for compatibility level. Fixes bug reported by Ondrej Oprala + + +support/bashbug.sh + - fix typo when echoing $USAGE. Report from Shantanu Kulkarni + + +execute_cmd.c + - shell_execve: before longjmp back to subshell_top_level, clear out the + FIFO fd list by calling clear_fifo_list so the FDs (which we inherited + from our parent) aren't closed every time through the read-eval loop. + Fix for bug reported by Harald Koenig + + 6/18 + ---- +subst.c + - extract_process_subst: add additional argument: xflags, allow callers to + pass flags like extract_command_subst + - extract_process_subst: call xparse_dolparen like command substitution + to avoid problems when parsing commands constructs with embedded open + parens. Fixes bug reported by Tim Friske + +subst.h + - extract_process_subst: modified prototype for extern declaration + + 6/19 + ---- +execute_cmd.c + - execute_pipeline: if running with lastpipe enabled, make sure that we + check whether or not the job id is valid using INVALID_JOB before + calling job_exit_status. the jobs list can get frozen and unfrozen in + the presence of nested pipelines and loops and wait_for can clear a + job table entry. Fixes bug reported by + +jobs.c + - freeze_jobs_list: now returns old value of jobs_list_frozen; unused at + current time + +jobs.h + - freeze_jobs_list: change return value + + 6/20 + ---- +lib/glob/smatch.c + - MEMCHR: single-byte and wide character defines (memchr/wmemchr) + +lib/glob/sm_loop.c + - GMATCH: when the wildcards are the last element of the pattern, make + sure they do not match a string containing a `/' if FNM_PATHNAME is + set in FLAGS + - GMATCH: when recursively calling GMATCH after we see a `*', don't + try to consume the rest of the pattern with `*' if FNM_PATHNAME is + set in FLAGS, just consume up to the next slash and then see whether + or not the rest of the pattern matches. Fixes bug reported by Ian + Kelling + - GMATCH: when processing `*' in the pattern, after skipping consecutive + wildcards, if we hit a literal `/' in the pattern and we're looking + for a pathname, skip characters in the string until we find a `/' + (no slash means the match fails), and try to match the rest of the + pattern against the portion of the string after the next `/'. Picked + up from gnulib/glibc + +pathexp.c + - split_ignorespec: since split_ignorespec gets globbing patterns, + make sure we call skip_to_delim with the SD_GLOB flag so delimiters + that occur within bracket expressions don't delimit the pattern. + Fixes problem with [[:digit:]] in GLOBIGNORE reported by Ian Kelling + + +unwind_prot.c + - unwind_protect_tag_on_stack: new function, returns 1 if unwind-protect + frame corresponding to `tag' argument is on unwind-protect stack + +unwind_prot.h + - unwind_protect_tag_on_stack: extern declaration + + 6/30 + ---- +lib/readline/misc.c + - _rl_revert_all_lines: set entry->data to 0 after assigning it to + rl_undo_list to avoid pointer aliasing problems that would result + in entry->line being freed by an undo. The subsequent free would + be a double free. Report and fix from Jared Yanovich + + +subst.c + - command_substitute: other shells do not appear to inherit the -v + option when reading and executing command substitutions. Reported + by Ondrej Oprala + + 7/1 + --- +config-top.h + - CHECKHASH_DEFAULT: new define that supplies the default value for + check_hashed_filenames (`checkhash' shopt option); still 0 by default + +findcmd.c + - check_hashed_filenames: initialize using CHECKHASH_DEFAULT + +lib/readline/histexpand.c + - history_expand: double quotes can inhibit recognition of the history + comment character if history_quotes_inhibit_expansion is non-zero + +lib/readline/doc/{history.3,hstech.texi} + - history_quotes_inhibit_expansion: expand definition to note that it + inhibits scanning for the history comment character as well; correct + typo to make it clear that it only works on double-quoted strings + +lib/sh/zgetline.c + - add new fourth argument: DELIM, allows delimiter to be something + other than newline (if DELIM != '\n', UNBUFFERED_READ should be + non-zero) + - UNBUFFERED_READ is now fifth argument + - check character against DELIM rather than strictly newline + +externs.h + - zgetline: change function prototype for extern declaration + +builtins/mapfile.def + - mapfile: change calling sequence for zgetline calls + - mapfile_builtin: new -d option: DELIM, like in read builtin + - mapfile_builtin: pass `delim' to mapfile() as new argument; default + to '\n' unless -d option supplied + - mapfile: take new DELIM argument, pass to zgetline + - mapfile: if DELIM != '\n', set unbuffered_read to 1 + +doc/{bash.1,bashref.texi} + - mapfile: document new `-d DELIM' option + + 7/5 + --- +lib/readline/histfile.c + - history_truncate_file: if there is an error writing the truncated + history list back to the history file, use the same strategy as + history_do_write: create a backup file, rename the history file to + the backup file, and restore the original history file from the + backup file name if the write or the close fails. Suggestion from + Chen Gang to bug-readline + +execute_cmd.c + - evalnest, evalnest_max: new variables establishing maximum number of + recursive `eval' calls; current max is 4096 + - execute_builtin: unwind-protect value of evalnest around calls to + eval builtin. Suggested by Oliver Morais + - {initialize_subshell,execute_subshell_builtin_or_function}: reset + evalnest to 0 in a subshell + +builtins/setattr.def + - show_name_attributes: show a variable's attributes even if it's + invisible (don't show any value since it has none). This means that + declare -p var will display VAR's attributes even when var marked + as invisible. Feature request from Peggy Russell + + - show_var_attributes: don't print assignment if array or assoc + attribute is set but variable marked as invisible + +tests/array.right + - special note: changed all declare -a output tests because the shell + will no longer print out values for invisible array variables. This + is a change, but one for correctness: + + declare -a foo='()' + and + declare -a foo + are not equivalent + + 7/22 + ---- +subst.c + - parameter_brace_expand: after calling parameter_brace_expand_indir, + turn off the W_ARRAYIND flag in the word it returns, because there + is no way for it to return the index that should be used, and the + rest of the function assumes that IND is valid if W_ARRAYIND is set. + Fixes bug reported by Corentin Peuvrel + + 8/2 + --- +parse.y + - read_token_word: if we read a character that will end a command + substitution, don't skip over quoted newlines when we read an + additional character to figure out whether it's a two-character + token. This lets the higher layers deal with quoted newlines after + the command substitution. Fixes bug reported by EmanueL Czirai + + + 8/11 + ---- +execute_cmd.c + - execute_pipeline: check whether lastpipe_jid corresponds to a valid + job before calling append_process, for the same reason as fix from + 6/19. Fixes bug reported by + + 8/12 + ---- +lib/sh/unicode.c + - stub_charset: use strncpy instead of strcpy because we are copying + into a local fixed-length buffer. Fixes vulnerability reported by + + +execute_cmd.c + - execute_pipeline: if we don't call append_process, call + wait_for_single_pid to get the status of `lastpid', since that will + check the status of already-reaped processes. Fixes spurious error + message about non-existent process from fix of 8/11 + + 8/15 + ---- +jobs.c + - running_in_background: new variable, keeps track of whether or not we + are running in the background (not perfect yet) + - initialize_job_control: even if we are not turning on job control, + get the terminal pgrp so we can use it later + - {set_job_control,initialize_job_control}: set running_in_background + to 1 if terminal pgrp != shell pgrp + - {stop_pipeline,make_child,wait_for}: if we are running in the + background, don't mess with the terminal's process group; assume that + the parent shell will do that. Fixes bug reprted by Greg Wooledge + + +shell.c + - shell_reinitialize: reset running_in_background back to 0 + + 8/24 + ---- +execute_cmd.c + - {execute_connection,execute_command_internal}: make sure that + asynchronous commands always set $? to 0 and are not affected by the + command's exit status being inverted using `!'. Fixes bug reported + by Vincent Lefevre + +lib/readline/display.c + - rl_message: call vsnprintf with full msg_bufsiz, since it counts + one fewer than the buffer length passed as an argument. Bug report + and fix from Dylan Cali + + 8/26 + ---- +builtins/evalstring.c + - evalstring: if CURRENT_TOKEN == yacc_EOF, reset it to newline. This + is instead of calling reset_parser(); that might still be needed. + Fixes bug with eval and a subsequent statement ending with EOF + reported by + +pcomplete.c + - filter_stringlist: when extglob is on, a leading ! in the filter + pattern should be left alone when it introduces a !(pat) pattern; + otherwise it messes up the pattern. Fixes bug reported by David + Korn + + 8/27 + ---- +doc/{bash.1,bashref.texi} + - clarify the behavior of bash when given the -c option, since $0 is + technically not a positional parameter. Bug reported by Stephane + Chazelas + + 8/28 + ---- +lib/readline/history.c + - add_history: use history_max_entries (if history is stifled) or + DEFAULT_HISTORY_INITIAL_SIZE if not (new define, defaults to 502) + to size the initial allocation of the history array. Assumption + is that this will reduce the number of allocations + + 8/29 + ---- +execute_command.c: + - sourcenest, sourcenest_max: new variables used to track level of + sourced files and (maybe) one day catch infinite source recursion + - execute_builtin: if current source level exceeds sourcenest_max, + trigger an error and jump back to the top level + - {initialize_subshell,execute_subshell_builtin_or_function}: reset + sourcenest to 0 in a subshell + + 9/2 + --- +variables.c + - bind_variable: if a nameref expands to an array reference, make + sure that assign_array_element gets called (maybe even + recursively) instead of bind_variable_internal, so invalid variable + names (like arr[0]) don't get created. Fixes bug reported by + + + 9/3 + --- +execute_cmd.c + - evalnest_max,sourcenest_max: initialize from EVALNEST_MAX and + SOURCENEST_MAX, respectively. Feature suggested by + + +config-top.h + - define EVALNEST_MAX and SOURCENEST_MAX to 0 + + 9/6 + --- +bashline.c + - find_cmd_start: fix to (crudely) deal with >| token; even though + skip_to_delim finds `|' as a delimiter, we call it again and use + what the second call finds. Fixes bug reported by Dan Jacobson + + +findcmd.c + - find_in_path_element: if in posix mode, do not expand a literal + tilde in a $PATH element + +doc/bashref.texi + - add change to tilde expansion in $PATH elements to posix mode + description + +builtins/common.h + - ISHELP: new define for builtins that do their own option parsing + and don't use internal_getopt(); checks whether argument is --help + - CHECK_HELPOPT: convenience define to help builtins that do their + own option parsing to check for --help with one line of code + - CASE_HELPOPT: convenience define to help builtins that use + internal_getopt() check for --help with one line of code + +builtins/help.def + - builtin_help: new function, prints out --help output for current + builtin + +builtins/{kill,let,pushd}.def + - add CHECK_HELPOPT to builtins that use ISOPTION; call builtin_help + and return EX_USAGE (kill/let/pushd/popd/dirs) + +builtins/{caller,fg_bg}.def + - use CHECK_HELPOPT to recognize --help, since these builtins perform + checks that can cause them to return before calling no_options + (caller/fg/bg) + +builtins/{exit,return}.def + - use CHECK_HELPOPT to recognize --help before calling get_exitstat() + (return/exit/logout) + +builtins/{break,shift}.def + - use CHECK_HELPOPT to recognize --help before any other checks + (break/continue/shift) + +builtins/bashgetopt.h + - GETOPT_EOF: convenience define + - GETOPT_HELP: new define, to indicate internal_getopt saw --help + +builtins/bashgetopt.c + - internal_getopt: return GETOPT_HELP for --help + +builtins/common.c + - no_options: recognize --help, call builtin_help and return 2 + (builtin/eval/source/./times) + +builtins/command.def + - use CASE_HELPOPT() to handle --help after calling internal_getopt() + (command) + +builtins/{colon,echo,test}.def + - do not recognize --help (:/true/false/echo/test) + + 9/8 + --- +sig.c + - termsig_sighandler: if readline is active now, set the bashline event + hook. Old code just set it for interactive shells. Part of fix for + bug reported by + +bashline.c + - bash_event_hook: call rl_cleanup_after_signal if terminating_signal + is non-zero, since check_signals_and_traps() will cause the shell to + exit if it is and we want to clean up the readline state first. Rest + of fix for bug reported by + + 9/9 + --- +jobs.c + - waitchld: when running the wait builtin in posix mode, with a trap set + on SIGCHLD, use queue_sigchld_trap instead of trap_handler (SIGCHLD), + otherwise you will lose SIGCHLDs when children_exited > 1. Fixes bug + reported by + +builtins/read.def + - read_builtin: if we are changing the tty settings, call + initialize_terminating_signals so we have a chance to catch all + terminating signals and potentially clean up the terminal before + exiting + - read_builtin: tty_modified: new variable, set to 1 if we change the + terminal attributes and have to call ttyrestore() to restore them + - if one of the `reads' returns -1/EINTR due to a terminating signal, + and we have modified the terminal, call ttyrestore before calling + CHECK_TERMSIG + - ttyrestore: set tty_modified to 0 when called + + 9/10 + ---- +builtins/read.def + - termsave: now global to file so other functions can use it + - read_tty_cleanup: if tty_modified is non-zero, call ttycleanup to restore + old terminal settings and turn off tty_modified + +sig.c + - termsig_handler: call read_tty_cleanup if currently executing read + builtin; it does the right thing. Final piece of fix for bug reported + by Jan Rome + + 9/11 + ---- +general.c + - printable_filename: general function to return a printable representation + of a string (presumed to be a filename) + +general.h + - extern declaration for printable_filename + +execute_cmd.c + - execute_disk_command: use printable_filename + +builtins/{bind,cd,enable,hash,source}.def + - use printable_filename as appropriate when printing error messages. + From a suggestion by Vincent Lefevre + +builtins/bind.def + - use CASE_HELPOPT() to handle --help after calling internal_getopt() + (bind) + + 9/12 + ---- +builtins/common.h + - SEVAL_FUNCDEF: new flag for parse_and_execute; it means that we only + accept a single function definition command, as when we are importing + functions from the environment + - SEVAL_ONECMD: new flag for parse_and_execute; for future use + +builtins/evalstring.c + - parse_and_execute: if the SEVAL_FUNCDEF flag is set, disallow anything + but a function definition command + +variables.c + - initialize_shell_variables: don't allow functions with invalid names + to be imported from the environment, even though we still allow them + to be defined + - initialize_shell_variables: when importing function definitions from + the environment, call parse_and_execute with the SEVAL_FUNCDEF flag + to force the command to be just a function definition + +subst.c + - param_expand: when expanding a $name variable expansion, make sure that + the variable is visible and set before following the nameref chain + - param_expand: when expanding a $name variable expansion and following the + nameref chain, make sure the resulting variable is visible and set + before using it + + 9/13 + ---- +variables.c + - initialize_shell_variables: when importing function definitions from + environment, use SEVAL_ONECMD flag for parse_and_execute. Part of + CVE-2014-6271 + +builtins/evalstring.c + - parse_and_execute: if SEVAL_ONECMD flag set, return immediately after + calling execute_command_internal. Final piece for fix for bug + reported by Stephane Chazelas . Part of + CVE-2014-6271 + + 9/24 + ---- +parse.y + - reset_parser: reset eol_ungetc_lookahead to 0 here, since we don't want + shell_getc returning it on the next call. Fixes problem reported by + Tavis Ormandy and Michal Zalewski + . Potentially part of CVE-2014-6271; fix for + CVE-2014-7169 + + 9/25 + ---- +parse.y + - push_heredoc: new function, pushes a here-doc redirection onto + redir_stack handling overflow of redir_stack. Exits on overflow. + Original fix from Florian Weimer . Fix for + CVE-2014-7186 + - change straight assignments to redir_stack to call push_redir + - add one to size of word_lineno stack to avoid off-by-one error + below in read_token_word. Overflow just results in line numbers + being wrong. Fix for CVE-2014-7187 + + 9/27 + ---- +{execute_cmd,trap}.c + - changes to make minimal-config builds work again, mostly missing + #ifdefs for optional features + +builtins/common.c + - builtin_help: dummy version to be included if HELP_BUILTIN not + defined, for minimal-config builds + +variables.c + - initialize_shell_variables: incorporated patches from Florian + Weimer to change the strings bash looks + for when importing shell functions from the environment. It + adds a prefix (BASH_FUNC_) and a suffix (%%) to the name to + mark it as having been created by bash as an exported function. + Fix for remote attacks part of CVE-2014-6271 and CVE-2014-7169 + - mk_env_string: takes new argument, indicating whether we are + constructing a function + - mk_env_string: encodes function names as described above, so + initialize_shell_variables can find them + + 9/28 + ---- +copy_cmd.c + - copy_redirects: before calling savestring on here_doc_eof, make + sure it's not NULL (it could have been the result of a here + document delimited by EOF or EOS). Fixes bug reported by + Michal Zalewski . Fix for CVE-2014-6277 + +make_cmd.c + - make_redirection: initialize here_doc_eof member to NULL. Rest of + fix for CVE-2014-6277 + + 9/29 + ---- +parse.y + - current_input_line_state: return a sh_input_line_state_t containing + the current shell_input_line and its index and size variables + +shell.h + - current_input_line_state: extern declaration + +builtins/evalstring.c + - parse_and_execute: call reset_parser() before returning if + SEVAL_ONECMD set. Fixes bug reported by Michal Zalewski + and designated CVE-2014-6278 + - parse_and_execute: if we parse a function definition when + SEVAL_FUNCDEF is set, but don't consume the entire passed string, + throw an error, reset the parser, and return. Part of fix for + CVE-2014-6278 + - parse_and_execute: if parsing the shell function definition when + SEVAL_FUNCDEF is set transforms the function name (e.g., if it + begins with a newline or begins or ends with whitespace), throw + an error, reset the parser, and return. Fixes bug reported by + Eric Kobrin + + 10/2 + ---- +jobs.c + - bgp_prune: don't do anything if bgpids.npid == 0 or bgpids.list == NULL. + This can happen if something gets run before the job control framework + is initialized. Bug report from + + 10/3 + ---- +parse.y + - xparse_dolparen: don't set token_to_read to newline after calling + parse_string() and cleaning up when the shell is not interactive. This + makes the parser thing it's ok to read new commands even if it's not in + a state where that should be possible. Underlying fix for bug reported + by Michal Zalewski and designated CVE-6278 + - parser_remaining_input: new function, returns the portion of + shell_input_line that hasn't yet been read + - current_input_line_state: removed + +shell.h + - parser_remaining_input: extern declaration + - current_input_line_state: removed + +builtins/evalstring.c + - parse_and_execute: change code that checks whether parse_command has + consumed the entire passed string when SEVAL_FUNCDEF is used to use + parser_remaining_input instead of messing around with (new) + current_input_line_state. Part of fix for CVE-2014-6278 + +variables.c + - initialize_shell_variables: if we don't call parse_and_execute, free the + temporary string, since parse_and_execute won't. Report and fix from + Eric Kobrin + + 10/4 + ---- +print_cmd.c + - print_function_def: when in posix mode, print shell function + definitions as posix specifies them, without the leading + `function' keyword + +general.c + - exportable_function_name: return 1 if the passed string can be + added to the environment as an exported function name. Currently + prohibits function names containing `/' and `=' from being + exported + +general.h + - exportable_function_name: extern declaration + +builtins/setattr.def + - set_or_show_attributes: if exporting a function with export -f, + call exportable_function_name to determine whether the function + should be exported; don't export function if it returns 0 + + 10/7 + ---- +builtins/setattr.def + - set_or_show_attributes: don't show identifiers that are invisible + and imported from the environment, since that combination of + attributes means that the imported variable is not a valid shell + identifier. Report from Stephane Chazelas + + 10/8 + ---- +shell.c + - shell_initialize: set new variable should_be_restricted, which + says whether or not the shell will be a restricted one based on the + shell name; use in calls to initialize_shell_variables (to inhibit + importing shell functions) and initialize_shell_options (to inhibit + parsing $SHELLOPTS) and initialize_bashopts (to inhibit parsing + $BASHOPTS). Report from + + 10/12 + ----- +execute_cmd.c + - execute_function: unwind-protect loop_level, set loop_level to 0 + when entering a function so break and continue in functions don't + break loops running outside of the function. Fix picked up from + dash via Herbert Xu + + 10/13 + ----- +doc/Makefile.in + - bashref.pdf: create using texi2dvi --pdf rather than postprocessing the + dvi file, so we have PDF bookmarks and links. Fix from + Siep Kroonenberg + + 10/14 + ----- +subst.h + - Q_ARITH: new quoting flag. Semantics are per Posix's spec for arithmetic + expansion: act as if string is quoted, but don't treat double quotes + specially (in this case, they will be removed by quote removal) + - Q_ARRAYSUB: new quoting flag, indicates we are expanding an indexed array + subscript + +subst.c + - expand_arith_string: if we are not expanding the string, but we saw a quote + with Q_ARITH specified as one of quoting flags, perform quote removal even + if Q_DOUBLE_QUOTES is specified + - param_expand: change calls to expand_arith_string for $[ and $(( cases to + specify Q_ARITH. Now $(( "$x" )) and $(( "x" )) work if x has a value that + evaluates to a valid number, as Posix specifies + - expand_word_internal: add test for quoted&Q_ARITH to the tilde case, so we + continue to perform tilde expansion in arithmetic contexts + - expand_word_internal: if quoted&Q_ARITH, continue processing when we see a + `"', acting as if the double quote isn't present (already Q_DOUBLE_QUOTED) + +arrayfunc.c + - array_expand_index: pass Q_DOUBLE_QUOTED|Q_ARITH|Q_ARRAYSUB as quoted argument + in call to expand_arith_string. This inhibits word splitting + (Q_DOUBLE_QUOTED) while discarding double quotes (Q_ARITH), identical to the + quote flags passed while expanding $(( )) and $[ ]. Q_ARRAYSUB reserved for + future use. Fixes problem reported by Stephane Chazelas + + + 10/16 + ----- +subst.c + - parameter_brace_expand_word: if the PF_ASSIGNRHS flag is set and we + are expanding what looks like an array subscripted with @ or *, + make sure the variable we're expanding is actually an array before + we add Q_DOUBLE_QUOTES to the flags. If we don't, things like + scalar[@] will remain quoted. Fixes ubuntu bug 1381567 + https://bugs.launchpad.net/ubuntu/+source/bash/+bug/1381567 + + 10/17 + ----- +{jobs,nojobs}.c + - get_original_tty_job_signals: get original signal dispostions for + SIGTSTP, SIGTTIN, SIGTTOU before we start manipulating them in + make_child + - default_tty_job_signals: make sure we set SIGTSTP, SIGTTIN, or + SIGTTOU to SIG_IGN if they were ignored at shell startup instead of + unconditionally setting them to SIG_DFL. Fixes bug reported by + idallen@idallen.ca + +jobs.h + - get_original_tty_job_signals: extern declaration + +trap.c + - initialize_traps: add call to get_original_tty_job_signals + + 10/22 + ----- +subst.c + - expand_string_for_rhs: when expanding in this context (rhs of a word + expansion or pattern removal), we don't perform word splitting, so + we don't want to split $* if IFS is empty. Fixes bug reported by + Stephane Chazelas + + 10/23 + ----- +subst.c + - param_expand: when expanding $* in a pattern context where the + expansion is quoted (Q_PATQUOTE), don't quote the expansion -- + the outer quotes don't make the characters in the expansion of + $* special. Posix interp 221. Reported by Stephane Chazelas + + + 10/28 + ----- +lib/readline/bind.c + - enable-bracketed-paste: new bindable variable, enables support for + a terminal's `bracketed paste mode'. Code contributed by + Daniel Colascione + +doc/bash.1,lib/readline/doc/{readline.3,rluser.texi} + - enable-bracketed-paste: add description + +lib/readline/{readline.c,rlprivate.h} + - _rl_enable_bracketed_paste: declarations + - #defines for use by bracketed paste implementation + +lib/readline/rltty.c + - rl_prep_terminal: send BRACK_PASTE_INIT string to terminal if we + are supposed to enable bracketed-paste mode; change terminal_prepped + to indicate we sent that string and need to clean up + - rl_deprep_terminal: if terminal_prepped indicates we sent the + bracketed-paste mode init string to the terminal, send the cleanup + string before restoring the terminal modes + +lib/readline/kill.c + - rl_bracketed_paste_begin: function to read bracketed paste until + BRACK_PASTE_SUFF; discard the suffix, and insert the rest of the + paste as a single (undoable) object. Bound to BRACK_PASTE_PREF + +lib/readline/funmap.c + - bracketed-paste-begin: new bindable command, executes + rl_bracketed_paste_begin + +lib/readline/readline.c + - bind_bracketed_paste_prefix: new function, sets up to recognize + the bracketed paste prefix sequence (BRACK_PASTE_PREF) in emacs + keymap and vi insertion keymap + - readline_initialize_everything: call bind_bracketed_paste_prefix + + 11/1 + ---- +builtins/ulimit.def + - RLIMIT_POSIXLOCKS: now synonym for RLIMIT_LOCKS + - -k: new option: RLIMIT_KQUEUES, max kqueues allocated for this + process + - -P: new option: RLIMIT_NPTS, max number of pseudoterminals available + to this process + +doc/{bash.1,bashref.texi} + - document `ulimit -k' option + - document `ulimit -P' option + +parse.y + - `timespec list_terminator' production: if the list terminator is `;' + set last_read_token to `;' to allow things like `time ; command' to + time null commands and not throw a syntax error. Patch from + Piotr Grzybowski + - `BANG list_terminator' production: do the same thing + +variables.c + - sv_optind: use find_shell_variable and get_variable_value so we can + have the variable's context in the case we need to do something + when we are restoring a previous variable context's value + +builtins/getopt.h + - sh_getopt_state_t: struct to save sh_getopt's internal state so we + can restore it around function calls in the event that we have a + local copy of OPTIND + +builtins/getopt.[ch] + - sh_getopt_{save,restore}_istate: new functions to save and restore + getopt's internal state + - sh_getopt_{alloc,dispose}_istate: new functions to allocate and + deallocate sh_getopt_istate_t objects + +execute_cmd.c + - maybe_restore_getopt_state: restore sh_getopt state after executing + function body iff the funtion declared a local copy of OPTIND + - execute_function: save sh_getopt state before executing function body + - execute_function: note in getopt_state->flags whether or not the + function declared a local copy of OPTIND; used by maybe_restore_getopt_state + - execute_function: maybe restore sh_getopt state before returning via + call to maybe_restore_getopt_state. Fixes bugs with getopts and + state between calls reported in 2011 by Bernd Eggink + and in 2014 by Oyvind Hvidsten + +configure.ac + - enable-function-import: new option, controls whether function imports + are included. Enabled by default. Patch from David Galos + + +config.h.in + - FUNCTION_IMPORT: define controlled by enable-function-import above + +variables.c + - initialize_shell_variables: include code to import function definitions + from the environment if FUNCTION_IMPORT is defined + +doc/bashref.texi + - --enable_function-import: document new configuration option + + 11/5 + ---- +lib/readline/history.c + - history_lines_read_from_file: new variable, set by read_history and + read_history_range to the actual number of lines read from the + history file. The value is valid immediately after a call to one + of those functions + - history_lines_written_to_file: new variable, set by write_history, + history_do_write, and history_truncate_file to the actual number of + lines written to the history file. The value is valid immediately + after a call to one of those functions + +variables.c + - sv_histsize: set history_lines_in_file after history_truncate_file() + only if hmax < history_lines_in_file (lines we've already read); a + cosmetic change only + +bashhist.c + - load_history: set history_lines_in_file after read_history() from + history_lines_read_from_file, since read_history reads all of the + lines from the history file even if it's more than $HISTSIZE + - maybe_save_shell_history: after calling write_history(), set + history_lines_in_file to history_lines_written_to_file, since we + can assume that we read everyhing we just wrote + +builtins/history.def + - history_builtin: after calling read_history (history -r), set the + new value of history_lines_in_file, for the same reason as above + - history_builtin: after calling read_history_range (history -n), set + history_lines_in_file from history_lines_read_from_file + + 11/6 + ---- +lib/readline/histfile.c + - history_truncate_file: since we move the old file to a backup copy + before truncating, make sure the new file is owned by the same uid + as the old + - history_do_write: use chown in the same way as history_truncate_file + + 11/12 + ----- +lib/readline/display.c + - expand_prompt: takes a new `flags' argument; only one flag defined + so far: PMT_MULTILINE + - expand_prompt: changed all callers to add new flags argument + - rl_expand_prompt, redraw_prompt: make sure to set PMT_MULTILINE in + FLAGS argument to expand_prompt if expanding parts of a prompt + containing embedded newlines + - expand_prompt: only add mode char to last line of a prompt with + embedded newlines, so mode indicator doesn't get lost and gets + updated properly. Fixes problem reported by Renlin Li + + + 11/13 + ----- + +lib/readline/display.c + - prompt_modestr: changed prompt_modechar to return a string denoting + the editing mode; default strings for emacs and both vi modes are + #defines in this file. prompt_modestr takes an argument in which + it returns the length of the mode string + - expand_prompt: if expanding mode strings in the prompt, get the + mode string to use and add it at the beginning of the prompt string, + before expanding it. This will allow future work allowing the mode + string to contain invisible characters + + 11/15 + ----- +lib/readline/rlprivate.h + - _rl_{emacs,vi_cmd,vi_ins}_mode_str: extern declarations for + variables to hold current values of user-settable mode strings; + variables to hold lengths + +lib/readline/rlconf.h + - defines for default values of the mode strings for each editing mode + and keymap + +lib/readline/display.c + - _rl_{emacs,vi_cmd,vi_ins}_mode_str: new variables to hold values of + user-settable mode strings + - _rl_{emacs,vi_cmd,vi_ins}_modestr_len: new variables to hold lengths + of corresponding mode string variables + - prompt_modestr: return appropriate user-settable mode string + variables + +lib/readline/bind.c + - {emacs,vi-ins,vi-cmd}-mode-string: new user-settable mode string + variables + - sv_{emacs,viins,vicmd}_modestr: variable handling functions for user- + settable mode string variables. Non-null values are run through + rl_translate_keyseq so users can include invisible character + sequences in the mode strings; null values restore the default + - _rl_get_string_variable_value: handle values for new user-settable + mode string variables. Original code contributed by Dylan Cali + + +lib/readline/doc/rluser.texi + - {emacs,vi-ins,vi-cmd}-mode-string: document, including the fact that + you can use \1 and \2 to bracket sequences of non-printing + characters + + 11/16 + ----- +lib/readline/history.c + - add_history: replace loop that copies history list down one item + with call to memmove to take advantage of whatever efficiencies + libc can offer. Won't be any slower than current loop + +lib/readline/display.c + - rl_redraw_prompt_last_line: new function, calls redraw_prompt if + the prompt contains multiple lines; calls rl_forced_update_display + if not + +lib/readline/readline.h + - rl_redraw_prompt_last_line: extern declaration, undocumented in + texinfo manual until I get it a little more work + +bashline.c + - bash_execute_unix_command: instead of unconditionally calling + rl_forced_update_display, call rl_redraw_prompt_last_line if we + cleared the last line before executing the command. This keeps + commands that don't display any other output but just manipulate + the contents of the line buffer from redisplaying the prompt lines + before the last newline multiple times. Fixes bug reported by + Jesper Nygards and Rob Foehl + . This means that commands that display output + will *only* display the final line of the prompt + - bash_execute_unix_command: if the command returns 124, we redraw + the line unconditionally, including all lines of the prompt + + 11/18 + ----- +builtins/mapfile.def + - mapfile_builtin: don't allow a valid array reference through to + mapfile(), since it will just create a shell variable with that name. + Bug and fix from Eduardo A. Bustamante López + + 11/19 + ----- +lib/readline/complete.c + - _rl_colored_completion_prefix: new variable, if non-zero, and color + support is compiled in, and the $LS_COLORS variable exists and + contains color definitions, display any common prefix of a set of + completions in blue when displaying all the possible completions. + Doesn't work with menu-complete, which inserts possible completions + inline + - colored_prefix_start(), colored_prefix_end(): new functions, used to + bracket colored completion prefixes + - fnprint: if prefix_bytes is non-zero, and _rl_colored_completion_prefix + is > 0, display the first PREFIX_BYTES bytes of the word bracketed + by calls to colored_prefix_start and colored_prefix_end + - print_filename: if _rl_colored_completion_prefix is > 0, compute the + length in bytes of the common prefix and pass that to fnprint + +lib/readline/readline.c + - readline_initialize_everything: initialize the colors from $LS_COLORS + if _rl_colored_completion_prefix is non-zero + +lib/readline/colors.c + - _rl_print_prefix_color: new function, changes text color to that + defined for the common prefix of a set of possible completions + (currently cyan, same as directories); currently uses C_PREFIX, + defined in colors.h as C_DIR + +lib/readline/colors.h + - _rl_print_prefix_color: new extern declaration + +lib/readline/bind.c + - colored-completion-prefix: new bindable variable, if set, common + prefix of a set of possible completions is displayed in color. + Feature requested by several, most recently by Richard Neill + (in a slightly different form) and + Duy Nguyen + + 11/20 + ----- +builtins/printf.def + - printf_builtin: allow null (empty) format strings supplied with + -v var to set `var' to the empty string. That is, printf -v var "" + is now the same as var="". Change suggested by Mike Frysinger + + +pathexp.h + - FNMATCH_NOCASEGLOB: macro to decide whether or not to pass + FNM_CASEFOLD flag to strmatch depending on whether glob_ignore_case + is set; analogout to FNMATCH_IGNCASE + +pathexp.c + - glob_name_is_acceptable: use FNMATCH_NOCASEMATCH to determine flags + passed to strmatch; if nocaseglob is used to generate glob matches, + it should be used to generate ignored matches + + 11/21 + ----- +pcomplete.c + - filter_stringlist: the call to strmatch now honors the setting of + nocasematch. Feature request from Ville Skytta + back in 2010 + +doc/bash.1,lib/readline/doc/rluser.texi + - complete -X: document that filtering the list of possible completions + honors the nocasematch option when performing matching + +lib/glob/gmisc.c + - include chartypes.h and strmatch.h for new defines + - match_pattern_{wchar,char}: now take new third FLAGS argument, flags + have same meanings as strmatch(); intent is to handle case + insensitive comparisons under same conditions as strmatch + - FOLD: imported case-folding define from sm_loop.c; wide and single- + byte character versions + - match_pattern_{wchar,char}: use FOLD when comparing characters to + honor FNM_CASEFOLD if set in FLAGS argument + +externs.h + - match_pattern_{wchar,char}: updated extern declarations + +subst.c + - match_{upattern,wpattern}: update strmatch/wcsmatch calls to include + FNMATCH_IGNCASE in flags argument + - match_{upattern,wpattern}: update match_pattern_{char,wchar} calls + to include FNMATCH_IGNCASE in flags argument (consistent with calls + to strmatch). This makes pattern substitution word expansion honor + nocasematch shell option. Feature requested by Davide Baldini + + - match_wpattern: make sure to fold case if necessary when doing simple + matching + +doc/{bash.1,bashref.texi} + - pattern substitution: updated description to include honoring setting + of nocasematch when performing matching + +subst.c + - expand_word_internal: optimize handling of "$@" idiom by calling + list_rest_of_args() and quote_list() directly at the top of the + function instead of going through normal code path + - cached_quoted_dollar_at: WORD_LIST of quoted positional parameters, + used by same code above that optimizes "$@"; if non-null we just + return a copy of the list; if null, we save a copy of the list we + create + - invalidate_cached_quoted_dollar_at: convenience function to allow + other parts of the shell (e.g., remember_args()) to destroy the + cached list of quoted positional parameter when the positional + parameters change + +builtins/common.c + - remember_args: call invalidate_cached_quoted_dollar_at() + +builtins/shift.def + - shift_builtin: call invalidate_cached_quoted_dollar_at after modifying + dollar_vars[] + +builtins/source.def + - maybe_pop_dollar_vars: call invalidate_cached_quoted_dollar_at just + to be safe + + 11/23 + ----- +builtins/evalfile.c + - _evalfile: return -1 if errno == ENOENT and the flags don't include + FEVAL_ENOENTOK. If we print an error message we should return an + error + - force_execute_file: new function, reads and executes commands from + a file but returns an error if file doesn't exist + +builtins/common.h + - force_execute_file: new extern declaration + +shell.c + - main: call start_debugger even if dollar_vars[1] == 0 if the shell + isn't interactive (interactive_shell == 0) + - start_debugger: call force_execute_file instead of maybe_execute_file; + turn off debugging mode if it returns value < 0 + + 11/24 + ----- +hashlib.h + - DEFAULT_HASH_BUCKETS: doubled to 128, cost in memory use is small but + changes traversal order when not sorting results + + 11/25 + ----- +doc/{bash.1,bashref.texi} + - make it clearer, by breaking it out into a separate paragraph, that + referencing an array without a subscript is equivalent to referencing + it with subscript 0 + - add text saying that referencing any variable using a valid subscript + is OK + + 11/28 + ----- + +arrayfunc.c + - bind_array_variable, bind_assoc_variable: allow binding value to a + readonly variable if the ASS_FORCE flag is set in the FLAGS + argument + +subst.h + - ASS_FORCE: new assignment flag; means to allow assignment even if + variable is marked readonly + +builtins/declare.def + - when assigning a value to an array or assoc variable using + something like `declare -r foo=bar' where foo is an existing array + variable, pass the ASS_FORCE to assign_array_var_from_string so + the assignment is allowed. Fixes debian bug 765759 + http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=765759 + +builtins/setattr.def + - var_attribute_string: new function to return (as argument) a char + array with attribute flag values for a given variable; returns the + length of the array + +lib/sh/shquote.c + - sh_quote_reusable: function returning a version of its string + argument that is quoted for reuse + +externs.h + - sh_quote_reusable: extern declaration + +builtins/common.h + - MAX_ATTRIBUTES: define used to size arrays for attribute flag + characters + - var_attribute_string: new extern function declaration + +subst.c + - array_remove_pattern: fixed a bug where `var' instead of `v' was + tested for invisible attribute + - get_var_and_type: fill in a valid *VARP if returning VT_VARIABLE + because callers may need to use it + - parameter_brace_transform: family of functions to implement the new + mksh-inspired ${param@spec} transformation word expansions. Some + of the operators transform the (expanded) value of the parameter, + the rest expand to information about the parameter itself + (array_transform, parameter_list_transform, list_transform, + string_transform, pos_params_assignment, array_var_assignment, + string_var_assignment) + - parameter_brace_expand: changes to parse the new `@' word expansion + operator and call parameter_brace_transform appropriately + - parameter_brace_expand: make sure we handle ${#@} as we have before + even in the presence of the new `@' operator + +variables.c + - push_temp_var: make sure to call bind_variable_internal with the + ASS_FORCE flag so we override readonly variables created with + something like `tempvar=foo declare -r foo'. + - bind_variable_internal: honor ASS_FORCE flag to allow binding even + if a variable is readonly + +execute_cmd.c + - struct func_array_state: new state to save state of BASH_LINENO, + BASH_SOURCE, and FUNCNAME during function execution so it can be + restored on a jump to top level + - restore_funcarray_state: new function to restore func_array_state + - execute_function: fill in func_array_state variable, add unwind- + protect to restore it on jump to top level, call explicitly at + end of function if subshell != 0 (may not be necessary, but safe + for now). Fixes bug with local assignments to FUNCNAME reported + by Arfrever Frehtes Taifersar Arahesis + + 11/29 + ----- +arrayfunc.c + - assign_compound_array_list: turn off ASS_APPEND flag when processing + each individual assignment inside the parens in var+=(...). The + outer += should not affect assignments to existing subscripts; + those should be treated like usual assignments unless += supplied + inside the parens. Bug report from Maarten Billemont + , fix from Eduardo A. Bustamante López + + +config.h.in + - HAVE_PSELECT: define if pselect(2) available + +configure.ac + - check for pselect(2), define HAVE_PSELECT if found + +lib/readline/input.c + - rl_getc: use pselect(2) to wait for input ready on readline's + input fd or for a signal to arrive, will handle SIGWINCH (which + does not interrupt read(2)) and thus allow resize to happen without + having to wait to read more input. Only works if pselect available + and returns -1/EINTR on a signal even if the signal was installed + with SA_RESTART. From a suggestion from Egmont Koblinger + + + 12/3 + ---- +variables.c + - flush_temporary_env: new function, disposes all temp variables in + temporary_env hash table + - bind_variable: only try to update a temporary variable's value in the + temporary env if the value argument is not null. Fixes bug reported + by + +variables.h + - flush_temporary_env: new extern declaration + +subst.c + - command_substitute: if running command substitution as part of + expanding a redirection (expanding_redir == 1), flush any temporary + environment we've inherited as part of this command, since we are not + supposed to have access to the temporary environment. Since + expanding_redir only controls access to the temporary environment for + variable lookup and binding, we can turn it off in the subshell + + 12/4 + ---- +builtins/printf.def + - printstr: make sure a missing precision specifier after a `.' is + treated as 0, as printf(3) specifies. Fixes ubuntu bash bug + 1399087 (https://bugs.launchpad.net/ubuntu/+source/bash/+bug/1399087) + + 12/5 + ---- +subst.c + - skip_to_delim: if scanning past process substitution (skipcmd == 1, + noprocsub == 0), use extract_delimited_string instead of + extract_process_subst, which was changed a while back (bash-4.3.23) + to use xparse_dolparen. xparse_dolparen complains if the command + or process substitution is unterminated, since it runs the parser, + which is not what we want here. Command substitution does the same + thing. Fixes bug reported by Daniel Kahn Gillmor + as Debian bash bug 771968 + (https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=771968) + + 12/6 + ---- +subst.c + - command_substitute: short-circuit without forking on a command string + that consists entirely of s and newlines + +jobs.c + - make_child: changes to allow interrupts through if fork fails and + we are sleeping for `forksleep' seconds + - waitchld: make things a little more resilient if CHILD ends up NULL + + 12/12 + ----- +lib/readline/complete.c + - rl_display_match_list: when calculating common prefix to display in + color, make sure we correctly handle a common prefix with a trailing + `/' as we do when checking whether or not to add an ellipis. + printable_part() doesn't return the whole pathname if it ends in a + slash, to avoid printing null strings, so we have to make sure we + have the entire prefix + +lib/readline/complete.c + - _rl_complete_display_matches_interrupt: new variable, set to 1 by + _rl_complete_sigcleanup to let rl_display_match_list know it has + freed the match list + - display_matches: check for signals during the printing loops with + RL_SIG_RECEIVED(), return immediately if there is a pending signal + (might not want to do this if it's SIGWINCH -- CHECK) + - rl_complete_internal: if _rl_complete_display_matches_interrupt + set after calling display_matches, just null out `matches' since + it's already been freed and call any application-set signal hook + + 12/14 + ----- +parse.y + - time_command_acceptable: if the token before a newline is `|', + return 0, since it's not really valid to time inside a pipeline. + Only handles a single newline but allows things like + echo a | + time cat + to invoke /usr/bin/time, which is probably enough to catch the + stray carriage return. Fixes bug reported by Andre Majorel + + +builtins/declare.def + - declare_internal: don't try to perform compound assignments unless + the WORD_DESC has flags including W_COMPASSIGN (maybe should check + W_ASSIGNMENT as well), avoiding unexpected evaluation if a word + is of the form (word) and is assigned to an array variable like so: + declare -x var=$value. Bug reported by Stephane Chazelas + . Will eventually be contingent on + compatibility level > 43, but not there yet + + 12/15 + ----- +lib/sh/Makefile.in + - add missing dependencies for shmatch.o. Pointed out by Sergey + Mikhailov + + 12/16 + ----- +{execute_cmd,subst}.c + - W_ASSIGNINT: remove, not used any more + +execute_cmd.c + - fix_assignment_words: don't look for `-i' option and set W_ASSIGNINT + flag any more; doing things a different way + - shell_expand_word_list: instead of using W_ASSIGNINT flag, since it + doesn't take into account all options that can transform values on + assignment (-l/-u/-c can also), go through option arguments looking + for options that need special handling and add them to the `opts' + array for make_internal_declare to use. Fixes bug with constructs + like `declare -al foo=(UPONE UPTWO UPTHREE)' not being lowercased on + assignment reported by Linda Walsh + + 12/18 + ----- +lib/readline/readline.c + - rl_internal_char: when we read EOF on a non-empty line, check for + signals and invoke any readline signal handling and any application- + installed signal hook + + 12/20 + ----- +lib/readline/readline.c + - rl_internal_char: if we read EOF on a non-empty line, set c to + _rl_eof_char the first time through. If we read EOF the next time, + return EOF from readline(). If callbacks are defined, this returns + EOF immediately, since lastc isn't available diff --git a/CWRU/POSIX.NOTES.old b/CWRU/POSIX.NOTES.old new file mode 100644 index 000000000..1707ab10c --- /dev/null +++ b/CWRU/POSIX.NOTES.old @@ -0,0 +1,82 @@ +Starting bash with the `--posix' command-line option or executing +`set -o posix' while bash is running will cause bash to conform more +closely to the Posix.2 standard by changing the behavior to match that +specified by Posix.2 in areas where the bash default differs. + +The following list is what's changed when `posix mode' is in effect: + +1. When a command in the hash table no longer exists, bash will re-search + $PATH to find the new location. This is also available with + `shopt -s checkhash'. + +2. The >& redirection does not redirect stdout and stderr. + +3. The message printed by the job control code and builtins when a job + exits with a non-zero status is `Done(status)'. + +4. Reserved words may not be aliased. + +5. The Posix.2 PS1 and PS2 expansions of `!' -> history number and + `!!' -> `!' are enabled, and parameter expansion is performed on + the value regardless of the setting of the `promptvars' option. + +6. Interactive comments are enabled by default. (Note that bash has + them on by default anyway.) + +7. The Posix.2 startup files are executed ($ENV) rather than the normal + bash files. + +8. Tilde expansion is only performed on assignments preceding a command + name, rather than on all assignment statements on the line. + +9. The default history file is ~/.sh_history (default value of $HISTFILE). + +10. The output of `kill -l' prints all the signal names on a single line, + separated by spaces. + +11. Non-interactive shells exit if `file' in `. file' is not found. + +12. Redirection operators do not perform pathname expansion on the word + in the redirection unless the shell is interactive + +13. Function names must be valid shell identifiers. That is, they may not + contain characters other than letters, digits, and underscores, and + may not start with a digit. Declaring a function with an illegal name + causes a fatal syntax error in non-interactive shells. + +14. Posix.2 `special' builtins are found before shell functions during command + lookup. + +15. If a Posix.2 special builtin returns an error status, a non-interactive + shell exits. The fatal errors are those listed in the POSIX.2 standard, + and include things like passing incorrect options, redirection errors, + variable assignment errors for assignments preceding the command name, + and so on. + +16. The environment passed to executed commands is not sorted. Neither is + the output of `set'. This is not strictly Posix.2 behavior, but sh + does it this way. Ksh does not. It's not necessary to sort the + environment; no program should rely on it being sorted. + +17. If the `cd' builtin finds a directory to change to using $CDPATH, the + value it assigns to $PWD does not contain any symbolic links, as if + `cd -P' had been executed. + +18. A non-interactive shell exits with an error status if a variable + assignment error occurs when no command name follows the assignment + statements. A variable assignment error occurs, for example, when + trying to assign a value to a read-only variable. + +19. A non-interactive shell exits with an error status if the iteration + variable in a for statement or the selection variable in a select + statement is a read-only variable. + +20. Process substitution is not available. + +21. Assignment statements preceding POSIX.2 `special' builtins persist in + the shell environment after the builtin completes. + +There is other Posix.2 behavior that bash does not implement. Specifically: + +1. Assignment statements affect the execution environment of all builtins, + not just special ones. diff --git a/CWRU/old/set.def.save b/CWRU/old/set.def.save new file mode 100644 index 000000000..87b78d7cc --- /dev/null +++ b/CWRU/old/set.def.save @@ -0,0 +1,544 @@ +This file is set.def, from which is created set.c. +It implements the "set" and "unset" builtins in Bash. + +Copyright (C) 1987, 1989, 1991 Free Software Foundation, Inc. + +This file is part of GNU Bash, the Bourne Again SHell. + +Bash is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 1, or (at your option) any later +version. + +Bash is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License along +with Bash; see the file COPYING. If not, write to the Free Software +Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. + +$PRODUCES set.c + +#include +#include "../shell.h" +#include "../flags.h" + +#include "bashgetopt.h" + +extern int interactive; +extern int noclobber, posixly_correct; +#if defined (READLINE) +extern int rl_editing_mode, no_line_editing; +#endif /* READLINE */ + +$BUILTIN set +$FUNCTION set_builtin +$SHORT_DOC set [--abefhkmnptuvxldBCHP] [-o option] [arg ...] + -a Mark variables which are modified or created for export. + -b Notify of job termination immediately. + -e Exit immediately if a command exits with a non-zero status. + -f Disable file name generation (globbing). + -h Locate and remember function commands as functions are + defined. Function commands are normally looked up when + the function is executed. + -i Force the shell to be an "interactive" one. Interactive shells + always read `~/.bashrc' on startup. + -k All keyword arguments are placed in the environment for a + command, not just those that precede the command name. + -m Job control is enabled. + -n Read commands but do not execute them. + -o option-name + Set the variable corresponding to option-name: + allexport same as -a + braceexpand same as -B +#if defined (READLINE) + emacs use an emacs-style line editing interface +#endif /* READLINE */ + errexit same as -e + histexpand same as -H + ignoreeof the shell will not exit upon reading EOF + interactive-comments + allow comments to appear in interactive commands + monitor same as -m + noclobber disallow redirection to existing files + noexec same as -n + noglob same as -f + nohash same as -d + notify save as -b + nounset same as -u + physical same as -P + posix change the behavior of bash where the default + operation differs from the 1003.2 standard to + match the standard + privileged same as -p + verbose same as -v +#if defined (READLINE) + vi use a vi-style line editing interface +#endif /* READLINE */ + xtrace same as -x + -p Turned on whenever the real and effective user ids do not match. + Disables processing of the $ENV file and importing of shell + functions. Turning this option off causes the effective uid and + gid to be set to the real uid and gid. + -t Exit after reading and executing one command. + -u Treat unset variables as an error when substituting. + -v Print shell input lines as they are read. + -x Print commands and their arguments as they are executed. + -l Save and restore the binding of the NAME in a FOR command. + -d Disable the hashing of commands that are looked up for execution. + Normally, commands are remembered in a hash table, and once + found, do not have to be looked up again. +#if defined (BRACE_EXPANSION) + -B the shell will perform brace expansion +#endif /* BRACE_EXPANSION */ +#if defined (BANG_HISTORY) + -H Enable ! style history substitution. This flag is on + by default. +#endif /* BANG_HISTORY */ + -C If set, disallow existing regular files to be overwritten + by redirection of output. + -P If set, do not follow symbolic links when executing commands + such as cd which change the current directory. + +Using + rather than - causes these flags to be turned off. The +flags can also be used upon invocation of the shell. The current +set of flags may be found in $-. The remaining n ARGs are positional +parameters and are assigned, in order, to $1, $2, .. $n. If no +ARGs are given, all shell variables are printed. +$END + +/* An a-list used to match long options for set -o to the corresponding + option letter. */ +struct { + char *name; + int letter; +} o_options[] = { + { "allexport", 'a' }, +#if defined (BRACE_EXPANSION) + { "braceexpand",'B' }, +#endif + { "errexit", 'e' }, + { "histexpand", 'H' }, + { "monitor", 'm' }, + { "noexec", 'n' }, + { "noglob", 'f' }, + { "nohash", 'd' }, +#if defined (JOB_CONTROL) + { "notify", 'b' }, +#endif /* JOB_CONTROL */ + {"nounset", 'u' }, + {"physical", 'P' }, + {"privileged", 'p' }, + {"verbose", 'v' }, + {"xtrace", 'x' }, + {(char *)NULL, 0}, +}; + +#define MINUS_O_FORMAT "%-15s\t%s\n" + +void +list_minus_o_opts () +{ + register int i; + char *on = "on", *off = "off"; + + printf (MINUS_O_FORMAT, "noclobber", (noclobber == 1) ? on : off); + + if (find_variable ("ignoreeof") || find_variable ("IGNOREEOF")) + printf (MINUS_O_FORMAT, "ignoreeof", on); + else + printf (MINUS_O_FORMAT, "ignoreeof", off); + + printf (MINUS_O_FORMAT, "interactive-comments", + interactive_comments ? on : off); + + printf (MINUS_O_FORMAT, "posix", posixly_correct ? on : off); + +#if defined (READLINE) + if (no_line_editing) + { + printf (MINUS_O_FORMAT, "emacs", off); + printf (MINUS_O_FORMAT, "vi", off); + } + else + { + /* Magic. This code `knows' how readline handles rl_editing_mode. */ + printf (MINUS_O_FORMAT, "emacs", (rl_editing_mode == 1) ? on : off); + printf (MINUS_O_FORMAT, "vi", (rl_editing_mode == 0) ? on : off); + } +#endif /* READLINE */ + + for (i = 0; o_options[i].name; i++) + { + int *on_or_off, zero = 0; + + on_or_off = find_flag (o_options[i].letter); + if (on_or_off == FLAG_UNKNOWN) + on_or_off = &zero; + printf (MINUS_O_FORMAT, o_options[i].name, (*on_or_off == 1) ? on : off); + } +} + +set_minus_o_option (on_or_off, option_name) + int on_or_off; + char *option_name; +{ + int option_char = -1; + + if (STREQ (option_name, "noclobber")) + { + if (on_or_off == FLAG_ON) + bind_variable ("noclobber", ""); + else + unbind_variable ("noclobber"); + stupidly_hack_special_variables ("noclobber"); + } + else if (STREQ (option_name, "ignoreeof")) + { + unbind_variable ("ignoreeof"); + unbind_variable ("IGNOREEOF"); + if (on_or_off == FLAG_ON) + bind_variable ("IGNOREEOF", "10"); + stupidly_hack_special_variables ("IGNOREEOF"); + } + +#if defined (READLINE) + else if ((STREQ (option_name, "emacs")) || (STREQ (option_name, "vi"))) + { + if (on_or_off == FLAG_ON) + { + rl_variable_bind ("editing-mode", option_name); + + if (interactive) + with_input_from_stdin (); + no_line_editing = 0; + } + else + { + int isemacs = (rl_editing_mode == 1); + if ((isemacs && STREQ (option_name, "emacs")) || + (!isemacs && STREQ (option_name, "vi"))) + { + if (interactive) + with_input_from_stream (stdin, "stdin"); + no_line_editing = 1; + } + else + builtin_error ("not in %s editing mode", option_name); + } + } +#endif /* READLINE */ + else if (STREQ (option_name, "interactive-comments")) + interactive_comments = (on_or_off == FLAG_ON); + else if (STREQ (option_name, "posix")) + { + posixly_correct = (on_or_off == FLAG_ON); + unbind_variable ("POSIXLY_CORRECT"); + unbind_variable ("POSIX_PEDANTIC"); + if (on_or_off == FLAG_ON) + { + bind_variable ("POSIXLY_CORRECT", ""); + stupidly_hack_special_variables ("POSIXLY_CORRECT"); + } + } + else + { + register int i; + for (i = 0; o_options[i].name; i++) + { + if (STREQ (option_name, o_options[i].name)) + { + option_char = o_options[i].letter; + break; + } + } + if (option_char == -1) + { + builtin_error ("%s: unknown option name", option_name); + return (EXECUTION_FAILURE); + } + if (change_flag (option_char, on_or_off) == FLAG_ERROR) + { + bad_option (option_name); + return (EXECUTION_FAILURE); + } + } + return (EXECUTION_SUCCESS); +} + +/* Set some flags from the word values in the input list. If LIST is empty, + then print out the values of the variables instead. If LIST contains + non-flags, then set $1 - $9 to the successive words of LIST. */ +set_builtin (list) + WORD_LIST *list; +{ + int on_or_off, flag_name, force_assignment = 0; + + if (!list) + { + SHELL_VAR **vars; + + vars = all_shell_variables (); + if (vars) + { + print_var_list (vars); + free (vars); + } + + vars = all_shell_functions (); + if (vars) + { + print_var_list (vars); + free (vars); + } + + return (EXECUTION_SUCCESS); + } + + /* Check validity of flag arguments. */ + if (*list->word->word == '-' || *list->word->word == '+') + { + register char *arg; + WORD_LIST *save_list = list; + + while (list && (arg = list->word->word)) + { + char c; + + if (arg[0] != '-' && arg[0] != '+') + break; + + /* `-' or `--' signifies end of flag arguments. */ + if (arg[0] == '-' && + (!arg[1] || (arg[1] == '-' && !arg[2]))) + break; + + while (c = *++arg) + { + if (find_flag (c) == FLAG_UNKNOWN && c != 'o') + { + char s[2]; + s[0] = c; s[1] = '\0'; + bad_option (s); + if (c == '?') + builtin_usage (); + return (c == '?' ? EXECUTION_SUCCESS : EXECUTION_FAILURE); + } + } + list = list->next; + } + list = save_list; + } + + /* Do the set command. While the list consists of words starting with + '-' or '+' treat them as flags, otherwise, start assigning them to + $1 ... $n. */ + while (list) + { + char *string = list->word->word; + + /* If the argument is `--' or `-' then signal the end of the list + and remember the remaining arguments. */ + if (string[0] == '-' && (!string[1] || (string[1] == '-' && !string[2]))) + { + list = list->next; + + /* `set --' unsets the positional parameters. */ + if (string[1] == '-') + force_assignment = 1; + + /* Until told differently, the old shell behaviour of + `set - [arg ...]' being equivalent to `set +xv [arg ...]' + stands. Posix.2 says the behaviour is marked as obsolescent. */ + else + { + change_flag ('x', '+'); + change_flag ('v', '+'); + } + + break; + } + + if ((on_or_off = *string) && + (on_or_off == '-' || on_or_off == '+')) + { + int i = 1; + while (flag_name = string[i++]) + { + if (flag_name == '?') + { + builtin_usage (); + return (EXECUTION_SUCCESS); + } + else if (flag_name == 'o') /* -+o option-name */ + { + char *option_name; + WORD_LIST *opt; + + opt = list->next; + + if (!opt) + { + list_minus_o_opts (); + continue; + } + + option_name = opt->word->word; + + if (!option_name || !*option_name || (*option_name == '-')) + { + list_minus_o_opts (); + continue; + } + list = list->next; /* Skip over option name. */ + + if (set_minus_o_option (on_or_off, option_name) != EXECUTION_SUCCESS) + return (EXECUTION_FAILURE); + } + else + { + if (change_flag (flag_name, on_or_off) == FLAG_ERROR) + { + char opt[3]; + opt[0] = on_or_off; + opt[1] = flag_name; + opt[2] = '\0'; + bad_option (opt); + builtin_usage (); + return (EXECUTION_FAILURE); + } + } + } + } + else + { + break; + } + list = list->next; + } + + /* Assigning $1 ... $n */ + if (list || force_assignment) + remember_args (list, 1); + return (EXECUTION_SUCCESS); +} + +$BUILTIN unset +$FUNCTION unset_builtin +$SHORT_DOC unset [-f] [-v] [name ...] +For each NAME, remove the corresponding variable or function. Given +the `-v', unset will only act on variables. Given the `-f' flag, +unset will only act on functions. With neither flag, unset first +tries to unset a variable, and if that fails, then tries to unset a +function. Some variables (such as PATH and IFS) cannot be unset; also +see readonly. +$END + +#define NEXT_VARIABLE() any_failed++; list = list->next; continue; + +unset_builtin (list) + WORD_LIST *list; +{ + int unset_function, unset_variable, unset_array, opt, any_failed; + char *name; + + unset_function = unset_variable = unset_array = any_failed = 0; + + reset_internal_getopt (); + while ((opt = internal_getopt (list, "fv")) != -1) + { + switch (opt) + { + case 'f': + unset_function = 1; + break; + case 'v': + unset_variable = 1; + break; + default: + builtin_usage (); + return (EXECUTION_FAILURE); + } + } + + list = loptend; + + if (unset_function && unset_variable) + { + builtin_error ("cannot simultaneously unset a function and a variable"); + return (EXECUTION_FAILURE); + } + + while (list) + { + SHELL_VAR *var; + int tem; +#if defined (ARRAY_VARS) + char *t; +#endif + + name = list->word->word; + +#if defined (ARRAY_VARS) + if (!unset_function && valid_array_reference (name)) + { + t = strchr (name, '['); + *t++ = '\0'; + unset_array++; + } +#endif + + var = unset_function ? find_function (name) : find_variable (name); + + if (var && !unset_function && non_unsettable_p (var)) + { + builtin_error ("%s: cannot unset", name); + NEXT_VARIABLE (); + } + + /* Posix.2 says that unsetting readonly variables is an error. */ + if (var && readonly_p (var)) + { + builtin_error ("%s: cannot unset: readonly %s", + name, unset_function ? "function" : "variable"); + NEXT_VARIABLE (); + } + + /* Unless the -f option is supplied, the name refers to a variable. */ +#if defined (ARRAY_VARS) + if (var && unset_array) + { + if (array_p (var) == 0) + { + builtin_error ("%s: not an array variable", name); + NEXT_VARIABLE (); + } + else + tem = unbind_array_element (var, t); + } + else +#endif /* ARRAY_VARS */ + tem = makunbound (name, unset_function ? shell_functions : shell_variables); + + /* This is what Posix.2 draft 11+ says. ``If neither -f nor -v + is specified, the name refers to a variable; if a variable by + that name does not exist, a function by that name, if any, + shall be unset.'' */ + if ((tem == -1) && !unset_function && !unset_variable) + tem = makunbound (name, shell_functions); + + if (tem == -1) + any_failed++; + else if (!unset_function) + stupidly_hack_special_variables (name); + + list = list->next; + } + + if (any_failed) + return (EXECUTION_FAILURE); + else + return (EXECUTION_SUCCESS); +} diff --git a/CWRU/save/unwind_prot.h.save b/CWRU/save/unwind_prot.h.save new file mode 100644 index 000000000..998fd72b6 --- /dev/null +++ b/CWRU/save/unwind_prot.h.save @@ -0,0 +1,50 @@ +/* unwind_prot.h - Macros and functions for hacking unwind protection. */ + +/* Copyright (C) 1993 Free Software Foundation, Inc. + + This file is part of GNU Bash, the Bourne Again SHell. + + Bash is free software; you can redistribute it and/or modify it under + the terms of the GNU General Public License as published by the Free + Software Foundation; either version 2, or (at your option) any later + version. + + Bash is distributed in the hope that it will be useful, but WITHOUT ANY + WARRANTY; without even the implied warranty of MERCHANTABILITY or + FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + for more details. + + You should have received a copy of the GNU General Public License along + with Bash; see the file COPYING. If not, write to the Free Software + Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ + +#if !defined (_UNWIND_PROT_H) +#define _UNWIND_PROT_H + +/* Run a function without interrupts. */ +extern void begin_unwind_frame (); +extern void discard_unwind_frame (); +extern void run_unwind_frame (); +extern void add_unwind_protect (); +extern void remove_unwind_protect (); +extern void run_unwind_protects (); +extern void unwind_protect_var (); + +/* Define for people who like their code to look a certain way. */ +#define end_unwind_frame() + +/* How to protect an integer. */ +#define unwind_protect_int(X) unwind_protect_var (&(X), (char *)(X), sizeof (int)) + +/* How to protect a pointer to a string. */ +#define unwind_protect_string(X) \ + unwind_protect_var ((int *)&(X), (X), sizeof (char *)) + +/* How to protect any old pointer. */ +#define unwind_protect_pointer(X) unwind_protect_string (X) + +/* How to protect the contents of a jmp_buf. */ +#define unwind_protect_jmp_buf(X) \ + unwind_protect_var ((int *)(X), (char *)(X), sizeof (procenv_t)) + +#endif /* _UNWIND_PROT_H */ diff --git a/builtins/declare.def b/builtins/declare.def index 6420de68c..639fa4e22 100644 --- a/builtins/declare.def +++ b/builtins/declare.def @@ -154,6 +154,8 @@ declare_internal (list, local_var) { flags = list_opttype == '+' ? &flags_off : &flags_on; + /* If you add options here, see whether or not they need to be added to + the loop in subst.c:shell_expand_word_list() */ switch (opt) { case 'a': @@ -287,6 +289,7 @@ declare_internal (list, local_var) int offset, aflags, wflags; #if defined (ARRAY_VARS) int making_array_special, compound_array_assign, simple_array_assign; + int var_exists, array_exists, array_subscript_assignment; #endif name = savestring (list->word->word); @@ -330,7 +333,9 @@ declare_internal (list, local_var) } #if defined (ARRAY_VARS) + var_exists = array_exists = 0; compound_array_assign = simple_array_assign = 0; + array_subscript_assignment = 0; subscript_start = (char *)NULL; if (t = strchr (name, '[')) /* ] */ { @@ -343,7 +348,8 @@ declare_internal (list, local_var) } subscript_start = t; *t = '\0'; - making_array_special = 1; + making_array_special = 1; /* XXX - should this check offset? */ + array_subscript_assignment = offset != 0; } else making_array_special = 0; @@ -475,10 +481,13 @@ declare_internal (list, local_var) if (refvar) var = mkglobal ? find_global_variable (nameref_cell (refvar)) : find_variable (nameref_cell (refvar)); } - + if (var == 0) var = mkglobal ? find_global_variable (name) : find_variable (name); + var_exists = var != 0; + array_exists = var && (array_p (var) || assoc_p (var)); + if (var == 0) { #if defined (ARRAY_VARS) @@ -537,7 +546,11 @@ declare_internal (list, local_var) } #if defined (ARRAY_VARS) - if ((making_array_special || (flags_on & (att_array|att_assoc)) || array_p (var) || assoc_p (var)) && offset) + /* make declare a[2]=foo as similar to a[2]=foo as possible if + a is already an array or assoc variable. */ + if (array_subscript_assignment && array_exists && (flags_on & (att_array|att_assoc)) == 0) + simple_array_assign = 1; + else if ((making_array_special || (flags_on & (att_array|att_assoc)) || array_p (var) || assoc_p (var)) && offset) { int vlen; vlen = STRLEN (value); @@ -545,7 +558,12 @@ declare_internal (list, local_var) #if 0 /* bash-4.4 */ if (value[0] == '(' && value[vlen-1] == ')' && (shell_compatibility_level <= 43 || (wflags & W_COMPASSIGN))) #else +# if 0 if (value[0] == '(' && value[vlen-1] == ')' && (wflags & W_COMPASSIGN)) +# else + /* This is the code as in bash-4.3 */ + if (array_exists == 0 && value[0] == '(' && value[vlen-1] == ')') +# endif #endif compound_array_assign = 1; else diff --git a/builtins/declare.def~ b/builtins/declare.def~ new file mode 100644 index 000000000..c3044ebef --- /dev/null +++ b/builtins/declare.def~ @@ -0,0 +1,721 @@ +This file is declare.def, from which is created declare.c. +It implements the builtins "declare" and "local" in Bash. + +Copyright (C) 1987-2014 Free Software Foundation, Inc. + +This file is part of GNU Bash, the Bourne Again SHell. + +Bash is free software: you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation, either version 3 of the License, or +(at your option) any later version. + +Bash is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with Bash. If not, see . + +$PRODUCES declare.c + +$BUILTIN declare +$FUNCTION declare_builtin +$SHORT_DOC declare [-aAfFgilnrtux] [-p] [name[=value] ...] +Set variable values and attributes. + +Declare variables and give them attributes. If no NAMEs are given, +display the attributes and values of all variables. + +Options: + -f restrict action or display to function names and definitions + -F restrict display to function names only (plus line number and + source file when debugging) + -g create global variables when used in a shell function; otherwise + ignored + -p display the attributes and value of each NAME + +Options which set attributes: + -a to make NAMEs indexed arrays (if supported) + -A to make NAMEs associative arrays (if supported) + -i to make NAMEs have the `integer' attribute + -l to convert NAMEs to lower case on assignment + -n make NAME a reference to the variable named by its value + -r to make NAMEs readonly + -t to make NAMEs have the `trace' attribute + -u to convert NAMEs to upper case on assignment + -x to make NAMEs export + +Using `+' instead of `-' turns off the given attribute. + +Variables with the integer attribute have arithmetic evaluation (see +the `let' command) performed when the variable is assigned a value. + +When used in a function, `declare' makes NAMEs local, as with the `local' +command. The `-g' option suppresses this behavior. + +Exit Status: +Returns success unless an invalid option is supplied or a variable +assignment error occurs. +$END + +$BUILTIN typeset +$FUNCTION declare_builtin +$SHORT_DOC typeset [-aAfFgilrtux] [-p] name[=value] ... +Set variable values and attributes. + +Obsolete. See `help declare'. +$END + +#include + +#if defined (HAVE_UNISTD_H) +# ifdef _MINIX +# include +# endif +# include +#endif + +#include + +#include "../bashansi.h" +#include "../bashintl.h" + +#include "../shell.h" +#include "../flags.h" +#include "common.h" +#include "builtext.h" +#include "bashgetopt.h" + +extern int array_needs_making; +extern int posixly_correct; + +static int declare_internal __P((register WORD_LIST *, int)); + +/* Declare or change variable attributes. */ +int +declare_builtin (list) + register WORD_LIST *list; +{ + return (declare_internal (list, 0)); +} + +$BUILTIN local +$FUNCTION local_builtin +$SHORT_DOC local [option] name[=value] ... +Define local variables. + +Create a local variable called NAME, and give it VALUE. OPTION can +be any option accepted by `declare'. + +Local variables can only be used within a function; they are visible +only to the function where they are defined and its children. + +Exit Status: +Returns success unless an invalid option is supplied, a variable +assignment error occurs, or the shell is not executing a function. +$END +int +local_builtin (list) + register WORD_LIST *list; +{ + if (variable_context) + return (declare_internal (list, 1)); + else + { + builtin_error (_("can only be used in a function")); + return (EXECUTION_FAILURE); + } +} + +#if defined (ARRAY_VARS) +# define DECLARE_OPTS "+acfgilnprtuxAF" +#else +# define DECLARE_OPTS "+cfgilnprtuxF" +#endif + +/* The workhorse function. */ +static int +declare_internal (list, local_var) + register WORD_LIST *list; + int local_var; +{ + int flags_on, flags_off, *flags; + int any_failed, assign_error, pflag, nodefs, opt, mkglobal, onref, offref; + char *t, *subscript_start; + SHELL_VAR *var, *refvar, *v; + FUNCTION_DEF *shell_fn; + + flags_on = flags_off = any_failed = assign_error = pflag = nodefs = mkglobal = 0; + refvar = (SHELL_VAR *)NULL; + reset_internal_getopt (); + while ((opt = internal_getopt (list, DECLARE_OPTS)) != -1) + { + flags = list_opttype == '+' ? &flags_off : &flags_on; + + /* If you add options here, see whether or not they need to be added to + the loop in subst.c:shell_expand_word_list() */ + switch (opt) + { + case 'a': +#if defined (ARRAY_VARS) + *flags |= att_array; + break; +#else + builtin_usage (); + return (EX_USAGE); +#endif + case 'A': +#if defined (ARRAY_VARS) + *flags |= att_assoc; + break; +#else + builtin_usage (); + return (EX_USAGE); +#endif + case 'p': + if (local_var == 0) + pflag++; + break; + case 'F': + nodefs++; + *flags |= att_function; + break; + case 'f': + *flags |= att_function; + break; + case 'g': + if (flags == &flags_on) + mkglobal = 1; + break; + case 'i': + *flags |= att_integer; + break; + case 'n': + *flags |= att_nameref; + break; + case 'r': + *flags |= att_readonly; + break; + case 't': + *flags |= att_trace; + break; + case 'x': + *flags |= att_exported; + array_needs_making = 1; + break; +#if defined (CASEMOD_ATTRS) +# if defined (CASEMOD_CAPCASE) + case 'c': + *flags |= att_capcase; + if (flags == &flags_on) + flags_off |= att_uppercase|att_lowercase; + break; +# endif + case 'l': + *flags |= att_lowercase; + if (flags == &flags_on) + flags_off |= att_capcase|att_uppercase; + break; + case 'u': + *flags |= att_uppercase; + if (flags == &flags_on) + flags_off |= att_capcase|att_lowercase; + break; +#endif /* CASEMOD_ATTRS */ + default: + builtin_usage (); + return (EX_USAGE); + } + } + + list = loptend; + + /* If there are no more arguments left, then we just want to show + some variables. */ + if (list == 0) /* declare -[aAfFirtx] */ + { + /* Show local variables defined at this context level if this is + the `local' builtin. */ + if (local_var) + { + register SHELL_VAR **vlist; + register int i; + + vlist = all_local_variables (); + + if (vlist) + { + for (i = 0; vlist[i]; i++) + print_assignment (vlist[i]); + + free (vlist); + } + } + else if (pflag && (flags_on == 0 || flags_on == att_function)) + show_all_var_attributes (flags_on == 0, nodefs); + else if (flags_on == 0) + return (set_builtin ((WORD_LIST *)NULL)); + else + set_or_show_attributes ((WORD_LIST *)NULL, flags_on, nodefs); + + return (sh_chkwrite (EXECUTION_SUCCESS)); + } + + if (pflag) /* declare -p [-aAfFirtx] name [name...] */ + { + for (any_failed = 0; list; list = list->next) + { + if (flags_on & att_function) + pflag = show_func_attributes (list->word->word, nodefs); + else + pflag = show_name_attributes (list->word->word, nodefs); + if (pflag) + { + sh_notfound (list->word->word); + any_failed++; + } + } + return (sh_chkwrite (any_failed ? EXECUTION_FAILURE : EXECUTION_SUCCESS)); + } + +#define NEXT_VARIABLE() free (name); list = list->next; continue + + /* There are arguments left, so we are making variables. */ + while (list) /* declare [-aAfFirx] name [name ...] */ + { + char *value, *name; + int offset, aflags, wflags; +#if defined (ARRAY_VARS) + int making_array_special, compound_array_assign, simple_array_assign; + int var_exists, array_exists, array_subscript_assignment; +#endif + + name = savestring (list->word->word); + wflags = list->word->flags; + offset = assignment (name, 0); + aflags = 0; + + if (offset) /* declare [-aAfFirx] name=value */ + { + name[offset] = '\0'; + value = name + offset + 1; + if (name[offset - 1] == '+') + { + aflags |= ASS_APPEND; + name[offset - 1] = '\0'; + } + } + else + value = ""; + + /* Do some lexical error checking on the LHS and RHS of the assignment + that is specific to nameref variables. */ + if (flags_on & att_nameref) + { +#if defined (ARRAY_VARIABLES) + if (valid_array_reference (name)) + { + builtin_error (_("%s: reference variable cannot be an array"), name); + assign_error++; + NEXT_VARIABLE (); + } + else +#endif + /* disallow self references at global scope */ + if (STREQ (name, value) && variable_context == 0) + { + builtin_error (_("%s: nameref variable self references not allowed"), name); + assign_error++; + NEXT_VARIABLE (); + } + } + +#if defined (ARRAY_VARS) + var_exists = array_exists = 0; + compound_array_assign = simple_array_assign = 0; + array_subscript_assignment = 0; + subscript_start = (char *)NULL; + if (t = strchr (name, '[')) /* ] */ + { + /* If offset != 0 we have already validated any array reference */ + if (offset == 0 && valid_array_reference (name) == 0) + { + sh_invalidid (name); + assign_error++; + NEXT_VARIABLE (); + } + subscript_start = t; + *t = '\0'; + making_array_special = 1; /* XXX - should this check offset? */ + array_subscript_assignment = offset != 0; + } + else + making_array_special = 0; +#endif + + /* If we're in posix mode or not looking for a shell function (since + shell function names don't have to be valid identifiers when the + shell's not in posix mode), check whether or not the argument is a + valid, well-formed shell identifier. */ + if ((posixly_correct || (flags_on & att_function) == 0) && legal_identifier (name) == 0) + { + sh_invalidid (name); + assign_error++; + NEXT_VARIABLE (); + } + + /* If VARIABLE_CONTEXT has a non-zero value, then we are executing + inside of a function. This means we should make local variables, + not global ones. */ + + /* XXX - this has consequences when we're making a local copy of a + variable that was in the temporary environment. Watch out + for this. */ + refvar = (SHELL_VAR *)NULL; + if (variable_context && mkglobal == 0 && ((flags_on & att_function) == 0)) + { +#if defined (ARRAY_VARS) + if (flags_on & att_assoc) + var = make_local_assoc_variable (name); + else if ((flags_on & att_array) || making_array_special) + var = make_local_array_variable (name, making_array_special); + else +#endif + var = make_local_variable (name); /* sets att_invisible for new vars */ + if (var == 0) + { + any_failed++; + NEXT_VARIABLE (); + } + } + else + var = (SHELL_VAR *)NULL; + + /* If we are declaring a function, then complain about it in some way. + We don't let people make functions by saying `typeset -f foo=bar'. */ + + /* There should be a way, however, to let people look at a particular + function definition by saying `typeset -f foo'. */ + + if (flags_on & att_function) + { + if (offset) /* declare -f [-rix] foo=bar */ + { + builtin_error (_("cannot use `-f' to make functions")); + free (name); + return (EXECUTION_FAILURE); + } + else /* declare -f [-rx] name [name...] */ + { + var = find_function (name); + + if (var) + { + if (readonly_p (var) && (flags_off & att_readonly)) + { + builtin_error (_("%s: readonly function"), name); + any_failed++; + NEXT_VARIABLE (); + } + + /* declare -[Ff] name [name...] */ + if (flags_on == att_function && flags_off == 0) + { +#if defined (DEBUGGER) + if (nodefs && debugging_mode) + { + shell_fn = find_function_def (var->name); + if (shell_fn) + printf ("%s %d %s\n", var->name, shell_fn->line, shell_fn->source_file); + else + printf ("%s\n", var->name); + } + else +#endif /* DEBUGGER */ + { + t = nodefs ? var->name + : named_function_string (name, function_cell (var), FUNC_MULTILINE|FUNC_EXTERNAL); + printf ("%s\n", t); + any_failed = sh_chkwrite (any_failed); + } + } + else /* declare -[fF] -[rx] name [name...] */ + { + VSETATTR (var, flags_on); + VUNSETATTR (var, flags_off); + } + } + else + any_failed++; + NEXT_VARIABLE (); + } + } + else /* declare -[aAirx] name [name...] */ + { + /* Non-null if we just created or fetched a local variable. */ + /* Here's what ksh93 seems to do. If we are modifying an existing + nameref variable, we don't follow the nameref chain past the last + nameref, and we set the nameref variable's value so future + references to that variable will return the value of the variable + we're assigning right now. */ + if (var == 0 && (flags_on & att_nameref)) + { + /* See if we are trying to modify an existing nameref variable */ + var = mkglobal ? find_global_variable_last_nameref (name) : find_variable_last_nameref (name); + if (var && nameref_p (var) == 0) + var = 0; + } + /* However, if we're turning off the nameref attribute on an existing + nameref variable, we first follow the nameref chain to the end, + modify the value of the variable this nameref variable references, + *CHANGING ITS VALUE AS A SIDE EFFECT* then turn off the nameref + flag *LEAVING THE NAMEREF VARIABLE'S VALUE UNCHANGED* */ + else if (var == 0 && (flags_off & att_nameref)) + { + /* See if we are trying to modify an existing nameref variable */ + refvar = mkglobal ? find_global_variable_last_nameref (name) : find_variable_last_nameref (name); + if (refvar && nameref_p (refvar) == 0) + refvar = 0; + if (refvar) + var = mkglobal ? find_global_variable (nameref_cell (refvar)) : find_variable (nameref_cell (refvar)); + } + + var_exists = var != 0; + array_exists = var && (array_p (var) || assoc_p (var)); + + if (var == 0) + var = mkglobal ? find_global_variable (name) : find_variable (name); + + if (var == 0) + { +#if defined (ARRAY_VARS) + if (flags_on & att_assoc) + { + var = make_new_assoc_variable (name); + if (offset == 0 && no_invisible_vars == 0) + VSETATTR (var, att_invisible); + } + else if ((flags_on & att_array) || making_array_special) + { + var = make_new_array_variable (name); + if (offset == 0 && no_invisible_vars == 0) + VSETATTR (var, att_invisible); + } + else +#endif + if (offset) + var = mkglobal ? bind_global_variable (name, "", 0) : bind_variable (name, "", 0); + else + { + var = mkglobal ? bind_global_variable (name, (char *)NULL, 0) : bind_variable (name, (char *)NULL, 0); + if (no_invisible_vars == 0) + VSETATTR (var, att_invisible); + } + } + /* Can't take an existing array variable and make it a nameref */ + else if ((array_p (var) || assoc_p (var)) && (flags_on & att_nameref)) + { + builtin_error (_("%s: reference variable cannot be an array"), name); + assign_error++; + NEXT_VARIABLE (); + } + else if (flags_on & att_nameref) + { + /* ksh93 compat: turning on nameref attribute turns off -ilu */ + VUNSETATTR (var, att_integer|att_uppercase|att_lowercase|att_capcase); + } + + /* Cannot use declare +r to turn off readonly attribute. */ + if (readonly_p (var) && (flags_off & att_readonly)) + { + sh_readonly (name); + any_failed++; + NEXT_VARIABLE (); + } + + /* Cannot use declare to assign value to readonly or noassign + variable. */ + if ((readonly_p (var) || noassign_p (var)) && offset) + { + if (readonly_p (var)) + sh_readonly (name); + assign_error++; + NEXT_VARIABLE (); + } + +#if defined (ARRAY_VARS) + /* make declare a[2]=foo as similar to a[2]=foo as possible if + a is already an array or assoc variable. */ + if (array_subscript_assignment && array_exists && (flags_on & (att_array|att_assoc)) == 0) + simple_array_assign = 1; + else if ((making_array_special || (flags_on & (att_array|att_assoc)) || array_p (var) || assoc_p (var)) && offset) + { + int vlen; + vlen = STRLEN (value); +/*itrace("declare_builtin: name = %s value = %s flags = %d", name, value, wflags);*/ +#if 0 /* bash-4.4 */ + if (value[0] == '(' && value[vlen-1] == ')' && (shell_compatibility_level <= 43 || (wflags & W_COMPASSIGN))) +#else +# if 0 + if (value[0] == '(' && value[vlen-1] == ')' && (wflags & W_COMPASSIGN)) +# else + /* This is the code as in bash-4.3 */ + if (array_exists == 0 && value[0] == '(' && value[vlen-1] == ')') +# endif +#endif + compound_array_assign = 1; + else + simple_array_assign = 1; + } + + /* Cannot use declare +a name or declare +A name to remove an + array variable. */ + if (((flags_off & att_array) && array_p (var)) || ((flags_off & att_assoc) && assoc_p (var))) + { + builtin_error (_("%s: cannot destroy array variables in this way"), name); + any_failed++; + NEXT_VARIABLE (); + } + + if ((flags_on & att_array) && assoc_p (var)) + { + builtin_error (_("%s: cannot convert associative to indexed array"), name); + any_failed++; + NEXT_VARIABLE (); + } + if ((flags_on & att_assoc) && array_p (var)) + { + builtin_error (_("%s: cannot convert indexed to associative array"), name); + any_failed++; + NEXT_VARIABLE (); + } + + /* declare -A name[[n]] makes name an associative array variable. */ + if (flags_on & att_assoc) + { + if (assoc_p (var) == 0) + var = convert_var_to_assoc (var); + } + /* declare -a name[[n]] or declare name[n] makes name an indexed + array variable. */ + else if ((making_array_special || (flags_on & att_array)) && array_p (var) == 0 && assoc_p (var) == 0) + var = convert_var_to_array (var); +#endif /* ARRAY_VARS */ + + /* XXX - we note that we are turning on nameref attribute and defer + setting it until the assignment has been made so we don't do an + inadvertent nameref lookup. Might have to do the same thing for + flags_off&att_nameref. */ + /* XXX - ksh93 makes it an error to set a readonly nameref variable + using a single typeset command. */ + onref = (flags_on & att_nameref); + flags_on &= ~att_nameref; +#if defined (ARRAY_VARS) + if (array_p (var) || assoc_p (var) + || (offset && compound_array_assign) + || simple_array_assign) + onref = 0; /* array variables may not be namerefs */ +#endif + + /* ksh93 seems to do this */ + offref = (flags_off & att_nameref); + flags_off &= ~att_nameref; + + VSETATTR (var, flags_on); + VUNSETATTR (var, flags_off); + +#if defined (ARRAY_VARS) + aflags |= ASS_FORCE; + if (offset && compound_array_assign) + assign_array_var_from_string (var, value, aflags); + else if (simple_array_assign && subscript_start) + { + /* declare [-aA] name[N]=value */ + *subscript_start = '['; /* ] */ + var = assign_array_element (name, value, 0); /* XXX - not aflags */ + *subscript_start = '\0'; + if (var == 0) /* some kind of assignment error */ + { + assign_error++; + flags_on |= onref; + flags_off |= offref; + NEXT_VARIABLE (); + } + } + else if (simple_array_assign) + { + /* let bind_{array,assoc}_variable take care of this. */ + if (assoc_p (var)) + bind_assoc_variable (var, name, savestring ("0"), value, aflags); + else + bind_array_variable (name, 0, value, aflags); + } + else +#endif + /* bind_variable_value duplicates the essential internals of + bind_variable() */ + if (offset) + { + if (onref) + aflags |= ASS_NAMEREF; + v = bind_variable_value (var, value, aflags); + if (v == 0 && onref) + { + sh_invalidid (value); + assign_error++; + /* XXX - unset this variable? or leave it as normal var? */ + delete_var (var->name, mkglobal ? global_variables : shell_variables); + NEXT_VARIABLE (); + } + } + + /* If we found this variable in the temporary environment, as with + `var=value declare -x var', make sure it is treated identically + to `var=value export var'. Do the same for `declare -r' and + `readonly'. Preserve the attributes, except for att_tempvar. */ + /* XXX -- should this create a variable in the global scope, or + modify the local variable flags? ksh93 has it modify the + global scope. + Need to handle case like in set_var_attribute where a temporary + variable is in the same table as the function local vars. */ + if ((flags_on & (att_exported|att_readonly)) && tempvar_p (var)) + { + SHELL_VAR *tv; + char *tvalue; + + tv = find_tempenv_variable (var->name); + if (tv) + { + tvalue = var_isset (var) ? savestring (value_cell (var)) : savestring (""); + tv = bind_variable (var->name, tvalue, 0); + tv->attributes |= var->attributes & ~att_tempvar; + if (tv->context > 0) + VSETATTR (tv, att_propagate); + free (tvalue); + } + VSETATTR (var, att_propagate); + } + } + + /* Turn on nameref attribute we deferred above. */ + /* XXX - should we turn on the noassign attribute for consistency with + ksh93 when we turn on the nameref attribute? */ + VSETATTR (var, onref); + flags_on |= onref; + VUNSETATTR (var, offref); + flags_off |= offref; + /* Yuck. ksh93 compatibility */ + if (refvar) + VUNSETATTR (refvar, flags_off); + + stupidly_hack_special_variables (name); + + NEXT_VARIABLE (); + } + + return (assign_error ? EX_BADASSIGN + : ((any_failed == 0) ? EXECUTION_SUCCESS + : EXECUTION_FAILURE)); +} diff --git a/command.h b/command.h index 6e9d1e4bc..7ff1da970 100644 --- a/command.h +++ b/command.h @@ -100,7 +100,6 @@ enum command_type { cm_for, cm_case, cm_while, cm_if, cm_simple, cm_select, #define W_ARRAYIND 0x1000000 /* word is an array index being expanded */ #define W_ASSNGLOBAL 0x2000000 /* word is a global assignment to declare (declare/typeset -g) */ #define W_NOBRACE 0x4000000 /* Don't perform brace expansion */ -#define W_ASSIGNINT 0x8000000 /* word is an integer assignment to declare */ /* Possible values for subshell_environment */ #define SUBSHELL_ASYNC 0x01 /* subshell caused by `command &' */ diff --git a/cross-build/cygwin32.cache.old b/cross-build/cygwin32.cache.old new file mode 100644 index 000000000..640390fbf --- /dev/null +++ b/cross-build/cygwin32.cache.old @@ -0,0 +1,42 @@ +# This file is a shell script that caches the results of configure +# tests for CYGWIN32 so they don't need to be done when cross-compiling. + +# AC_FUNC_GETPGRP should also define GETPGRP_VOID +ac_cv_func_getpgrp_void=${ac_cv_func_getpgrp_void='yes'} +# AC_FUNC_SETVBUF_REVERSED should not define anything else +ac_cv_func_setvbuf_reversed=${ac_cv_func_setvbuf_reversed='no'} +# on CYGWIN32, system calls do not restart +ac_cv_sys_restartable_syscalls=${ac_cv_sys_restartable_syscalls='no'} +bash_cv_sys_restartable_syscalls=${bash_cv_sys_restartable_syscalls='no'} + +# these may be necessary, but they are currently commented out +#ac_cv_c_bigendian=${ac_cv_c_bigendian='no'} +ac_cv_sizeof_char_p=${ac_cv_sizeof_char_p='4'} +ac_cv_sizeof_int=${ac_cv_sizeof_int='4'} +ac_cv_sizeof_long=${ac_cv_sizeof_long='4'} +ac_cv_sizeof_double=${ac_cv_sizeof_double='8'} + +bash_cv_dup2_broken=${bash_cv_dup2_broken='no'} +bash_cv_pgrp_pipe=${bash_cv_pgrp_pipe='no'} +bash_cv_type_rlimit=${bash_cv_type_rlimit='long'} +bash_cv_decl_under_sys_siglist=${bash_cv_decl_under_sys_siglist='no'} +bash_cv_under_sys_siglist=${bash_cv_under_sys_siglist='no'} +bash_cv_sys_siglist=${bash_cv_sys_siglist='no'} +bash_cv_opendir_not_robust=${bash_cv_opendir_not_robust='no'} +bash_cv_getenv_redef=${bash_cv_getenv_redef='yes'} +bash_cv_printf_declared=${bash_cv_printf_declared='yes'} +bash_cv_ulimit_maxfds=${bash_cv_ulimit_maxfds='no'} +bash_cv_getcwd_calls_popen=${bash_cv_getcwd_calls_popen='no'} +bash_cv_must_reinstall_sighandlers=${bash_cv_must_reinstall_sighandlers='no'} +bash_cv_job_control_missing=${bash_cv_job_control_missing='present'} +bash_cv_sys_named_pipes=${bash_cv_sys_named_pipes='missing'} +bash_cv_func_sigsetjmp=${bash_cv_func_sigsetjmp='missing'} +bash_cv_mail_dir=${bash_cv_mail_dir='unknown'} +bash_cv_func_strcoll_broken=${bash_cv_func_strcoll_broken='no'} + +bash_cv_type_int32_t=${bash_cv_type_int32_t='int'} +bash_cv_type_u_int32_t=${bash_cv_type_u_int32_t='int'} + +ac_cv_type_bits64_t=${ac_cv_type_bits64_t='no'} + +# end of cross-build/cygwin32.cache diff --git a/doc/FAQ.orig b/doc/FAQ.orig new file mode 100644 index 000000000..1cff3c8ef --- /dev/null +++ b/doc/FAQ.orig @@ -0,0 +1,1745 @@ +This is the Bash FAQ, version 3.24, for Bash version 2.05b. + +This document contains a set of frequently-asked questions concerning +Bash, the GNU Bourne-Again Shell. Bash is a freely-available command +interpreter with advanced features for both interactive use and shell +programming. + +Another good source of basic information about shells is the collection +of FAQ articles periodically posted to comp.unix.shell. + +Questions and comments concerning this document should be sent to +chet@po.cwru.edu. + +This document is available for anonymous FTP with the URL + +ftp://ftp.cwru.edu/pub/bash/FAQ + +The Bash home page is http://cnswww.cns.cwru.edu/~chet/bash/bashtop.html + +---------- +Contents: + +Section A: The Basics + +A1) What is it? +A2) What's the latest version? +A3) Where can I get it? +A4) On what machines will bash run? +A5) Will bash run on operating systems other than Unix? +A6) How can I build bash with gcc? +A7) How can I make bash my login shell? +A8) I just changed my login shell to bash, and now I can't FTP into my + machine. Why not? +A9) What's the `POSIX 1003.2 standard'? +A10) What is the bash `posix mode'? + +Section B: The latest version + +B1) What's new in version 2.05b? +B2) Are there any user-visible incompatibilities between bash-2.05b and + bash-1.14.7? + +Section C: Differences from other Unix shells + +C1) How does bash differ from sh, the Bourne shell? +C2) How does bash differ from the Korn shell, version ksh88? +C3) Which new features in ksh-93 are not in bash, and which are? + +Section D: Why does bash do some things differently than other Unix shells? + +D1) Why does bash run a different version of `command' than + `which command' says it will? +D2) Why doesn't bash treat brace expansions exactly like csh? +D3) Why doesn't bash have csh variable modifiers? +D4) How can I make my csh aliases work when I convert to bash? +D5) How can I pipe standard output and standard error from one command to + another, like csh does with `|&'? +D6) Now that I've converted from ksh to bash, are there equivalents to + ksh features like autoloaded functions and the `whence' command? + +Section E: Why does bash do certain things the way it does? + +E1) Why is the bash builtin `test' slightly different from /bin/test? +E2) Why does bash sometimes say `Broken pipe'? +E3) When I have terminal escape sequences in my prompt, why does bash + wrap lines at the wrong column? +E4) If I pipe the output of a command into `read variable', why doesn't + the output show up in $variable when the read command finishes? +E5) I have a bunch of shell scripts that use backslash-escaped characters + in arguments to `echo'. Bash doesn't interpret these characters. Why + not, and how can I make it understand them? +E6) Why doesn't a while or for loop get suspended when I type ^Z? +E7) What about empty for loops in Makefiles? +E8) Why does the arithmetic evaluation code complain about `08'? +E9) Why does the pattern matching expression [A-Z]* match files beginning + with every letter except `z'? +E10) Why does `cd //' leave $PWD as `//'? +E11) If I resize my xterm while another program is running, why doesn't bash + notice the change? + +Section F: Things to watch out for on certain Unix versions + +F1) Why can't I use command line editing in my `cmdtool'? +F2) I built bash on Solaris 2. Why do globbing expansions and filename + completion chop off the first few characters of each filename? +F3) Why does bash dump core after I interrupt username completion or + `~user' tilde expansion on a machine running NIS? +F4) I'm running SVR4.2. Why is the line erased every time I type `@'? +F5) Why does bash report syntax errors when my C News scripts use a + redirection before a subshell command? +F6) Why can't I use vi-mode editing on Red Hat Linux 6.1? +F7) Why do bash-2.05a and bash-2.05b fail to compile `printf.def' on + HP/UX 11.x? + +Section G: How can I get bash to do certain common things? + +G1) How can I get bash to read and display eight-bit characters? +G2) How do I write a function `x' to replace builtin command `x', but + still invoke the command from within the function? +G3) How can I find the value of a shell variable whose name is the value + of another shell variable? +G4) How can I make the bash `time' reserved word print timing output that + looks like the output from my system's /usr/bin/time? +G5) How do I get the current directory into my prompt? +G6) How can I rename "*.foo" to "*.bar"? +G7) How can I translate a filename from uppercase to lowercase? +G8) How can I write a filename expansion (globbing) pattern that will match + all files in the current directory except "." and ".."? + +Section H: Where do I go from here? + +H1) How do I report bugs in bash, and where should I look for fixes and + advice? +H2) What kind of bash documentation is there? +H3) What's coming in future versions? +H4) What's on the bash `wish list'? +H5) When will the next release appear? + +---------- +Section A: The Basics + +A1) What is it? + +Bash is a Unix command interpreter (shell). It is an implementation of +the Posix 1003.2 shell standard, and resembles the Korn and System V +shells. + +Bash contains a number of enhancements over those shells, both +for interactive use and shell programming. Features geared +toward interactive use include command line editing, command +history, job control, aliases, and prompt expansion. Programming +features include additional variable expansions, shell +arithmetic, and a number of variables and options to control +shell behavior. + +Bash was originally written by Brian Fox of the Free Software +Foundation. The current developer and maintainer is Chet Ramey +of Case Western Reserve University. + +A2) What's the latest version? + +The latest version is 2.05b, first made available on Wednesday, 17 +July, 2002. + +A3) Where can I get it? + +Bash is the GNU project's shell, and so is available from the +master GNU archive site, ftp.gnu.org, and its mirrors. The +latest version is also available for FTP from ftp.cwru.edu. +The following URLs tell how to get version 2.05b: + +ftp://ftp.gnu.org/pub/gnu/bash/bash-2.05b.tar.gz +ftp://ftp.cwru.edu/pub/bash/bash-2.05b.tar.gz + +Formatted versions of the documentation are available with the URLs: + +ftp://ftp.gnu.org/pub/gnu/bash/bash-doc-2.05b.tar.gz +ftp://ftp.cwru.edu/pub/bash/bash-doc-2.05b.tar.gz + +A4) On what machines will bash run? + +Bash has been ported to nearly every version of UNIX. All you +should have to do to build it on a machine for which a port +exists is to type `configure' and then `make'. The build process +will attempt to discover the version of UNIX you have and tailor +itself accordingly, using a script created by GNU autoconf. + +More information appears in the file `INSTALL' in the distribution. + +The Bash web page (http://cnswww.cns.cwru.edu/~chet/bash/bashtop.html) +explains how to obtain binary versions of bash for most of the major +commercial Unix systems. + +A5) Will bash run on operating systems other than Unix? + +Configuration specifics for Unix-like systems such as QNX and +LynxOS are included in the distribution. Bash-2.05 and later +versions should compile and run on Minix 2.0 (patches were +contributed), but I don't believe anyone has built bash-2.x on +earlier Minix versions yet. + +Bash has been ported to versions of Windows implementing the Win32 +programming interface. This includes Windows 95 and Windows NT. +The port was done by Cygnus Solutions as part of their CYGWIN +project. For more information about the project, look at the URLs + +http://www.cygwin.com/ +http://sourceware.cygnus.com/cygwin + +Cygnus originally ported bash-1.14.7, and that port was part of their +early GNU-Win32 (the original name) releases. Cygnus has also done a +port of bash-2.05 to the CYGWIN environment, and it is available as +part of their current release. + +Bash-2.05b should require no local Cygnus changes to build and run under +CYGWIN. + +The Cygnus port works only on Intel machines. There is a port of bash +(I don't know which version) to the alpha/NT environment available from + +ftp://ftp.gnustep.org//pub/win32/bash-alpha-nt-1.01.tar.gz + +DJ Delorie has a port of bash-2.x which runs under MS-DOS, as part +of the DJGPP project. For more information on the project, see + +http://www.delorie.com/djgpp/ + +I have been told that the original DJGPP port was done by Daisuke Aoyama. + +Mark Elbrecht has sent me notice that bash-2.04 +is available for DJGPP V2. The files are available as: + +ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu/bsh204b.zip binary +ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu/bsh204d.zip documentation +ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu/bsh204s.zip source + +Mark has begun to work with bash-2.05, but I don't know the status. + +Ports of bash-1.12 and bash-2.0 are available for OS/2 from + +ftp://hobbes.nmsu.edu/pub/os2/util/shell/bash_112.zip +ftp://hobbes.nmsu.edu/pub/os2/util/shell/bash-2.0(253).zip + +I haven't looked at either, but the second appears to be a binary-only +distribution. Beware. + +I have received word that Bash (I'm not sure which version, but I +believe that it's at least bash-2.02.1) is the standard shell on +BeOS. + +A6) How can I build bash with gcc? + +Bash configures to use gcc by default if it is available. Read the +file INSTALL in the distribution for more information. + +A7) How can I make bash my login shell? + +Some machines let you use `chsh' to change your login shell. Other +systems use `passwd -s' or `passwd -e'. If one of these works for +you, that's all you need. Note that many systems require the full +pathname to a shell to appear in /etc/shells before you can make it +your login shell. For this, you may need the assistance of your +friendly local system administrator. + +If you cannot do this, you can still use bash as your login shell, but +you need to perform some tricks. The basic idea is to add a command +to your login shell's startup file to replace your login shell with +bash. + +For example, if your login shell is csh or tcsh, and you have installed +bash in /usr/gnu/bin/bash, add the following line to ~/.login: + + if ( -f /usr/gnu/bin/bash ) exec /usr/gnu/bin/bash --login + +(the `--login' tells bash that it is a login shell). + +It's not a good idea to put this command into ~/.cshrc, because every +csh you run without the `-f' option, even ones started to run csh scripts, +reads that file. If you must put the command in ~/.cshrc, use something +like + + if ( $?prompt ) exec /usr/gnu/bin/bash --login + +to ensure that bash is exec'd only when the csh is interactive. + +If your login shell is sh or ksh, you have to do two things. + +First, create an empty file in your home directory named `.bash_profile'. +The existence of this file will prevent the exec'd bash from trying to +read ~/.profile, and re-execing itself over and over again. ~/.bash_profile +is the first file bash tries to read initialization commands from when +it is invoked as a login shell. + +Next, add a line similar to the above to ~/.profile: + + [ -f /usr/gnu/bin/bash ] && [ -x /usr/gnu/bin/bash ] && \ + exec /usr/gnu/bin/bash --login + +This will cause login shells to replace themselves with bash running as +a login shell. Once you have this working, you can copy your initialization +code from ~/.profile to ~/.bash_profile. + +I have received word that the recipe supplied above is insufficient for +machines running CDE. CDE has a maze of twisty little startup files, all +slightly different. + +If you cannot change your login shell in the password file to bash, you +will have to (apparently) live with CDE using the shell in the password +file to run its startup scripts. If you have changed your shell to bash, +there is code in the CDE startup files (on Solaris, at least) that attempts +to do the right thing. It is, however, often broken, and may require that +you use the $BASH_ENV trick described below. + +`dtterm' claims to use $SHELL as the default program to start, so if you +can change $SHELL in the CDE startup files, you should be able to use bash +in your terminal windows. + +Setting DTSOURCEPROFILE in ~/.dtprofile will cause the `Xsession' program +to read your login shell's startup files. You may be able to use bash for +the rest of the CDE programs by setting SHELL to bash in ~/.dtprofile as +well, but I have not tried this. + +You can use the above `exec' recipe to start bash when not logging in with +CDE by testing the value of the DT variable: + + if [ -n "$DT" ]; then + [ -f /usr/gnu/bin/bash ] && exec /usr/gnu/bin/bash --login + fi + +If CDE starts its shells non-interactively during login, the login shell +startup files (~/.profile, ~/.bash_profile) will not be sourced at login. +To get around this problem, append a line similar to the following to your +~/.dtprofile: + + BASH_ENV=${HOME}/.bash_profile ; export BASH_ENV + +and add the following line to the beginning of ~/.bash_profile: + + unset BASH_ENV + +A8) I just changed my login shell to bash, and now I can't FTP into my + machine. Why not? + +You must add the full pathname to bash to the file /etc/shells. As +noted in the answer to the previous question, many systems require +this before you can make bash your login shell. + +Most versions of ftpd use this file to prohibit `special' users +such as `uucp' and `news' from using FTP. + +A9) What's the `POSIX 1003.2 standard'? + +POSIX is a name originally coined by Richard Stallman for a +family of open system standards based on UNIX. There are a +number of aspects of UNIX under consideration for +standardization, from the basic system services at the system +call and C library level to applications and tools to system +administration and management. Each area of standardization is +assigned to a working group in the 1003 series. + +The POSIX Shell and Utilities standard has been developed by IEEE +Working Group 1003.2 (POSIX.2). It concentrates on the command +interpreter interface and utility programs commonly executed from +the command line or by other programs. An initial version of the +standard has been approved and published by the IEEE, and work is +currently underway to update it. + +Bash is concerned with the aspects of the shell's behavior +defined by POSIX.2. The shell command language has of course +been standardized, including the basic flow control and program +execution constructs, I/O redirection and pipelining, argument +handling, variable expansion, and quoting. + +The `special' builtins, which must be implemented as part of the +shell to provide the desired functionality, are specified as +being part of the shell; examples of these are `eval' and +`export'. Other utilities appear in the sections of POSIX.2 not +devoted to the shell which are commonly (and in some cases must +be) implemented as builtin commands, such as `read' and `test'. +POSIX.2 also specifies aspects of the shell's interactive +behavior as part of the UPE, including job control and command +line editing. Only vi-style line editing commands have been +standardized; emacs editing commands were left out due to +objections. + +The Open Group has made an older version of its Single Unix +Specification (version 2), which is very similar to POSIX.2, +available on the web at + +http://www.opengroup.org/onlinepubs/007908799/ + +The Single Unix Specification, version 3, is available on the web at + +http://www.opengroup.org/onlinepubs/007904975/ + +A10) What is the bash `posix mode'? + +Although bash is an implementation of the POSIX.2 shell +specification, there are areas where the bash default behavior +differs from that spec. The bash `posix mode' changes the bash +behavior in these areas so that it obeys the spec more closely. + +Posix mode is entered by starting bash with the --posix or +'-o posix' option or executing `set -o posix' after bash is running. + +The specific aspects of bash which change when posix mode is +active are listed in the file POSIX in the bash distribution. +They are also listed in a section in the Bash Reference Manual +(from which that file is generated). + +Section B: The latest version + +B1) What's new in version 2.05b? + +The raison d'etre for bash-2.05b is to make a second intermediate +release containing the first of the new features to be available +in bash-3.0 and get feedback on those features before proceeding. +The major new feature is multibyte character support in both Bash +and Readline. + +Bash-2.05b contains the following new features (see the manual page for +complete descriptions and the CHANGES and NEWS files in the bash-2.05b +distribution): + +o support for multibyte characters has been added to both bash and readline + +o the DEBUG trap is now run *before* simple commands, ((...)) commands, + [[...]] conditional commands, and for ((...)) loops + +o the shell now performs arithmetic in the largest integer size the machine + supports (intmax_t) + +o there is a new \D{...} prompt expansion; passes the `...' to strftime(3) + and inserts the result into the expanded prompt + +o there is a new `here-string' redirection operator: <<< word + +o when displaying variables, function attributes and definitions are shown + separately, allowing them to be re-used as input (attempting to re-use + the old output would result in syntax errors). + +o `read' has a new `-u fd' option to read from a specified file descriptor + +o the bash debugger in examples/bashdb has been modified to work with the + new DEBUG trap semantics, the command set has been made more gdb-like, + and the changes to $LINENO make debugging functions work better + +o the expansion of $LINENO inside a shell function is only relative to the + function start if the shell is interactive -- if the shell is running a + script, $LINENO expands to the line number in the script. This is as + POSIX-2001 requires + + +A short feature history dating from Bash-2.0: + +Bash-2.05a introduced the following new features: + +o The `printf' builtin has undergone major work + +o There is a new read-only `shopt' option: login_shell, which is set by + login shells and unset otherwise + +o New `\A' prompt string escape sequence; expanding to time in 24-hour + HH:MM format + +o New `-A group/-g' option to complete and compgen; goes group name + completion + +o New [+-]O invocation option to set and unset `shopt' options at startup + +o ksh-like `ERR' trap + +o `for' loops now allow empty word lists after the `in' reserved word + +o new `hard' and `soft' arguments for the `ulimit' builtin + +o Readline can be configured to place the user at the same point on the line + when retrieving commands from the history list + +o Readline can be configured to skip `hidden' files (filenames with a leading + `.' on Unix) when performing completion + +Bash-2.05 introduced the following new features: + +o This version has once again reverted to using locales and strcoll(3) when + processing pattern matching bracket expressions, as POSIX requires. +o Added a new `--init-file' invocation argument as a synonym for `--rcfile', + per the new GNU coding standards. +o The /dev/tcp and /dev/udp redirections now accept service names as well as + port numbers. +o `complete' and `compgen' now take a `-o value' option, which controls some + of the aspects of that compspec. Valid values are: + + default - perform bash default completion if programmable + completion produces no matches + dirnames - perform directory name completion if programmable + completion produces no matches + filenames - tell readline that the compspec produces filenames, + so it can do things like append slashes to + directory names and suppress trailing spaces +o A new loadable builtin, realpath, which canonicalizes and expands symlinks + in pathname arguments. +o When `set' is called without options, it prints function defintions in a + way that allows them to be reused as input. This affects `declare' and + `declare -p' as well. This only happens when the shell is not in POSIX + mode, since POSIX.2 forbids this behavior. + +Bash-2.04 introduced the following new features: + +o Programmable word completion with the new `complete' and `compgen' builtins; + examples are provided in examples/complete/complete-examples +o `history' has a new `-d' option to delete a history entry +o `bind' has a new `-x' option to bind key sequences to shell commands +o The prompt expansion code has new `\j' and `\l' escape sequences +o The `no_empty_cmd_completion' shell option, if enabled, inhibits + command completion when TAB is typed on an empty line +o `help' has a new `-s' option to print a usage synopsis +o New arithmetic operators: var++, var--, ++var, --var, expr1,expr2 (comma) +o New ksh93-style arithmetic for command: + for ((expr1 ; expr2; expr3 )); do list; done +o `read' has new options: `-t', `-n', `-d', `-s' +o The redirection code handles several filenames specially: /dev/fd/N, + /dev/stdin, /dev/stdout, /dev/stderr +o The redirection code now recognizes /dev/tcp/HOST/PORT and + /dev/udp/HOST/PORT and tries to open a TCP or UDP socket, respectively, + to the specified port on the specified host +o The ${!prefix*} expansion has been implemented +o A new FUNCNAME variable, which expands to the name of a currently-executing + function +o The GROUPS variable is no longer readonly +o A new shopt `xpg_echo' variable, to control the behavior of echo with + respect to backslash-escape sequences at runtime +o The NON_INTERACTIVE_LOGIN_SHELLS #define has returned + +The version of Readline released with Bash-2.04, Readline-4.1, had several +new features as well: + +o Parentheses matching is always compiled into readline, and controllable + with the new `blink-matching-paren' variable +o The history-search-forward and history-search-backward functions now leave + point at the end of the line when the search string is empty, like + reverse-search-history, and forward-search-history +o A new function for applications: rl_on_new_line_with_prompt() +o New variables for applications: rl_already_prompted, and rl_gnu_readline_p + + +Bash-2.03 had very few new features, in keeping with the convention +that odd-numbered releases provide mainly bug fixes. A number of new +features were added to Readline, mostly at the request of the Cygnus +folks. + +A new shopt option, `restricted_shell', so that startup files can test + whether or not the shell was started in restricted mode +Filename generation is now performed on the words between ( and ) in + compound array assignments (this is really a bug fix) +OLDPWD is now auto-exported, as POSIX.2 requires +ENV and BASH_ENV are read-only variables in a restricted shell +Bash may now be linked against an already-installed Readline library, + as long as the Readline library is version 4 or newer +All shells begun with the `--login' option will source the login shell + startup files, even if the shell is not interactive + +There were lots of changes to the version of the Readline library released +along with Bash-2.03. For a complete list of the changes, read the file +CHANGES in the Bash-2.03 distribution. + +Bash-2.02 contained the following new features: + +a new version of malloc (based on the old GNU malloc code in previous + bash versions) that is more page-oriented, more conservative + with memory usage, does not `orphan' large blocks when they + are freed, is usable on 64-bit machines, and has allocation + checking turned on unconditionally +POSIX.2-style globbing character classes ([:alpha:], [:alnum:], etc.) +POSIX.2-style globbing equivalence classes +POSIX.2-style globbing collating symbols +the ksh [[...]] extended conditional command +the ksh egrep-style extended pattern matching operators +a new `printf' builtin +the ksh-like $(, &>, >|, <<<, [n]<&word-, [n]>&word- + prompt string special char translation and variable expansion + auto-export of variables in initial environment + command search finds functions before builtins + bash return builtin will exit a file sourced with `.' + builtins: cd -/-L/-P, exec -l/-c/-a, echo -e/-E, hash -d/-l/-p/-t. + export -n/-f/-p/name=value, pwd -L/-P, + read -e/-p/-a/-t/-n/-d/-s/-u, + readonly -a/-f/name=value, trap -l, set +o, + set -b/-m/-o option/-h/-p/-B/-C/-H/-P, + unset -f/-v, ulimit -m/-p/-u, + type -a/-p/-t/-f/-P, suspend -f, kill -n, + test -o optname/s1 == s2/s1 < s2/s1 > s2/-nt/-ot/-ef/-O/-G/-S + bash reads ~/.bashrc for interactive shells, $ENV for non-interactive + bash restricted shell mode is more extensive + bash allows functions and variables with the same name + brace expansion + tilde expansion + arithmetic expansion with $((...)) and `let' builtin + the `[[...]]' extended conditional command + process substitution + aliases and alias/unalias builtins + local variables in functions and `local' builtin + readline and command-line editing with programmable completion + command history and history/fc builtins + csh-like history expansion + other new bash builtins: bind, command, compgen, complete, builtin, + declare/typeset, dirs, enable, fc, help, + history, logout, popd, pushd, disown, shopt, + printf + exported functions + filename generation when using output redirection (command >a*) + POSIX.2-style globbing character classes + POSIX.2-style globbing equivalence classes + POSIX.2-style globbing collating symbols + egrep-like extended pattern matching operators + case-insensitive pattern matching and globbing + variable assignments preceding commands affect only that command, + even for builtins and functions + posix mode + redirection to /dev/fd/N, /dev/stdin, /dev/stdout, /dev/stderr, + /dev/tcp/host/port, /dev/udp/host/port + +Things sh has that bash does not: + uses variable SHACCT to do shell accounting + includes `stop' builtin (bash can use alias stop='kill -s STOP') + `newgrp' builtin + turns on job control if called as `jsh' + $TIMEOUT (like bash $TMOUT) + `^' is a synonym for `|' + new SVR4.2 sh builtins: mldmode, priv + +Implementation differences: + redirection to/from compound commands causes sh to create a subshell + bash does not allow unbalanced quotes; sh silently inserts them at EOF + bash does not mess with signal 11 + sh sets (euid, egid) to (uid, gid) if -p not supplied and uid < 100 + bash splits only the results of expansions on IFS, using POSIX.2 + field splitting rules; sh splits all words on IFS + sh does not allow MAILCHECK to be unset (?) + sh does not allow traps on SIGALRM or SIGCHLD + bash allows multiple option arguments when invoked (e.g. -x -v); + sh allows only a single option argument (`sh -x -v' attempts + to open a file named `-v', and, on SunOS 4.1.4, dumps core. + On Solaris 2.4 and earlier versions, sh goes into an infinite + loop.) + sh exits a script if any builtin fails; bash exits only if one of + the POSIX.2 `special' builtins fails + +C2) How does bash differ from the Korn shell, version ksh88? + +Things bash has or uses that ksh88 does not: + long invocation options + [-+]O invocation option + -l invocation option + `!' reserved word + arithmetic for command: for ((expr1 ; expr2; expr3 )); do list; done + arithmetic in largest machine-supported size (intmax_t) + posix mode and posix conformance + command hashing + tilde expansion for assignment statements that look like $PATH + process substitution with named pipes if /dev/fd is not available + the ${!param} indirect parameter expansion operator + the ${!param*} prefix expansion operator + the ${param:offset[:length]} parameter substring operator + the ${param/pat[/string]} parameter pattern substitution operator + variables: BASH, BASH_VERSION, BASH_VERSINFO, UID, EUID, SHLVL, + TIMEFORMAT, HISTCMD, HOSTTYPE, OSTYPE, MACHTYPE, + HISTFILESIZE, HISTIGNORE, HISTCONTROL, PROMPT_COMMAND, + IGNOREEOF, FIGNORE, INPUTRC, HOSTFILE, DIRSTACK, + PIPESTATUS, HOSTNAME, OPTERR, SHELLOPTS, GLOBIGNORE, + GROUPS, FUNCNAME, histchars, auto_resume + prompt expansion with backslash escapes and command substitution + redirection: &> (stdout and stderr), <<<, [n]<&word-, [n]>&word- + more extensive and extensible editing and programmable completion + builtins: bind, builtin, command, declare, dirs, echo -e/-E, enable, + exec -l/-c/-a, fc -s, export -n/-f/-p, hash, help, history, + jobs -x/-r/-s, kill -s/-n/-l, local, logout, popd, pushd, + read -e/-p/-a/-t/-n/-d/-s, readonly -a/-n/-f/-p, + set -o braceexpand/-o histexpand/-o interactive-comments/ + -o notify/-o physical/-o posix/-o hashall/-o onecmd/ + -h/-B/-C/-b/-H/-P, set +o, suspend, trap -l, type, + typeset -a/-F/-p, ulimit -u, umask -S, alias -p, shopt, + disown, printf, complete, compgen + `!' csh-style history expansion + POSIX.2-style globbing character classes + POSIX.2-style globbing equivalence classes + POSIX.2-style globbing collating symbols + egrep-like extended pattern matching operators + case-insensitive pattern matching and globbing + `**' arithmetic operator to do exponentiation + redirection to /dev/fd/N, /dev/stdin, /dev/stdout, /dev/stderr + arrays of unlimited size + TMOUT is default timeout for `read' and `select' + +Things ksh88 has or uses that bash does not: + tracked aliases (alias -t) + variables: ERRNO, FPATH, EDITOR, VISUAL + co-processes (|&, >&p, <&p) + weirdly-scoped functions + typeset +f to list all function names without definitions + text of command history kept in a file, not memory + builtins: alias -x, cd old new, fc -e -, newgrp, print, + read -p/-s/var?prompt, set -A/-o gmacs/ + -o bgnice/-o markdirs/-o nolog/-o trackall/-o viraw/-s, + typeset -H/-L/-R/-Z/-A/-ft/-fu/-fx/-l/-u/-t, whence + using environment to pass attributes of exported variables + arithmetic evaluation done on arguments to some builtins + reads .profile from $PWD when invoked as login shell + +Implementation differences: + ksh runs last command of a pipeline in parent shell context + bash has brace expansion by default (ksh88 compile-time option) + bash has fixed startup file for all interactive shells; ksh reads $ENV + bash has exported functions + bash command search finds functions before builtins + bash waits for all commands in pipeline to exit before returning status + emacs-mode editing has some slightly different key bindings + +C3) Which new features in ksh-93 are not in bash, and which are? + +New things in ksh-93 not in bash-2.05b: + associative arrays + floating point arithmetic and variables + math library functions + ${!name[sub]} name of subscript for associative array + `.' is allowed in variable names to create a hierarchical namespace + more extensive compound assignment syntax + discipline functions + `sleep' and `getconf' builtins (bash has loadable versions) + typeset -n and `nameref' variables + KEYBD trap + variables: .sh.edchar, .sh.edmode, .sh.edcol, .sh.edtext, .sh.version, + .sh.name, .sh.subscript, .sh.value, .sh.match, HISTEDIT + backreferences in pattern matching (\N) + `&' operator in pattern lists for matching + print -f (bash uses printf) + `fc' has been renamed to `hist' + `.' can execute shell functions + exit statuses between 0 and 255 + set -o pipefail + `+=' variable assignment operator + FPATH and PATH mixing + getopts -a + -I invocation option + DEBUG trap now executed before each simple command, instead of after + printf %H, %P, %T, %Z modifiers, output base for %d + lexical scoping for local variables in `ksh' functions + no scoping for local variables in `POSIX' functions + +New things in ksh-93 present in bash-2.05b: + [n]<&word- and [n]>&word- redirections (combination dup and close) + for (( expr1; expr2; expr3 )) ; do list; done - arithmetic for command + ?:, ++, --, `expr1 , expr2' arithmetic operators + expansions: ${!param}, ${param:offset[:len]}, ${param/pat[/str]}, + ${!param*} + compound array assignment + the `!' reserved word + loadable builtins -- but ksh uses `builtin' while bash uses `enable' + `command', `builtin', `disown' builtins + new $'...' and $"..." quoting + FIGNORE (but bash uses GLOBIGNORE), HISTCMD + set -o notify/-C + changes to kill builtin + read -A (bash uses read -a) + read -t/-d + trap -p + exec -c/-a + `.' restores the positional parameters when it completes + POSIX.2 `test' + umask -S + unalias -a + command and arithmetic substitution performed on PS1, PS4, and ENV + command name completion + ENV processed only for interactive shells + +Section D: Why does bash do some things differently than other Unix shells? + +D1) Why does bash run a different version of `command' than + `which command' says it will? + +On many systems, `which' is actually a csh script that assumes +you're running csh. In tcsh, `which' and its cousin `where' +are builtins. On other Unix systems, `which' is a perl script +that uses the PATH environment variable. + +The csh script version reads the csh startup files from your +home directory and uses those to determine which `command' will +be invoked. Since bash doesn't use any of those startup files, +there's a good chance that your bash environment differs from +your csh environment. The bash `type' builtin does everything +`which' does, and will report correct results for the running +shell. If you're really wedded to the name `which', try adding +the following function definition to your .bashrc: + + which() + { + builtin type "$@" + } + +If you're moving from tcsh and would like to bring `where' along +as well, use this function: + + where() + { + builtin type -a "$@" + } + +D2) Why doesn't bash treat brace expansions exactly like csh? + +The only difference between bash and csh brace expansion is that +bash requires a brace expression to contain at least one unquoted +comma if it is to be expanded. Any brace-surrounded word not +containing an unquoted comma is left unchanged by the brace +expansion code. This affords the greatest degree of sh +compatibility. + +Bash, ksh, zsh, and pd-ksh all implement brace expansion this way. + +D3) Why doesn't bash have csh variable modifiers? + +Posix has specified a more powerful, albeit somewhat more cryptic, +mechanism cribbed from ksh, and bash implements it. + +${parameter%word} + Remove smallest suffix pattern. The WORD is expanded to produce + a pattern. It then expands to the value of PARAMETER, with the + smallest portion of the suffix matched by the pattern deleted. + + x=file.c + echo ${x%.c}.o + -->file.o + +${parameter%%word} + + Remove largest suffix pattern. The WORD is expanded to produce + a pattern. It then expands to the value of PARAMETER, with the + largest portion of the suffix matched by the pattern deleted. + + x=posix/src/std + echo ${x%%/*} + -->posix + +${parameter#word} + Remove smallest prefix pattern. The WORD is expanded to produce + a pattern. It then expands to the value of PARAMETER, with the + smallest portion of the prefix matched by the pattern deleted. + + x=$HOME/src/cmd + echo ${x#$HOME} + -->/src/cmd + +${parameter##word} + Remove largest prefix pattern. The WORD is expanded to produce + a pattern. It then expands to the value of PARAMETER, with the + largest portion of the prefix matched by the pattern deleted. + + x=/one/two/three + echo ${x##*/} + -->three + + +Given + a=/a/b/c/d + b=b.xxx + + csh bash result + --- ---- ------ + $a:h ${a%/*} /a/b/c + $a:t ${a##*/} d + $b:r ${b%.*} b + $b:e ${b##*.} xxx + + +D4) How can I make my csh aliases work when I convert to bash? + +Bash uses a different syntax to support aliases than csh does. +The details can be found in the documentation. We have provided +a shell script which does most of the work of conversion for you; +this script can be found in ./examples/misc/aliasconv.sh. Here is +how you use it: + +Start csh in the normal way for you. (e.g., `csh') + +Pipe the output of `alias' through `aliasconv.sh', saving the +results into `bash_aliases': + + alias | bash aliasconv.sh >bash_aliases + +Edit `bash_aliases', carefully reading through any created +functions. You will need to change the names of some csh specific +variables to the bash equivalents. The script converts $cwd to +$PWD, $term to $TERM, $home to $HOME, $user to $USER, and $prompt +to $PS1. You may also have to add quotes to avoid unwanted +expansion. + +For example, the csh alias: + + alias cd 'cd \!*; echo $cwd' + +is converted to the bash function: + + cd () { command cd "$@"; echo $PWD ; } + +The only thing that needs to be done is to quote $PWD: + + cd () { command cd "$@"; echo "$PWD" ; } + +Merge the edited file into your ~/.bashrc. + +There is an additional, more ambitious, script in +examples/misc/cshtobash that attempts to convert your entire csh +environment to its bash equivalent. This script can be run as +simply `cshtobash' to convert your normal interactive +environment, or as `cshtobash ~/.login' to convert your login +environment. + +D5) How can I pipe standard output and standard error from one command to + another, like csh does with `|&'? + +Use + command 2>&1 | command2 + +The key is to remember that piping is performed before redirection, so +file descriptor 1 points to the pipe when it is duplicated onto file +descriptor 2. + +D6) Now that I've converted from ksh to bash, are there equivalents to + ksh features like autoloaded functions and the `whence' command? + +There are features in ksh-88 and ksh-93 that do not have direct bash +equivalents. Most, however, can be emulated with very little trouble. + +ksh-88 feature Bash equivalent +-------------- --------------- +compiled-in aliases set up aliases in .bashrc; some ksh aliases are + bash builtins (hash, history, type) +coprocesses named pipe pairs (one for read, one for write) +typeset +f declare -F +cd, print, whence function substitutes in examples/functions/kshenv +autoloaded functions examples/functions/autoload is the same as typeset -fu +read var?prompt read -p prompt var + +ksh-93 feature Bash equivalent +-------------- --------------- +sleep, getconf Bash has loadable versions in examples/loadables +${.sh.version} $BASH_VERSION +print -f printf +hist alias hist=fc +$HISTEDIT $FCEDIT + +Section E: How can I get bash to do certain things, and why does bash do + things the way it does? + +E1) Why is the bash builtin `test' slightly different from /bin/test? + +The specific example used here is [ ! x -o x ], which is false. + +Bash's builtin `test' implements the Posix.2 spec, which can be +summarized as follows (the wording is due to David Korn): + +Here is the set of rules for processing test arguments. + + 0 Args: False + 1 Arg: True iff argument is not null. + 2 Args: If first arg is !, True iff second argument is null. + If first argument is unary, then true if unary test is true + Otherwise error. + 3 Args: If second argument is a binary operator, do binary test of $1 $3 + If first argument is !, negate two argument test of $2 $3 + If first argument is `(' and third argument is `)', do the + one-argument test of the second argument. + Otherwise error. + 4 Args: If first argument is !, negate three argument test of $2 $3 $4. + Otherwise unspecified + 5 or more Args: unspecified. (Historical shells would use their + current algorithm). + +The operators -a and -o are considered binary operators for the purpose +of the 3 Arg case. + +As you can see, the test becomes (not (x or x)), which is false. + +E2) Why does bash sometimes say `Broken pipe'? + +If a sequence of commands appears in a pipeline, and one of the +reading commands finishes before the writer has finished, the +writer receives a SIGPIPE signal. Many other shells special-case +SIGPIPE as an exit status in the pipeline and do not report it. +For example, in: + + ps -aux | head + +`head' can finish before `ps' writes all of its output, and ps +will try to write on a pipe without a reader. In that case, bash +will print `Broken pipe' to stderr when ps is killed by a +SIGPIPE. + +You can build a version of bash that will not report SIGPIPE errors +by uncommenting the definition of DONT_REPORT_SIGPIPE in the file +config-top.h. + +E3) When I have terminal escape sequences in my prompt, why does bash + wrap lines at the wrong column? + +Readline, the line editing library that bash uses, does not know +that the terminal escape sequences do not take up space on the +screen. The redisplay code assumes, unless told otherwise, that +each character in the prompt is a `printable' character that +takes up one character position on the screen. + +You can use the bash prompt expansion facility (see the PROMPTING +section in the manual page) to tell readline that sequences of +characters in the prompt strings take up no screen space. + +Use the \[ escape to begin a sequence of non-printing characters, +and the \] escape to signal the end of such a sequence. + +E4) If I pipe the output of a command into `read variable', why doesn't + the output show up in $variable when the read command finishes? + +This has to do with the parent-child relationship between Unix +processes. It affects all commands run in pipelines, not just +simple calls to `read'. For example, piping a command's output +into a `while' loop that repeatedly calls `read' will result in +the same behavior. + +Each element of a pipeline runs in a separate process, a child of +the shell running the pipeline. A subprocess cannot affect its +parent's environment. When the `read' command sets the variable +to the input, that variable is set only in the subshell, not the +parent shell. When the subshell exits, the value of the variable +is lost. + +Many pipelines that end with `read variable' can be converted +into command substitutions, which will capture the output of +a specified command. The output can then be assigned to a +variable: + + grep ^gnu /usr/lib/news/active | wc -l | read ngroup + +can be converted into + + ngroup=$(grep ^gnu /usr/lib/news/active | wc -l) + +This does not, unfortunately, work to split the text among +multiple variables, as read does when given multiple variable +arguments. If you need to do this, you can either use the +command substitution above to read the output into a variable +and chop up the variable using the bash pattern removal +expansion operators or use some variant of the following +approach. + +Say /usr/local/bin/ipaddr is the following shell script: + +#! /bin/sh +host `hostname` | awk '/address/ {print $NF}' + +Instead of using + + /usr/local/bin/ipaddr | read A B C D + +to break the local machine's IP address into separate octets, use + + OIFS="$IFS" + IFS=. + set -- $(/usr/local/bin/ipaddr) + IFS="$OIFS" + A="$1" B="$2" C="$3" D="$4" + +Beware, however, that this will change the shell's positional +parameters. If you need them, you should save them before doing +this. + +This is the general approach -- in most cases you will not need to +set $IFS to a different value. + +Some other user-supplied alternatives include: + +read A B C D << HERE + $(IFS=.; echo $(/usr/local/bin/ipaddr)) +HERE + +and, where process substitution is available, + +read A B C D < <(IFS=.; echo $(/usr/local/bin/ipaddr)) + +E5) I have a bunch of shell scripts that use backslash-escaped characters + in arguments to `echo'. Bash doesn't interpret these characters. Why + not, and how can I make it understand them? + +This is the behavior of echo on most Unix System V machines. + +The bash builtin `echo' is modeled after the 9th Edition +Research Unix version of `echo'. It does not interpret +backslash-escaped characters in its argument strings by default; +it requires the use of the -e option to enable the +interpretation. The System V echo provides no way to disable the +special characters; the bash echo has a -E option to disable +them. + +There is a configuration option that will make bash behave like +the System V echo and interpret things like `\t' by default. Run +configure with the --enable-xpg-echo-default option to turn this +on. Be aware that this will cause some of the tests run when you +type `make tests' to fail. + +There is a shell option, `xpg_echo', settable with `shopt', that will +change the behavior of echo at runtime. Enabling this option turns +on expansion of backslash-escape sequences. + +E6) Why doesn't a while or for loop get suspended when I type ^Z? + +This is a consequence of how job control works on Unix. The only +thing that can be suspended is the process group. This is a single +command or pipeline of commands that the shell forks and executes. + +When you run a while or for loop, the only thing that the shell forks +and executes are any commands in the while loop test and commands in +the loop bodies. These, therefore, are the only things that can be +suspended when you type ^Z. + +If you want to be able to stop the entire loop, you need to put it +within parentheses, which will force the loop into a subshell that +may be stopped (and subsequently restarted) as a single unit. + +E7) What about empty for loops in Makefiles? + +It's fairly common to see constructs like this in automatically-generated +Makefiles: + +SUBDIRS = @SUBDIRS@ + + ... + +subdirs-clean: + for d in ${SUBDIRS}; do \ + ( cd $$d && ${MAKE} ${MFLAGS} clean ) \ + done + +When SUBDIRS is empty, this results in a command like this being passed to +bash: + + for d in ; do + ( cd $d && ${MAKE} ${MFLAGS} clean ) + done + +In versions of bash before bash-2.05a, this was a syntax error. If the +reserved word `in' was present, a word must follow it before the semicolon +or newline. The language in the manual page referring to the list of words +being empty referred to the list after it is expanded. These versions of +bash required that there be at least one word following the `in' when the +construct was parsed. + +The idiomatic Makefile solution is something like: + +SUBDIRS = @SUBDIRS@ + +subdirs-clean: + subdirs=$SUBDIRS ; for d in $$subdirs; do \ + ( cd $$d && ${MAKE} ${MFLAGS} clean ) \ + done + +The latest drafts of the updated POSIX standard have changed this: the +word list is no longer required. Bash versions 2.05a and later accept +the new syntax. + +E8) Why does the arithmetic evaluation code complain about `08'? + +The bash arithmetic evaluation code (used for `let', $(()), (()), and in +other places), interprets a leading `0' in numeric constants as denoting +an octal number, and a leading `0x' as denoting hexadecimal. This is +in accordance with the POSIX.2 spec, section 2.9.2.1, which states that +arithmetic constants should be handled as signed long integers as defined +by the ANSI/ISO C standard. + +The POSIX.2 interpretation committee has confirmed this: + +http://www.pasc.org/interps/unofficial/db/p1003.2/pasc-1003.2-173.html + +E9) Why does the pattern matching expression [A-Z]* match files beginning + with every letter except `z'? + +Bash-2.03, Bash-2.05 and later versions honor the current locale setting +when processing ranges within pattern matching bracket expressions ([A-Z]). +This is what POSIX.2 and SUSv3/XPG6 specify. + +The behavior of the matcher in bash-2.05 and later versions depends on the +current LC_COLLATE setting. Setting this variable to `C' or `POSIX' will +result in the traditional behavior ([A-Z] matches all uppercase ASCII +characters). Many other locales, including the en_US locale (the default +on many US versions of Linux) collate the upper and lower case letters like +this: + + AaBb...Zz + +which means that [A-Z] matches every letter except `z'. Others collate like + + aAbBcC...zZ + +which means that [A-Z] matches every letter except `a'. + +The portable way to specify upper case letters is [:upper:] instead of +A-Z; lower case may be specified as [:lower:] instead of a-z. + +Look at the manual pages for setlocale(3), strcoll(3), and, if it is +present, locale(1). If you have locale(1), you can use it to find +your current locale information even if you do not have any of the +LC_ variables set. + +My advice is to put + + export LC_COLLATE=C + +into /etc/profile and inspect any shell scripts run from cron for +constructs like [A-Z]. This will prevent things like + + rm [A-Z]* + +from removing every file in the current directory except those beginning +with `z' and still allow individual users to change the collation order. +Users may put the above command into their own profiles as well, of course. + +E10) Why does `cd //' leave $PWD as `//'? + +POSIX.2, in its description of `cd', says that *three* or more leading +slashes may be replaced with a single slash when canonicalizing the +current working directory. + +This is, I presume, for historical compatibility. Certain versions of +Unix, and early network file systems, used paths of the form +//hostname/path to access `path' on server `hostname'. + +E11) If I resize my xterm while another program is running, why doesn't bash + notice the change? + +This is another issue that deals with job control. + +The kernel maintains a notion of a current terminal process group. Members +of this process group (processes whose process group ID is equal to the +current terminal process group ID) receive terminal-generated signals like +SIGWINCH. (For more details, see the JOB CONTROL section of the bash +man page.) + +If a terminal is resized, the kernel sends SIGWINCH to each member of +the terminal's current process group (the `foreground' process group). + +When bash is running with job control enabled, each pipeline (which may be +a single command) is run in its own process group, different from bash's +process group. This foreground process group receives the SIGWINCH; bash +does not. Bash has no way of knowing that the terminal has been resized. + +There is a `checkwinsize' option, settable with the `shopt' builtin, that +will cause bash to check the window size and adjust its idea of the +terminal's dimensions each time a process stops or exits and returns control +of the terminal to bash. Enable it with `shopt -s checkwinsize'. + +Section F: Things to watch out for on certain Unix versions + +F1) Why can't I use command line editing in my `cmdtool'? + +The problem is `cmdtool' and bash fighting over the input. When +scrolling is enabled in a cmdtool window, cmdtool puts the tty in +`raw mode' to permit command-line editing using the mouse for +applications that cannot do it themselves. As a result, bash and +cmdtool each try to read keyboard input immediately, with neither +getting enough of it to be useful. + +This mode also causes cmdtool to not implement many of the +terminal functions and control sequences appearing in the +`sun-cmd' termcap entry. For a more complete explanation, see +that file examples/suncmd.termcap in the bash distribution. + +`xterm' is a better choice, and gets along with bash much more +smoothly. + +If you must use cmdtool, you can use the termcap description in +examples/suncmd.termcap. Set the TERMCAP variable to the terminal +description contained in that file, i.e. + +TERMCAP='Mu|sun-cmd:am:bs:km:pt:li#34:co#80:cl=^L:ce=\E[K:cd=\E[J:rs=\E[s:' + +Then export TERMCAP and start a new cmdtool window from that shell. +The bash command-line editing should behave better in the new +cmdtool. If this works, you can put the assignment to TERMCAP +in your bashrc file. + +F2) I built bash on Solaris 2. Why do globbing expansions and filename + completion chop off the first few characters of each filename? + +This is the consequence of building bash on SunOS 5 and linking +with the libraries in /usr/ucblib, but using the definitions +and structures from files in /usr/include. + +The actual conflict is between the dirent structure in +/usr/include/dirent.h and the struct returned by the version of +`readdir' in libucb.a (a 4.3-BSD style `struct direct'). + +Make sure you've got /usr/ccs/bin ahead of /usr/ucb in your $PATH +when configuring and building bash. This will ensure that you +use /usr/ccs/bin/cc or acc instead of /usr/ucb/cc and that you +link with libc before libucb. + +If you have installed the Sun C compiler, you may also need to +put /usr/ccs/bin and /opt/SUNWspro/bin into your $PATH before +/usr/ucb. + +F3) Why does bash dump core after I interrupt username completion or + `~user' tilde expansion on a machine running NIS? + +This is a famous and long-standing bug in the SunOS YP (sorry, NIS) +client library, which is part of libc. + +The YP library code keeps static state -- a pointer into the data +returned from the server. When YP initializes itself (setpwent), +it looks at this pointer and calls free on it if it's non-null. +So far, so good. + +If one of the YP functions is interrupted during getpwent (the +exact function is interpretwithsave()), and returns NULL, the +pointer is freed without being reset to NULL, and the function +returns. The next time getpwent is called, it sees that this +pointer is non-null, calls free, and the bash free() blows up +because it's being asked to free freed memory. + +The traditional Unix mallocs allow memory to be freed multiple +times; that's probably why this has never been fixed. You can +run configure with the `--without-gnu-malloc' option to use +the C library malloc and avoid the problem. + +F4) I'm running SVR4.2. Why is the line erased every time I type `@'? + +The `@' character is the default `line kill' character in most +versions of System V, including SVR4.2. You can change this +character to whatever you want using `stty'. For example, to +change the line kill character to control-u, type + + stty kill ^U + +where the `^' and `U' can be two separate characters. + +F5) Why does bash report syntax errors when my C News scripts use a + redirection before a subshell command? + +The actual command in question is something like + + < file ( command ) + +According to the grammar given in the POSIX.2 standard, this construct +is, in fact, a syntax error. Redirections may only precede `simple +commands'. A subshell construct such as the above is one of the shell's +`compound commands'. A redirection may only follow a compound command. + +This affects the mechanical transformation of commands that use `cat' +to pipe a file into a command (a favorite Useless-Use-Of-Cat topic on +comp.unix.shell). While most commands of the form + + cat file | command + +can be converted to `< file command', shell control structures such as +loops and subshells require `command < file'. + +The file CWRU/sh-redir-hack in the bash-2.05a distribution is an +(unofficial) patch to parse.y that will modify the grammar to +support this construct. It will not apply with `patch'; you must +modify parse.y by hand. Note that if you apply this, you must +recompile with -DREDIRECTION_HACK. This introduces a large +number of reduce/reduce conflicts into the shell grammar. + +F6) Why can't I use vi-mode editing on Red Hat Linux 6.1? + +The short answer is that Red Hat screwed up. + +The long answer is that they shipped an /etc/inputrc that only works +for emacs mode editing, and then screwed all the vi users by setting +INPUTRC to /etc/inputrc in /etc/profile. + +The short fix is to do one of the following: remove or rename +/etc/inputrc, set INPUTRC=~/.inputrc in ~/.bashrc (or .bash_profile, +but make sure you export it if you do), remove the assignment to +INPUTRC from /etc/profile, add + + set keymap emacs + +to the beginning of /etc/inputrc, or bracket the key bindings in +/etc/inputrc with these lines + + $if mode=emacs + [...] + $endif + +F7) Why do bash-2.05a and bash-2.05b fail to compile `printf.def' on + HP/UX 11.x? + +HP/UX's support for long double is imperfect at best. + +GCC will support it without problems, but the HP C library functions +like strtold(3) and printf(3) don't actually work with long doubles. +HP implemented a `long_double' type as a 4-element array of 32-bit +ints, and that is what the library functions use. The ANSI C +`long double' type is a 128-bit floating point scalar. + +The easiest fix, until HP fixes things up, is to edit the generated +config.h and #undef the HAVE_LONG_DOUBLE line. After doing that, +the compilation should complete successfully. + +Section G: How can I get bash to do certain common things? + +G1) How can I get bash to read and display eight-bit characters? + +This is a process requiring several steps. + +First, you must ensure that the `physical' data path is a full eight +bits. For xterms, for example, the `vt100' resources `eightBitInput' +and `eightBitOutput' should be set to `true'. + +Once you have set up an eight-bit path, you must tell the kernel and +tty driver to leave the eighth bit of characters alone when processing +keyboard input. Use `stty' to do this: + + stty cs8 -istrip -parenb + +For old BSD-style systems, you can use + + stty pass8 + +You may also need + + stty even odd + +Finally, you need to tell readline that you will be inputting and +displaying eight-bit characters. You use readline variables to do +this. These variables can be set in your .inputrc or using the bash +`bind' builtin. Here's an example using `bind': + + bash$ bind 'set convert-meta off' + bash$ bind 'set meta-flag on' + bash$ bind 'set output-meta on' + +The `set' commands between the single quotes may also be placed +in ~/.inputrc. + +G2) How do I write a function `x' to replace builtin command `x', but + still invoke the command from within the function? + +This is why the `command' and `builtin' builtins exist. The +`command' builtin executes the command supplied as its first +argument, skipping over any function defined with that name. The +`builtin' builtin executes the builtin command given as its first +argument directly. + +For example, to write a function to replace `cd' that writes the +hostname and current directory to an xterm title bar, use +something like the following: + + cd() + { + builtin cd "$@" && xtitle "$HOST: $PWD" + } + +This could also be written using `command' instead of `builtin'; +the version above is marginally more efficient. + +G3) How can I find the value of a shell variable whose name is the value + of another shell variable? + +Versions of Bash newer than Bash-2.0 support this directly. You can use + + ${!var} + +For example, the following sequence of commands will echo `z': + + var1=var2 + var2=z + echo ${!var1} + +For sh compatibility, use the `eval' builtin. The important +thing to remember is that `eval' expands the arguments you give +it again, so you need to quote the parts of the arguments that +you want `eval' to act on. + +For example, this expression prints the value of the last positional +parameter: + + eval echo \"\$\{$#\}\" + +The expansion of the quoted portions of this expression will be +deferred until `eval' runs, while the `$#' will be expanded +before `eval' is executed. In versions of bash later than bash-2.0, + + echo ${!#} + +does the same thing. + +This is not the same thing as ksh93 `nameref' variables, though the syntax +is similar. I may add namerefs in a future bash version. + +G4) How can I make the bash `time' reserved word print timing output that + looks like the output from my system's /usr/bin/time? + +The bash command timing code looks for a variable `TIMEFORMAT' and +uses its value as a format string to decide how to display the +timing statistics. + +The value of TIMEFORMAT is a string with `%' escapes expanded in a +fashion similar in spirit to printf(3). The manual page explains +the meanings of the escape sequences in the format string. + +If TIMEFORMAT is not set, bash acts as if the following assignment had +been performed: + + TIMEFORMAT=$'\nreal\t%3lR\nuser\t%3lU\nsys\t%3lS' + +The POSIX.2 default time format (used by `time -p command') is + + TIMEFORMAT=$'real %2R\nuser %2U\nsys %2S' + +The BSD /usr/bin/time format can be emulated with: + + TIMEFORMAT=$'\t%1R real\t%1U user\t%1S sys' + +The System V /usr/bin/time format can be emulated with: + + TIMEFORMAT=$'\nreal\t%1R\nuser\t%1U\nsys\t%1S' + +The ksh format can be emulated with: + + TIMEFORMAT=$'\nreal\t%2lR\nuser\t%2lU\nsys\t%2lS' + +G5) How do I get the current directory into my prompt? + +Bash provides a number of backslash-escape sequences which are expanded +when the prompt string (PS1 or PS2) is displayed. The full list is in +the manual page. + +The \w expansion gives the full pathname of the current directory, with +a tilde (`~') substituted for the current value of $HOME. The \W +expansion gives the basename of the current directory. To put the full +pathname of the current directory into the path without any tilde +subsitution, use $PWD. Here are some examples: + + PS1='\w$ ' # current directory with tilde + PS1='\W$ ' # basename of current directory + PS1='$PWD$ ' # full pathname of current directory + +The single quotes are important in the final example to prevent $PWD from +being expanded when the assignment to PS1 is performed. + +G6) How can I rename "*.foo" to "*.bar"? + +Use the pattern removal functionality described in D3. The following `for' +loop will do the trick: + + for f in *.foo; do + mv $f ${f%foo}bar + done + +G7) How can I translate a filename from uppercase to lowercase? + +The script examples/functions/lowercase, originally written by John DuBois, +will do the trick. The converse is left as an exercise. + +G8) How can I write a filename expansion (globbing) pattern that will match + all files in the current directory except "." and ".."? + +You must have set the `extglob' shell option using `shopt -s extglob' to use +this: + + echo .!(.|) * + +A solution that works without extended globbing is given in the Unix Shell +FAQ, posted periodically to comp.unix.shell. + +Section H: Where do I go from here? + +H1) How do I report bugs in bash, and where should I look for fixes and + advice? + +Use the `bashbug' script to report bugs. It is built and +installed at the same time as bash. It provides a standard +template for reporting a problem and automatically includes +information about your configuration and build environment. + +`bashbug' sends its reports to bug-bash@gnu.org, which +is a large mailing list gatewayed to the usenet newsgroup gnu.bash.bug. + +Bug fixes, answers to questions, and announcements of new releases +are all posted to gnu.bash.bug. Discussions concerning bash features +and problems also take place there. + +To reach the bash maintainers directly, send mail to +bash-maintainers@gnu.org. + +H2) What kind of bash documentation is there? + +First, look in the doc directory in the bash distribution. It should +contain at least the following files: + +bash.1 an extensive, thorough Unix-style manual page +builtins.1 a manual page covering just bash builtin commands +bashref.texi a reference manual in GNU tex`info format +bashref.info an info version of the reference manual +FAQ this file +article.ms text of an article written for The Linux Journal +readline.3 a man page describing readline + +Postscript, HTML, and ASCII files created from the above source are +available in the documentation distribution. + +There is additional documentation available for anonymous FTP from host +ftp.cwru.edu in the `pub/bash' directory. + +Cameron Newham and Bill Rosenblatt have written a book on bash, published +by O'Reilly and Associates. The book is based on Bill Rosenblatt's Korn +Shell book. The title is ``Learning the Bash Shell'', and the ISBN number +is 1-56592-147-X. Look for it in fine bookstores near you. This book +covers bash-1.14, but has an appendix describing some of the new features +in bash-2.0. + +A second edition of this book is available, published in January, 1998. +The ISBN number is 1-56592-347-2. Look for it in the same fine bookstores +or on the web. + +The GNU Bash Reference Manual has been published as a printed book by +Network Theory Ltd (Paperback, ISBN: 0-9541617-7-7, Feb 2003). It covers +bash-2.0 and is available from most online bookstores (see +http://www.network-theory.co.uk/bash/manual/ for details). The publisher +will donate $1 to the Free Software Foundation for each copy sold. + +H3) What's coming in future versions? + +These are features I hope to include in a future version of bash. + +a better bash debugger (a minimally-tested version is included with bash-2.05b) +associative arrays +co-processes, but with a new-style syntax that looks like function declaration + +H4) What's on the bash `wish list' for future versions? + +These are features that may or may not appear in a future version of bash. + +breaking some of the shell functionality into embeddable libraries +a module system like zsh's, using dynamic loading like builtins +better internationalization using GNU `gettext' +date-stamped command history +a bash programmer's guide with a chapter on creating loadable builtins +a better loadable interface to perl with access to the shell builtins and + variables (contributions gratefully accepted) +ksh93-like `nameref' variables +ksh93-like `+=' variable assignment operator +ksh93-like `xx.yy' variables (including some of the .sh.* variables) and + associated disipline functions +Some of the new ksh93 pattern matching operators, like backreferencing + +H5) When will the next release appear? + +The next version will appear sometime in 2002. Never make predictions. + + +This document is Copyright 1995-2003 by Chester Ramey. + +Permission is hereby granted, without written agreement and +without license or royalty fees, to use, copy, and distribute +this document for any purpose, provided that the above copyright +notice appears in all copies of this document and that the +contents of this document remain unaltered. diff --git a/doc/aosa-bash.pdf.old b/doc/aosa-bash.pdf.old new file mode 100644 index 000000000..006a76776 Binary files /dev/null and b/doc/aosa-bash.pdf.old differ diff --git a/doc/bash.1 b/doc/bash.1 index 7e6e50bd7..a095da9f1 100644 --- a/doc/bash.1 +++ b/doc/bash.1 @@ -5,12 +5,12 @@ .\" Case Western Reserve University .\" chet.ramey@case.edu .\" -.\" Last Change: Fri Nov 28 18:21:13 EST 2014 +.\" Last Change: Sat Dec 20 13:51:56 EST 2014 .\" .\" bash_builtins, strip all but Built-Ins section .if \n(zZ=1 .ig zZ .if \n(zY=1 .ig zY -.TH BASH 1 "2014 November 28" "GNU Bash 4.3" +.TH BASH 1 "2014 December 20" "GNU Bash 4.3" .\" .\" There's some problem with having a `@' .\" in a tagged paragraph with the BSD man macros. @@ -2815,12 +2815,16 @@ The \fIparameter\fP is a shell parameter as described above .PD .PP If the first character of \fIparameter\fP is an exclamation point (\fB!\fP), +and \fIparameter\fP is not a \fInameref\fP, it introduces a level of variable indirection. \fBBash\fP uses the value of the variable formed from the rest of \fIparameter\fP as the name of the variable; this variable is then expanded and that value is used in the rest of the substitution, rather than the value of \fIparameter\fP itself. This is known as \fIindirect expansion\fP. +If \fIparameter\fP is a nameref, this expands to the name of the +variable referenced by \fIparameter\fP instead of performing the +complete indirect expansion. The exceptions to this are the expansions of ${\fB!\fP\fIprefix\fP\fB*\fP} and ${\fB!\fP\fIname\fP[\fI@\fP]} described below. The exclamation point must immediately follow the left brace in order to diff --git a/doc/bash.1~ b/doc/bash.1~ new file mode 100644 index 000000000..7e6e50bd7 --- /dev/null +++ b/doc/bash.1~ @@ -0,0 +1,10471 @@ +.\" +.\" MAN PAGE COMMENTS to +.\" +.\" Chet Ramey +.\" Case Western Reserve University +.\" chet.ramey@case.edu +.\" +.\" Last Change: Fri Nov 28 18:21:13 EST 2014 +.\" +.\" bash_builtins, strip all but Built-Ins section +.if \n(zZ=1 .ig zZ +.if \n(zY=1 .ig zY +.TH BASH 1 "2014 November 28" "GNU Bash 4.3" +.\" +.\" There's some problem with having a `@' +.\" in a tagged paragraph with the BSD man macros. +.\" It has to do with `@' appearing in the }1 macro. +.\" This is a problem on 4.3 BSD and Ultrix, but Sun +.\" appears to have fixed it. +.\" If you're seeing the characters +.\" `@u-3p' appearing before the lines reading +.\" `possible-hostname-completions +.\" and `complete-hostname' down in READLINE, +.\" then uncomment this redefinition. +.\" +.de }1 +.ds ]X \&\\*(]B\\ +.nr )E 0 +.if !"\\$1"" .nr )I \\$1n +.}f +.ll \\n(LLu +.in \\n()Ru+\\n(INu+\\n()Iu +.ti \\n(INu +.ie !\\n()Iu+\\n()Ru-\w\\*(]Xu-3p \{\\*(]X +.br\} +.el \\*(]X\h|\\n()Iu+\\n()Ru\c +.}f +.. +.\" +.\" File Name macro. This used to be `.PN', for Path Name, +.\" but Sun doesn't seem to like that very much. +.\" +.de FN +\fI\|\\$1\|\fP +.. +.SH NAME +bash \- GNU Bourne-Again SHell +.SH SYNOPSIS +.B bash +[options] +[command_string | file] +.SH COPYRIGHT +.if n Bash is Copyright (C) 1989-2014 by the Free Software Foundation, Inc. +.if t Bash is Copyright \(co 1989-2014 by the Free Software Foundation, Inc. +.SH DESCRIPTION +.B Bash +is an \fBsh\fR-compatible command language interpreter that +executes commands read from the standard input or from a file. +.B Bash +also incorporates useful features from the \fIKorn\fP and \fIC\fP +shells (\fBksh\fP and \fBcsh\fP). +.PP +.B Bash +is intended to be a conformant implementation of the +Shell and Utilities portion of the IEEE POSIX specification +(IEEE Standard 1003.1). +.B Bash +can be configured to be POSIX-conformant by default. +.SH OPTIONS +All of the single-character shell options documented in the +description of the \fBset\fR builtin command can be used as options +when the shell is invoked. +In addition, \fBbash\fR +interprets the following options when it is invoked: +.PP +.PD 0 +.TP 10 +.B \-c +If the +.B \-c +option is present, then commands are read from the first non-option argument +.IR command_string . +If there are arguments after the +.IR command_string , +the first argument is assigned to +.B $0 +and any remaining arguments are assigned to the positional parameters. +The assignment to +.B $0 +sets the name of the shell, which is used in warning and error messages. +.TP +.B \-i +If the +.B \-i +option is present, the shell is +.IR interactive . +.TP +.B \-l +Make +.B bash +act as if it had been invoked as a login shell (see +.SM +.B INVOCATION +below). +.TP +.B \-r +If the +.B \-r +option is present, the shell becomes +.I restricted +(see +.SM +.B "RESTRICTED SHELL" +below). +.TP +.B \-s +If the +.B \-s +option is present, or if no arguments remain after option +processing, then commands are read from the standard input. +This option allows the positional parameters to be set +when invoking an interactive shell. +.TP +.B \-D +A list of all double-quoted strings preceded by \fB$\fP +is printed on the standard output. +These are the strings that +are subject to language translation when the current locale +is not \fBC\fP or \fBPOSIX\fP. +This implies the \fB\-n\fP option; no commands will be executed. +.TP +.B [\-+]O [\fIshopt_option\fP] +\fIshopt_option\fP is one of the shell options accepted by the +\fBshopt\fP builtin (see +.SM +.B SHELL BUILTIN COMMANDS +below). +If \fIshopt_option\fP is present, \fB\-O\fP sets the value of that option; +\fB+O\fP unsets it. +If \fIshopt_option\fP is not supplied, the names and values of the shell +options accepted by \fBshopt\fP are printed on the standard output. +If the invocation option is \fB+O\fP, the output is displayed in a format +that may be reused as input. +.TP +.B \-\- +A +.B \-\- +signals the end of options and disables further option processing. +Any arguments after the +.B \-\- +are treated as filenames and arguments. An argument of +.B \- +is equivalent to \fB\-\-\fP. +.PD +.PP +.B Bash +also interprets a number of multi-character options. +These options must appear on the command line before the +single-character options to be recognized. +.PP +.PD 0 +.TP +.B \-\-debugger +Arrange for the debugger profile to be executed before the shell +starts. +Turns on extended debugging mode (see the description of the +.B extdebug +option to the +.B shopt +builtin below). +.TP +.B \-\-dump\-po\-strings +Equivalent to \fB\-D\fP, but the output is in the GNU \fIgettext\fP +\fBpo\fP (portable object) file format. +.TP +.B \-\-dump\-strings +Equivalent to \fB\-D\fP. +.TP +.B \-\-help +Display a usage message on standard output and exit successfully. +.TP +\fB\-\-init\-file\fP \fIfile\fP +.PD 0 +.TP +\fB\-\-rcfile\fP \fIfile\fP +.PD +Execute commands from +.I file +instead of the standard personal initialization file +.I ~/.bashrc +if the shell is interactive (see +.SM +.B INVOCATION +below). +.TP +.B \-\-login +Equivalent to \fB\-l\fP. +.TP +.B \-\-noediting +Do not use the GNU +.B readline +library to read command lines when the shell is interactive. +.TP +.B \-\-noprofile +Do not read either the system-wide startup file +.FN /etc/profile +or any of the personal initialization files +.IR ~/.bash_profile , +.IR ~/.bash_login , +or +.IR ~/.profile . +By default, +.B bash +reads these files when it is invoked as a login shell (see +.SM +.B INVOCATION +below). +.TP +.B \-\-norc +Do not read and execute the personal initialization file +.I ~/.bashrc +if the shell is interactive. +This option is on by default if the shell is invoked as +.BR sh . +.TP +.B \-\-posix +Change the behavior of \fBbash\fP where the default operation differs +from the POSIX standard to match the standard (\fIposix mode\fP). +See +.SM +.B "SEE ALSO" +below for a reference to a document that details how posix mode affects +bash's behavior. +.TP +.B \-\-restricted +The shell becomes restricted (see +.SM +.B "RESTRICTED SHELL" +below). +.TP +.B \-\-verbose +Equivalent to \fB\-v\fP. +.TP +.B \-\-version +Show version information for this instance of +.B bash +on the standard output and exit successfully. +.PD +.SH ARGUMENTS +If arguments remain after option processing, and neither the +.B \-c +nor the +.B \-s +option has been supplied, the first argument is assumed to +be the name of a file containing shell commands. +If +.B bash +is invoked in this fashion, +.B $0 +is set to the name of the file, and the positional parameters +are set to the remaining arguments. +.B Bash +reads and executes commands from this file, then exits. +\fBBash\fP's exit status is the exit status of the last command +executed in the script. +If no commands are executed, the exit status is 0. +An attempt is first made to open the file in the current directory, and, +if no file is found, then the shell searches the directories in +.SM +.B PATH +for the script. +.SH INVOCATION +A \fIlogin shell\fP is one whose first character of argument zero is a +.BR \- , +or one started with the +.B \-\-login +option. +.PP +An \fIinteractive\fP shell is one started without non-option arguments +and without the +.B \-c +option +whose standard input and error are +both connected to terminals (as determined by +.IR isatty (3)), +or one started with the +.B \-i +option. +.SM +.B PS1 +is set and +.B $\- +includes +.B i +if +.B bash +is interactive, +allowing a shell script or a startup file to test this state. +.PP +The following paragraphs describe how +.B bash +executes its startup files. +If any of the files exist but cannot be read, +.B bash +reports an error. +Tildes are expanded in filenames as described below under +.B "Tilde Expansion" +in the +.SM +.B EXPANSION +section. +.PP +When +.B bash +is invoked as an interactive login shell, or as a non-interactive shell +with the \fB\-\-login\fP option, it first reads and +executes commands from the file \fI/etc/profile\fP, if that +file exists. +After reading that file, it looks for \fI~/.bash_profile\fP, +\fI~/.bash_login\fP, and \fI~/.profile\fP, in that order, and reads +and executes commands from the first one that exists and is readable. +The +.B \-\-noprofile +option may be used when the shell is started to inhibit this behavior. +.PP +When a login shell exits, +.B bash +reads and executes commands from the file \fI~/.bash_logout\fP, if it +exists. +.PP +When an interactive shell that is not a login shell is started, +.B bash +reads and executes commands from \fI~/.bashrc\fP, if that file exists. +This may be inhibited by using the +.B \-\-norc +option. +The \fB\-\-rcfile\fP \fIfile\fP option will force +.B bash +to read and execute commands from \fIfile\fP instead of \fI~/.bashrc\fP. +.PP +When +.B bash +is started non-interactively, to run a shell script, for example, it +looks for the variable +.SM +.B BASH_ENV +in the environment, expands its value if it appears there, and uses the +expanded value as the name of a file to read and execute. +.B Bash +behaves as if the following command were executed: +.sp .5 +.RS +.if t \f(CWif [ \-n "$BASH_ENV" ]; then . "$BASH_ENV"; fi\fP +.if n if [ \-n "$BASH_ENV" ]; then . "$BASH_ENV"; fi +.RE +.sp .5 +but the value of the +.SM +.B PATH +variable is not used to search for the filename. +.PP +If +.B bash +is invoked with the name +.BR sh , +it tries to mimic the startup behavior of historical versions of +.B sh +as closely as possible, +while conforming to the POSIX standard as well. +When invoked as an interactive login shell, or a non-interactive +shell with the \fB\-\-login\fP option, it first attempts to +read and execute commands from +.I /etc/profile +and +.IR ~/.profile , +in that order. +The +.B \-\-noprofile +option may be used to inhibit this behavior. +When invoked as an interactive shell with the name +.BR sh , +.B bash +looks for the variable +.SM +.BR ENV , +expands its value if it is defined, and uses the +expanded value as the name of a file to read and execute. +Since a shell invoked as +.B sh +does not attempt to read and execute commands from any other startup +files, the +.B \-\-rcfile +option has no effect. +A non-interactive shell invoked with the name +.B sh +does not attempt to read any other startup files. +When invoked as +.BR sh , +.B bash +enters +.I posix +mode after the startup files are read. +.PP +When +.B bash +is started in +.I posix +mode, as with the +.B \-\-posix +command line option, it follows the POSIX standard for startup files. +In this mode, interactive shells expand the +.SM +.B ENV +variable and commands are read and executed from the file +whose name is the expanded value. +No other startup files are read. +.PP +.B Bash +attempts to determine when it is being run with its standard input +connected to a network connection, as when executed by the remote shell +daemon, usually \fIrshd\fP, or the secure shell daemon \fIsshd\fP. +If +.B bash +determines it is being run in this fashion, it reads and executes +commands from \fI~/.bashrc\fP, if that file exists and is readable. +It will not do this if invoked as \fBsh\fP. +The +.B \-\-norc +option may be used to inhibit this behavior, and the +.B \-\-rcfile +option may be used to force another file to be read, but neither +\fIrshd\fP nor \fIsshd\fP generally invoke the shell with those options +or allow them to be specified. +.PP +If the shell is started with the effective user (group) id not equal to the +real user (group) id, and the \fB\-p\fP option is not supplied, no startup +files are read, shell functions are not inherited from the environment, the +.SM +.BR SHELLOPTS , +.SM +.BR BASHOPTS , +.SM +.BR CDPATH , +and +.SM +.B GLOBIGNORE +variables, if they appear in the environment, are ignored, +and the effective user id is set to the real user id. +If the \fB\-p\fP option is supplied at invocation, the startup behavior is +the same, but the effective user id is not reset. +.SH DEFINITIONS +.PP +The following definitions are used throughout the rest of this +document. +.PD 0 +.TP +.B blank +A space or tab. +.TP +.B word +A sequence of characters considered as a single unit by the shell. +Also known as a +.BR token . +.TP +.B name +A +.I word +consisting only of alphanumeric characters and underscores, and +beginning with an alphabetic character or an underscore. Also +referred to as an +.BR identifier . +.TP +.B metacharacter +A character that, when unquoted, separates words. One of the following: +.br +.RS +.PP +.if t \fB| & ; ( ) < > space tab\fP +.if n \fB| & ; ( ) < > space tab\fP +.RE +.PP +.TP +.B control operator +A \fItoken\fP that performs a control function. It is one of the following +symbols: +.RS +.PP +.if t \fB|| & && ; ;; ( ) | |& \fP +.if n \fB|| & && ; ;; ( ) | |& \fP +.RE +.PD +.SH "RESERVED WORDS" +\fIReserved words\fP are words that have a special meaning to the shell. +The following words are recognized as reserved when unquoted and either +the first word of a simple command (see +.SM +.B SHELL GRAMMAR +below) or the third word of a +.B case +or +.B for +command: +.if t .RS +.PP +.B +.if n ! case coproc do done elif else esac fi for function if in select then until while { } time [[ ]] +.if t ! case coproc do done elif else esac fi for function if in select then until while { } time [[ ]] +.if t .RE +.SH "SHELL GRAMMAR" +.SS Simple Commands +.PP +A \fIsimple command\fP is a sequence of optional variable assignments +followed by \fBblank\fP-separated words and redirections, and +terminated by a \fIcontrol operator\fP. The first word +specifies the command to be executed, and is passed as argument zero. +The remaining words are passed as arguments to the invoked command. +.PP +The return value of a \fIsimple command\fP is its exit status, or +128+\fIn\^\fP if the command is terminated by signal +.IR n . +.SS Pipelines +.PP +A \fIpipeline\fP is a sequence of one or more commands separated by +one of the control operators +.B | +or \fB|&\fP. +The format for a pipeline is: +.RS +.PP +[\fBtime\fP [\fB\-p\fP]] [ ! ] \fIcommand\fP [ [\fB|\fP\(bv\fB|&\fP] \fIcommand2\fP ... ] +.RE +.PP +The standard output of +.I command +is connected via a pipe to the standard input of +.IR command2 . +This connection is performed before any redirections specified by the +command (see +.SM +.B REDIRECTION +below). +If \fB|&\fP is used, \fIcommand\fP's standard error, in addition to its +standard output, is connected to +\fIcommand2\fP's standard input through the pipe; +it is shorthand for \fB2>&1 |\fP. +This implicit redirection of the standard error to the standard output is +performed after any redirections specified by the command. +.PP +The return status of a pipeline is the exit status of the last +command, unless the \fBpipefail\fP option is enabled. +If \fBpipefail\fP is enabled, the pipeline's return status is the +value of the last (rightmost) command to exit with a non-zero status, +or zero if all commands exit successfully. +If the reserved word +.B ! +precedes a pipeline, the exit status of that pipeline is the logical +negation of the exit status as described above. +The shell waits for all commands in the pipeline to +terminate before returning a value. +.PP +If the +.B time +reserved word precedes a pipeline, the elapsed as well as user and +system time consumed by its execution are reported when the pipeline +terminates. +The \fB\-p\fP option changes the output format to that specified by POSIX. +When the shell is in \fIposix mode\fP, it does not recognize +\fBtime\fP as a reserved word if the next token begins with a `-'. +The +.SM +.B TIMEFORMAT +variable may be set to a format string that specifies how the timing +information should be displayed; see the description of +.SM +.B TIMEFORMAT +under +.B "Shell Variables" +below. +.PP +When the shell is in \fIposix mode\fP, \fBtime\fP +may be followed by a newline. In this case, the shell displays the +total user and system time consumed by the shell and its children. +The +.SM +.B TIMEFORMAT +variable may be used to specify the format of +the time information. +.PP +Each command in a pipeline is executed as a separate process (i.e., in a +subshell). +.SS Lists +.PP +A \fIlist\fP is a sequence of one or more pipelines separated by one +of the operators +.BR ; , +.BR & , +.BR && , +or +.BR || , +and optionally terminated by one of +.BR ; , +.BR & , +or +.BR . +.PP +Of these list operators, +.B && +and +.B || +have equal precedence, followed by +.B ; +and +.BR & , +which have equal precedence. +.PP +A sequence of one or more newlines may appear in a \fIlist\fP instead +of a semicolon to delimit commands. +.PP +If a command is terminated by the control operator +.BR & , +the shell executes the command in the \fIbackground\fP +in a subshell. The shell does not wait for the command to +finish, and the return status is 0. Commands separated by a +.B ; +are executed sequentially; the shell waits for each +command to terminate in turn. The return status is the +exit status of the last command executed. +.PP +AND and OR lists are sequences of one of more pipelines separated by the +\fB&&\fP and \fB||\fP control operators, respectively. +AND and OR lists are executed with left associativity. +An AND list has the form +.RS +.PP +\fIcommand1\fP \fB&&\fP \fIcommand2\fP +.RE +.PP +.I command2 +is executed if, and only if, +.I command1 +returns an exit status of zero. +.PP +An OR list has the form +.RS +.PP +\fIcommand1\fP \fB||\fP \fIcommand2\fP +.PP +.RE +.PP +.I command2 +is executed if and only if +.I command1 +returns a non-zero exit status. +The return status of +AND and OR lists is the exit status of the last command +executed in the list. +.SS Compound Commands +.PP +A \fIcompound command\fP is one of the following. +In most cases a \fIlist\fP in a command's description may be separated from +the rest of the command by one or more newlines, and may be followed by a +newline in place of a semicolon. +.TP +(\fIlist\fP) +\fIlist\fP is executed in a subshell environment (see +.SM +\fBCOMMAND EXECUTION ENVIRONMENT\fP +below). +Variable assignments and builtin +commands that affect the shell's environment do not remain in effect +after the command completes. The return status is the exit status of +\fIlist\fP. +.TP +{ \fIlist\fP; } +\fIlist\fP is simply executed in the current shell environment. +\fIlist\fP must be terminated with a newline or semicolon. +This is known as a \fIgroup command\fP. +The return status is the exit status of +\fIlist\fP. +Note that unlike the metacharacters \fB(\fP and \fB)\fP, \fB{\fP and +\fB}\fP are \fIreserved words\fP and must occur where a reserved +word is permitted to be recognized. Since they do not cause a word +break, they must be separated from \fIlist\fP by whitespace or another +shell metacharacter. +.TP +((\fIexpression\fP)) +The \fIexpression\fP is evaluated according to the rules described +below under +.SM +.BR "ARITHMETIC EVALUATION" . +If the value of the expression is non-zero, the return status is 0; +otherwise the return status is 1. This is exactly equivalent to +\fBlet "\fIexpression\fP"\fR. +.TP +\fB[[\fP \fIexpression\fP \fB]]\fP +Return a status of 0 or 1 depending on the evaluation of +the conditional expression \fIexpression\fP. +Expressions are composed of the primaries described below under +.SM +.BR "CONDITIONAL EXPRESSIONS" . +Word splitting and pathname expansion are not performed on the words +between the \fB[[\fP and \fB]]\fP; tilde expansion, +parameter and variable expansion, +arithmetic expansion, command substitution, process +substitution, and quote removal are performed. +Conditional operators such as \fB\-f\fP must be unquoted to be recognized +as primaries. +.if t .sp 0.5 +.if n .sp 1 +When used with \fB[[\fP, the \fB<\fP and \fB>\fP operators sort +lexicographically using the current locale. +.if t .sp 0.5 +.if n .sp 1 +When the \fB==\fP and \fB!=\fP operators are used, the string to the +right of the operator is considered a pattern and matched according +to the rules described below under \fBPattern Matching\fP, +as if the \fBextglob\fP shell option were enabled. +The \fB=\fP operator is equivalent to \fB==\fP. +If the +.B nocasematch +shell option is enabled, the match is performed without regard to the case +of alphabetic characters. +The return value is 0 if the string matches (\fB==\fP) or does not match +(\fB!=\fP) the pattern, and 1 otherwise. +Any part of the pattern may be quoted to force the quoted portion +to be matched as a string. +.if t .sp 0.5 +.if n .sp 1 +An additional binary operator, \fB=~\fP, is available, with the same +precedence as \fB==\fP and \fB!=\fP. +When it is used, the string to the right of the operator is considered +an extended regular expression and matched accordingly (as in \fIregex\fP(3)). +The return value is 0 if the string matches +the pattern, and 1 otherwise. +If the regular expression is syntactically incorrect, the conditional +expression's return value is 2. +If the +.B nocasematch +shell option is enabled, the match is performed without regard to the case +of alphabetic characters. +Any part of the pattern may be quoted to force the quoted portion +to be matched as a string. +Bracket expressions in regular expressions must be treated carefully, +since normal quoting characters lose their meanings between brackets. +If the pattern is stored in a shell variable, quoting the variable +expansion forces the entire pattern to be matched as a string. +Substrings matched by parenthesized subexpressions within the regular +expression are saved in the array variable +.SM +.BR BASH_REMATCH . +The element of +.SM +.B BASH_REMATCH +with index 0 is the portion of the string +matching the entire regular expression. +The element of +.SM +.B BASH_REMATCH +with index \fIn\fP is the portion of the +string matching the \fIn\fPth parenthesized subexpression. +.if t .sp 0.5 +.if n .sp 1 +Expressions may be combined using the following operators, listed +in decreasing order of precedence: +.if t .sp 0.5 +.if n .sp 1 +.RS +.PD 0 +.TP +.B ( \fIexpression\fP ) +Returns the value of \fIexpression\fP. +This may be used to override the normal precedence of operators. +.TP +.B ! \fIexpression\fP +True if +.I expression +is false. +.TP +\fIexpression1\fP \fB&&\fP \fIexpression2\fP +True if both +.I expression1 +and +.I expression2 +are true. +.TP +\fIexpression1\fP \fB||\fP \fIexpression2\fP +True if either +.I expression1 +or +.I expression2 +is true. +.PD +.LP +The \fB&&\fP and \fB||\fP +operators do not evaluate \fIexpression2\fP if the value of +\fIexpression1\fP is sufficient to determine the return value of +the entire conditional expression. +.RE +.TP +\fBfor\fP \fIname\fP [ [ \fBin\fP [ \fIword ...\fP ] ] ; ] \fBdo\fP \fIlist\fP ; \fBdone\fP +The list of words following \fBin\fP is expanded, generating a list +of items. +The variable \fIname\fP is set to each element of this list +in turn, and \fIlist\fP is executed each time. +If the \fBin\fP \fIword\fP is omitted, the \fBfor\fP command executes +\fIlist\fP once for each positional parameter that is set (see +.SM +.B PARAMETERS +below). +The return status is the exit status of the last command that executes. +If the expansion of the items following \fBin\fP results in an empty +list, no commands are executed, and the return status is 0. +.TP +\fBfor\fP (( \fIexpr1\fP ; \fIexpr2\fP ; \fIexpr3\fP )) ; \fBdo\fP \fIlist\fP ; \fBdone\fP +First, the arithmetic expression \fIexpr1\fP is evaluated according +to the rules described below under +.SM +.BR "ARITHMETIC EVALUATION" . +The arithmetic expression \fIexpr2\fP is then evaluated repeatedly +until it evaluates to zero. +Each time \fIexpr2\fP evaluates to a non-zero value, \fIlist\fP is +executed and the arithmetic expression \fIexpr3\fP is evaluated. +If any expression is omitted, it behaves as if it evaluates to 1. +The return value is the exit status of the last command in \fIlist\fP +that is executed, or false if any of the expressions is invalid. +.TP +\fBselect\fP \fIname\fP [ \fBin\fP \fIword\fP ] ; \fBdo\fP \fIlist\fP ; \fBdone\fP +The list of words following \fBin\fP is expanded, generating a list +of items. The set of expanded words is printed on the standard +error, each preceded by a number. If the \fBin\fP +\fIword\fP is omitted, the positional parameters are printed (see +.SM +.B PARAMETERS +below). The +.SM +.B PS3 +prompt is then displayed and a line read from the standard input. +If the line consists of a number corresponding to one of +the displayed words, then the value of +.I name +is set to that word. If the line is empty, the words and prompt +are displayed again. If EOF is read, the command completes. Any +other value read causes +.I name +to be set to null. The line read is saved in the variable +.SM +.BR REPLY . +The +.I list +is executed after each selection until a +.B break +command is executed. +The exit status of +.B select +is the exit status of the last command executed in +.IR list , +or zero if no commands were executed. +.TP +\fBcase\fP \fIword\fP \fBin\fP [ [(] \fIpattern\fP [ \fB|\fP \fIpattern\fP ] \ +... ) \fIlist\fP ;; ] ... \fBesac\fP +A \fBcase\fP command first expands \fIword\fP, and tries to match +it against each \fIpattern\fP in turn, using the same matching rules +as for pathname expansion (see +.B Pathname Expansion +below). +The \fIword\fP is expanded using tilde +expansion, parameter and variable expansion, arithmetic expansion, +command substitution, process substitution and quote removal. +Each \fIpattern\fP examined is expanded using tilde +expansion, parameter and variable expansion, arithmetic expansion, +command substitution, and process substitution. +If the +.B nocasematch +shell option is enabled, the match is performed without regard to the case +of alphabetic characters. +When a match is found, the corresponding \fIlist\fP is executed. +If the \fB;;\fP operator is used, no subsequent matches are attempted after +the first pattern match. +Using \fB;&\fP in place of \fB;;\fP causes execution to continue with +the \fIlist\fP associated with the next set of patterns. +Using \fB;;&\fP in place of \fB;;\fP causes the shell to test the next +pattern list in the statement, if any, and execute any associated \fIlist\fP +on a successful match. +The exit status is zero if no +pattern matches. Otherwise, it is the exit status of the +last command executed in \fIlist\fP. +.TP +\fBif\fP \fIlist\fP; \fBthen\fP \fIlist\fP; \ +[ \fBelif\fP \fIlist\fP; \fBthen\fP \fIlist\fP; ] ... \ +[ \fBelse\fP \fIlist\fP; ] \fBfi\fP +The +.B if +.I list +is executed. If its exit status is zero, the +\fBthen\fP \fIlist\fP is executed. Otherwise, each \fBelif\fP +\fIlist\fP is executed in turn, and if its exit status is zero, +the corresponding \fBthen\fP \fIlist\fP is executed and the +command completes. Otherwise, the \fBelse\fP \fIlist\fP is +executed, if present. The exit status is the exit status of the +last command executed, or zero if no condition tested true. +.TP +\fBwhile\fP \fIlist-1\fP; \fBdo\fP \fIlist-2\fP; \fBdone\fP +.PD 0 +.TP +\fBuntil\fP \fIlist-1\fP; \fBdo\fP \fIlist-2\fP; \fBdone\fP +.PD +The \fBwhile\fP command continuously executes the list +\fIlist-2\fP as long as the last command in the list \fIlist-1\fP returns +an exit status of zero. The \fBuntil\fP command is identical +to the \fBwhile\fP command, except that the test is negated; +.I list-2 +is executed as long as the last command in +.I list-1 +returns a non-zero exit status. +The exit status of the \fBwhile\fP and \fBuntil\fP commands +is the exit status +of the last command executed in \fIlist-2\fP, or zero if +none was executed. +.SS Coprocesses +.PP +A \fIcoprocess\fP is a shell command preceded by the \fBcoproc\fP reserved +word. +A coprocess is executed asynchronously in a subshell, as if the command +had been terminated with the \fB&\fP control operator, with a two-way pipe +established between the executing shell and the coprocess. +.PP +The format for a coprocess is: +.RS +.PP +\fBcoproc\fP [\fINAME\fP] \fIcommand\fP [\fIredirections\fP] +.RE +.PP +This creates a coprocess named \fINAME\fP. +If \fINAME\fP is not supplied, the default name is \fBCOPROC\fP. +\fINAME\fP must not be supplied if \fIcommand\fP is a \fIsimple +command\fP (see above); otherwise, it is interpreted as the first word +of the simple command. +When the coprocess is executed, the shell creates an array variable (see +.B Arrays +below) named \fINAME\fP in the context of the executing shell. +The standard output of +.I command +is connected via a pipe to a file descriptor in the executing shell, +and that file descriptor is assigned to \fINAME\fP[0]. +The standard input of +.I command +is connected via a pipe to a file descriptor in the executing shell, +and that file descriptor is assigned to \fINAME\fP[1]. +This pipe is established before any redirections specified by the +command (see +.SM +.B REDIRECTION +below). +The file descriptors can be utilized as arguments to shell commands +and redirections using standard word expansions. +The file descriptors are not available in subshells. +The process ID of the shell spawned to execute the coprocess is +available as the value of the variable \fINAME\fP_PID. +The \fBwait\fP +builtin command may be used to wait for the coprocess to terminate. +.PP +Since the coprocess is created as an asynchronous command, +the \fBcoproc\fP command always returns success. +The return status of a coprocess is the exit status of \fIcommand\fP. +.SS Shell Function Definitions +.PP +A shell function is an object that is called like a simple command and +executes a compound command with a new set of positional parameters. +Shell functions are declared as follows: +.TP +\fIname\fP () \fIcompound\-command\fP [\fIredirection\fP] +.PD 0 +.TP +\fBfunction\fP \fIname\fP [()] \fIcompound\-command\fP [\fIredirection\fP] +.PD +This defines a function named \fIname\fP. +The reserved word \fBfunction\fP is optional. +If the \fBfunction\fP reserved word is supplied, the parentheses are optional. +The \fIbody\fP of the function is the compound command +.I compound\-command +(see \fBCompound Commands\fP above). +That command is usually a \fIlist\fP of commands between { and }, but +may be any command listed under \fBCompound Commands\fP above, +with one exception: If the \fBfunction\fP reserved word is used, but the +parentheses are not supplied, the braces are required. +\fIcompound\-command\fP is executed whenever \fIname\fP is specified as the +name of a simple command. +When in \fIposix mode\fP, \fIname\fP may not be the name of one of the +POSIX \fIspecial builtins\fP. +Any redirections (see +.SM +.B REDIRECTION +below) specified when a function is defined are performed +when the function is executed. +The exit status of a function definition is zero unless a syntax error +occurs or a readonly function with the same name already exists. +When executed, the exit status of a function is the exit status of the +last command executed in the body. (See +.SM +.B FUNCTIONS +below.) +.SH COMMENTS +In a non-interactive shell, or an interactive shell in which the +.B interactive_comments +option to the +.B shopt +builtin is enabled (see +.SM +.B "SHELL BUILTIN COMMANDS" +below), a word beginning with +.B # +causes that word and all remaining characters on that line to +be ignored. An interactive shell without the +.B interactive_comments +option enabled does not allow comments. The +.B interactive_comments +option is on by default in interactive shells. +.SH QUOTING +\fIQuoting\fP is used to remove the special meaning of certain +characters or words to the shell. Quoting can be used to +disable special treatment for special characters, to prevent +reserved words from being recognized as such, and to prevent +parameter expansion. +.PP +Each of the \fImetacharacters\fP listed above under +.SM +.B DEFINITIONS +has special meaning to the shell and must be quoted if it is to +represent itself. +.PP +When the command history expansion facilities are being used +(see +.SM +.B HISTORY EXPANSION +below), the +\fIhistory expansion\fP character, usually \fB!\fP, must be quoted +to prevent history expansion. +.PP +There are three quoting mechanisms: the +.IR "escape character" , +single quotes, and double quotes. +.PP +A non-quoted backslash (\fB\e\fP) is the +.IR "escape character" . +It preserves the literal value of the next character that follows, +with the exception of . If a \fB\e\fP pair +appears, and the backslash is not itself quoted, the \fB\e\fP +is treated as a line continuation (that is, it is removed from the +input stream and effectively ignored). +.PP +Enclosing characters in single quotes preserves the literal value +of each character within the quotes. A single quote may not occur +between single quotes, even when preceded by a backslash. +.PP +Enclosing characters in double quotes preserves the literal value +of all characters within the quotes, with the exception of +.BR $ , +.BR \` , +.BR \e , +and, when history expansion is enabled, +.BR ! . +The characters +.B $ +and +.B \` +retain their special meaning within double quotes. The backslash +retains its special meaning only when followed by one of the following +characters: +.BR $ , +.BR \` , +\^\fB"\fP\^, +.BR \e , +or +.BR . +A double quote may be quoted within double quotes by preceding it with +a backslash. +If enabled, history expansion will be performed unless an +.B ! +appearing in double quotes is escaped using a backslash. +The backslash preceding the +.B ! +is not removed. +.PP +The special parameters +.B * +and +.B @ +have special meaning when in double +quotes (see +.SM +.B PARAMETERS +below). +.PP +Words of the form \fB$\fP\(aq\fIstring\fP\(aq are treated specially. The +word expands to \fIstring\fP, with backslash-escaped characters replaced +as specified by the ANSI C standard. Backslash escape sequences, if +present, are decoded as follows: +.RS +.PD 0 +.TP +.B \ea +alert (bell) +.TP +.B \eb +backspace +.TP +.B \ee +.TP +.B \eE +an escape character +.TP +.B \ef +form feed +.TP +.B \en +new line +.TP +.B \er +carriage return +.TP +.B \et +horizontal tab +.TP +.B \ev +vertical tab +.TP +.B \e\e +backslash +.TP +.B \e\(aq +single quote +.TP +.B \e\(dq +double quote +.TP +.B \e\fInnn\fP +the eight-bit character whose value is the octal value \fInnn\fP +(one to three digits) +.TP +.B \ex\fIHH\fP +the eight-bit character whose value is the hexadecimal value \fIHH\fP +(one or two hex digits) +.TP +.B \eu\fIHHHH\fP +the Unicode (ISO/IEC 10646) character whose value is the hexadecimal value +\fIHHHH\fP (one to four hex digits) +.TP +.B \eU\fIHHHHHHHH\fP +the Unicode (ISO/IEC 10646) character whose value is the hexadecimal value +\fIHHHHHHHH\fP (one to eight hex digits) +.TP +.B \ec\fIx\fP +a control-\fIx\fP character +.PD +.RE +.LP +The expanded result is single-quoted, as if the dollar sign had +not been present. +.PP +A double-quoted string preceded by a dollar sign (\fB$\fP\(dq\fIstring\fP\(dq) +will cause the string to be translated according to the current locale. +If the current locale is \fBC\fP or \fBPOSIX\fP, the dollar sign +is ignored. +If the string is translated and replaced, the replacement is +double-quoted. +.SH PARAMETERS +A +.I parameter +is an entity that stores values. +It can be a +.IR name , +a number, or one of the special characters listed below under +.BR "Special Parameters" . +A +.I variable +is a parameter denoted by a +.IR name . +A variable has a \fIvalue\fP and zero or more \fIattributes\fP. +Attributes are assigned using the +.B declare +builtin command (see +.B declare +below in +.SM +.BR "SHELL BUILTIN COMMANDS" ). +.PP +A parameter is set if it has been assigned a value. The null string is +a valid value. Once a variable is set, it may be unset only by using +the +.B unset +builtin command (see +.SM +.B SHELL BUILTIN COMMANDS +below). +.PP +A +.I variable +may be assigned to by a statement of the form +.RS +.PP +\fIname\fP=[\fIvalue\fP] +.RE +.PP +If +.I value +is not given, the variable is assigned the null string. All +.I values +undergo tilde expansion, parameter and variable expansion, +command substitution, arithmetic expansion, and quote +removal (see +.SM +.B EXPANSION +below). If the variable has its +.B integer +attribute set, then +.I value +is evaluated as an arithmetic expression even if the $((...)) expansion is +not used (see +.B "Arithmetic Expansion" +below). +Word splitting is not performed, with the exception +of \fB"$@"\fP as explained below under +.BR "Special Parameters" . +Pathname expansion is not performed. +Assignment statements may also appear as arguments to the +.BR alias , +.BR declare , +.BR typeset , +.BR export , +.BR readonly , +and +.B local +builtin commands (\fIdeclaration\fP commands). +When in \fIposix mode\fP, these builtins may appear in a command after +one or more instances of the \fBcommand\fP builtin and retain these +assignment statement properties. +.PP +In the context where an assignment statement is assigning a value +to a shell variable or array index, the += operator can be used to +append to or add to the variable's previous value. +This includes arguments to builtin commands such as \fBdeclare\fP that +accept assignment statements (\fIdeclaration\fP commands). +When += is applied to a variable for which the \fIinteger\fP attribute has been +set, \fIvalue\fP is evaluated as an arithmetic expression and added to the +variable's current value, which is also evaluated. +When += is applied to an array variable using compound assignment (see +.B Arrays +below), the +variable's value is not unset (as it is when using =), and new values are +appended to the array beginning at one greater than the array's maximum index +(for indexed arrays) or added as additional key\-value pairs in an +associative array. +When applied to a string-valued variable, \fIvalue\fP is expanded and +appended to the variable's value. +.PP +A variable can be assigned the \fInameref\fP attribute using the +\fB\-n\fP option to the \fBdeclare\fP or \fBlocal\fP builtin commands +(see the descriptions of \fBdeclare\fP and \fBlocal\fP below) +to create a \fInameref\fP, or a reference to another variable. +This allows variables to be manipulated indirectly. +Whenever the nameref variable is referenced, assigned to, unset, or has +its attributes modified (other than the \fInameref\fP attribute itself), the +operation is actually performed on the variable specified by the nameref +variable's value. +A nameref is commonly used within shell functions to refer to a variable +whose name is passed as an argument to the function. +For instance, if a variable name is passed to a shell function as its first +argument, running +.sp .5 +.RS +.if t \f(CWdeclare -n ref=$1\fP +.if n declare -n ref=$1 +.RE +.sp .5 +inside the function creates a nameref variable \fBref\fP whose value is +the variable name passed as the first argument. +References and assignments to \fBref\fP, and changes to its attributes, +are treated as references, assignments, and attribute modifications +to the variable whose name was passed as \fB$1\fP. +If the control variable in a \fBfor\fP loop has the nameref attribute, +the list of words can be a list of shell variables, and a name reference +will be established for each word in the list, in turn, when the loop is +executed. +Array variables cannot be given the \fBnameref\fP attribute. +However, nameref variables can reference array variables and subscripted +array variables. +Namerefs can be unset using the \fB\-n\fP option to the \fBunset\fP builtin. +Otherwise, if \fBunset\fP is executed with the name of a nameref variable +as an argument, the variable referenced by the nameref variable will be unset. +.SS Positional Parameters +.PP +A +.I positional parameter +is a parameter denoted by one or more +digits, other than the single digit 0. Positional parameters are +assigned from the shell's arguments when it is invoked, +and may be reassigned using the +.B set +builtin command. Positional parameters may not be assigned to +with assignment statements. The positional parameters are +temporarily replaced when a shell function is executed (see +.SM +.B FUNCTIONS +below). +.PP +When a positional parameter consisting of more than a single +digit is expanded, it must be enclosed in braces (see +.SM +.B EXPANSION +below). +.SS Special Parameters +.PP +The shell treats several parameters specially. These parameters may +only be referenced; assignment to them is not allowed. +.PD 0 +.TP +.B * +Expands to the positional parameters, starting from one. +When the expansion is not within double quotes, each positional parameter +expands to a separate word. +In contexts where it is performed, those words +are subject to further word splitting and pathname expansion. +When the expansion occurs within double quotes, it expands to a single word +with the value of each parameter separated by the first character of the +.SM +.B IFS +special variable. That is, "\fB$*\fP" is equivalent +to "\fB$1\fP\fIc\fP\fB$2\fP\fIc\fP\fB...\fP", where +.I c +is the first character of the value of the +.SM +.B IFS +variable. If +.SM +.B IFS +is unset, the parameters are separated by spaces. +If +.SM +.B IFS +is null, the parameters are joined without intervening separators. +.TP +.B @ +Expands to the positional parameters, starting from one. When the +expansion occurs within double quotes, each parameter expands to a +separate word. That is, "\fB$@\fP" is equivalent to +"\fB$1\fP" "\fB$2\fP" ... +If the double-quoted expansion occurs within a word, the expansion of +the first parameter is joined with the beginning part of the original +word, and the expansion of the last parameter is joined with the last +part of the original word. +When there are no positional parameters, "\fB$@\fP" and +.B $@ +expand to nothing (i.e., they are removed). +.TP +.B # +Expands to the number of positional parameters in decimal. +.TP +.B ? +Expands to the exit status of the most recently executed foreground +pipeline. +.TP +.B \- +Expands to the current option flags as specified upon invocation, +by the +.B set +builtin command, or those set by the shell itself +(such as the +.B \-i +option). +.TP +.B $ +Expands to the process ID of the shell. In a () subshell, it +expands to the process ID of the current shell, not the +subshell. +.TP +.B ! +Expands to the process ID of the job most recently placed into the +background, whether executed as an asynchronous command or using +the \fBbg\fP builtin (see +.SM +.B "JOB CONTROL" +below). +.TP +.B 0 +Expands to the name of the shell or shell script. This is set at +shell initialization. If +.B bash +is invoked with a file of commands, +.B $0 +is set to the name of that file. If +.B bash +is started with the +.B \-c +option, then +.B $0 +is set to the first argument after the string to be +executed, if one is present. Otherwise, it is set +to the filename used to invoke +.BR bash , +as given by argument zero. +.TP +.B _ +At shell startup, set to the absolute pathname used to invoke the +shell or shell script being executed as passed in the environment +or argument list. +Subsequently, expands to the last argument to the previous command, +after expansion. +Also set to the full pathname used to invoke each command executed +and placed in the environment exported to that command. +When checking mail, this parameter holds the name of the mail file +currently being checked. +.PD +.SS Shell Variables +.PP +The following variables are set by the shell: +.PP +.PD 0 +.TP +.B BASH +Expands to the full filename used to invoke this instance of +.BR bash . +.TP +.B BASHOPTS +A colon-separated list of enabled shell options. Each word in +the list is a valid argument for the +.B \-s +option to the +.B shopt +builtin command (see +.SM +.B "SHELL BUILTIN COMMANDS" +below). The options appearing in +.SM +.B BASHOPTS +are those reported as +.I on +by \fBshopt\fP. +If this variable is in the environment when +.B bash +starts up, each shell option in the list will be enabled before +reading any startup files. +This variable is read-only. +.TP +.B BASHPID +Expands to the process ID of the current \fBbash\fP process. +This differs from \fB$$\fP under certain circumstances, such as subshells +that do not require \fBbash\fP to be re-initialized. +.TP +.B BASH_ALIASES +An associative array variable whose members correspond to the internal +list of aliases as maintained by the \fBalias\fP builtin. +Elements added to this array appear in the alias list; unsetting array +elements cause aliases to be removed from the alias list. +.TP +.B BASH_ARGC +An array variable whose values are the number of parameters in each +frame of the current \fBbash\fP execution call stack. +The number of +parameters to the current subroutine (shell function or script executed +with \fB.\fP or \fBsource\fP) is at the top of the stack. +When a subroutine is executed, the number of parameters passed is pushed onto +.SM +.BR BASH_ARGC . +The shell sets +.SM +.B BASH_ARGC +only when in extended debugging mode (see the description of the +.B extdebug +option to the +.B shopt +builtin below) +.TP +.B BASH_ARGV +An array variable containing all of the parameters in the current \fBbash\fP +execution call stack. The final parameter of the last subroutine call +is at the top of the stack; the first parameter of the initial call is +at the bottom. When a subroutine is executed, the parameters supplied +are pushed onto +.SM +.BR BASH_ARGV . +The shell sets +.SM +.B BASH_ARGV +only when in extended debugging mode +(see the description of the +.B extdebug +option to the +.B shopt +builtin below) +.TP +.B BASH_CMDS +An associative array variable whose members correspond to the internal +hash table of commands as maintained by the \fBhash\fP builtin. +Elements added to this array appear in the hash table; unsetting array +elements cause commands to be removed from the hash table. +.TP +.B BASH_COMMAND +The command currently being executed or about to be executed, unless the +shell is executing a command as the result of a trap, +in which case it is the command executing at the time of the trap. +.TP +.B BASH_EXECUTION_STRING +The command argument to the \fB\-c\fP invocation option. +.TP +.B BASH_LINENO +An array variable whose members are the line numbers in source files +where each corresponding member of +.SM +.B FUNCNAME +was invoked. +\fB${BASH_LINENO[\fP\fI$i\fP\fB]}\fP is the line number in the source +file (\fB${BASH_SOURCE[\fP\fI$i+1\fP\fB]}\fP) where +\fB${FUNCNAME[\fP\fI$i\fP\fB]}\fP was called +(or \fB${BASH_LINENO[\fP\fI$i-1\fP\fB]}\fP if referenced within another +shell function). +Use +.SM +.B LINENO +to obtain the current line number. +.TP +.B BASH_REMATCH +An array variable whose members are assigned by the \fB=~\fP binary +operator to the \fB[[\fP conditional command. +The element with index 0 is the portion of the string +matching the entire regular expression. +The element with index \fIn\fP is the portion of the +string matching the \fIn\fPth parenthesized subexpression. +This variable is read-only. +.TP +.B BASH_SOURCE +An array variable whose members are the source filenames +where the corresponding shell function names in the +.SM +.B FUNCNAME +array variable are defined. +The shell function +\fB${FUNCNAME[\fP\fI$i\fP\fB]}\fP is defined in the file +\fB${BASH_SOURCE[\fP\fI$i\fP\fB]}\fP and called from +\fB${BASH_SOURCE[\fP\fI$i+1\fP\fB]}\fP. +.TP +.B BASH_SUBSHELL +Incremented by one within each subshell or subshell environment when +the shell begins executing in that environment. +The initial value is 0. +.TP +.B BASH_VERSINFO +A readonly array variable whose members hold version information for +this instance of +.BR bash . +The values assigned to the array members are as follows: +.sp .5 +.RS +.TP 24 +.B BASH_VERSINFO[\fR0\fP] +The major version number (the \fIrelease\fP). +.TP +.B BASH_VERSINFO[\fR1\fP] +The minor version number (the \fIversion\fP). +.TP +.B BASH_VERSINFO[\fR2\fP] +The patch level. +.TP +.B BASH_VERSINFO[\fR3\fP] +The build version. +.TP +.B BASH_VERSINFO[\fR4\fP] +The release status (e.g., \fIbeta1\fP). +.TP +.B BASH_VERSINFO[\fR5\fP] +The value of +.SM +.BR MACHTYPE . +.RE +.TP +.B BASH_VERSION +Expands to a string describing the version of this instance of +.BR bash . +.TP +.B COMP_CWORD +An index into \fB${COMP_WORDS}\fP of the word containing the current +cursor position. +This variable is available only in shell functions invoked by the +programmable completion facilities (see \fBProgrammable Completion\fP +below). +.TP +.B COMP_KEY +The key (or final key of a key sequence) used to invoke the current +completion function. +.TP +.B COMP_LINE +The current command line. +This variable is available only in shell functions and external +commands invoked by the +programmable completion facilities (see \fBProgrammable Completion\fP +below). +.TP +.B COMP_POINT +The index of the current cursor position relative to the beginning of +the current command. +If the current cursor position is at the end of the current command, +the value of this variable is equal to \fB${#COMP_LINE}\fP. +This variable is available only in shell functions and external +commands invoked by the +programmable completion facilities (see \fBProgrammable Completion\fP +below). +.TP +.B COMP_TYPE +Set to an integer value corresponding to the type of completion attempted +that caused a completion function to be called: +\fITAB\fP, for normal completion, +\fI?\fP, for listing completions after successive tabs, +\fI!\fP, for listing alternatives on partial word completion, +\fI@\fP, to list completions if the word is not unmodified, +or +\fI%\fP, for menu completion. +This variable is available only in shell functions and external +commands invoked by the +programmable completion facilities (see \fBProgrammable Completion\fP +below). +.TP +.B COMP_WORDBREAKS +The set of characters that the \fBreadline\fP library treats as word +separators when performing word completion. +If +.SM +.B COMP_WORDBREAKS +is unset, it loses its special properties, even if it is +subsequently reset. +.TP +.B COMP_WORDS +An array variable (see \fBArrays\fP below) consisting of the individual +words in the current command line. +The line is split into words as \fBreadline\fP would split it, using +.SM +.B COMP_WORDBREAKS +as described above. +This variable is available only in shell functions invoked by the +programmable completion facilities (see \fBProgrammable Completion\fP +below). +.TP +.B COPROC +An array variable (see \fBArrays\fP below) created to hold the file descriptors +for output from and input to an unnamed coprocess (see \fBCoprocesses\fP +above). +.TP +.B DIRSTACK +An array variable (see +.B Arrays +below) containing the current contents of the directory stack. +Directories appear in the stack in the order they are displayed by the +.B dirs +builtin. +Assigning to members of this array variable may be used to modify +directories already in the stack, but the +.B pushd +and +.B popd +builtins must be used to add and remove directories. +Assignment to this variable will not change the current directory. +If +.SM +.B DIRSTACK +is unset, it loses its special properties, even if it is +subsequently reset. +.TP +.B EUID +Expands to the effective user ID of the current user, initialized at +shell startup. This variable is readonly. +.TP +.B FUNCNAME +An array variable containing the names of all shell functions +currently in the execution call stack. +The element with index 0 is the name of any currently-executing +shell function. +The bottom-most element (the one with the highest index) is +.if t \f(CW"main"\fP. +.if n "main". +This variable exists only when a shell function is executing. +Assignments to +.SM +.B FUNCNAME +have no effect and return an error status. +If +.SM +.B FUNCNAME +is unset, it loses its special properties, even if it is +subsequently reset. +.if t .sp 0.5 +.if n .sp 1 +This variable can be used with \fBBASH_LINENO\fP and \fBBASH_SOURCE\fP. +Each element of \fBFUNCNAME\fP has corresponding elements in +\fBBASH_LINENO\fP and \fBBASH_SOURCE\fP to describe the call stack. +For instance, \fB${FUNCNAME[\fP\fI$i\fP\fB]}\fP was called from the file +\fB${BASH_SOURCE[\fP\fI$i+1\fP\fB]}\fP at line number +\fB${BASH_LINENO[\fP\fI$i\fP\fB]}\fP. +The \fBcaller\fP builtin displays the current call stack using this +information. +.TP +.B GROUPS +An array variable containing the list of groups of which the current +user is a member. +Assignments to +.SM +.B GROUPS +have no effect and return an error status. +If +.SM +.B GROUPS +is unset, it loses its special properties, even if it is +subsequently reset. +.TP +.B HISTCMD +The history number, or index in the history list, of the current +command. +If +.SM +.B HISTCMD +is unset, it loses its special properties, even if it is +subsequently reset. +.TP +.B HOSTNAME +Automatically set to the name of the current host. +.TP +.B HOSTTYPE +Automatically set to a string that uniquely +describes the type of machine on which +.B bash +is executing. +The default is system-dependent. +.TP +.B LINENO +Each time this parameter is referenced, the shell substitutes +a decimal number representing the current sequential line number +(starting with 1) within a script or function. When not in a +script or function, the value substituted is not guaranteed to +be meaningful. +If +.SM +.B LINENO +is unset, it loses its special properties, even if it is +subsequently reset. +.TP +.B MACHTYPE +Automatically set to a string that fully describes the system +type on which +.B bash +is executing, in the standard GNU \fIcpu-company-system\fP format. +The default is system-dependent. +.TP +.B MAPFILE +An array variable (see \fBArrays\fP below) created to hold the text +read by the \fBmapfile\fP builtin when no variable name is supplied. +.TP +.B OLDPWD +The previous working directory as set by the +.B cd +command. +.TP +.B OPTARG +The value of the last option argument processed by the +.B getopts +builtin command (see +.SM +.B SHELL BUILTIN COMMANDS +below). +.TP +.B OPTIND +The index of the next argument to be processed by the +.B getopts +builtin command (see +.SM +.B SHELL BUILTIN COMMANDS +below). +.TP +.B OSTYPE +Automatically set to a string that +describes the operating system on which +.B bash +is executing. +The default is system-dependent. +.TP +.B PIPESTATUS +An array variable (see +.B Arrays +below) containing a list of exit status values from the processes +in the most-recently-executed foreground pipeline (which may +contain only a single command). +.TP +.B PPID +The process ID of the shell's parent. This variable is readonly. +.TP +.B PWD +The current working directory as set by the +.B cd +command. +.TP +.B RANDOM +Each time this parameter is referenced, a random integer between +0 and 32767 is +generated. The sequence of random numbers may be initialized by assigning +a value to +.SM +.BR RANDOM . +If +.SM +.B RANDOM +is unset, it loses its special properties, even if it is +subsequently reset. +.TP +.B READLINE_LINE +The contents of the +.B readline +line buffer, for use with +.if t \f(CWbind -x\fP +.if n "bind -x" +(see +.SM +.B "SHELL BUILTIN COMMANDS" +below). +.TP +.B READLINE_POINT +The position of the insertion point in the +.B readline +line buffer, for use with +.if t \f(CWbind -x\fP +.if n "bind -x" +(see +.SM +.B "SHELL BUILTIN COMMANDS" +below). +.TP +.B REPLY +Set to the line of input read by the +.B read +builtin command when no arguments are supplied. +.TP +.B SECONDS +Each time this parameter is +referenced, the number of seconds since shell invocation is returned. If a +value is assigned to +.SM +.BR SECONDS , +the value returned upon subsequent +references is +the number of seconds since the assignment plus the value assigned. +If +.SM +.B SECONDS +is unset, it loses its special properties, even if it is +subsequently reset. +.TP +.B SHELLOPTS +A colon-separated list of enabled shell options. Each word in +the list is a valid argument for the +.B \-o +option to the +.B set +builtin command (see +.SM +.B "SHELL BUILTIN COMMANDS" +below). The options appearing in +.SM +.B SHELLOPTS +are those reported as +.I on +by \fBset \-o\fP. +If this variable is in the environment when +.B bash +starts up, each shell option in the list will be enabled before +reading any startup files. +This variable is read-only. +.TP +.B SHLVL +Incremented by one each time an instance of +.B bash +is started. +.TP +.B UID +Expands to the user ID of the current user, initialized at shell startup. +This variable is readonly. +.PD +.PP +The following variables are used by the shell. In some cases, +.B bash +assigns a default value to a variable; these cases are noted +below. +.PP +.PD 0 +.TP +.B BASH_COMPAT +The value is used to set the shell's compatibility level. +See the description of the \fBshopt\fP builtin below under +\fBSHELL BUILTIN COMMANDS\fP +for a description of the various compatibility +levels and their effects. +The value may be a decimal number (e.g., 4.2) or an integer (e.g., 42) +corresponding to the desired compatibility level. +If \fBBASH_COMPAT\fP is unset or set to the empty string, the compatibility +level is set to the default for the current version. +If \fBBASH_COMPAT\fP is set to a value that is not one of the valid +compatibility levels, the shell prints an error message and sets the +compatibility level to the default for the current version. +The valid compatibility levels correspond to the compatibility options +accepted by the \fBshopt\fP builtin described below (for example, +\fBcompat42\fP means that 4.2 and 42 are valid values). +The current version is also a valid value. +.TP +.B BASH_ENV +If this parameter is set when \fBbash\fP is executing a shell script, +its value is interpreted as a filename containing commands to +initialize the shell, as in +.IR ~/.bashrc . +The value of +.SM +.B BASH_ENV +is subjected to parameter expansion, command substitution, and arithmetic +expansion before being interpreted as a filename. +.SM +.B PATH +is not used to search for the resultant filename. +.TP +.B BASH_XTRACEFD +If set to an integer corresponding to a valid file descriptor, \fBbash\fP +will write the trace output generated when +.if t \f(CWset -x\fP +.if n \fIset -x\fP +is enabled to that file descriptor. +The file descriptor is closed when +.SM +.B BASH_XTRACEFD +is unset or assigned a new value. +Unsetting +.SM +.B BASH_XTRACEFD +or assigning it the empty string causes the +trace output to be sent to the standard error. +Note that setting +.SM +.B BASH_XTRACEFD +to 2 (the standard error file +descriptor) and then unsetting it will result in the standard error +being closed. +.TP +.B CDPATH +The search path for the +.B cd +command. +This is a colon-separated list of directories in which the shell looks +for destination directories specified by the +.B cd +command. +A sample value is +.if t \f(CW".:~:/usr"\fP. +.if n ".:~:/usr". +.TP +.B CHILD_MAX +Set the number of exited child status values for the shell to remember. +Bash will not allow this value to be decreased below a POSIX-mandated +minimum, and there is a maximum value (currently 8192) that this may +not exceed. +The minimum value is system-dependent. +.TP +.B COLUMNS +Used by the \fBselect\fP compound command to determine the terminal width +when printing selection lists. +Automatically set if the +.B checkwinsize +option is enabled or in an interactive shell upon receipt of a +.SM +.BR SIGWINCH . +.TP +.B COMPREPLY +An array variable from which \fBbash\fP reads the possible completions +generated by a shell function invoked by the programmable completion +facility (see \fBProgrammable Completion\fP below). +Each array element contains one possible completion. +.TP +.B EMACS +If \fBbash\fP finds this variable in the environment when the shell starts +with value +.if t \f(CWt\fP, +.if n "t", +it assumes that the shell is running in an Emacs shell buffer and disables +line editing. +.TP +.B ENV +Similar to +.SM +.BR BASH_ENV ; +used when the shell is invoked in POSIX mode. +.TP +.B FCEDIT +The default editor for the +.B fc +builtin command. +.TP +.B FIGNORE +A colon-separated list of suffixes to ignore when performing +filename completion (see +.SM +.B READLINE +below). +A filename whose suffix matches one of the entries in +.SM +.B FIGNORE +is excluded from the list of matched filenames. +A sample value is +.if t \f(CW".o:~"\fP. +.if n ".o:~". +.TP +.B FUNCNEST +If set to a numeric value greater than 0, defines a maximum function +nesting level. Function invocations that exceed this nesting level +will cause the current command to abort. +.TP +.B GLOBIGNORE +A colon-separated list of patterns defining the set of filenames to +be ignored by pathname expansion. +If a filename matched by a pathname expansion pattern also matches one +of the patterns in +.SM +.BR GLOBIGNORE , +it is removed from the list of matches. +.TP +.B HISTCONTROL +A colon-separated list of values controlling how commands are saved on +the history list. +If the list of values includes +.IR ignorespace , +lines which begin with a +.B space +character are not saved in the history list. +A value of +.I ignoredups +causes lines matching the previous history entry to not be saved. +A value of +.I ignoreboth +is shorthand for \fIignorespace\fP and \fIignoredups\fP. +A value of +.IR erasedups +causes all previous lines matching the current line to be removed from +the history list before that line is saved. +Any value not in the above list is ignored. +If +.SM +.B HISTCONTROL +is unset, or does not include a valid value, +all lines read by the shell parser are saved on the history list, +subject to the value of +.SM +.BR HISTIGNORE . +The second and subsequent lines of a multi-line compound command are +not tested, and are added to the history regardless of the value of +.SM +.BR HISTCONTROL . +.TP +.B HISTFILE +The name of the file in which command history is saved (see +.SM +.B HISTORY +below). The default value is \fI~/.bash_history\fP. If unset, the +command history is not saved when a shell exits. +.TP +.B HISTFILESIZE +The maximum number of lines contained in the history file. When this +variable is assigned a value, the history file is truncated, if +necessary, +to contain no more than that number of lines by removing the oldest entries. +The history file is also truncated to this size after +writing it when a shell exits. +If the value is 0, the history file is truncated to zero size. +Non-numeric values and numeric values less than zero inhibit truncation. +The shell sets the default value to the value of \fBHISTSIZE\fP +after reading any startup files. +.TP +.B HISTIGNORE +A colon-separated list of patterns used to decide which command lines +should be saved on the history list. Each pattern is anchored at the +beginning of the line and must match the complete line (no implicit +`\fB*\fP' is appended). Each pattern is tested against the line +after the checks specified by +.SM +.B HISTCONTROL +are applied. +In addition to the normal shell pattern matching characters, `\fB&\fP' +matches the previous history line. `\fB&\fP' may be escaped using a +backslash; the backslash is removed before attempting a match. +The second and subsequent lines of a multi-line compound command are +not tested, and are added to the history regardless of the value of +.SM +.BR HISTIGNORE . +.TP +.B HISTSIZE +The number of commands to remember in the command history (see +.SM +.B HISTORY +below). +If the value is 0, commands are not saved in the history list. +Numeric values less than zero result in every command being saved +on the history list (there is no limit). +The shell sets the default value to 500 after reading any startup files. +.TP +.B HISTTIMEFORMAT +If this variable is set and not null, its value is used as a format string +for \fIstrftime\fP(3) to print the time stamp associated with each history +entry displayed by the \fBhistory\fP builtin. +If this variable is set, time stamps are written to the history file so +they may be preserved across shell sessions. +This uses the history comment character to distinguish timestamps from +other history lines. +.TP +.B HOME +The home directory of the current user; the default argument for the +\fBcd\fP builtin command. +The value of this variable is also used when performing tilde expansion. +.TP +.B HOSTFILE +Contains the name of a file in the same format as +.FN /etc/hosts +that should be read when the shell needs to complete a +hostname. +The list of possible hostname completions may be changed while the +shell is running; +the next time hostname completion is attempted after the +value is changed, +.B bash +adds the contents of the new file to the existing list. +If +.SM +.B HOSTFILE +is set, but has no value, or does not name a readable file, +\fBbash\fP attempts to read +.FN /etc/hosts +to obtain the list of possible hostname completions. +When +.SM +.B HOSTFILE +is unset, the hostname list is cleared. +.TP +.B IFS +The +.I Internal Field Separator +that is used +for word splitting after expansion and to +split lines into words with the +.B read +builtin command. The default value is +``''. +.TP +.B IGNOREEOF +Controls the +action of an interactive shell on receipt of an +.SM +.B EOF +character as the sole input. If set, the value is the number of +consecutive +.SM +.B EOF +characters which must be +typed as the first characters on an input line before +.B bash +exits. If the variable exists but does not have a numeric value, or +has no value, the default value is 10. If it does not exist, +.SM +.B EOF +signifies the end of input to the shell. +.TP +.B INPUTRC +The filename for the +.B readline +startup file, overriding the default of +.FN ~/.inputrc +(see +.SM +.B READLINE +below). +.TP +.B LANG +Used to determine the locale category for any category not specifically +selected with a variable starting with \fBLC_\fP. +.TP +.B LC_ALL +This variable overrides the value of +.SM +.B LANG +and any other +\fBLC_\fP variable specifying a locale category. +.TP +.B LC_COLLATE +This variable determines the collation order used when sorting the +results of pathname expansion, and determines the behavior of range +expressions, equivalence classes, and collating sequences within +pathname expansion and pattern matching. +.TP +.B LC_CTYPE +This variable determines the interpretation of characters and the +behavior of character classes within pathname expansion and pattern +matching. +.TP +.B LC_MESSAGES +This variable determines the locale used to translate double-quoted +strings preceded by a \fB$\fP. +.TP +.B LC_NUMERIC +This variable determines the locale category used for number formatting. +.TP +.B LINES +Used by the \fBselect\fP compound command to determine the column length +for printing selection lists. +Automatically set if the +.B checkwinsize +option is enabled or in an interactive shell upon receipt of a +.SM +.BR SIGWINCH . +.TP +.B MAIL +If this parameter is set to a file or directory name and the +.SM +.B MAILPATH +variable is not set, +.B bash +informs the user of the arrival of mail in the specified file or +Maildir-format directory. +.TP +.B MAILCHECK +Specifies how +often (in seconds) +.B bash +checks for mail. The default is 60 seconds. When it is time to check +for mail, the shell does so before displaying the primary prompt. +If this variable is unset, or set to a value that is not a number +greater than or equal to zero, the shell disables mail checking. +.TP +.B MAILPATH +A colon-separated list of filenames to be checked for mail. +The message to be printed when mail arrives in a particular file +may be specified by separating the filename from the message with a `?'. +When used in the text of the message, \fB$_\fP expands to the name of +the current mailfile. +Example: +.RS +.PP +\fBMAILPATH\fP=\(aq/var/mail/bfox?"You have mail":~/shell\-mail?"$_ has mail!"\(aq +.PP +.B Bash +supplies a default value for this variable, but the location of the user +mail files that it uses is system dependent (e.g., /var/mail/\fB$USER\fP). +.RE +.TP +.B OPTERR +If set to the value 1, +.B bash +displays error messages generated by the +.B getopts +builtin command (see +.SM +.B SHELL BUILTIN COMMANDS +below). +.SM +.B OPTERR +is initialized to 1 each time the shell is invoked or a shell +script is executed. +.TP +.B PATH +The search path for commands. It +is a colon-separated list of directories in which +the shell looks for commands (see +.SM +.B COMMAND EXECUTION +below). +A zero-length (null) directory name in the value of +.SM +.B PATH +indicates the current directory. +A null directory name may appear as two adjacent colons, or as an initial +or trailing colon. +The default path is system-dependent, +and is set by the administrator who installs +.BR bash . +A common value is +.if t \f(CW/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin\fP. +.if n ``/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin''. +.TP +.B POSIXLY_CORRECT +If this variable is in the environment when \fBbash\fP starts, the shell +enters \fIposix mode\fP before reading the startup files, as if the +.B \-\-posix +invocation option had been supplied. If it is set while the shell is +running, \fBbash\fP enables \fIposix mode\fP, as if the command +.if t \f(CWset -o posix\fP +.if n \fIset -o posix\fP +had been executed. +.TP +.B PROMPT_COMMAND +If set, the value is executed as a command prior to issuing each primary +prompt. +.TP +.B PROMPT_DIRTRIM +If set to a number greater than zero, the value is used as the number of +trailing directory components to retain when expanding the \fB\ew\fP and +\fB\eW\fP prompt string escapes (see +.SM +.B PROMPTING +below). Characters removed are replaced with an ellipsis. +.TP +.B PS1 +The value of this parameter is expanded (see +.SM +.B PROMPTING +below) and used as the primary prompt string. The default value is +``\fB\es\-\ev\e$ \fP''. +.TP +.B PS2 +The value of this parameter is expanded as with +.SM +.B PS1 +and used as the secondary prompt string. The default is +``\fB> \fP''. +.TP +.B PS3 +The value of this parameter is used as the prompt for the +.B select +command (see +.SM +.B SHELL GRAMMAR +above). +.TP +.B PS4 +The value of this parameter is expanded as with +.SM +.B PS1 +and the value is printed before each command +.B bash +displays during an execution trace. The first character of +.SM +.B PS4 +is replicated multiple times, as necessary, to indicate multiple +levels of indirection. The default is ``\fB+ \fP''. +.TP +.B SHELL +The full pathname to the shell is kept in this environment variable. +If it is not set when the shell starts, +.B bash +assigns to it the full pathname of the current user's login shell. +.TP +.B TIMEFORMAT +The value of this parameter is used as a format string specifying +how the timing information for pipelines prefixed with the +.B time +reserved word should be displayed. +The \fB%\fP character introduces an escape sequence that is +expanded to a time value or other information. +The escape sequences and their meanings are as follows; the +braces denote optional portions. +.sp .5 +.RS +.PD 0 +.TP 10 +.B %% +A literal \fB%\fP. +.TP +.B %[\fIp\fP][l]R +The elapsed time in seconds. +.TP +.B %[\fIp\fP][l]U +The number of CPU seconds spent in user mode. +.TP +.B %[\fIp\fP][l]S +The number of CPU seconds spent in system mode. +.TP +.B %P +The CPU percentage, computed as (%U + %S) / %R. +.PD +.RE +.IP +The optional \fIp\fP is a digit specifying the \fIprecision\fP, +the number of fractional digits after a decimal point. +A value of 0 causes no decimal point or fraction to be output. +At most three places after the decimal point may be specified; +values of \fIp\fP greater than 3 are changed to 3. +If \fIp\fP is not specified, the value 3 is used. +.IP +The optional \fBl\fP specifies a longer format, including +minutes, of the form \fIMM\fPm\fISS\fP.\fIFF\fPs. +The value of \fIp\fP determines whether or not the fraction is +included. +.IP +If this variable is not set, \fBbash\fP acts as if it had the +value \fB$\(aq\enreal\et%3lR\enuser\et%3lU\ensys\et%3lS\(aq\fP. +If the value is null, no timing information is displayed. +A trailing newline is added when the format string is displayed. +.PD 0 +.TP +.B TMOUT +If set to a value greater than zero, +.SM +.B TMOUT +is treated as the +default timeout for the \fBread\fP builtin. +The \fBselect\fP command terminates if input does not arrive +after +.SM +.B TMOUT +seconds when input is coming from a terminal. +In an interactive shell, the value is interpreted as the +number of seconds to wait for a line of input after issuing the +primary prompt. +.B Bash +terminates after waiting for that number of seconds if a complete +line of input does not arrive. +.TP +.B TMPDIR +If set, \fBbash\fP uses its value as the name of a directory in which +\fBbash\fP creates temporary files for the shell's use. +.TP +.B auto_resume +This variable controls how the shell interacts with the user and +job control. If this variable is set, single word simple +commands without redirections are treated as candidates for resumption +of an existing stopped job. There is no ambiguity allowed; if there is +more than one job beginning with the string typed, the job most recently +accessed is selected. The +.I name +of a stopped job, in this context, is the command line used to +start it. +If set to the value +.IR exact , +the string supplied must match the name of a stopped job exactly; +if set to +.IR substring , +the string supplied needs to match a substring of the name of a +stopped job. The +.I substring +value provides functionality analogous to the +.B %? +job identifier (see +.SM +.B JOB CONTROL +below). If set to any other value, the supplied string must +be a prefix of a stopped job's name; this provides functionality +analogous to the \fB%\fP\fIstring\fP job identifier. +.TP +.B histchars +The two or three characters which control history expansion +and tokenization (see +.SM +.B HISTORY EXPANSION +below). The first character is the \fIhistory expansion\fP character, +the character which signals the start of a history +expansion, normally `\fB!\fP'. +The second character is the \fIquick substitution\fP +character, which is used as shorthand for re-running the previous +command entered, substituting one string for another in the command. +The default is `\fB^\fP'. +The optional third character is the character +which indicates that the remainder of the line is a comment when found +as the first character of a word, normally `\fB#\fP'. The history +comment character causes history substitution to be skipped for the +remaining words on the line. It does not necessarily cause the shell +parser to treat the rest of the line as a comment. +.PD +.SS Arrays +.B Bash +provides one-dimensional indexed and associative array variables. +Any variable may be used as an indexed array; the +.B declare +builtin will explicitly declare an array. +There is no maximum +limit on the size of an array, nor any requirement that members +be indexed or assigned contiguously. +Indexed arrays are referenced using integers (including arithmetic +expressions) and are zero-based; associative arrays are referenced +using arbitrary strings. +Unless otherwise noted, indexed array indices must be non-negative integers. +.PP +An indexed array is created automatically if any variable is assigned to +using the syntax \fIname\fP[\fIsubscript\fP]=\fIvalue\fP. The +.I subscript +is treated as an arithmetic expression that must evaluate to a number. +To explicitly declare an indexed array, use +.B declare \-a \fIname\fP +(see +.SM +.B SHELL BUILTIN COMMANDS +below). +.B declare \-a \fIname\fP[\fIsubscript\fP] +is also accepted; the \fIsubscript\fP is ignored. +.PP +Associative arrays are created using +.BR "declare \-A \fIname\fP" . +.PP +Attributes may be +specified for an array variable using the +.B declare +and +.B readonly +builtins. Each attribute applies to all members of an array. +.PP +Arrays are assigned to using compound assignments of the form +\fIname\fP=\fB(\fPvalue\fI1\fP ... value\fIn\fP\fB)\fP, where each +\fIvalue\fP is of the form [\fIsubscript\fP]=\fIstring\fP. +Indexed array assignments do not require anything but \fIstring\fP. +When assigning to indexed arrays, if the optional brackets and subscript +are supplied, that index is assigned to; +otherwise the index of the element assigned is the last index assigned +to by the statement plus one. Indexing starts at zero. +.PP +When assigning to an associative array, the subscript is required. +.PP +This syntax is also accepted by the +.B declare +builtin. Individual array elements may be assigned to using the +\fIname\fP[\fIsubscript\fP]=\fIvalue\fP syntax introduced above. +When assigning to an indexed array, if +.I name +is subscripted by a negative number, that number is +interpreted as relative to one greater than the maximum index of +\fIname\fP, so negative indices count back from the end of the +array, and an index of \-1 references the last element. +.PP +Any element of an array may be referenced using +${\fIname\fP[\fIsubscript\fP]}. The braces are required to avoid +conflicts with pathname expansion. If +\fIsubscript\fP is \fB@\fP or \fB*\fP, the word expands to +all members of \fIname\fP. These subscripts differ only when the +word appears within double quotes. If the word is double-quoted, +${\fIname\fP[*]} expands to a single +word with the value of each array member separated by the first +character of the +.SM +.B IFS +special variable, and ${\fIname\fP[@]} expands each element of +\fIname\fP to a separate word. When there are no array members, +${\fIname\fP[@]} expands to nothing. +If the double-quoted expansion occurs within a word, the expansion of +the first parameter is joined with the beginning part of the original +word, and the expansion of the last parameter is joined with the last +part of the original word. +This is analogous to the expansion +of the special parameters \fB*\fP and \fB@\fP (see +.B Special Parameters +above). ${#\fIname\fP[\fIsubscript\fP]} expands to the length of +${\fIname\fP[\fIsubscript\fP]}. If \fIsubscript\fP is \fB*\fP or +\fB@\fP, the expansion is the number of elements in the array. +If the +.I subscript +used to reference an element of an indexed array +evaluates to a number less than zero, it is +interpreted as relative to one greater than the maximum index of the array, +so negative indices count back from the end of the +array, and an index of \-1 references the last element. +.PP +Referencing an array variable without a subscript is equivalent to +referencing the array with a subscript of 0. +Any reference to a variable using a valid subscript is legal, and +.B bash +will create an array if necessary. +.PP +An array variable is considered set if a subscript has been assigned a +value. The null string is a valid value. +.PP +It is possible to obtain the keys (indices) of an array as well as the values. +${\fB!\fP\fIname\fP[\fI@\fP]} and ${\fB!\fP\fIname\fP[\fI*\fP]} +expand to the indices assigned in array variable \fIname\fP. +The treatment when in double quotes is similar to the expansion of the +special parameters \fI@\fP and \fI*\fP within double quotes. +.PP +The +.B unset +builtin is used to destroy arrays. \fBunset\fP \fIname\fP[\fIsubscript\fP] +destroys the array element at index \fIsubscript\fP. +Negative subscripts to indexed arrays are interpreted as described above. +Care must be taken to avoid unwanted side effects caused by pathname +expansion. +\fBunset\fP \fIname\fP, where \fIname\fP is an array, or +\fBunset\fP \fIname\fP[\fIsubscript\fP], where +\fIsubscript\fP is \fB*\fP or \fB@\fP, removes the entire array. +.PP +The +.BR declare , +.BR local , +and +.B readonly +builtins each accept a +.B \-a +option to specify an indexed array and a +.B \-A +option to specify an associative array. +If both options are supplied, +.B \-A +takes precedence. +The +.B read +builtin accepts a +.B \-a +option to assign a list of words read from the standard input +to an array. The +.B set +and +.B declare +builtins display array values in a way that allows them to be +reused as assignments. +.SH EXPANSION +Expansion is performed on the command line after it has been split into +words. There are seven kinds of expansion performed: +.IR "brace expansion" , +.IR "tilde expansion" , +.IR "parameter and variable expansion" , +.IR "command substitution" , +.IR "arithmetic expansion" , +.IR "word splitting" , +and +.IR "pathname expansion" . +.PP +The order of expansions is: +brace expansion; +tilde expansion, parameter and variable expansion, arithmetic expansion, +and command substitution (done in a left-to-right fashion); +word splitting; +and pathname expansion. +.PP +On systems that can support it, there is an additional expansion +available: \fIprocess substitution\fP. +This is performed at the +same time as tilde, parameter, variable, and arithmetic expansion and +command substitution. +.PP +Only brace expansion, word splitting, and pathname expansion +can change the number of words of the expansion; other expansions +expand a single word to a single word. +The only exceptions to this are the expansions of +"\fB$@\fP" and "\fB${\fP\fIname\fP\fB[@]}\fP" +as explained above (see +.SM +.BR PARAMETERS ). +.SS Brace Expansion +.PP +.I "Brace expansion" +is a mechanism by which arbitrary strings +may be generated. This mechanism is similar to +\fIpathname expansion\fP, but the filenames generated +need not exist. Patterns to be brace expanded take +the form of an optional +.IR preamble , +followed by either a series of comma-separated strings or +a sequence expression between a pair of braces, followed by +an optional +.IR postscript . +The preamble is prefixed to each string contained +within the braces, and the postscript is then appended +to each resulting string, expanding left to right. +.PP +Brace expansions may be nested. The results of each expanded +string are not sorted; left to right order is preserved. +For example, a\fB{\fPd,c,b\fB}\fPe expands into `ade ace abe'. +.PP +A sequence expression takes the form +\fB{\fP\fIx\fP\fB..\fP\fIy\fP\fB[..\fP\fIincr\fP\fB]}\fP, +where \fIx\fP and \fIy\fP are either integers or single characters, +and \fIincr\fP, an optional increment, is an integer. +When integers are supplied, the expression expands to each number between +\fIx\fP and \fIy\fP, inclusive. +Supplied integers may be prefixed with \fI0\fP to force each term to have the +same width. +When either \fIx\fP or \fPy\fP begins with a zero, the shell +attempts to force all generated terms to contain the same number of digits, +zero-padding where necessary. +When characters are supplied, the expression expands to each character +lexicographically between \fIx\fP and \fIy\fP, inclusive, +using the default C locale. +Note that both \fIx\fP and \fIy\fP must be of the same type. +When the increment is supplied, it is used as the difference between +each term. The default increment is 1 or -1 as appropriate. +.PP +Brace expansion is performed before any other expansions, +and any characters special to other expansions are preserved +in the result. It is strictly textual. +.B Bash +does not apply any syntactic interpretation to the context of the +expansion or the text between the braces. +.PP +A correctly-formed brace expansion must contain unquoted opening +and closing braces, and at least one unquoted comma or a valid +sequence expression. +Any incorrectly formed brace expansion is left unchanged. +A \fB{\fP or \fB,\fP may be quoted with a backslash to prevent its +being considered part of a brace expression. +To avoid conflicts with parameter expansion, the string \fB${\fP +is not considered eligible for brace expansion. +.PP +This construct is typically used as shorthand when the common +prefix of the strings to be generated is longer than in the +above example: +.RS +.PP +mkdir /usr/local/src/bash/{old,new,dist,bugs} +.RE +or +.RS +chown root /usr/{ucb/{ex,edit},lib/{ex?.?*,how_ex}} +.RE +.PP +Brace expansion introduces a slight incompatibility with +historical versions of +.BR sh . +.B sh +does not treat opening or closing braces specially when they +appear as part of a word, and preserves them in the output. +.B Bash +removes braces from words as a consequence of brace +expansion. For example, a word entered to +.B sh +as \fIfile{1,2}\fP +appears identically in the output. The same word is +output as +.I file1 file2 +after expansion by +.BR bash . +If strict compatibility with +.B sh +is desired, start +.B bash +with the +.B +B +option or disable brace expansion with the +.B +B +option to the +.B set +command (see +.SM +.B SHELL BUILTIN COMMANDS +below). +.SS Tilde Expansion +.PP +If a word begins with an unquoted tilde character (`\fB~\fP'), all of +the characters preceding the first unquoted slash (or all characters, +if there is no unquoted slash) are considered a \fItilde-prefix\fP. +If none of the characters in the tilde-prefix are quoted, the +characters in the tilde-prefix following the tilde are treated as a +possible \fIlogin name\fP. +If this login name is the null string, the tilde is replaced with the +value of the shell parameter +.SM +.BR HOME . +If +.SM +.B HOME +is unset, the home directory of the user executing the shell is +substituted instead. +Otherwise, the tilde-prefix is replaced with the home directory +associated with the specified login name. +.PP +If the tilde-prefix is a `~+', the value of the shell variable +.SM +.B PWD +replaces the tilde-prefix. +If the tilde-prefix is a `~\-', the value of the shell variable +.SM +.BR OLDPWD , +if it is set, is substituted. +If the characters following the tilde in the tilde-prefix consist +of a number \fIN\fP, optionally prefixed +by a `+' or a `\-', the tilde-prefix is replaced with the corresponding +element from the directory stack, as it would be displayed by the +.B dirs +builtin invoked with the tilde-prefix as an argument. +If the characters following the tilde in the tilde-prefix consist of a +number without a leading `+' or `\-', `+' is assumed. +.PP +If the login name is invalid, or the tilde expansion fails, the word +is unchanged. +.PP +Each variable assignment is checked for unquoted tilde-prefixes immediately +following a +.B : +or the first +.BR = . +In these cases, tilde expansion is also performed. +Consequently, one may use filenames with tildes in assignments to +.SM +.BR PATH , +.SM +.BR MAILPATH , +and +.SM +.BR CDPATH , +and the shell assigns the expanded value. +.SS Parameter Expansion +.PP +The `\fB$\fP' character introduces parameter expansion, +command substitution, or arithmetic expansion. The parameter name +or symbol to be expanded may be enclosed in braces, which +are optional but serve to protect the variable to be expanded from +characters immediately following it which could be +interpreted as part of the name. +.PP +When braces are used, the matching ending brace is the first `\fB}\fP' +not escaped by a backslash or within a quoted string, and not within an +embedded arithmetic expansion, command substitution, or parameter +expansion. +.PP +.PD 0 +.TP +${\fIparameter\fP} +The value of \fIparameter\fP is substituted. The braces are required +when +.I parameter +is a positional parameter with more than one digit, +or when +.I parameter +is followed by a character which is not to be +interpreted as part of its name. +The \fIparameter\fP is a shell parameter as described above +\fBPARAMETERS\fP) or an array reference (\fBArrays\fP). +.PD +.PP +If the first character of \fIparameter\fP is an exclamation point (\fB!\fP), +it introduces a level of variable indirection. +\fBBash\fP uses the value of the variable formed from the rest of +\fIparameter\fP as the name of the variable; this variable is then +expanded and that value is used in the rest of the substitution, rather +than the value of \fIparameter\fP itself. +This is known as \fIindirect expansion\fP. +The exceptions to this are the expansions of ${\fB!\fP\fIprefix\fP\fB*\fP} and +${\fB!\fP\fIname\fP[\fI@\fP]} described below. +The exclamation point must immediately follow the left brace in order to +introduce indirection. +.PP +In each of the cases below, \fIword\fP is subject to tilde expansion, +parameter expansion, command substitution, and arithmetic expansion. +.PP +When not performing substring expansion, using the forms documented below +(e.g., \fB:-\fP), +\fBbash\fP tests for a parameter that is unset or null. Omitting the colon +results in a test only for a parameter that is unset. +.PP +.PD 0 +.TP +${\fIparameter\fP\fB:\-\fP\fIword\fP} +\fBUse Default Values\fP. If +.I parameter +is unset or null, the expansion of +.I word +is substituted. Otherwise, the value of +.I parameter +is substituted. +.TP +${\fIparameter\fP\fB:=\fP\fIword\fP} +\fBAssign Default Values\fP. +If +.I parameter +is unset or null, the expansion of +.I word +is assigned to +.IR parameter . +The value of +.I parameter +is then substituted. Positional parameters and special parameters may +not be assigned to in this way. +.TP +${\fIparameter\fP\fB:?\fP\fIword\fP} +\fBDisplay Error if Null or Unset\fP. +If +.I parameter +is null or unset, the expansion of \fIword\fP (or a message to that effect +if +.I word +is not present) is written to the standard error and the shell, if it +is not interactive, exits. Otherwise, the value of \fIparameter\fP is +substituted. +.TP +${\fIparameter\fP\fB:+\fP\fIword\fP} +\fBUse Alternate Value\fP. +If +.I parameter +is null or unset, nothing is substituted, otherwise the expansion of +.I word +is substituted. +.TP +${\fIparameter\fP\fB:\fP\fIoffset\fP} +.PD 0 +.TP +${\fIparameter\fP\fB:\fP\fIoffset\fP\fB:\fP\fIlength\fP} +.PD +\fBSubstring Expansion\fP. +Expands to up to \fIlength\fP characters of the value of \fIparameter\fP +starting at the character specified by \fIoffset\fP. +If \fIparameter\fP is \fB@\fP, an indexed array subscripted by +\fB@\fP or \fB*\fP, or an associative array name, the results differ as +described below. +If \fIlength\fP is omitted, expands to the substring of the value of +\fIparameter\fP starting at the character specified by \fIoffset\fP +and extending to the end of the value. +\fIlength\fP and \fIoffset\fP are arithmetic expressions (see +.SM +.B +ARITHMETIC EVALUATION +below). +.sp 1 +If \fIoffset\fP evaluates to a number less than zero, the value +is used as an offset in characters +from the end of the value of \fIparameter\fP. +If \fIlength\fP evaluates to a number less than zero, +it is interpreted as an offset in characters +from the end of the value of \fIparameter\fP rather than +a number of characters, and the expansion is the characters between +\fIoffset\fP and that result. +Note that a negative offset must be separated from the colon by at least +one space to avoid being confused with the \fB:-\fP expansion. +.sp 1 +If \fIparameter\fP is \fB@\fP, the result is \fIlength\fP positional +parameters beginning at \fIoffset\fP. +A negative \fIoffset\fP is taken relative to one greater than the greatest +positional parameter, so an offset of -1 evaluates to the last positional +parameter. +It is an expansion error if \fIlength\fP evaluates to a number less than +zero. +.sp 1 +If \fIparameter\fP is an indexed array name subscripted by @ or *, +the result is the \fIlength\fP +members of the array beginning with ${\fIparameter\fP[\fIoffset\fP]}. +A negative \fIoffset\fP is taken relative to one greater than the maximum +index of the specified array. +It is an expansion error if \fIlength\fP evaluates to a number less than +zero. +.sp 1 +Substring expansion applied to an associative array produces undefined +results. +.sp 1 +Substring indexing is zero-based unless the positional parameters +are used, in which case the indexing starts at 1 by default. +If \fIoffset\fP is 0, and the positional parameters are used, \fB$0\fP is +prefixed to the list. +.TP +${\fB!\fP\fIprefix\fP\fB*\fP} +.PD 0 +.TP +${\fB!\fP\fIprefix\fP\fB@\fP} +.PD +\fBNames matching prefix\fP. +Expands to the names of variables whose names begin with \fIprefix\fP, +separated by the first character of the +.SM +.B IFS +special variable. +When \fI@\fP is used and the expansion appears within double quotes, each +variable name expands to a separate word. +.TP +${\fB!\fP\fIname\fP[\fI@\fP]} +.PD 0 +.TP +${\fB!\fP\fIname\fP[\fI*\fP]} +.PD +\fBList of array keys\fP. +If \fIname\fP is an array variable, expands to the list of array indices +(keys) assigned in \fIname\fP. +If \fIname\fP is not an array, expands to 0 if \fIname\fP is set and null +otherwise. +When \fI@\fP is used and the expansion appears within double quotes, each +key expands to a separate word. +.TP +${\fB#\fP\fIparameter\fP} +\fBParameter length\fP. +The length in characters of the value of \fIparameter\fP is substituted. +If +.I parameter +is +.B * +or +.BR @ , +the value substituted is the number of positional parameters. +If +.I parameter +is an array name subscripted by +.B * +or +.BR @ , +the value substituted is the number of elements in the array. +If +.I parameter +is an indexed array name subscripted by a negative number, that number is +interpreted as relative to one greater than the maximum index of +\fIparameter\fP, so negative indices count back from the end of the +array, and an index of \-1 references the last element. +.TP +${\fIparameter\fP\fB#\fP\fIword\fP} +.PD 0 +.TP +${\fIparameter\fP\fB##\fP\fIword\fP} +.PD +\fBRemove matching prefix pattern\fP. +The +.I word +is expanded to produce a pattern just as in pathname +expansion. If the pattern matches the beginning of +the value of +.IR parameter , +then the result of the expansion is the expanded value of +.I parameter +with the shortest matching pattern (the ``\fB#\fP'' case) or the +longest matching pattern (the ``\fB##\fP'' case) deleted. +If +.I parameter +is +.B @ +or +.BR * , +the pattern removal operation is applied to each positional +parameter in turn, and the expansion is the resultant list. +If +.I parameter +is an array variable subscripted with +.B @ +or +.BR * , +the pattern removal operation is applied to each member of the +array in turn, and the expansion is the resultant list. +.TP +${\fIparameter\fP\fB%\fP\fIword\fP} +.PD 0 +.TP +${\fIparameter\fP\fB%%\fP\fIword\fP} +.PD +\fBRemove matching suffix pattern\fP. +The \fIword\fP is expanded to produce a pattern just as in +pathname expansion. +If the pattern matches a trailing portion of the expanded value of +.IR parameter , +then the result of the expansion is the expanded value of +.I parameter +with the shortest matching pattern (the ``\fB%\fP'' case) or the +longest matching pattern (the ``\fB%%\fP'' case) deleted. +If +.I parameter +is +.B @ +or +.BR * , +the pattern removal operation is applied to each positional +parameter in turn, and the expansion is the resultant list. +If +.I parameter +is an array variable subscripted with +.B @ +or +.BR * , +the pattern removal operation is applied to each member of the +array in turn, and the expansion is the resultant list. +.TP +${\fIparameter\fP\fB/\fP\fIpattern\fP\fB/\fP\fIstring\fP} +\fBPattern substitution\fP. +The \fIpattern\fP is expanded to produce a pattern just as in +pathname expansion. +\fIParameter\fP is expanded and the longest match of \fIpattern\fP +against its value is replaced with \fIstring\fP. +If \fIpattern\fP begins with \fB/\fP, all matches of \fIpattern\fP are +replaced with \fIstring\fP. Normally only the first match is replaced. +If \fIpattern\fP begins with \fB#\fP, it must match at the beginning +of the expanded value of \fIparameter\fP. +If \fIpattern\fP begins with \fB%\fP, it must match at the end +of the expanded value of \fIparameter\fP. +If \fIstring\fP is null, matches of \fIpattern\fP are deleted +and the \fB/\fP following \fIpattern\fP may be omitted. +If the +.B nocasematch +shell option is enabled, the match is performed without regard to the case +of alphabetic characters. +If +.I parameter +is +.B @ +or +.BR * , +the substitution operation is applied to each positional +parameter in turn, and the expansion is the resultant list. +If +.I parameter +is an array variable subscripted with +.B @ +or +.BR * , +the substitution operation is applied to each member of the +array in turn, and the expansion is the resultant list. +.TP +${\fIparameter\fP\fB^\fP\fIpattern\fP} +.PD 0 +.TP +${\fIparameter\fP\fB^^\fP\fIpattern\fP} +.TP +${\fIparameter\fP\fB,\fP\fIpattern\fP} +.TP +${\fIparameter\fP\fB,,\fP\fIpattern\fP} +.PD +\fBCase modification\fP. +This expansion modifies the case of alphabetic characters in \fIparameter\fP. +The \fIpattern\fP is expanded to produce a pattern just as in +pathname expansion. +Each character in the expanded value of \fIparameter\fP is tested against +\fIpattern\fP, and, if it matches the pattern, its case is converted. +The pattern should not attempt to match more than one character. +The \fB^\fP operator converts lowercase letters matching \fIpattern\fP +to uppercase; the \fB,\fP operator converts matching uppercase letters +to lowercase. +The \fB^^\fP and \fB,,\fP expansions convert each matched character in the +expanded value; the \fB^\fP and \fB,\fP expansions match and convert only +the first character in the expanded value. +If \fIpattern\fP is omitted, it is treated like a \fB?\fP, which matches +every character. +If +.I parameter +is +.B @ +or +.BR * , +the case modification operation is applied to each positional +parameter in turn, and the expansion is the resultant list. +If +.I parameter +is an array variable subscripted with +.B @ +or +.BR * , +the case modification operation is applied to each member of the +array in turn, and the expansion is the resultant list. +.TP +${\fIparameter\fP\fB@\fP\fIoperator\fP} +\fBParameter transformation\fP. +The expansion is either a transformation of the value of \fIparameter\fP +or information about \fIparameter\fP itself, depending on the value of +\fIoperator\fP. Each \fIoperator\fP is a single letter: +.sp 1 +.RS +.PD 0 +.TP +.B Q +The expansion is a string that is the value of \fIparameter\fP quoted in a +format that can be reused as input. +.TP +.B E +The expansion is a string that is the value of \fIparameter\fP with backslash +escape sequences expanded as with the \fB$'...'\fP quoting mechansim. +.TP +.B P +The expansion is a string that is the result of expanding the value of +\fIparameter\fP as if it were a prompt string (see \fBPROMPTING\fP below). +.TP +.B A +The expansion is a string in the form of a \fBdeclare\fP command that, if +evaluated, will recreate \fIparameter\fP with its attributes and value. +.TP +.B a +The expansion is a string consisting of flag values representing +\fIparameter\fP's attributes. +.PD +.PP +If +.I parameter +is +.B @ +or +.BR * , +the operation is applied to each positional +parameter in turn, and the expansion is the resultant list. +If +.I parameter +is an array variable subscripted with +.B @ +or +.BR * , +the case modification operation is applied to each member of the +array in turn, and the expansion is the resultant list. +.sp 1 +The result of the expansion is subject to word splitting and pathname +expansion as described below. +.RE +.SS Command Substitution +.PP +\fICommand substitution\fP allows the output of a command to replace +the command name. There are two forms: +.RS +.PP +\fB$(\fP\fIcommand\fP\|\fB)\fP +.RE +or +.RS +\fB\`\fP\fIcommand\fP\fB\`\fP +.RE +.PP +.B Bash +performs the expansion by executing \fIcommand\fP and +replacing the command substitution with the standard output of the +command, with any trailing newlines deleted. +Embedded newlines are not deleted, but they may be removed during +word splitting. +The command substitution \fB$(cat \fIfile\fP)\fR can be replaced by +the equivalent but faster \fB$(< \fIfile\fP)\fR. +.PP +When the old-style backquote form of substitution is used, +backslash retains its literal meaning except when followed by +.BR $ , +.BR \` , +or +.BR \e . +The first backquote not preceded by a backslash terminates the +command substitution. +When using the $(\^\fIcommand\fP\|) form, all characters between the +parentheses make up the command; none are treated specially. +.PP +Command substitutions may be nested. To nest when using the backquoted form, +escape the inner backquotes with backslashes. +.PP +If the substitution appears within double quotes, word splitting and +pathname expansion are not performed on the results. +.SS Arithmetic Expansion +.PP +Arithmetic expansion allows the evaluation of an arithmetic expression +and the substitution of the result. The format for arithmetic expansion is: +.RS +.PP +\fB$((\fP\fIexpression\fP\fB))\fP +.RE +.PP +The +.I expression +is treated as if it were within double quotes, but a double quote +inside the parentheses is not treated specially. +All tokens in the expression undergo parameter and variable expansion, +command substitution, and quote removal. +The result is treated as the arithmetic expression to be evaluated. +Arithmetic expansions may be nested. +.PP +The evaluation is performed according to the rules listed below under +.SM +.BR "ARITHMETIC EVALUATION" . +If +.I expression +is invalid, +.B bash +prints a message indicating failure and no substitution occurs. +.SS Process Substitution +.PP +\fIProcess substitution\fP is supported on systems that support named +pipes (\fIFIFOs\fP) or the \fB/dev/fd\fP method of naming open files. +It takes the form of +\fB<(\fP\fIlist\^\fP\fB)\fP +or +\fB>(\fP\fIlist\^\fP\fB)\fP. +The process \fIlist\fP is run with its input or output connected to a +\fIFIFO\fP or some file in \fB/dev/fd\fP. The name of this file is +passed as an argument to the current command as the result of the +expansion. If the \fB>(\fP\fIlist\^\fP\fB)\fP form is used, writing to +the file will provide input for \fIlist\fP. If the +\fB<(\fP\fIlist\^\fP\fB)\fP form is used, the file passed as an +argument should be read to obtain the output of \fIlist\fP. +.PP +When available, process substitution is performed +simultaneously with parameter and variable expansion, +command substitution, +and arithmetic expansion. +.SS Word Splitting +.PP +The shell scans the results of +parameter expansion, +command substitution, +and +arithmetic expansion +that did not occur within double quotes for +.IR "word splitting" . +.PP +The shell treats each character of +.SM +.B IFS +as a delimiter, and splits the results of the other +expansions into words using these characters as field terminators. +If +.SM +.B IFS +is unset, or its +value is exactly +.BR , +the default, then +sequences of +.BR , +.BR , +and +.B +at the beginning and end of the results of the previous +expansions are ignored, and +any sequence of +.SM +.B IFS +characters not at the beginning or end serves to delimit words. +If +.SM +.B IFS +has a value other than the default, then sequences of +the whitespace characters +.B space +and +.B tab +are ignored at the beginning and end of the +word, as long as the whitespace character is in the +value of +.SM +.BR IFS +(an +.SM +.B IFS +whitespace character). +Any character in +.SM +.B IFS +that is not +.SM +.B IFS +whitespace, along with any adjacent +.SM +.B IFS +whitespace characters, delimits a field. +A sequence of +.SM +.B IFS +whitespace characters is also treated as a delimiter. +If the value of +.SM +.B IFS +is null, no word splitting occurs. +.PP +Explicit null arguments (\^\f3"\^"\fP or \^\f3\(aq\^\(aq\fP\^) are retained. +Unquoted implicit null arguments, resulting from the expansion of +parameters that have no values, are removed. +If a parameter with no value is expanded within double quotes, a +null argument results and is retained. +.PP +Note that if no expansion occurs, no splitting +is performed. +.SS Pathname Expansion +.PP +After word splitting, +unless the +.B \-f +option has been set, +.B bash +scans each word for the characters +.BR * , +.BR ? , +and +.BR [ . +If one of these characters appears, then the word is +regarded as a +.IR pattern , +and replaced with an alphabetically sorted list of +filenames matching the pattern +(see +.SM +.B "Pattern Matching" +below). +If no matching filenames are found, +and the shell option +.B nullglob +is not enabled, the word is left unchanged. +If the +.B nullglob +option is set, and no matches are found, +the word is removed. +If the +.B failglob +shell option is set, and no matches are found, an error message +is printed and the command is not executed. +If the shell option +.B nocaseglob +is enabled, the match is performed without regard to the case +of alphabetic characters. +When a pattern is used for pathname expansion, +the character +.B ``.'' +at the start of a name or immediately following a slash +must be matched explicitly, unless the shell option +.B dotglob +is set. +When matching a pathname, the slash character must always be +matched explicitly. +In other cases, the +.B ``.'' +character is not treated specially. +See the description of +.B shopt +below under +.SM +.B SHELL BUILTIN COMMANDS +for a description of the +.BR nocaseglob , +.BR nullglob , +.BR failglob , +and +.B dotglob +shell options. +.PP +The +.SM +.B GLOBIGNORE +shell variable may be used to restrict the set of filenames matching a +.IR pattern . +If +.SM +.B GLOBIGNORE +is set, each matching filename that also matches one of the patterns in +.SM +.B GLOBIGNORE +is removed from the list of matches. +If the \fBnocaseglob\fP option is set, the matching against the patterns in +.SM +.B GLOBIGNORE +is performed without regard to case. +The filenames +.B ``.'' +and +.B ``..'' +are always ignored when +.SM +.B GLOBIGNORE +is set and not null. However, setting +.SM +.B GLOBIGNORE +to a non-null value has the effect of enabling the +.B dotglob +shell option, so all other filenames beginning with a +.B ``.'' +will match. +To get the old behavior of ignoring filenames beginning with a +.BR ``.'' , +make +.B ``.*'' +one of the patterns in +.SM +.BR GLOBIGNORE . +The +.B dotglob +option is disabled when +.SM +.B GLOBIGNORE +is unset. +.PP +\fBPattern Matching\fP +.PP +Any character that appears in a pattern, other than the special pattern +characters described below, matches itself. The NUL character may not +occur in a pattern. A backslash escapes the following character; the +escaping backslash is discarded when matching. +The special pattern characters must be quoted if +they are to be matched literally. +.PP +The special pattern characters have the following meanings: +.PP +.PD 0 +.RS +.TP +.B * +Matches any string, including the null string. +When the \fBglobstar\fP shell option is enabled, and \fB*\fP is used in +a pathname expansion context, two adjacent \fB*\fPs used as a single +pattern will match all files and zero or more directories and +subdirectories. +If followed by a \fB/\fP, two adjacent \fB*\fPs will match only directories +and subdirectories. +.TP +.B ? +Matches any single character. +.TP +.B [...] +Matches any one of the enclosed characters. A pair of characters +separated by a hyphen denotes a +\fIrange expression\fP; +any character that falls between those two characters, inclusive, +using the current locale's collating sequence and character set, +is matched. If the first character following the +.B [ +is a +.B ! +or a +.B ^ +then any character not enclosed is matched. +The sorting order of characters in range expressions is determined by +the current locale and the values of the +.SM +.B LC_COLLATE +or +.SM +.B LC_ALL +shell variables, if set. +To obtain the traditional interpretation of range expressions, where +.B [a\-d] +is equivalent to +.BR [abcd] , +set value of the +.B LC_ALL +shell variable to +.BR C , +or enable the +.B globasciiranges +shell option. +A +.B \- +may be matched by including it as the first or last character +in the set. +A +.B ] +may be matched by including it as the first character +in the set. +.br +.if t .sp 0.5 +.if n .sp 1 +Within +.B [ +and +.BR ] , +\fIcharacter classes\fP can be specified using the syntax +\fB[:\fP\fIclass\fP\fB:]\fP, where \fIclass\fP is one of the +following classes defined in the POSIX standard: +.PP +.RS +.B +.if n alnum alpha ascii blank cntrl digit graph lower print punct space upper word xdigit +.if t alnum alpha ascii blank cntrl digit graph lower print punct space upper word xdigit +.br +A character class matches any character belonging to that class. +The \fBword\fP character class matches letters, digits, and the character _. +.br +.if t .sp 0.5 +.if n .sp 1 +Within +.B [ +and +.BR ] , +an \fIequivalence class\fP can be specified using the syntax +\fB[=\fP\fIc\fP\fB=]\fP, which matches all characters with the +same collation weight (as defined by the current locale) as +the character \fIc\fP. +.br +.if t .sp 0.5 +.if n .sp 1 +Within +.B [ +and +.BR ] , +the syntax \fB[.\fP\fIsymbol\fP\fB.]\fP matches the collating symbol +\fIsymbol\fP. +.RE +.RE +.PD +.PP +If the \fBextglob\fP shell option is enabled using the \fBshopt\fP +builtin, several extended pattern matching operators are recognized. +In the following description, a \fIpattern-list\fP is a list of one +or more patterns separated by a \fB|\fP. +Composite patterns may be formed using one or more of the following +sub-patterns: +.sp 1 +.PD 0 +.RS +.TP +\fB?(\fP\^\fIpattern-list\^\fP\fB)\fP +Matches zero or one occurrence of the given patterns +.TP +\fB*(\fP\^\fIpattern-list\^\fP\fB)\fP +Matches zero or more occurrences of the given patterns +.TP +\fB+(\fP\^\fIpattern-list\^\fP\fB)\fP +Matches one or more occurrences of the given patterns +.TP +\fB@(\fP\^\fIpattern-list\^\fP\fB)\fP +Matches one of the given patterns +.TP +\fB!(\fP\^\fIpattern-list\^\fP\fB)\fP +Matches anything except one of the given patterns +.RE +.PD +.SS Quote Removal +.PP +After the preceding expansions, all unquoted occurrences of the +characters +.BR \e , +.BR \(aq , +and \^\f3"\fP\^ that did not result from one of the above +expansions are removed. +.SH REDIRECTION +Before a command is executed, its input and output +may be +.I redirected +using a special notation interpreted by the shell. +Redirection allows commands' file handles to be +duplicated, opened, closed, +made to refer to different files, +and can change the files the command reads from and writes to. +Redirection may also be used to modify file handles in the +current shell execution environment. +The following redirection +operators may precede or appear anywhere within a +.I simple command +or may follow a +.IR command . +Redirections are processed in the order they appear, from +left to right. +.PP +Each redirection that may be preceded by a file descriptor number +may instead be preceded by a word of the form {\fIvarname\fP}. +In this case, for each redirection operator except +>&- and <&-, the shell will allocate a file descriptor greater +than or equal to 10 and assign it to \fIvarname\fP. +If >&- or <&- is preceded +by {\fIvarname\fP}, the value of \fIvarname\fP defines the file +descriptor to close. +.PP +In the following descriptions, if the file descriptor number is +omitted, and the first character of the redirection operator is +.BR < , +the redirection refers to the standard input (file descriptor +0). If the first character of the redirection operator is +.BR > , +the redirection refers to the standard output (file descriptor +1). +.PP +The word following the redirection operator in the following +descriptions, unless otherwise noted, is subjected to +brace expansion, tilde expansion, parameter and variable expansion, +command substitution, arithmetic expansion, quote removal, +pathname expansion, and word splitting. +If it expands to more than one word, +.B bash +reports an error. +.PP +Note that the order of redirections is significant. For example, +the command +.RS +.PP +ls \fB>\fP dirlist 2\fB>&\fP1 +.RE +.PP +directs both standard output and standard error to the file +.IR dirlist , +while the command +.RS +.PP +ls 2\fB>&\fP1 \fB>\fP dirlist +.RE +.PP +directs only the standard output to file +.IR dirlist , +because the standard error was duplicated from the standard output +before the standard output was redirected to +.IR dirlist . +.PP +\fBBash\fP handles several filenames specially when they are used in +redirections, as described in the following table: +.RS +.PP +.PD 0 +.TP +.B /dev/fd/\fIfd\fP +If \fIfd\fP is a valid integer, file descriptor \fIfd\fP is duplicated. +.TP +.B /dev/stdin +File descriptor 0 is duplicated. +.TP +.B /dev/stdout +File descriptor 1 is duplicated. +.TP +.B /dev/stderr +File descriptor 2 is duplicated. +.TP +.B /dev/tcp/\fIhost\fP/\fIport\fP +If \fIhost\fP is a valid hostname or Internet address, and \fIport\fP +is an integer port number or service name, \fBbash\fP attempts to open +the corresponding TCP socket. +.TP +.B /dev/udp/\fIhost\fP/\fIport\fP +If \fIhost\fP is a valid hostname or Internet address, and \fIport\fP +is an integer port number or service name, \fBbash\fP attempts to open +the corresponding UDP socket. +.PD +.RE +.PP +A failure to open or create a file causes the redirection to fail. +.PP +Redirections using file descriptors greater than 9 should be used with +care, as they may conflict with file descriptors the shell uses +internally. +.SS Redirecting Input +.PP +Redirection of input causes the file whose name results from +the expansion of +.I word +to be opened for reading on file descriptor +.IR n , +or the standard input (file descriptor 0) if +.I n +is not specified. +.PP +The general format for redirecting input is: +.RS +.PP +[\fIn\fP]\fB<\fP\fIword\fP +.RE +.SS Redirecting Output +.PP +Redirection of output causes the file whose name results from +the expansion of +.I word +to be opened for writing on file descriptor +.IR n , +or the standard output (file descriptor 1) if +.I n +is not specified. If the file does not exist it is created; +if it does exist it is truncated to zero size. +.PP +The general format for redirecting output is: +.RS +.PP +[\fIn\fP]\fB>\fP\fIword\fP +.RE +.PP +If the redirection operator is +.BR > , +and the +.B noclobber +option to the +.B set +builtin has been enabled, the redirection will fail if the file +whose name results from the expansion of \fIword\fP exists and is +a regular file. +If the redirection operator is +.BR >| , +or the redirection operator is +.B > +and the +.B noclobber +option to the +.B set +builtin command is not enabled, the redirection is attempted even +if the file named by \fIword\fP exists. +.SS Appending Redirected Output +.PP +Redirection of output in this fashion +causes the file whose name results from +the expansion of +.I word +to be opened for appending on file descriptor +.IR n , +or the standard output (file descriptor 1) if +.I n +is not specified. If the file does not exist it is created. +.PP +The general format for appending output is: +.RS +.PP +[\fIn\fP]\fB>>\fP\fIword\fP +.RE +.PP +.SS Redirecting Standard Output and Standard Error +.PP +This construct allows both the +standard output (file descriptor 1) and +the standard error output (file descriptor 2) +to be redirected to the file whose name is the +expansion of +.IR word . +.PP +There are two formats for redirecting standard output and +standard error: +.RS +.PP +\fB&>\fP\fIword\fP +.RE +and +.RS +\fB>&\fP\fIword\fP +.RE +.PP +Of the two forms, the first is preferred. +This is semantically equivalent to +.RS +.PP +\fB>\fP\fIword\fP 2\fB>&\fP1 +.RE +.PP +When using the second form, \fIword\fP may not expand to a number or +\fB\-\fP. If it does, other redirection operators apply +(see \fBDuplicating File Descriptors\fP below) for compatibility +reasons. +.SS Appending Standard Output and Standard Error +.PP +This construct allows both the +standard output (file descriptor 1) and +the standard error output (file descriptor 2) +to be appended to the file whose name is the +expansion of +.IR word . +.PP +The format for appending standard output and standard error is: +.RS +.PP +\fB&>>\fP\fIword\fP +.RE +.PP +This is semantically equivalent to +.RS +.PP +\fB>>\fP\fIword\fP 2\fB>&\fP1 +.RE +.PP +(see \fBDuplicating File Descriptors\fP below). +.SS Here Documents +.PP +This type of redirection instructs the shell to read input from the +current source until a line containing only +.I delimiter +(with no trailing blanks) +is seen. All of +the lines read up to that point are then used as the standard +input (or file descriptor \fIn\fP if \fIn\fP is specified) for a command. +.PP +The format of here-documents is: +.RS +.PP +.nf +[\fIn\fP]\fB<<\fP[\fB\-\fP]\fIword\fP + \fIhere-document\fP +\fIdelimiter\fP +.fi +.RE +.PP +No parameter and variable expansion, command substitution, +arithmetic expansion, or pathname expansion is performed on +.IR word . +If any characters in +.I word +are quoted, the +.I delimiter +is the result of quote removal on +.IR word , +and the lines in the here-document are not expanded. +If \fIword\fP is unquoted, +all lines of the here-document are subjected to +parameter expansion, command substitution, and arithmetic expansion, +the character sequence +.B \e +is ignored, and +.B \e +must be used to quote the characters +.BR \e , +.BR $ , +and +.BR \` . +.PP +If the redirection operator is +.BR <<\- , +then all leading tab characters are stripped from input lines and the +line containing +.IR delimiter . +This allows +here-documents within shell scripts to be indented in a +natural fashion. +.SS "Here Strings" +A variant of here documents, the format is: +.RS +.PP +.nf +[\fIn\fP]\fB<<<\fP\fIword\fP +.fi +.RE +.PP +The \fIword\fP undergoes +brace expansion, tilde expansion, parameter and variable expansion, +command substitution, arithmetic expansion, and quote removal. +Pathname expansion and word splitting are not performed. +The result is supplied as a single string to the command on its +standard input (or file descriptor \fIn\fP if \fIn\fP is specified). +.SS "Duplicating File Descriptors" + +.PP +The redirection operator +.RS +.PP +[\fIn\fP]\fB<&\fP\fIword\fP +.RE +.PP +is used to duplicate input file descriptors. +If +.I word +expands to one or more digits, the file descriptor denoted by +.I n +is made to be a copy of that file descriptor. +If the digits in +.I word +do not specify a file descriptor open for input, a redirection error occurs. +If +.I word +evaluates to +.BR \- , +file descriptor +.I n +is closed. If +.I n +is not specified, the standard input (file descriptor 0) is used. +.PP +The operator +.RS +.PP +[\fIn\fP]\fB>&\fP\fIword\fP +.RE +.PP +is used similarly to duplicate output file descriptors. If +.I n +is not specified, the standard output (file descriptor 1) is used. +If the digits in +.I word +do not specify a file descriptor open for output, a redirection error occurs. +If +.I word +evaluates to +.BR \- , +file descriptor +.I n +is closed. +As a special case, if \fIn\fP is omitted, and \fIword\fP does not +expand to one or more digits or \fB\-\fP, the standard output and standard +error are redirected as described previously. +.SS "Moving File Descriptors" +.PP +The redirection operator +.RS +.PP +[\fIn\fP]\fB<&\fP\fIdigit\fP\fB\-\fP +.RE +.PP +moves the file descriptor \fIdigit\fP to file descriptor +.IR n , +or the standard input (file descriptor 0) if \fIn\fP is not specified. +\fIdigit\fP is closed after being duplicated to \fIn\fP. +.PP +Similarly, the redirection operator +.RS +.PP +[\fIn\fP]\fB>&\fP\fIdigit\fP\fB\-\fP +.RE +.PP +moves the file descriptor \fIdigit\fP to file descriptor +.IR n , +or the standard output (file descriptor 1) if \fIn\fP is not specified. +.SS "Opening File Descriptors for Reading and Writing" +.PP +The redirection operator +.RS +.PP +[\fIn\fP]\fB<>\fP\fIword\fP +.RE +.PP +causes the file whose name is the expansion of +.I word +to be opened for both reading and writing on file descriptor +.IR n , +or on file descriptor 0 if +.I n +is not specified. If the file does not exist, it is created. +.SH ALIASES +\fIAliases\fP allow a string to be substituted for a word when it is used +as the first word of a simple command. +The shell maintains a list of aliases that may be set and unset with the +.B alias +and +.B unalias +builtin commands (see +.SM +.B SHELL BUILTIN COMMANDS +below). +The first word of each simple command, if unquoted, +is checked to see if it has an +alias. If so, that word is replaced by the text of the alias. +The characters \fB/\fP, \fB$\fP, \fB\`\fP, and \fB=\fP and +any of the shell \fImetacharacters\fP or quoting characters +listed above may not appear in an alias name. +The replacement text may contain any valid shell input, +including shell metacharacters. +The first word of the replacement text is tested +for aliases, but a word that is identical to an alias being expanded +is not expanded a second time. +This means that one may alias +.B ls +to +.BR "ls \-F" , +for instance, and +.B bash +does not try to recursively expand the replacement text. +If the last character of the alias value is a +.IR blank , +then the next command +word following the alias is also checked for alias expansion. +.PP +Aliases are created and listed with the +.B alias +command, and removed with the +.B unalias +command. +.PP +There is no mechanism for using arguments in the replacement text. +If arguments are needed, a shell function should be used (see +.SM +.B FUNCTIONS +below). +.PP +Aliases are not expanded when the shell is not interactive, unless +the +.B expand_aliases +shell option is set using +.B shopt +(see the description of +.B shopt +under +.SM +\fBSHELL BUILTIN COMMANDS\fP +below). +.PP +The rules concerning the definition and use of aliases are +somewhat confusing. +.B Bash +always reads at least one complete line +of input before executing any +of the commands on that line. Aliases are expanded when a +command is read, not when it is executed. Therefore, an +alias definition appearing on the same line as another +command does not take effect until the next line of input is read. +The commands following the alias definition +on that line are not affected by the new alias. +This behavior is also an issue when functions are executed. +Aliases are expanded when a function definition is read, +not when the function is executed, because a function definition +is itself a command. As a consequence, aliases +defined in a function are not available until after that +function is executed. To be safe, always put +alias definitions on a separate line, and do not use +.B alias +in compound commands. +.PP +For almost every purpose, aliases are superseded by +shell functions. +.SH FUNCTIONS +A shell function, defined as described above under +.SM +.BR "SHELL GRAMMAR" , +stores a series of commands for later execution. +When the name of a shell function is used as a simple command name, +the list of commands associated with that function name is executed. +Functions are executed in the context of the +current shell; no new process is created to interpret +them (contrast this with the execution of a shell script). +When a function is executed, the arguments to the +function become the positional parameters +during its execution. +The special parameter +.B # +is updated to reflect the change. Special parameter \fB0\fP +is unchanged. +The first element of the +.SM +.B FUNCNAME +variable is set to the name of the function while the function +is executing. +.PP +All other aspects of the shell execution +environment are identical between a function and its caller +with these exceptions: the +.SM +.B DEBUG +and +.B RETURN +traps (see the description of the +.B trap +builtin under +.SM +.B SHELL BUILTIN COMMANDS +below) are not inherited unless the function has been given the +\fBtrace\fP attribute (see the description of the +.SM +.B declare +builtin below) or the +\fB\-o functrace\fP shell option has been enabled with +the \fBset\fP builtin +(in which case all functions inherit the \fBDEBUG\fP and \fBRETURN\fP traps), +and the +.SM +.B ERR +trap is not inherited unless the \fB\-o errtrace\fP shell option has +been enabled. +.PP +Variables local to the function may be declared with the +.B local +builtin command. Ordinarily, variables and their values +are shared between the function and its caller. +.PP +The \fBFUNCNEST\fP variable, if set to a numeric value greater +than 0, defines a maximum function nesting level. Function +invocations that exceed the limit cause the entire command to +abort. +.PP +If the builtin command +.B return +is executed in a function, the function completes and +execution resumes with the next command after the function +call. +Any command associated with the \fBRETURN\fP trap is executed +before execution resumes. +When a function completes, the values of the +positional parameters and the special parameter +.B # +are restored to the values they had prior to the function's +execution. +.PP +Function names and definitions may be listed with the +.B \-f +option to the +.B declare +or +.B typeset +builtin commands. The +.B \-F +option to +.B declare +or +.B typeset +will list the function names only +(and optionally the source file and line number, if the \fBextdebug\fP +shell option is enabled). +Functions may be exported so that subshells +automatically have them defined with the +.B \-f +option to the +.B export +builtin. +A function definition may be deleted using the \fB\-f\fP option to +the +.B unset +builtin. +Note that shell functions and variables with the same name may result +in multiple identically-named entries in the environment passed to the +shell's children. +Care should be taken in cases where this may cause a problem. +.PP +Functions may be recursive. +The \fBFUNCNEST\fP variable may be used to limit the depth of the +function call stack and restrict the number of function invocations. +By default, no limit is imposed on the number of recursive calls. +.SH "ARITHMETIC EVALUATION" +The shell allows arithmetic expressions to be evaluated, under +certain circumstances (see the \fBlet\fP and \fBdeclare\fP builtin +commands and \fBArithmetic Expansion\fP). +Evaluation is done in fixed-width integers with no check for overflow, +though division by 0 is trapped and flagged as an error. +The operators and their precedence, associativity, and values +are the same as in the C language. +The following list of operators is grouped into levels of +equal-precedence operators. +The levels are listed in order of decreasing precedence. +.PP +.PD 0 +.TP +.B \fIid\fP++ \fIid\fP\-\- +variable post-increment and post-decrement +.TP +.B ++\fIid\fP \-\-\fIid\fP +variable pre-increment and pre-decrement +.TP +.B \- + +unary minus and plus +.TP +.B ! ~ +logical and bitwise negation +.TP +.B ** +exponentiation +.TP +.B * / % +multiplication, division, remainder +.TP +.B + \- +addition, subtraction +.TP +.B << >> +left and right bitwise shifts +.TP +.B <= >= < > +comparison +.TP +.B == != +equality and inequality +.TP +.B & +bitwise AND +.TP +.B ^ +bitwise exclusive OR +.TP +.B | +bitwise OR +.TP +.B && +logical AND +.TP +.B || +logical OR +.TP +.B \fIexpr\fP?\fIexpr\fP:\fIexpr\fP +conditional operator +.TP +.B = *= /= %= += \-= <<= >>= &= ^= |= +assignment +.TP +.B \fIexpr1\fP , \fIexpr2\fP +comma +.PD +.PP +Shell variables are allowed as operands; parameter expansion is +performed before the expression is evaluated. +Within an expression, shell variables may also be referenced by name +without using the parameter expansion syntax. +A shell variable that is null or unset evaluates to 0 when referenced +by name without using the parameter expansion syntax. +The value of a variable is evaluated as an arithmetic expression +when it is referenced, or when a variable which has been given the +\fIinteger\fP attribute using \fBdeclare -i\fP is assigned a value. +A null value evaluates to 0. +A shell variable need not have its \fIinteger\fP attribute +turned on to be used in an expression. +.PP +Constants with a leading 0 are interpreted as octal numbers. +A leading 0x or 0X denotes hexadecimal. +Otherwise, numbers take the form [\fIbase#\fP]n, where the optional \fIbase\fP +is a decimal number between 2 and 64 representing the arithmetic +base, and \fIn\fP is a number in that base. +If \fIbase#\fP is omitted, then base 10 is used. +When specifying \fIn\fP, +the digits greater< than 9 are represented by the lowercase letters, +the uppercase letters, @, and _, in that order. +If \fIbase\fP is less than or equal to 36, lowercase and uppercase +letters may be used interchangeably to represent numbers between 10 +and 35. +.PP +Operators are evaluated in order of precedence. Sub-expressions in +parentheses are evaluated first and may override the precedence +rules above. +.SH "CONDITIONAL EXPRESSIONS" +Conditional expressions are used by the \fB[[\fP compound command and +the \fBtest\fP and \fB[\fP builtin commands to test file attributes +and perform string and arithmetic comparisons. +Expressions are formed from the following unary or binary primaries. +If any \fIfile\fP argument to one of the primaries is of the form +\fI/dev/fd/n\fP, then file descriptor \fIn\fP is checked. +If the \fIfile\fP argument to one of the primaries is one of +\fI/dev/stdin\fP, \fI/dev/stdout\fP, or \fI/dev/stderr\fP, file +descriptor 0, 1, or 2, respectively, is checked. +.PP +Unless otherwise specified, primaries that operate on files follow symbolic +links and operate on the target of the link, rather than the link itself. +.if t .sp 0.5 +.if n .sp 1 +When used with \fB[[\fP, the \fB<\fP and \fB>\fP operators sort +lexicographically using the current locale. +The \fBtest\fP command sorts using ASCII ordering. +.sp 1 +.PD 0 +.TP +.B \-a \fIfile\fP +True if \fIfile\fP exists. +.TP +.B \-b \fIfile\fP +True if \fIfile\fP exists and is a block special file. +.TP +.B \-c \fIfile\fP +True if \fIfile\fP exists and is a character special file. +.TP +.B \-d \fIfile\fP +True if \fIfile\fP exists and is a directory. +.TP +.B \-e \fIfile\fP +True if \fIfile\fP exists. +.TP +.B \-f \fIfile\fP +True if \fIfile\fP exists and is a regular file. +.TP +.B \-g \fIfile\fP +True if \fIfile\fP exists and is set-group-id. +.TP +.B \-h \fIfile\fP +True if \fIfile\fP exists and is a symbolic link. +.TP +.B \-k \fIfile\fP +True if \fIfile\fP exists and its ``sticky'' bit is set. +.TP +.B \-p \fIfile\fP +True if \fIfile\fP exists and is a named pipe (FIFO). +.TP +.B \-r \fIfile\fP +True if \fIfile\fP exists and is readable. +.TP +.B \-s \fIfile\fP +True if \fIfile\fP exists and has a size greater than zero. +.TP +.B \-t \fIfd\fP +True if file descriptor +.I fd +is open and refers to a terminal. +.TP +.B \-u \fIfile\fP +True if \fIfile\fP exists and its set-user-id bit is set. +.TP +.B \-w \fIfile\fP +True if \fIfile\fP exists and is writable. +.TP +.B \-x \fIfile\fP +True if \fIfile\fP exists and is executable. +.TP +.B \-G \fIfile\fP +True if \fIfile\fP exists and is owned by the effective group id. +.TP +.B \-L \fIfile\fP +True if \fIfile\fP exists and is a symbolic link. +.TP +.B \-N \fIfile\fP +True if \fIfile\fP exists and has been modified since it was last read. +.TP +.B \-O \fIfile\fP +True if \fIfile\fP exists and is owned by the effective user id. +.TP +.B \-S \fIfile\fP +True if \fIfile\fP exists and is a socket. +.TP +\fIfile1\fP \fB\-ef\fP \fIfile2\fP +True if \fIfile1\fP and \fIfile2\fP refer to the same device and +inode numbers. +.TP +\fIfile1\fP \-\fBnt\fP \fIfile2\fP +True if \fIfile1\fP is newer (according to modification date) than \fIfile2\fP, +or if \fIfile1\fP exists and \fPfile2\fP does not. +.TP +\fIfile1\fP \-\fBot\fP \fIfile2\fP +True if \fIfile1\fP is older than \fIfile2\fP, or if \fIfile2\fP exists +and \fIfile1\fP does not. +.TP +.B \-o \fIoptname\fP +True if the shell option +.I optname +is enabled. +See the list of options under the description of the +.B \-o +option to the +.B set +builtin below. +.TP +.B \-v \fIvarname\fP +True if the shell variable +.I varname +is set (has been assigned a value). +.TP +.B \-R \fIvarname\fP +True if the shell variable +.I varname +is set and is a name reference. +.TP +.B \-z \fIstring\fP +True if the length of \fIstring\fP is zero. +.TP +\fIstring\fP +.PD 0 +.TP +.B \-n \fIstring\fP +.PD +True if the length of +.I string +is non-zero. +.TP +\fIstring1\fP \fB==\fP \fIstring2\fP +.PD 0 +.TP +\fIstring1\fP \fB=\fP \fIstring2\fP +.PD +True if the strings are equal. \fB=\fP should be used +with the \fBtest\fP command for POSIX conformance. +When used with the \fB[[\fP command, this performs pattern matching as +described above (\fBCompound Commands\fP). +.TP +\fIstring1\fP \fB!=\fP \fIstring2\fP +True if the strings are not equal. +.TP +\fIstring1\fP \fB<\fP \fIstring2\fP +True if \fIstring1\fP sorts before \fIstring2\fP lexicographically. +.TP +\fIstring1\fP \fB>\fP \fIstring2\fP +True if \fIstring1\fP sorts after \fIstring2\fP lexicographically. +.TP +.I \fIarg1\fP \fBOP\fP \fIarg2\fP +.SM +.B OP +is one of +.BR \-eq , +.BR \-ne , +.BR \-lt , +.BR \-le , +.BR \-gt , +or +.BR \-ge . +These arithmetic binary operators return true if \fIarg1\fP +is equal to, not equal to, less than, less than or equal to, +greater than, or greater than or equal to \fIarg2\fP, respectively. +.I Arg1 +and +.I arg2 +may be positive or negative integers. +.PD +.SH "SIMPLE COMMAND EXPANSION" +When a simple command is executed, the shell performs the following +expansions, assignments, and redirections, from left to right. +.IP 1. +The words that the parser has marked as variable assignments (those +preceding the command name) and redirections are saved for later +processing. +.IP 2. +The words that are not variable assignments or redirections are +expanded. If any words remain after expansion, the first word +is taken to be the name of the command and the remaining words are +the arguments. +.IP 3. +Redirections are performed as described above under +.SM +.BR REDIRECTION . +.IP 4. +The text after the \fB=\fP in each variable assignment undergoes tilde +expansion, parameter expansion, command substitution, arithmetic expansion, +and quote removal before being assigned to the variable. +.PP +If no command name results, the variable assignments affect the current +shell environment. Otherwise, the variables are added to the environment +of the executed command and do not affect the current shell environment. +If any of the assignments attempts to assign a value to a readonly variable, +an error occurs, and the command exits with a non-zero status. +.PP +If no command name results, redirections are performed, but do not +affect the current shell environment. A redirection error causes the +command to exit with a non-zero status. +.PP +If there is a command name left after expansion, execution proceeds as +described below. Otherwise, the command exits. If one of the expansions +contained a command substitution, the exit status of the command is +the exit status of the last command substitution performed. If there +were no command substitutions, the command exits with a status of zero. +.SH "COMMAND EXECUTION" +After a command has been split into words, if it results in a +simple command and an optional list of arguments, the following +actions are taken. +.PP +If the command name contains no slashes, the shell attempts to +locate it. If there exists a shell function by that name, that +function is invoked as described above in +.SM +.BR FUNCTIONS . +If the name does not match a function, the shell searches for +it in the list of shell builtins. If a match is found, that +builtin is invoked. +.PP +If the name is neither a shell function nor a builtin, +and contains no slashes, +.B bash +searches each element of the +.SM +.B PATH +for a directory containing an executable file by that name. +.B Bash +uses a hash table to remember the full pathnames of executable +files (see +.B hash +under +.SM +.B "SHELL BUILTIN COMMANDS" +below). +A full search of the directories in +.SM +.B PATH +is performed only if the command is not found in the hash table. +If the search is unsuccessful, the shell searches for a defined shell +function named \fBcommand_not_found_handle\fP. +If that function exists, it is invoked with the original command and +the original command's arguments as its arguments, and the function's +exit status becomes the exit status of the shell. +If that function is not defined, the shell prints an error +message and returns an exit status of 127. +.PP +If the search is successful, or if the command name contains +one or more slashes, the shell executes the named program in a +separate execution environment. +Argument 0 is set to the name given, and the remaining arguments +to the command are set to the arguments given, if any. +.PP +If this execution fails because the file is not in executable +format, and the file is not a directory, it is assumed to be +a \fIshell script\fP, a file +containing shell commands. A subshell is spawned to execute +it. This subshell reinitializes itself, so +that the effect is as if a new shell had been invoked +to handle the script, with the exception that the locations of +commands remembered by the parent (see +.B hash +below under +.SM +\fBSHELL BUILTIN COMMANDS\fP) +are retained by the child. +.PP +If the program is a file beginning with +.BR #! , +the remainder of the first line specifies an interpreter +for the program. The shell executes the +specified interpreter on operating systems that do not +handle this executable format themselves. The arguments to the +interpreter consist of a single optional argument following the +interpreter name on the first line of the program, followed +by the name of the program, followed by the command +arguments, if any. +.SH COMMAND EXECUTION ENVIRONMENT +The shell has an \fIexecution environment\fP, which consists of the +following: +.IP \(bu +open files inherited by the shell at invocation, as modified by +redirections supplied to the \fBexec\fP builtin +.IP \(bu +the current working directory as set by \fBcd\fP, \fBpushd\fP, or +\fBpopd\fP, or inherited by the shell at invocation +.IP \(bu +the file creation mode mask as set by \fBumask\fP or inherited from +the shell's parent +.IP \(bu +current traps set by \fBtrap\fP +.IP \(bu +shell parameters that are set by variable assignment or with \fBset\fP +or inherited from the shell's parent in the environment +.IP \(bu +shell functions defined during execution or inherited from the shell's +parent in the environment +.IP \(bu +options enabled at invocation (either by default or with command-line +arguments) or by \fBset\fP +.IP \(bu +options enabled by \fBshopt\fP +.IP \(bu +shell aliases defined with \fBalias\fP +.IP \(bu +various process IDs, including those of background jobs, the value +of \fB$$\fP, and the value of +.SM +.B PPID +.PP +When a simple command other than a builtin or shell function +is to be executed, it +is invoked in a separate execution environment that consists of +the following. Unless otherwise noted, the values are inherited +from the shell. +.if n .sp 1 +.IP \(bu +the shell's open files, plus any modifications and additions specified +by redirections to the command +.IP \(bu +the current working directory +.IP \(bu +the file creation mode mask +.IP \(bu +shell variables and functions marked for export, along with variables +exported for the command, passed in the environment +.IP \(bu +traps caught by the shell are reset to the values inherited from the +shell's parent, and traps ignored by the shell are ignored +.PP +A command invoked in this separate environment cannot affect the +shell's execution environment. +.PP +Command substitution, commands grouped with parentheses, +and asynchronous commands are invoked in a +subshell environment that is a duplicate of the shell environment, +except that traps caught by the shell are reset to the values +that the shell inherited from its parent at invocation. Builtin +commands that are invoked as part of a pipeline are also executed in a +subshell environment. Changes made to the subshell environment +cannot affect the shell's execution environment. +.PP +Subshells spawned to execute command substitutions inherit the value of +the \fB\-e\fP option from the parent shell. When not in \fIposix\fP mode, +\fBbash\fP clears the \fB\-e\fP option in such subshells. +.PP +If a command is followed by a \fB&\fP and job control is not active, the +default standard input for the command is the empty file \fI/dev/null\fP. +Otherwise, the invoked command inherits the file descriptors of the calling +shell as modified by redirections. +.SH ENVIRONMENT +When a program is invoked it is given an array of strings +called the +.IR environment . +This is a list of +\fIname\fP\-\fIvalue\fP pairs, of the form +.IR "name\fR=\fPvalue" . +.PP +The shell provides several ways to manipulate the environment. +On invocation, the shell scans its own environment and +creates a parameter for each name found, automatically marking +it for +.I export +to child processes. Executed commands inherit the environment. +The +.B export +and +.B declare \-x +commands allow parameters and functions to be added to and +deleted from the environment. If the value of a parameter +in the environment is modified, the new value becomes part +of the environment, replacing the old. The environment +inherited by any executed command consists of the shell's +initial environment, whose values may be modified in the shell, +less any pairs removed by the +.B unset +command, plus any additions via the +.B export +and +.B declare \-x +commands. +.PP +The environment for any +.I simple command +or function may be augmented temporarily by prefixing it with +parameter assignments, as described above in +.SM +.BR PARAMETERS . +These assignment statements affect only the environment seen +by that command. +.PP +If the +.B \-k +option is set (see the +.B set +builtin command below), then +.I all +parameter assignments are placed in the environment for a command, +not just those that precede the command name. +.PP +When +.B bash +invokes an external command, the variable +.B _ +is set to the full filename of the command and passed to that +command in its environment. +.SH "EXIT STATUS" +.PP +The exit status of an executed command is the value returned by the +\fIwaitpid\fP system call or equivalent function. Exit statuses +fall between 0 and 255, though, as explained below, the shell may +use values above 125 specially. Exit statuses from shell builtins and +compound commands are also limited to this range. Under certain +circumstances, the shell will use special values to indicate specific +failure modes. +.PP +For the shell's purposes, a command which exits with a +zero exit status has succeeded. An exit status of zero +indicates success. A non-zero exit status indicates failure. +When a command terminates on a fatal signal \fIN\fP, \fBbash\fP uses +the value of 128+\fIN\fP as the exit status. +.PP +If a command is not found, the child process created to +execute it returns a status of 127. If a command is found +but is not executable, the return status is 126. +.PP +If a command fails because of an error during expansion or redirection, +the exit status is greater than zero. +.PP +Shell builtin commands return a status of 0 (\fItrue\fP) if +successful, and non-zero (\fIfalse\fP) if an error occurs +while they execute. +All builtins return an exit status of 2 to indicate incorrect usage, +generally invalid options or missing arguments. +.PP +\fBBash\fP itself returns the exit status of the last command +executed, unless a syntax error occurs, in which case it exits +with a non-zero value. See also the \fBexit\fP builtin +command below. +.SH SIGNALS +When \fBbash\fP is interactive, in the absence of any traps, it ignores +.SM +.B SIGTERM +(so that \fBkill 0\fP does not kill an interactive shell), +and +.SM +.B SIGINT +is caught and handled (so that the \fBwait\fP builtin is interruptible). +In all cases, \fBbash\fP ignores +.SM +.BR SIGQUIT . +If job control is in effect, +.B bash +ignores +.SM +.BR SIGTTIN , +.SM +.BR SIGTTOU , +and +.SM +.BR SIGTSTP . +.PP +Non-builtin commands run by \fBbash\fP have signal handlers +set to the values inherited by the shell from its parent. +When job control is not in effect, asynchronous commands +ignore +.SM +.B SIGINT +and +.SM +.B SIGQUIT +in addition to these inherited handlers. +Commands run as a result of command substitution ignore the +keyboard-generated job control signals +.SM +.BR SIGTTIN , +.SM +.BR SIGTTOU , +and +.SM +.BR SIGTSTP . +.PP +The shell exits by default upon receipt of a +.SM +.BR SIGHUP . +Before exiting, an interactive shell resends the +.SM +.B SIGHUP +to all jobs, running or stopped. +Stopped jobs are sent +.SM +.B SIGCONT +to ensure that they receive the +.SM +.BR SIGHUP . +To prevent the shell from +sending the signal to a particular job, it should be removed from the +jobs table with the +.B disown +builtin (see +.SM +.B "SHELL BUILTIN COMMANDS" +below) or marked +to not receive +.SM +.B SIGHUP +using +.BR "disown \-h" . +.PP +If the +.B huponexit +shell option has been set with +.BR shopt , +.B bash +sends a +.SM +.B SIGHUP +to all jobs when an interactive login shell exits. +.PP +If \fBbash\fP is waiting for a command to complete and receives a signal +for which a trap has been set, the trap will not be executed until +the command completes. +When \fBbash\fP is waiting for an asynchronous command via the \fBwait\fP +builtin, the reception of a signal for which a trap has been set will +cause the \fBwait\fP builtin to return immediately with an exit status +greater than 128, immediately after which the trap is executed. +.SH "JOB CONTROL" +.I Job control +refers to the ability to selectively stop (\fIsuspend\fP) +the execution of processes and continue (\fIresume\fP) +their execution at a later point. A user typically employs +this facility via an interactive interface supplied jointly +by the operating system kernel's terminal driver and +.BR bash . +.PP +The shell associates a +.I job +with each pipeline. It keeps a table of currently executing +jobs, which may be listed with the +.B jobs +command. When +.B bash +starts a job asynchronously (in the +.IR background ), +it prints a line that looks like: +.RS +.PP +[1] 25647 +.RE +.PP +indicating that this job is job number 1 and that the process ID +of the last process in the pipeline associated with this job is 25647. +All of the processes in a single pipeline are members of the same job. +.B Bash +uses the +.I job +abstraction as the basis for job control. +.PP +To facilitate the implementation of the user interface to job +control, the operating system maintains the notion of a \fIcurrent terminal +process group ID\fP. Members of this process group (processes whose +process group ID is equal to the current terminal process group ID) +receive keyboard-generated signals such as +.SM +.BR SIGINT . +These processes are said to be in the +.IR foreground . +.I Background +processes are those whose process group ID differs from the terminal's; +such processes are immune to keyboard-generated signals. +Only foreground processes are allowed to read from or, if the +user so specifies with \f(CWstty tostop\fP, write to the +terminal. +Background processes which attempt to read from (write to when +\f(CWstty tostop\fP is in effect) the +terminal are sent a +.SM +.B SIGTTIN (SIGTTOU) +signal by the kernel's terminal driver, +which, unless caught, suspends the process. +.PP +If the operating system on which +.B bash +is running supports +job control, +.B bash +contains facilities to use it. +Typing the +.I suspend +character (typically +.BR ^Z , +Control-Z) while a process is running +causes that process to be stopped and returns control to +.BR bash . +Typing the +.I "delayed suspend" +character (typically +.BR ^Y , +Control-Y) causes the process to be stopped when it +attempts to read input from the terminal, and control to +be returned to +.BR bash . +The user may then manipulate the state of this job, using the +.B bg +command to continue it in the background, the +.B fg +command to continue it in the foreground, or +the +.B kill +command to kill it. A \fB^Z\fP takes effect immediately, +and has the additional side effect of causing pending output +and typeahead to be discarded. +.PP +There are a number of ways to refer to a job in the shell. +The character +.B % +introduces a job specification (\fIjobspec\fP). Job number +.I n +may be referred to as +.BR %n . +A job may also be referred to using a prefix of the name used to +start it, or using a substring that appears in its command line. +For example, +.B %ce +refers to a stopped +.B ce +job. If a prefix matches more than one job, +.B bash +reports an error. Using +.BR %?ce , +on the other hand, refers to any job containing the string +.B ce +in its command line. If the substring matches more than one job, +.B bash +reports an error. The symbols +.B %% +and +.B %+ +refer to the shell's notion of the +.IR "current job" , +which is the last job stopped while it was in +the foreground or started in the background. +The +.I "previous job" +may be referenced using +.BR %\- . +If there is only a single job, \fB%+\fP and \fB%\-\fP can both be used +to refer to that job. +In output pertaining to jobs (e.g., the output of the +.B jobs +command), the current job is always flagged with a +.BR + , +and the previous job with a +.BR \- . +A single % (with no accompanying job specification) also refers to the +current job. +.PP +Simply naming a job can be used to bring it into the +foreground: +.B %1 +is a synonym for +\fB``fg %1''\fP, +bringing job 1 from the background into the foreground. +Similarly, +.B ``%1 &'' +resumes job 1 in the background, equivalent to +\fB``bg %1''\fP. +.PP +The shell learns immediately whenever a job changes state. +Normally, +.B bash +waits until it is about to print a prompt before reporting +changes in a job's status so as to not interrupt +any other output. If the +.B \-b +option to the +.B set +builtin command +is enabled, +.B bash +reports such changes immediately. +Any trap on +.SM +.B SIGCHLD +is executed for each child that exits. +.PP +If an attempt to exit +.B bash +is made while jobs are stopped (or, if the \fBcheckjobs\fP shell option has +been enabled using the \fBshopt\fP builtin, running), the shell prints a +warning message, and, if the \fBcheckjobs\fP option is enabled, lists the +jobs and their statuses. +The +.B jobs +command may then be used to inspect their status. +If a second attempt to exit is made without an intervening command, +the shell does not print another warning, and any stopped +jobs are terminated. +.SH PROMPTING +When executing interactively, +.B bash +displays the primary prompt +.SM +.B PS1 +when it is ready to read a command, and the secondary prompt +.SM +.B PS2 +when it needs more input to complete a command. +.B Bash +allows these prompt strings to be customized by inserting a number of +backslash-escaped special characters that are decoded as follows: +.RS +.PD 0 +.TP +.B \ea +an ASCII bell character (07) +.TP +.B \ed +the date in "Weekday Month Date" format (e.g., "Tue May 26") +.TP +.B \eD{\fIformat\fP} +the \fIformat\fP is passed to \fIstrftime\fP(3) and the result is inserted +into the prompt string; an empty \fIformat\fP results in a locale-specific +time representation. The braces are required +.TP +.B \ee +an ASCII escape character (033) +.TP +.B \eh +the hostname up to the first `.' +.TP +.B \eH +the hostname +.TP +.B \ej +the number of jobs currently managed by the shell +.TP +.B \el +the basename of the shell's terminal device name +.TP +.B \en +newline +.TP +.B \er +carriage return +.TP +.B \es +the name of the shell, the basename of +.B $0 +(the portion following the final slash) +.TP +.B \et +the current time in 24-hour HH:MM:SS format +.TP +.B \eT +the current time in 12-hour HH:MM:SS format +.TP +.B \e@ +the current time in 12-hour am/pm format +.TP +.B \eA +the current time in 24-hour HH:MM format +.TP +.B \eu +the username of the current user +.TP +.B \ev +the version of \fBbash\fP (e.g., 2.00) +.TP +.B \eV +the release of \fBbash\fP, version + patch level (e.g., 2.00.0) +.TP +.B \ew +the current working directory, with +.SM +.B $HOME +abbreviated with a tilde +(uses the value of the +.SM +.B PROMPT_DIRTRIM +variable) +.TP +.B \eW +the basename of the current working directory, with +.SM +.B $HOME +abbreviated with a tilde +.TP +.B \e! +the history number of this command +.TP +.B \e# +the command number of this command +.TP +.B \e$ +if the effective UID is 0, a +.BR # , +otherwise a +.B $ +.TP +.B \e\fInnn\fP +the character corresponding to the octal number \fInnn\fP +.TP +.B \e\e +a backslash +.TP +.B \e[ +begin a sequence of non-printing characters, which could be used to +embed a terminal control sequence into the prompt +.TP +.B \e] +end a sequence of non-printing characters +.PD +.RE +.PP +The command number and the history number are usually different: +the history number of a command is its position in the history +list, which may include commands restored from the history file +(see +.SM +.B HISTORY +below), while the command number is the position in the sequence +of commands executed during the current shell session. +After the string is decoded, it is expanded via +parameter expansion, command substitution, arithmetic +expansion, and quote removal, subject to the value of the +.B promptvars +shell option (see the description of the +.B shopt +command under +.SM +.B "SHELL BUILTIN COMMANDS" +below). +.SH READLINE +This is the library that handles reading input when using an interactive +shell, unless the +.B \-\-noediting +option is given at shell invocation. +Line editing is also used when using the \fB\-e\fP option to the +\fBread\fP builtin. +By default, the line editing commands are similar to those of Emacs. +A vi-style line editing interface is also available. +Line editing can be enabled at any time using the +.B \-o emacs +or +.B \-o vi +options to the +.B set +builtin (see +.SM +.B SHELL BUILTIN COMMANDS +below). +To turn off line editing after the shell is running, use the +.B +o emacs +or +.B +o vi +options to the +.B set +builtin. +.SS "Readline Notation" +.PP +In this section, the Emacs-style notation is used to denote +keystrokes. Control keys are denoted by C\-\fIkey\fR, e.g., C\-n +means Control\-N. Similarly, +.I meta +keys are denoted by M\-\fIkey\fR, so M\-x means Meta\-X. (On keyboards +without a +.I meta +key, M\-\fIx\fP means ESC \fIx\fP, i.e., press the Escape key +then the +.I x +key. This makes ESC the \fImeta prefix\fP. +The combination M\-C\-\fIx\fP means ESC\-Control\-\fIx\fP, +or press the Escape key +then hold the Control key while pressing the +.I x +key.) +.PP +Readline commands may be given numeric +.IR arguments , +which normally act as a repeat count. +Sometimes, however, it is the sign of the argument that is significant. +Passing a negative argument to a command that acts in the forward +direction (e.g., \fBkill\-line\fP) causes that command to act in a +backward direction. +Commands whose behavior with arguments deviates from this are noted +below. +.PP +When a command is described as \fIkilling\fP text, the text +deleted is saved for possible future retrieval +(\fIyanking\fP). The killed text is saved in a +\fIkill ring\fP. Consecutive kills cause the text to be +accumulated into one unit, which can be yanked all at once. +Commands which do not kill text separate the chunks of text +on the kill ring. +.SS "Readline Initialization" +.PP +Readline is customized by putting commands in an initialization +file (the \fIinputrc\fP file). +The name of this file is taken from the value of the +.SM +.B INPUTRC +variable. If that variable is unset, the default is +.IR ~/.inputrc . +When a program which uses the readline library starts up, the +initialization file is read, and the key bindings and variables +are set. +There are only a few basic constructs allowed in the +readline initialization file. +Blank lines are ignored. +Lines beginning with a \fB#\fP are comments. +Lines beginning with a \fB$\fP indicate conditional constructs. +Other lines denote key bindings and variable settings. +.PP +The default key-bindings may be changed with an +.I inputrc +file. +Other programs that use this library may add their own commands +and bindings. +.PP +For example, placing +.RS +.PP +M\-Control\-u: universal\-argument +.RE +or +.RS +C\-Meta\-u: universal\-argument +.RE +into the +.I inputrc +would make M\-C\-u execute the readline command +.IR universal\-argument . +.PP +The following symbolic character names are recognized: +.IR RUBOUT , +.IR DEL , +.IR ESC , +.IR LFD , +.IR NEWLINE , +.IR RET , +.IR RETURN , +.IR SPC , +.IR SPACE , +and +.IR TAB . +.PP +In addition to command names, readline allows keys to be bound +to a string that is inserted when the key is pressed (a \fImacro\fP). +.SS "Readline Key Bindings" +.PP +The syntax for controlling key bindings in the +.I inputrc +file is simple. All that is required is the name of the +command or the text of a macro and a key sequence to which +it should be bound. The name may be specified in one of two ways: +as a symbolic key name, possibly with \fIMeta\-\fP or \fIControl\-\fP +prefixes, or as a key sequence. +.PP +When using the form \fBkeyname\fP:\^\fIfunction\-name\fP or \fImacro\fP, +.I keyname +is the name of a key spelled out in English. For example: +.sp +.RS +Control-u: universal\-argument +.br +Meta-Rubout: backward-kill-word +.br +Control-o: "> output" +.RE +.LP +In the above example, +.I C\-u +is bound to the function +.BR universal\-argument , +.I M\-DEL +is bound to the function +.BR backward\-kill\-word , +and +.I C\-o +is bound to run the macro +expressed on the right hand side (that is, to insert the text +.if t \f(CW> output\fP +.if n ``> output'' +into the line). +.PP +In the second form, \fB"keyseq"\fP:\^\fIfunction\-name\fP or \fImacro\fP, +.B keyseq +differs from +.B keyname +above in that strings denoting +an entire key sequence may be specified by placing the sequence +within double quotes. Some GNU Emacs style key escapes can be +used, as in the following example, but the symbolic character names +are not recognized. +.sp +.RS +"\eC\-u": universal\-argument +.br +"\eC\-x\eC\-r": re\-read\-init\-file +.br +"\ee[11~": "Function Key 1" +.RE +.PP +In this example, +.I C\-u +is again bound to the function +.BR universal\-argument . +.I "C\-x C\-r" +is bound to the function +.BR re\-read\-init\-file , +and +.I "ESC [ 1 1 ~" +is bound to insert the text +.if t \f(CWFunction Key 1\fP. +.if n ``Function Key 1''. +.PP +The full set of GNU Emacs style escape sequences is +.RS +.PD 0 +.TP +.B \eC\- +control prefix +.TP +.B \eM\- +meta prefix +.TP +.B \ee +an escape character +.TP +.B \e\e +backslash +.TP +.B \e" +literal " +.TP +.B \e\(aq +literal \(aq +.RE +.PD +.PP +In addition to the GNU Emacs style escape sequences, a second +set of backslash escapes is available: +.RS +.PD 0 +.TP +.B \ea +alert (bell) +.TP +.B \eb +backspace +.TP +.B \ed +delete +.TP +.B \ef +form feed +.TP +.B \en +newline +.TP +.B \er +carriage return +.TP +.B \et +horizontal tab +.TP +.B \ev +vertical tab +.TP +.B \e\fInnn\fP +the eight-bit character whose value is the octal value \fInnn\fP +(one to three digits) +.TP +.B \ex\fIHH\fP +the eight-bit character whose value is the hexadecimal value \fIHH\fP +(one or two hex digits) +.RE +.PD +.PP +When entering the text of a macro, single or double quotes must +be used to indicate a macro definition. +Unquoted text is assumed to be a function name. +In the macro body, the backslash escapes described above are expanded. +Backslash will quote any other character in the macro text, +including " and \(aq. +.PP +.B Bash +allows the current readline key bindings to be displayed or modified +with the +.B bind +builtin command. The editing mode may be switched during interactive +use by using the +.B \-o +option to the +.B set +builtin command (see +.SM +.B SHELL BUILTIN COMMANDS +below). +.SS "Readline Variables" +.PP +Readline has variables that can be used to further customize its +behavior. A variable may be set in the +.I inputrc +file with a statement of the form +.RS +.PP +\fBset\fP \fIvariable\-name\fP \fIvalue\fP +.RE +.PP +Except where noted, readline variables can take the values +.B On +or +.B Off +(without regard to case). +Unrecognized variable names are ignored. +When a variable value is read, empty or null values, "on" (case-insensitive), +and "1" are equivalent to \fBOn\fP. All other values are equivalent to +\fBOff\fP. +The variables and their default values are: +.PP +.PD 0 +.TP +.B bell\-style (audible) +Controls what happens when readline wants to ring the terminal bell. +If set to \fBnone\fP, readline never rings the bell. If set to +\fBvisible\fP, readline uses a visible bell if one is available. +If set to \fBaudible\fP, readline attempts to ring the terminal's bell. +.TP +.B bind\-tty\-special\-chars (On) +If set to \fBOn\fP, readline attempts to bind the control characters +treated specially by the kernel's terminal driver to their readline +equivalents. +.TP +.B colored\-completion\-prefix (Off) +If set to \fBOn\fP, when listing completions, readline displays the +common prefix of the set of possible completions using a different color. +The color definitions are taken from the value of the \fBLS_COLORS\fP +environment variable. +.TP +.B colored\-stats (Off) +If set to \fBOn\fP, readline displays possible completions using different +colors to indicate their file type. +The color definitions are taken from the value of the \fBLS_COLORS\fP +environment variable. +.TP +.B comment\-begin (``#'') +The string that is inserted when the readline +.B insert\-comment +command is executed. +This command is bound to +.B M\-# +in emacs mode and to +.B # +in vi command mode. +.TP +.B completion\-ignore\-case (Off) +If set to \fBOn\fP, readline performs filename matching and completion +in a case\-insensitive fashion. +.TP +.B completion\-prefix\-display\-length (0) +The length in characters of the common prefix of a list of possible +completions that is displayed without modification. When set to a +value greater than zero, common prefixes longer than this value are +replaced with an ellipsis when displaying possible completions. +.TP +.B completion\-query\-items (100) +This determines when the user is queried about viewing +the number of possible completions +generated by the \fBpossible\-completions\fP command. +It may be set to any integer value greater than or equal to +zero. If the number of possible completions is greater than +or equal to the value of this variable, the user is asked whether +or not he wishes to view them; otherwise they are simply listed +on the terminal. +.TP +.B convert\-meta (On) +If set to \fBOn\fP, readline will convert characters with the +eighth bit set to an ASCII key sequence +by stripping the eighth bit and prefixing an +escape character (in effect, using escape as the \fImeta prefix\fP). +.TP +.B disable\-completion (Off) +If set to \fBOn\fP, readline will inhibit word completion. Completion +characters will be inserted into the line as if they had been +mapped to \fBself-insert\fP. +.TP +.B editing\-mode (emacs) +Controls whether readline begins with a set of key bindings similar +to \fIEmacs\fP or \fIvi\fP. +.B editing\-mode +can be set to either +.B emacs +or +.BR vi . +.TP +.B echo\-control\-characters (On) +When set to \fBOn\fP, on operating systems that indicate they support it, +readline echoes a character corresponding to a signal generated from the +keyboard. +.TP +.B enable\-bracketed\-paste (Off) +When set to \fBOn\fP, readline will configure the terminal in a way +that will enable it to insert each paste into the editing buffer as a +single string of characters, instead of treating each character as if +it had been read from the keyboard. This can prevent pasted characters +from being interpreted as editing commands. +.TP +.B enable\-keypad (Off) +When set to \fBOn\fP, readline will try to enable the application +keypad when it is called. Some systems need this to enable the +arrow keys. +.TP +.B enable\-meta\-key (On) +When set to \fBOn\fP, readline will try to enable any meta modifier +key the terminal claims to support when it is called. On many terminals, +the meta key is used to send eight-bit characters. +.TP +.B expand\-tilde (Off) +If set to \fBOn\fP, tilde expansion is performed when readline +attempts word completion. +.TP +.B history\-preserve\-point (Off) +If set to \fBOn\fP, the history code attempts to place point at the +same location on each history line retrieved with \fBprevious-history\fP +or \fBnext-history\fP. +.TP +.B history\-size (unset) +Set the maximum number of history entries saved in the history list. +If set to zero, any existing history entries are deleted and no new entries +are saved. +If set to a value less than zero, the number of history entries is not +limited. +By default, the number of history entries is not limited. +.TP +.B horizontal\-scroll\-mode (Off) +When set to \fBOn\fP, makes readline use a single line for display, +scrolling the input horizontally on a single screen line when it +becomes longer than the screen width rather than wrapping to a new line. +.TP +.B input\-meta (Off) +If set to \fBOn\fP, readline will enable eight-bit input (that is, +it will not strip the high bit from the characters it reads), +regardless of what the terminal claims it can support. The name +.B meta\-flag +is a synonym for this variable. +.TP +.B isearch\-terminators (``C\-[C\-J'') +The string of characters that should terminate an incremental +search without subsequently executing the character as a command. +If this variable has not been given a value, the characters +\fIESC\fP and \fIC\-J\fP will terminate an incremental search. +.TP +.B keymap (emacs) +Set the current readline keymap. The set of valid keymap names is +\fIemacs, emacs\-standard, emacs\-meta, emacs\-ctlx, vi, +vi\-command\fP, and +.IR vi\-insert . +\fIvi\fP is equivalent to \fIvi\-command\fP; \fIemacs\fP is +equivalent to \fIemacs\-standard\fP. The default value is +.IR emacs ; +the value of +.B editing\-mode +also affects the default keymap. +.TP +.B emacs\-mode\-string (@) +This string is displayed immediately before the last line of the primary +prompt when emacs editing mode is active. The value is expanded like a +key binding, so the standard set of meta- and control prefixes and +backslash escape sequences is available. +Use the \e1 and \e2 escapes to begin and end sequences of +non-printing characters, which can be used to embed a terminal control +sequence into the mode string. +.TP +.B keyseq\-timeout (500) +Specifies the duration \fIreadline\fP will wait for a character when reading an +ambiguous key sequence (one that can form a complete key sequence using +the input read so far, or can take additional input to complete a longer +key sequence). +If no input is received within the timeout, \fIreadline\fP will use the shorter +but complete key sequence. +The value is specified in milliseconds, so a value of 1000 means that +\fIreadline\fP will wait one second for additional input. +If this variable is set to a value less than or equal to zero, or to a +non-numeric value, \fIreadline\fP will wait until another key is pressed to +decide which key sequence to complete. +.TP +.B mark\-directories (On) +If set to \fBOn\fP, completed directory names have a slash +appended. +.TP +.B mark\-modified\-lines (Off) +If set to \fBOn\fP, history lines that have been modified are displayed +with a preceding asterisk (\fB*\fP). +.TP +.B mark\-symlinked\-directories (Off) +If set to \fBOn\fP, completed names which are symbolic links to directories +have a slash appended (subject to the value of +\fBmark\-directories\fP). +.TP +.B match\-hidden\-files (On) +This variable, when set to \fBOn\fP, causes readline to match files whose +names begin with a `.' (hidden files) when performing filename +completion. +If set to \fBOff\fP, the leading `.' must be +supplied by the user in the filename to be completed. +.TP +.B menu\-complete\-display\-prefix (Off) +If set to \fBOn\fP, menu completion displays the common prefix of the +list of possible completions (which may be empty) before cycling through +the list. +.TP +.B output\-meta (Off) +If set to \fBOn\fP, readline will display characters with the +eighth bit set directly rather than as a meta-prefixed escape +sequence. +.TP +.B page\-completions (On) +If set to \fBOn\fP, readline uses an internal \fImore\fP-like pager +to display a screenful of possible completions at a time. +.TP +.B print\-completions\-horizontally (Off) +If set to \fBOn\fP, readline will display completions with matches +sorted horizontally in alphabetical order, rather than down the screen. +.TP +.B revert\-all\-at\-newline (Off) +If set to \fBOn\fP, readline will undo all changes to history lines +before returning when \fBaccept\-line\fP is executed. By default, +history lines may be modified and retain individual undo lists across +calls to \fBreadline\fP. +.TP +.B show\-all\-if\-ambiguous (Off) +This alters the default behavior of the completion functions. If +set to +.BR On , +words which have more than one possible completion cause the +matches to be listed immediately instead of ringing the bell. +.TP +.B show\-all\-if\-unmodified (Off) +This alters the default behavior of the completion functions in +a fashion similar to \fBshow\-all\-if\-ambiguous\fP. +If set to +.BR On , +words which have more than one possible completion without any +possible partial completion (the possible completions don't share +a common prefix) cause the matches to be listed immediately instead +of ringing the bell. +.TP +.B show\-mode\-in\-prompt (Off) +If set to \fBOn\fP, add a character to the beginning of the prompt +indicating the editing mode: emacs (@), vi command (:) or vi +insertion (+). +.TP +.B skip\-completed\-text (Off) +If set to \fBOn\fP, this alters the default completion behavior when +inserting a single match into the line. It's only active when +performing completion in the middle of a word. If enabled, readline +does not insert characters from the completion that match characters +after point in the word being completed, so portions of the word +following the cursor are not duplicated. +.TP +.B vi\-cmd\-mode\-string ((cmd)) +This string is displayed immediately before the last line of the primary +prompt when vi editing mode is active and in command mode. +The value is expanded like a +key binding, so the standard set of meta- and control prefixes and +backslash escape sequences is available. +Use the \e1 and \e2 escapes to begin and end sequences of +non-printing characters, which can be used to embed a terminal control +sequence into the mode string. +.TP +.B vi\-ins\-mode\-string ((ins)) +This string is displayed immediately before the last line of the primary +prompt when vi editing mode is active and in insertion mode. +The value is expanded like a +key binding, so the standard set of meta- and control prefixes and +backslash escape sequences is available. +Use the \e1 and \e2 escapes to begin and end sequences of +non-printing characters, which can be used to embed a terminal control +sequence into the mode string. +.TP +.B visible\-stats (Off) +If set to \fBOn\fP, a character denoting a file's type as reported +by \fIstat\fP(2) is appended to the filename when listing possible +completions. +.PD +.SS "Readline Conditional Constructs" +.PP +Readline implements a facility similar in spirit to the conditional +compilation features of the C preprocessor which allows key +bindings and variable settings to be performed as the result +of tests. There are four parser directives used. +.IP \fB$if\fP +The +.B $if +construct allows bindings to be made based on the +editing mode, the terminal being used, or the application using +readline. The text of the test extends to the end of the line; +no characters are required to isolate it. +.RS +.IP \fBmode\fP +The \fBmode=\fP form of the \fB$if\fP directive is used to test +whether readline is in emacs or vi mode. +This may be used in conjunction +with the \fBset keymap\fP command, for instance, to set bindings in +the \fIemacs\-standard\fP and \fIemacs\-ctlx\fP keymaps only if +readline is starting out in emacs mode. +.IP \fBterm\fP +The \fBterm=\fP form may be used to include terminal-specific +key bindings, perhaps to bind the key sequences output by the +terminal's function keys. The word on the right side of the +.B = +is tested against the both full name of the terminal and the portion +of the terminal name before the first \fB\-\fP. This allows +.I sun +to match both +.I sun +and +.IR sun\-cmd , +for instance. +.IP \fBapplication\fP +The \fBapplication\fP construct is used to include +application-specific settings. Each program using the readline +library sets the \fIapplication name\fP, and an initialization +file can test for a particular value. +This could be used to bind key sequences to functions useful for +a specific program. For instance, the following command adds a +key sequence that quotes the current or previous word in \fBbash\fP: +.sp 1 +.RS +.nf +\fB$if\fP Bash +# Quote the current or previous word +"\eC\-xq": "\eeb\e"\eef\e"" +\fB$endif\fP +.fi +.RE +.RE +.IP \fB$endif\fP +This command, as seen in the previous example, terminates an +\fB$if\fP command. +.IP \fB$else\fP +Commands in this branch of the \fB$if\fP directive are executed if +the test fails. +.IP \fB$include\fP +This directive takes a single filename as an argument and reads commands +and bindings from that file. For example, the following directive +would read \fI/etc/inputrc\fP: +.sp 1 +.RS +.nf +\fB$include\fP \^ \fI/etc/inputrc\fP +.fi +.RE +.SS Searching +.PP +Readline provides commands for searching through the command history +(see +.SM +.B HISTORY +below) for lines containing a specified string. +There are two search modes: +.I incremental +and +.IR non-incremental . +.PP +Incremental searches begin before the user has finished typing the +search string. +As each character of the search string is typed, readline displays +the next entry from the history matching the string typed so far. +An incremental search requires only as many characters as needed to +find the desired history entry. +The characters present in the value of the \fBisearch-terminators\fP +variable are used to terminate an incremental search. +If that variable has not been assigned a value the Escape and +Control-J characters will terminate an incremental search. +Control-G will abort an incremental search and restore the original +line. +When the search is terminated, the history entry containing the +search string becomes the current line. +.PP +To find other matching entries in the history list, type Control-S or +Control-R as appropriate. +This will search backward or forward in the history for the next +entry matching the search string typed so far. +Any other key sequence bound to a readline command will terminate +the search and execute that command. +For instance, a \fInewline\fP will terminate the search and accept +the line, thereby executing the command from the history list. +.PP +Readline remembers the last incremental search string. If two +Control-Rs are typed without any intervening characters defining a +new search string, any remembered search string is used. +.PP +Non-incremental searches read the entire search string before starting +to search for matching history lines. The search string may be +typed by the user or be part of the contents of the current line. +.SS "Readline Command Names" +.PP +The following is a list of the names of the commands and the default +key sequences to which they are bound. +Command names without an accompanying key sequence are unbound by default. +In the following descriptions, \fIpoint\fP refers to the current cursor +position, and \fImark\fP refers to a cursor position saved by the +\fBset\-mark\fP command. +The text between the point and mark is referred to as the \fIregion\fP. +.SS Commands for Moving +.PP +.PD 0 +.TP +.B beginning\-of\-line (C\-a) +Move to the start of the current line. +.TP +.B end\-of\-line (C\-e) +Move to the end of the line. +.TP +.B forward\-char (C\-f) +Move forward a character. +.TP +.B backward\-char (C\-b) +Move back a character. +.TP +.B forward\-word (M\-f) +Move forward to the end of the next word. Words are composed of +alphanumeric characters (letters and digits). +.TP +.B backward\-word (M\-b) +Move back to the start of the current or previous word. +Words are composed of alphanumeric characters (letters and digits). +.TP +.B shell\-forward\-word +Move forward to the end of the next word. +Words are delimited by non-quoted shell metacharacters. +.TP +.B shell\-backward\-word +Move back to the start of the current or previous word. +Words are delimited by non-quoted shell metacharacters. +.TP +.B clear\-screen (C\-l) +Clear the screen leaving the current line at the top of the screen. +With an argument, refresh the current line without clearing the +screen. +.TP +.B redraw\-current\-line +Refresh the current line. +.PD +.SS Commands for Manipulating the History +.PP +.PD 0 +.TP +.B accept\-line (Newline, Return) +Accept the line regardless of where the cursor is. If this line is +non-empty, add it to the history list according to the state of the +.SM +.B HISTCONTROL +variable. If the line is a modified history +line, then restore the history line to its original state. +.TP +.B previous\-history (C\-p) +Fetch the previous command from the history list, moving back in +the list. +.TP +.B next\-history (C\-n) +Fetch the next command from the history list, moving forward in the +list. +.TP +.B beginning\-of\-history (M\-<) +Move to the first line in the history. +.TP +.B end\-of\-history (M\->) +Move to the end of the input history, i.e., the line currently being +entered. +.TP +.B reverse\-search\-history (C\-r) +Search backward starting at the current line and moving `up' through +the history as necessary. This is an incremental search. +.TP +.B forward\-search\-history (C\-s) +Search forward starting at the current line and moving `down' through +the history as necessary. This is an incremental search. +.TP +.B non\-incremental\-reverse\-search\-history (M\-p) +Search backward through the history starting at the current line +using a non-incremental search for a string supplied by the user. +.TP +.B non\-incremental\-forward\-search\-history (M\-n) +Search forward through the history using a non-incremental search for +a string supplied by the user. +.TP +.B history\-search\-forward +Search forward through the history for the string of characters +between the start of the current line and the point. +This is a non-incremental search. +.TP +.B history\-search\-backward +Search backward through the history for the string of characters +between the start of the current line and the point. +This is a non-incremental search. +.TP +.B yank\-nth\-arg (M\-C\-y) +Insert the first argument to the previous command (usually +the second word on the previous line) at point. +With an argument +.IR n , +insert the \fIn\fPth word from the previous command (the words +in the previous command begin with word 0). A negative argument +inserts the \fIn\fPth word from the end of the previous command. +Once the argument \fIn\fP is computed, the argument is extracted +as if the "!\fIn\fP" history expansion had been specified. +.TP +.B +yank\-last\-arg (M\-.\^, M\-_\^) +Insert the last argument to the previous command (the last word of +the previous history entry). +With a numeric argument, behave exactly like \fByank\-nth\-arg\fP. +Successive calls to \fByank\-last\-arg\fP move back through the history +list, inserting the last word (or the word specified by the argument to +the first call) of each line in turn. +Any numeric argument supplied to these successive calls determines +the direction to move through the history. A negative argument switches +the direction through the history (back or forward). +The history expansion facilities are used to extract the last word, +as if the "!$" history expansion had been specified. +.TP +.B shell\-expand\-line (M\-C\-e) +Expand the line as the shell does. This +performs alias and history expansion as well as all of the shell +word expansions. See +.SM +.B HISTORY EXPANSION +below for a description of history expansion. +.TP +.B history\-expand\-line (M\-^) +Perform history expansion on the current line. +See +.SM +.B HISTORY EXPANSION +below for a description of history expansion. +.TP +.B magic\-space +Perform history expansion on the current line and insert a space. +See +.SM +.B HISTORY EXPANSION +below for a description of history expansion. +.TP +.B alias\-expand\-line +Perform alias expansion on the current line. +See +.SM +.B ALIASES +above for a description of alias expansion. +.TP +.B history\-and\-alias\-expand\-line +Perform history and alias expansion on the current line. +.TP +.B insert\-last\-argument (M\-.\^, M\-_\^) +A synonym for \fByank\-last\-arg\fP. +.TP +.B operate\-and\-get\-next (C\-o) +Accept the current line for execution and fetch the next line +relative to the current line from the history for editing. Any +argument is ignored. +.TP +.B edit\-and\-execute\-command (C\-xC\-e) +Invoke an editor on the current command line, and execute the result as shell +commands. +\fBBash\fP attempts to invoke +.SM +.BR $VISUAL , +.SM +.BR $EDITOR , +and \fIemacs\fP as the editor, in that order. +.PD +.SS Commands for Changing Text +.PP +.PD 0 +.TP +.B \fIend\-of\-file\fP (usually C\-d) +The character indicating end-of-file as set, for example, by +.if t \f(CWstty\fP. +.if n ``stty''. +If this character is read when there are no characters +on the line, and point is at the beginning of the line, Readline +interprets it as the end of input and returns +.SM +.BR EOF . +.TP +.B delete\-char (C\-d) +Delete the character at point. +If this function is bound to the +same character as the tty \fBEOF\fP character, as \fBC\-d\fP +commonly is, see above for the effects. +.TP +.B backward\-delete\-char (Rubout) +Delete the character behind the cursor. When given a numeric argument, +save the deleted text on the kill ring. +.TP +.B forward\-backward\-delete\-char +Delete the character under the cursor, unless the cursor is at the +end of the line, in which case the character behind the cursor is +deleted. +.TP +.B quoted\-insert (C\-q, C\-v) +Add the next character typed to the line verbatim. This is +how to insert characters like \fBC\-q\fP, for example. +.TP +.B tab\-insert (C\-v TAB) +Insert a tab character. +.TP +.B self\-insert (a,\ b,\ A,\ 1,\ !,\ ...) +Insert the character typed. +.TP +.B transpose\-chars (C\-t) +Drag the character before point forward over the character at point, +moving point forward as well. +If point is at the end of the line, then this transposes +the two characters before point. +Negative arguments have no effect. +.TP +.B transpose\-words (M\-t) +Drag the word before point past the word after point, +moving point over that word as well. +If point is at the end of the line, this transposes +the last two words on the line. +.TP +.B upcase\-word (M\-u) +Uppercase the current (or following) word. With a negative argument, +uppercase the previous word, but do not move point. +.TP +.B downcase\-word (M\-l) +Lowercase the current (or following) word. With a negative argument, +lowercase the previous word, but do not move point. +.TP +.B capitalize\-word (M\-c) +Capitalize the current (or following) word. With a negative argument, +capitalize the previous word, but do not move point. +.TP +.B overwrite\-mode +Toggle overwrite mode. With an explicit positive numeric argument, +switches to overwrite mode. With an explicit non-positive numeric +argument, switches to insert mode. This command affects only +\fBemacs\fP mode; \fBvi\fP mode does overwrite differently. +Each call to \fIreadline()\fP starts in insert mode. +In overwrite mode, characters bound to \fBself\-insert\fP replace +the text at point rather than pushing the text to the right. +Characters bound to \fBbackward\-delete\-char\fP replace the character +before point with a space. By default, this command is unbound. +.PD +.SS Killing and Yanking +.PP +.PD 0 +.TP +.B kill\-line (C\-k) +Kill the text from point to the end of the line. +.TP +.B backward\-kill\-line (C\-x Rubout) +Kill backward to the beginning of the line. +.TP +.B unix\-line\-discard (C\-u) +Kill backward from point to the beginning of the line. +The killed text is saved on the kill-ring. +.\" There is no real difference between this and backward-kill-line +.TP +.B kill\-whole\-line +Kill all characters on the current line, no matter where point is. +.TP +.B kill\-word (M\-d) +Kill from point to the end of the current word, or if between +words, to the end of the next word. +Word boundaries are the same as those used by \fBforward\-word\fP. +.TP +.B backward\-kill\-word (M\-Rubout) +Kill the word behind point. +Word boundaries are the same as those used by \fBbackward\-word\fP. +.TP +.B shell\-kill\-word +Kill from point to the end of the current word, or if between +words, to the end of the next word. +Word boundaries are the same as those used by \fBshell\-forward\-word\fP. +.TP +.B shell\-backward\-kill\-word +Kill the word behind point. +Word boundaries are the same as those used by \fBshell\-backward\-word\fP. +.TP +.B unix\-word\-rubout (C\-w) +Kill the word behind point, using white space as a word boundary. +The killed text is saved on the kill-ring. +.TP +.B unix\-filename\-rubout +Kill the word behind point, using white space and the slash character +as the word boundaries. +The killed text is saved on the kill-ring. +.TP +.B delete\-horizontal\-space (M\-\e) +Delete all spaces and tabs around point. +.TP +.B kill\-region +Kill the text in the current region. +.TP +.B copy\-region\-as\-kill +Copy the text in the region to the kill buffer. +.TP +.B copy\-backward\-word +Copy the word before point to the kill buffer. +The word boundaries are the same as \fBbackward\-word\fP. +.TP +.B copy\-forward\-word +Copy the word following point to the kill buffer. +The word boundaries are the same as \fBforward\-word\fP. +.TP +.B yank (C\-y) +Yank the top of the kill ring into the buffer at point. +.TP +.B yank\-pop (M\-y) +Rotate the kill ring, and yank the new top. Only works following +.B yank +or +.BR yank\-pop . +.PD +.SS Numeric Arguments +.PP +.PD 0 +.TP +.B digit\-argument (M\-0, M\-1, ..., M\-\-) +Add this digit to the argument already accumulating, or start a new +argument. M\-\- starts a negative argument. +.TP +.B universal\-argument +This is another way to specify an argument. +If this command is followed by one or more digits, optionally with a +leading minus sign, those digits define the argument. +If the command is followed by digits, executing +.B universal\-argument +again ends the numeric argument, but is otherwise ignored. +As a special case, if this command is immediately followed by a +character that is neither a digit or minus sign, the argument count +for the next command is multiplied by four. +The argument count is initially one, so executing this function the +first time makes the argument count four, a second time makes the +argument count sixteen, and so on. +.PD +.SS Completing +.PP +.PD 0 +.TP +.B complete (TAB) +Attempt to perform completion on the text before point. +.B Bash +attempts completion treating the text as a variable (if the +text begins with \fB$\fP), username (if the text begins with +\fB~\fP), hostname (if the text begins with \fB@\fP), or +command (including aliases and functions) in turn. If none +of these produces a match, filename completion is attempted. +.TP +.B possible\-completions (M\-?) +List the possible completions of the text before point. +.TP +.B insert\-completions (M\-*) +Insert all completions of the text before point +that would have been generated by +\fBpossible\-completions\fP. +.TP +.B menu\-complete +Similar to \fBcomplete\fP, but replaces the word to be completed +with a single match from the list of possible completions. +Repeated execution of \fBmenu\-complete\fP steps through the list +of possible completions, inserting each match in turn. +At the end of the list of completions, the bell is rung +(subject to the setting of \fBbell\-style\fP) +and the original text is restored. +An argument of \fIn\fP moves \fIn\fP positions forward in the list +of matches; a negative argument may be used to move backward +through the list. +This command is intended to be bound to \fBTAB\fP, but is unbound +by default. +.TP +.B menu\-complete\-backward +Identical to \fBmenu\-complete\fP, but moves backward through the list +of possible completions, as if \fBmenu\-complete\fP had been given a +negative argument. This command is unbound by default. +.TP +.B delete\-char\-or\-list +Deletes the character under the cursor if not at the beginning or +end of the line (like \fBdelete\-char\fP). +If at the end of the line, behaves identically to +\fBpossible\-completions\fP. +This command is unbound by default. +.TP +.B complete\-filename (M\-/) +Attempt filename completion on the text before point. +.TP +.B possible\-filename\-completions (C\-x /) +List the possible completions of the text before point, +treating it as a filename. +.TP +.B complete\-username (M\-~) +Attempt completion on the text before point, treating +it as a username. +.TP +.B possible\-username\-completions (C\-x ~) +List the possible completions of the text before point, +treating it as a username. +.TP +.B complete\-variable (M\-$) +Attempt completion on the text before point, treating +it as a shell variable. +.TP +.B possible\-variable\-completions (C\-x $) +List the possible completions of the text before point, +treating it as a shell variable. +.TP +.B complete\-hostname (M\-@) +Attempt completion on the text before point, treating +it as a hostname. +.TP +.B possible\-hostname\-completions (C\-x @) +List the possible completions of the text before point, +treating it as a hostname. +.TP +.B complete\-command (M\-!) +Attempt completion on the text before point, treating +it as a command name. Command completion attempts to +match the text against aliases, reserved words, shell +functions, shell builtins, and finally executable filenames, +in that order. +.TP +.B possible\-command\-completions (C\-x !) +List the possible completions of the text before point, +treating it as a command name. +.TP +.B dynamic\-complete\-history (M\-TAB) +Attempt completion on the text before point, comparing +the text against lines from the history list for possible +completion matches. +.TP +.B dabbrev\-expand +Attempt menu completion on the text before point, comparing +the text against lines from the history list for possible +completion matches. +.TP +.B complete\-into\-braces (M\-{) +Perform filename completion and insert the list of possible completions +enclosed within braces so the list is available to the shell (see +.B Brace Expansion +above). +.PD +.SS Keyboard Macros +.PP +.PD 0 +.TP +.B start\-kbd\-macro (C\-x (\^) +Begin saving the characters typed into the current keyboard macro. +.TP +.B end\-kbd\-macro (C\-x )\^) +Stop saving the characters typed into the current keyboard macro +and store the definition. +.TP +.B call\-last\-kbd\-macro (C\-x e) +Re-execute the last keyboard macro defined, by making the characters +in the macro appear as if typed at the keyboard. +.TP +.B print\-last\-kbd\-macro () +Print the last keyboard macro defined in a format suitable for the +\fIinputrc\fP file. +.PD +.SS Miscellaneous +.PP +.PD 0 +.TP +.B re\-read\-init\-file (C\-x C\-r) +Read in the contents of the \fIinputrc\fP file, and incorporate +any bindings or variable assignments found there. +.TP +.B abort (C\-g) +Abort the current editing command and +ring the terminal's bell (subject to the setting of +.BR bell\-style ). +.TP +.B do\-uppercase\-version (M\-a, M\-b, M\-\fIx\fP, ...) +If the metafied character \fIx\fP is lowercase, run the command +that is bound to the corresponding uppercase character. +.TP +.B prefix\-meta (ESC) +Metafy the next character typed. +.SM +.B ESC +.B f +is equivalent to +.BR Meta\-f . +.TP +.B undo (C\-_, C\-x C\-u) +Incremental undo, separately remembered for each line. +.TP +.B revert\-line (M\-r) +Undo all changes made to this line. This is like executing the +.B undo +command enough times to return the line to its initial state. +.TP +.B tilde\-expand (M\-&) +Perform tilde expansion on the current word. +.TP +.B set\-mark (C\-@, M\-) +Set the mark to the point. If a +numeric argument is supplied, the mark is set to that position. +.TP +.B exchange\-point\-and\-mark (C\-x C\-x) +Swap the point with the mark. The current cursor position is set to +the saved position, and the old cursor position is saved as the mark. +.TP +.B character\-search (C\-]) +A character is read and point is moved to the next occurrence of that +character. A negative count searches for previous occurrences. +.TP +.B character\-search\-backward (M\-C\-]) +A character is read and point is moved to the previous occurrence of that +character. A negative count searches for subsequent occurrences. +.TP +.B skip\-csi\-sequence +Read enough characters to consume a multi-key sequence such as those +defined for keys like Home and End. Such sequences begin with a +Control Sequence Indicator (CSI), usually ESC\-[. If this sequence is +bound to "\e[", keys producing such sequences will have no effect +unless explicitly bound to a readline command, instead of inserting +stray characters into the editing buffer. This is unbound by default, +but usually bound to ESC\-[. +.TP +.B insert\-comment (M\-#) +Without a numeric argument, the value of the readline +.B comment\-begin +variable is inserted at the beginning of the current line. +If a numeric argument is supplied, this command acts as a toggle: if +the characters at the beginning of the line do not match the value +of \fBcomment\-begin\fP, the value is inserted, otherwise +the characters in \fBcomment\-begin\fP are deleted from the beginning of +the line. +In either case, the line is accepted as if a newline had been typed. +The default value of +\fBcomment\-begin\fP causes this command to make the current line +a shell comment. +If a numeric argument causes the comment character to be removed, the line +will be executed by the shell. +.TP +.B glob\-complete\-word (M\-g) +The word before point is treated as a pattern for pathname expansion, +with an asterisk implicitly appended. This pattern is used to +generate a list of matching filenames for possible completions. +.TP +.B glob\-expand\-word (C\-x *) +The word before point is treated as a pattern for pathname expansion, +and the list of matching filenames is inserted, replacing the word. +If a numeric argument is supplied, an asterisk is appended before +pathname expansion. +.TP +.B glob\-list\-expansions (C\-x g) +The list of expansions that would have been generated by +.B glob\-expand\-word +is displayed, and the line is redrawn. +If a numeric argument is supplied, an asterisk is appended before +pathname expansion. +.TP +.B dump\-functions +Print all of the functions and their key bindings to the +readline output stream. If a numeric argument is supplied, +the output is formatted in such a way that it can be made part +of an \fIinputrc\fP file. +.TP +.B dump\-variables +Print all of the settable readline variables and their values to the +readline output stream. If a numeric argument is supplied, +the output is formatted in such a way that it can be made part +of an \fIinputrc\fP file. +.TP +.B dump\-macros +Print all of the readline key sequences bound to macros and the +strings they output. If a numeric argument is supplied, +the output is formatted in such a way that it can be made part +of an \fIinputrc\fP file. +.TP +.B display\-shell\-version (C\-x C\-v) +Display version information about the current instance of +.BR bash . +.PD +.SS Programmable Completion +.PP +When word completion is attempted for an argument to a command for +which a completion specification (a \fIcompspec\fP) has been defined +using the \fBcomplete\fP builtin (see +.SM +.B "SHELL BUILTIN COMMANDS" +below), the programmable completion facilities are invoked. +.PP +First, the command name is identified. +If the command word is the empty string (completion attempted at the +beginning of an empty line), any compspec defined with +the \fB\-E\fP option to \fBcomplete\fP is used. +If a compspec has been defined for that command, the +compspec is used to generate the list of possible completions for the word. +If the command word is a full pathname, a compspec for the full +pathname is searched for first. +If no compspec is found for the full pathname, an attempt is made to +find a compspec for the portion following the final slash. +If those searches do not result in a compspec, any compspec defined with +the \fB\-D\fP option to \fBcomplete\fP is used as the default. +.PP +Once a compspec has been found, it is used to generate the list of +matching words. +If a compspec is not found, the default \fBbash\fP completion as +described above under \fBCompleting\fP is performed. +.PP +First, the actions specified by the compspec are used. +Only matches which are prefixed by the word being completed are +returned. +When the +.B \-f +or +.B \-d +option is used for filename or directory name completion, the shell +variable +.SM +.B FIGNORE +is used to filter the matches. +.PP +Any completions specified by a pathname expansion pattern to the +\fB\-G\fP option are generated next. +The words generated by the pattern need not match the word +being completed. +The +.SM +.B GLOBIGNORE +shell variable is not used to filter the matches, but the +.SM +.B FIGNORE +variable is used. +.PP +Next, the string specified as the argument to the \fB\-W\fP option +is considered. +The string is first split using the characters in the +.SM +.B IFS +special variable as delimiters. +Shell quoting is honored. +Each word is then expanded using +brace expansion, tilde expansion, parameter and variable expansion, +command substitution, and arithmetic expansion, +as described above under +.SM +.BR EXPANSION . +The results are split using the rules described above under +\fBWord Splitting\fP. +The results of the expansion are prefix-matched against the word being +completed, and the matching words become the possible completions. +.PP +After these matches have been generated, any shell function or command +specified with the \fB\-F\fP and \fB\-C\fP options is invoked. +When the command or function is invoked, the +.SM +.BR COMP_LINE , +.SM +.BR COMP_POINT , +.SM +.BR COMP_KEY , +and +.SM +.B COMP_TYPE +variables are assigned values as described above under +\fBShell Variables\fP. +If a shell function is being invoked, the +.SM +.B COMP_WORDS +and +.SM +.B COMP_CWORD +variables are also set. +When the function or command is invoked, +the first argument (\fB$1\fP) is the name of the command whose arguments are +being completed, +the second argument (\fB$2\fP) is the word being completed, +and the third argument (\fB$3\fP) is the word preceding the word being +completed on the current command line. +No filtering of the generated completions against the word being completed +is performed; the function or command has complete freedom in generating +the matches. +.PP +Any function specified with \fB\-F\fP is invoked first. +The function may use any of the shell facilities, including the +\fBcompgen\fP builtin described below, to generate the matches. +It must put the possible completions in the +.SM +.B COMPREPLY +array variable, one per array element. +.PP +Next, any command specified with the \fB\-C\fP option is invoked +in an environment equivalent to command substitution. +It should print a list of completions, one per line, to the +standard output. +Backslash may be used to escape a newline, if necessary. +.PP +After all of the possible completions are generated, any filter +specified with the \fB\-X\fP option is applied to the list. +The filter is a pattern as used for pathname expansion; a \fB&\fP +in the pattern is replaced with the text of the word being completed. +A literal \fB&\fP may be escaped with a backslash; the backslash +is removed before attempting a match. +Any completion that matches the pattern will be removed from the list. +A leading \fB!\fP negates the pattern; in this case any completion +not matching the pattern will be removed. +If the +.B nocasematch +shell option is enabled, the match is performed without regard to the case +of alphabetic characters. +.PP +Finally, any prefix and suffix specified with the \fB\-P\fP and \fB\-S\fP +options are added to each member of the completion list, and the result is +returned to the readline completion code as the list of possible +completions. +.PP +If the previously-applied actions do not generate any matches, and the +\fB\-o dirnames\fP option was supplied to \fBcomplete\fP when the +compspec was defined, directory name completion is attempted. +.PP +If the \fB\-o plusdirs\fP option was supplied to \fBcomplete\fP when the +compspec was defined, directory name completion is attempted and any +matches are added to the results of the other actions. +.PP +By default, if a compspec is found, whatever it generates is returned +to the completion code as the full set of possible completions. +The default \fBbash\fP completions are not attempted, and the readline +default of filename completion is disabled. +If the \fB\-o bashdefault\fP option was supplied to \fBcomplete\fP when +the compspec was defined, the \fBbash\fP default completions are attempted +if the compspec generates no matches. +If the \fB\-o default\fP option was supplied to \fBcomplete\fP when the +compspec was defined, readline's default completion will be performed +if the compspec (and, if attempted, the default \fBbash\fP completions) +generate no matches. +.PP +When a compspec indicates that directory name completion is desired, +the programmable completion functions force readline to append a slash +to completed names which are symbolic links to directories, subject to +the value of the \fBmark\-directories\fP readline variable, regardless +of the setting of the \fBmark-symlinked\-directories\fP readline variable. +.PP +There is some support for dynamically modifying completions. This is +most useful when used in combination with a default completion specified +with \fBcomplete -D\fP. +It's possible for shell functions executed as completion +handlers to indicate that completion should be retried by returning an +exit status of 124. If a shell function returns 124, and changes +the compspec associated with the command on which completion is being +attempted (supplied as the first argument when the function is executed), +programmable completion restarts from the beginning, with an +attempt to find a new compspec for that command. This allows a set of +completions to be built dynamically as completion is attempted, rather than +being loaded all at once. +.PP +For instance, assuming that there is a library of compspecs, each kept in a +file corresponding to the name of the command, the following default +completion function would load completions dynamically: +.PP +\f(CW_completion_loader() +.br +{ +.br + . "/etc/bash_completion.d/$1.sh" >/dev/null 2>&1 && return 124 +.br +} +.br +complete -D -F _completion_loader -o bashdefault -o default +.br +\fP +.SH HISTORY +When the +.B \-o history +option to the +.B set +builtin is enabled, the shell provides access to the +\fIcommand history\fP, +the list of commands previously typed. +The value of the +.SM +.B HISTSIZE +variable is used as the +number of commands to save in a history list. +The text of the last +.SM +.B HISTSIZE +commands (default 500) is saved. The shell +stores each command in the history list prior to parameter and +variable expansion (see +.SM +.B EXPANSION +above) but after history expansion is performed, subject to the +values of the shell variables +.SM +.B HISTIGNORE +and +.SM +.BR HISTCONTROL . +.PP +On startup, the history is initialized from the file named by +the variable +.SM +.B HISTFILE +(default \fI~/.bash_history\fP). +The file named by the value of +.SM +.B HISTFILE +is truncated, if necessary, to contain no more than +the number of lines specified by the value of +.SM +.BR HISTFILESIZE . +If \fBHISTFILESIZE\fP is unset, or set to null, a non-numeric value, +or a numeric value less than zero, the history file is not truncated. +When the history file is read, +lines beginning with the history comment character followed immediately +by a digit are interpreted as timestamps for the preceding history line. +These timestamps are optionally displayed depending on the value of the +.SM +.B HISTTIMEFORMAT +variable. +When a shell with history enabled exits, the last +.SM +.B $HISTSIZE +lines are copied from the history list to +.SM +.BR $HISTFILE . +If the +.B histappend +shell option is enabled +(see the description of +.B shopt +under +.SM +.B "SHELL BUILTIN COMMANDS" +below), the lines are appended to the history file, +otherwise the history file is overwritten. +If +.SM +.B HISTFILE +is unset, or if the history file is unwritable, the history is +not saved. +If the +.SM +.B HISTTIMEFORMAT +variable is set, time stamps are written to the history file, marked +with the history comment character, so +they may be preserved across shell sessions. +This uses the history comment character to distinguish timestamps from +other history lines. +After saving the history, the history file is truncated +to contain no more than +.SM +.B HISTFILESIZE +lines. If +.SM +.B HISTFILESIZE +is unset, or set to null, a non-numeric value, +or a numeric value less than zero, the history file is not truncated. +.PP +The builtin command +.B fc +(see +.SM +.B SHELL BUILTIN COMMANDS +below) may be used to list or edit and re-execute a portion of +the history list. +The +.B history +builtin may be used to display or modify the history list and +manipulate the history file. +When using command-line editing, search commands +are available in each editing mode that provide access to the +history list. +.PP +The shell allows control over which commands are saved on the history +list. The +.SM +.B HISTCONTROL +and +.SM +.B HISTIGNORE +variables may be set to cause the shell to save only a subset of the +commands entered. +The +.B cmdhist +shell option, if enabled, causes the shell to attempt to save each +line of a multi-line command in the same history entry, adding +semicolons where necessary to preserve syntactic correctness. +The +.B lithist +shell option causes the shell to save the command with embedded newlines +instead of semicolons. See the description of the +.B shopt +builtin below under +.SM +.B "SHELL BUILTIN COMMANDS" +for information on setting and unsetting shell options. +.SH "HISTORY EXPANSION" +.PP +The shell supports a history expansion feature that +is similar to the history expansion in +.BR csh. +This section describes what syntax features are available. This +feature is enabled by default for interactive shells, and can be +disabled using the +.B +H +option to the +.B set +builtin command (see +.SM +.B SHELL BUILTIN COMMANDS +below). Non-interactive shells do not perform history expansion +by default. +.PP +History expansions introduce words from the history list into +the input stream, making it easy to repeat commands, insert the +arguments to a previous command into the current input line, or +fix errors in previous commands quickly. +.PP +History expansion is performed immediately after a complete line +is read, before the shell breaks it into words. +It takes place in two parts. +The first is to determine which line from the history list +to use during substitution. +The second is to select portions of that line for inclusion into +the current one. +The line selected from the history is the \fIevent\fP, +and the portions of that line that are acted upon are \fIwords\fP. +Various \fImodifiers\fP are available to manipulate the selected words. +The line is broken into words in the same fashion as when reading input, +so that several \fImetacharacter\fP-separated words surrounded by +quotes are considered one word. +History expansions are introduced by the appearance of the +history expansion character, which is \^\fB!\fP\^ by default. +Only backslash (\^\fB\e\fP\^) and single quotes can quote +the history expansion character. +.PP +Several characters inhibit history expansion if found immediately +following the history expansion character, even if it is unquoted: +space, tab, newline, carriage return, and \fB=\fP. +If the \fBextglob\fP shell option is enabled, \fB(\fP will also +inhibit expansion. +.PP +Several shell options settable with the +.B shopt +builtin may be used to tailor the behavior of history expansion. +If the +.B histverify +shell option is enabled (see the description of the +.B shopt +builtin below), and +.B readline +is being used, history substitutions are not immediately passed to +the shell parser. +Instead, the expanded line is reloaded into the +.B readline +editing buffer for further modification. +If +.B readline +is being used, and the +.B histreedit +shell option is enabled, a failed history substitution will be reloaded +into the +.B readline +editing buffer for correction. +The +.B \-p +option to the +.B history +builtin command may be used to see what a history expansion will +do before using it. +The +.B \-s +option to the +.B history +builtin may be used to add commands to the end of the history list +without actually executing them, so that they are available for +subsequent recall. +.PP +The shell allows control of the various characters used by the +history expansion mechanism (see the description of +.B histchars +above under +.BR "Shell Variables" ). +The shell uses +the history comment character to mark history timestamps when +writing the history file. +.SS Event Designators +.PP +An event designator is a reference to a command line entry in the +history list. +Unless the reference is absolute, events are relative to the current +position in the history list. +.PP +.PD 0 +.TP +.B ! +Start a history substitution, except when followed by a +.BR blank , +newline, carriage return, = +or ( (when the \fBextglob\fP shell option is enabled using +the \fBshopt\fP builtin). +.TP +.B !\fIn\fR +Refer to command line +.IR n . +.TP +.B !\-\fIn\fR +Refer to the current command minus +.IR n . +.TP +.B !! +Refer to the previous command. This is a synonym for `!\-1'. +.TP +.B !\fIstring\fR +Refer to the most recent command preceding the current position in the +history list starting with +.IR string . +.TP +.B !?\fIstring\fR\fB[?]\fR +Refer to the most recent command preceding the current position in the +history list containing +.IR string . +The trailing \fB?\fP may be omitted if +.I string +is followed immediately by a newline. +.TP +.B \d\s+2^\s-2\u\fIstring1\fP\d\s+2^\s-2\u\fIstring2\fP\d\s+2^\s-2\u +Quick substitution. Repeat the previous command, replacing +.I string1 +with +.IR string2 . +Equivalent to +``!!:s/\fIstring1\fP/\fIstring2\fP/'' +(see \fBModifiers\fP below). +.TP +.B !# +The entire command line typed so far. +.PD +.SS Word Designators +.PP +Word designators are used to select desired words from the event. +A +.B : +separates the event specification from the word designator. +It may be omitted if the word designator begins with a +.BR ^ , +.BR $ , +.BR * , +.BR \- , +or +.BR % . +Words are numbered from the beginning of the line, +with the first word being denoted by 0 (zero). +Words are inserted into the current line separated by single spaces. +.PP +.PD 0 +.TP +.B 0 (zero) +The zeroth word. For the shell, this is the command +word. +.TP +.I n +The \fIn\fRth word. +.TP +.B ^ +The first argument. That is, word 1. +.TP +.B $ +The last word. This is usually the last argument, but will expand to the +zeroth word if there is only one word in the line. +.TP +.B % +The word matched by the most recent `?\fIstring\fR?' search. +.TP +.I x\fB\-\fPy +A range of words; `\-\fIy\fR' abbreviates `0\-\fIy\fR'. +.TP +.B * +All of the words but the zeroth. This is a synonym +for `\fI1\-$\fP'. It is not an error to use +.B * +if there is just one +word in the event; the empty string is returned in that case. +.TP +.B x* +Abbreviates \fIx\-$\fP. +.TP +.B x\- +Abbreviates \fIx\-$\fP like \fBx*\fP, but omits the last word. +.PD +.PP +If a word designator is supplied without an event specification, the +previous command is used as the event. +.SS Modifiers +.PP +After the optional word designator, there may appear a sequence of +one or more of the following modifiers, each preceded by a `:'. +.PP +.PD 0 +.PP +.TP +.B h +Remove a trailing filename component, leaving only the head. +.TP +.B t +Remove all leading filename components, leaving the tail. +.TP +.B r +Remove a trailing suffix of the form \fI.xxx\fP, leaving the +basename. +.TP +.B e +Remove all but the trailing suffix. +.TP +.B p +Print the new command but do not execute it. +.TP +.B q +Quote the substituted words, escaping further substitutions. +.TP +.B x +Quote the substituted words as with +.BR q , +but break into words at +.B blanks +and newlines. +.TP +.B s/\fIold\fP/\fInew\fP/ +Substitute +.I new +for the first occurrence of +.I old +in the event line. Any delimiter can be used in place of /. The +final delimiter is optional if it is the last character of the +event line. The delimiter may be quoted in +.I old +and +.I new +with a single backslash. If & appears in +.IR new , +it is replaced by +.IR old . +A single backslash will quote the &. If +.I old +is null, it is set to the last +.I old +substituted, or, if no previous history substitutions took place, +the last +.I string +in a +.B !?\fIstring\fR\fB[?]\fR +search. +.TP +.B & +Repeat the previous substitution. +.TP +.B g +Cause changes to be applied over the entire event line. This is +used in conjunction with `\fB:s\fP' (e.g., `\fB:gs/\fIold\fP/\fInew\fP/\fR') +or `\fB:&\fP'. If used with +`\fB:s\fP', any delimiter can be used +in place of /, and the final delimiter is optional +if it is the last character of the event line. +An \fBa\fP may be used as a synonym for \fBg\fP. +.TP +.B G +Apply the following `\fBs\fP' modifier once to each word in the event line. +.PD +.SH "SHELL BUILTIN COMMANDS" +.\" start of bash_builtins +.zZ +.PP +Unless otherwise noted, each builtin command documented in this +section as accepting options preceded by +.B \- +accepts +.B \-\- +to signify the end of the options. +The \fB:\fP, \fBtrue\fP, \fBfalse\fP, and \fBtest\fP builtins +do not accept options and do not treat \fB\-\-\fP specially. +The \fBexit\fP, \fBlogout\fP, \fBbreak\fP, \fBcontinue\fP, \fBlet\fP, +and \fBshift\fP builtins accept and process arguments beginning with +\fB\-\fP without requiring \fB\-\-\fP. +Other builtins that accept arguments but are not specified as accepting +options interpret arguments beginning with \fB\-\fP as invalid options and +require \fB\-\-\fP to prevent this interpretation. +.sp .5 +.PD 0 +.TP +\fB:\fP [\fIarguments\fP] +.PD +No effect; the command does nothing beyond expanding +.I arguments +and performing any specified +redirections. A zero exit code is returned. +.TP +\fB .\| \fP \fIfilename\fP [\fIarguments\fP] +.PD 0 +.TP +\fBsource\fP \fIfilename\fP [\fIarguments\fP] +.PD +Read and execute commands from +.I filename +in the current +shell environment and return the exit status of the last command +executed from +.IR filename . +If +.I filename +does not contain a slash, filenames in +.SM +.B PATH +are used to find the directory containing +.IR filename . +The file searched for in +.SM +.B PATH +need not be executable. +When \fBbash\fP is not in \fIposix mode\fP, the current directory is +searched if no file is found in +.SM +.BR PATH . +If the +.B sourcepath +option to the +.B shopt +builtin command is turned off, the +.SM +.B PATH +is not searched. +If any \fIarguments\fP are supplied, they become the positional +parameters when \fIfilename\fP is executed. Otherwise the positional +parameters are unchanged. +The return status is the status of the last command exited within +the script (0 if no commands are executed), and false if +.I filename +is not found or cannot be read. +.TP +\fBalias\fP [\fB\-p\fP] [\fIname\fP[=\fIvalue\fP] ...] +\fBAlias\fP with no arguments or with the +.B \-p +option prints the list of aliases in the form +\fBalias\fP \fIname\fP=\fIvalue\fP on standard output. +When arguments are supplied, an alias is defined for +each \fIname\fP whose \fIvalue\fP is given. +A trailing space in \fIvalue\fP causes the next word to be +checked for alias substitution when the alias is expanded. +For each \fIname\fP in the argument list for which no \fIvalue\fP +is supplied, the name and value of the alias is printed. +\fBAlias\fP returns true unless a \fIname\fP is given for which +no alias has been defined. +.TP +\fBbg\fP [\fIjobspec\fP ...] +Resume each suspended job \fIjobspec\fP in the background, as if it +had been started with +.BR & . +If +.I jobspec +is not present, the shell's notion of the \fIcurrent job\fP is used. +.B bg +.I jobspec +returns 0 unless run when job control is disabled or, when run with +job control enabled, any specified \fIjobspec\fP was not found +or was started without job control. +.TP +\fBbind\fP [\fB\-m\fP \fIkeymap\fP] [\fB\-lpsvPSVX\fP] +.PD 0 +.TP +\fBbind\fP [\fB\-m\fP \fIkeymap\fP] [\fB\-q\fP \fIfunction\fP] [\fB\-u\fP \fIfunction\fP] [\fB\-r\fP \fIkeyseq\fP] +.TP +\fBbind\fP [\fB\-m\fP \fIkeymap\fP] \fB\-f\fP \fIfilename\fP +.TP +\fBbind\fP [\fB\-m\fP \fIkeymap\fP] \fB\-x\fP \fIkeyseq\fP:\fIshell\-command\fP +.TP +\fBbind\fP [\fB\-m\fP \fIkeymap\fP] \fIkeyseq\fP:\fIfunction\-name\fP +.TP +\fBbind\fP [\fB\-m\fP \fIkeymap\fP] \fIkeyseq\fP:\fIreadline\-command\fP +.PD +Display current +.B readline +key and function bindings, bind a key sequence to a +.B readline +function or macro, or set a +.B readline +variable. +Each non-option argument is a command as it would appear in +.IR .inputrc , +but each binding or command must be passed as a separate argument; +e.g., '"\eC\-x\eC\-r": re\-read\-init\-file'. +Options, if supplied, have the following meanings: +.RS +.PD 0 +.TP +.B \-m \fIkeymap\fP +Use +.I keymap +as the keymap to be affected by the subsequent bindings. +Acceptable +.I keymap +names are +\fIemacs, emacs\-standard, emacs\-meta, emacs\-ctlx, vi, +vi\-move, vi\-command\fP, and +.IR vi\-insert . +\fIvi\fP is equivalent to \fIvi\-command\fP; \fIemacs\fP is +equivalent to \fIemacs\-standard\fP. +.TP +.B \-l +List the names of all \fBreadline\fP functions. +.TP +.B \-p +Display \fBreadline\fP function names and bindings in such a way +that they can be re-read. +.TP +.B \-P +List current \fBreadline\fP function names and bindings. +.TP +.B \-s +Display \fBreadline\fP key sequences bound to macros and the strings +they output in such a way that they can be re-read. +.TP +.B \-S +Display \fBreadline\fP key sequences bound to macros and the strings +they output. +.TP +.B \-v +Display \fBreadline\fP variable names and values in such a way that they +can be re-read. +.TP +.B \-V +List current \fBreadline\fP variable names and values. +.TP +.B \-f \fIfilename\fP +Read key bindings from \fIfilename\fP. +.TP +.B \-q \fIfunction\fP +Query about which keys invoke the named \fIfunction\fP. +.TP +.B \-u \fIfunction\fP +Unbind all keys bound to the named \fIfunction\fP. +.TP +.B \-r \fIkeyseq\fP +Remove any current binding for \fIkeyseq\fP. +.TP +.B \-x \fIkeyseq\fP:\fIshell\-command\fP +Cause \fIshell\-command\fP to be executed whenever \fIkeyseq\fP is +entered. +When \fIshell\-command\fP is executed, the shell sets the +.SM +.B READLINE_LINE +variable to the contents of the \fBreadline\fP line buffer and the +.SM +.B READLINE_POINT +variable to the current location of the insertion point. +If the executed command changes the value of +.SM +.B READLINE_LINE +or +.SM +.BR READLINE_POINT , +those new values will be reflected in the editing state. +.TP +.B \-X +List all key sequences bound to shell commands and the associated commands +in a format that can be reused as input. +.PD +.PP +The return value is 0 unless an unrecognized option is given or an +error occurred. +.RE +.TP +\fBbreak\fP [\fIn\fP] +Exit from within a +.BR for , +.BR while , +.BR until , +or +.B select +loop. If \fIn\fP is specified, break \fIn\fP levels. +.I n +must be \(>= 1. If +.I n +is greater than the number of enclosing loops, all enclosing loops +are exited. +The return value is 0 unless \fIn\fP is not greater than or equal to 1. +.TP +\fBbuiltin\fP \fIshell\-builtin\fP [\fIarguments\fP] +Execute the specified shell builtin, passing it +.IR arguments , +and return its exit status. +This is useful when defining a +function whose name is the same as a shell builtin, +retaining the functionality of the builtin within the function. +The \fBcd\fP builtin is commonly redefined this way. +The return status is false if +.I shell\-builtin +is not a shell builtin command. +.TP +\fBcaller\fP [\fIexpr\fP] +Returns the context of any active subroutine call (a shell function or +a script executed with the \fB.\fP or \fBsource\fP builtins). +Without \fIexpr\fP, \fBcaller\fP displays the line number and source +filename of the current subroutine call. +If a non-negative integer is supplied as \fIexpr\fP, \fBcaller\fP +displays the line number, subroutine name, and source file corresponding +to that position in the current execution call stack. This extra +information may be used, for example, to print a stack trace. The +current frame is frame 0. +The return value is 0 unless the shell is not executing a subroutine +call or \fIexpr\fP does not correspond to a valid position in the +call stack. +.TP +\fBcd\fP [\fB\-L\fP|[\fB\-P\fP [\fB\-e\fP]] [\-@]] [\fIdir\fP] +Change the current directory to \fIdir\fP. +if \fIdir\fP is not supplied, the value of the +.SM +.B HOME +shell variable is the default. +Any additional arguments following \fIdir\fP are ignored. +The variable +.SM +.B CDPATH +defines the search path for the directory containing +.IR dir : +each directory name in +.SM +.B CDPATH +is searched for \fIdir\fP. +Alternative directory names in +.SM +.B CDPATH +are separated by a colon (:). A null directory name in +.SM +.B CDPATH +is the same as the current directory, i.e., ``\fB.\fP''. If +.I dir +begins with a slash (/), +then +.SM +.B CDPATH +is not used. The +.B \-P +option causes \fBcd\fP to use the physical directory structure +by resolving symbolic links while traversing \fIdir\fP and +before processing instances of \fI..\fP in \fIdir\fP (see also the +.B \-P +option to the +.B set +builtin command); the +.B \-L +option forces symbolic links to be followed by resolving the link +after processing instances of \fI..\fP in \fIdir\fP. +If \fI..\fP appears in \fIdir\fP, it is processed by removing the +immediately previous pathname component from \fIdir\fP, back to a slash +or the beginning of \fIdir\fP. +If the +.B \-e +option is supplied with +.BR \-P , +and the current working directory cannot be successfully determined +after a successful directory change, \fBcd\fP will return an unsuccessful +status. +On systems that support it, the \fB\-@\fP option presents the extended +attributes associated with a file as a directory. +An argument of +.B \- +is converted to +.SM +.B $OLDPWD +before the directory change is attempted. +If a non-empty directory name from +.SM +.B CDPATH +is used, or if +\fB\-\fP is the first argument, and the directory change is +successful, the absolute pathname of the new working directory is +written to the standard output. +The return value is true if the directory was successfully changed; +false otherwise. +.TP +\fBcommand\fP [\fB\-pVv\fP] \fIcommand\fP [\fIarg\fP ...] +Run +.I command +with +.I args +suppressing the normal shell function lookup. +Only builtin commands or commands found in the +.SM +.B PATH +are executed. If the +.B \-p +option is given, the search for +.I command +is performed using a default value for +.SM +.B PATH +that is guaranteed to find all of the standard utilities. +If either the +.B \-V +or +.B \-v +option is supplied, a description of +.I command +is printed. The +.B \-v +option causes a single word indicating the command or filename +used to invoke +.I command +to be displayed; the +.B \-V +option produces a more verbose description. +If the +.B \-V +or +.B \-v +option is supplied, the exit status is 0 if +.I command +was found, and 1 if not. If neither option is supplied and +an error occurred or +.I command +cannot be found, the exit status is 127. Otherwise, the exit status of the +.B command +builtin is the exit status of +.IR command . +.TP +\fBcompgen\fP [\fIoption\fP] [\fIword\fP] +Generate possible completion matches for \fIword\fP according to +the \fIoption\fPs, which may be any option accepted by the +.B complete +builtin with the exception of \fB\-p\fP and \fB\-r\fP, and write +the matches to the standard output. +When using the \fB\-F\fP or \fB\-C\fP options, the various shell variables +set by the programmable completion facilities, while available, will not +have useful values. +.sp 1 +The matches will be generated in the same way as if the programmable +completion code had generated them directly from a completion specification +with the same flags. +If \fIword\fP is specified, only those completions matching \fIword\fP +will be displayed. +.sp 1 +The return value is true unless an invalid option is supplied, or no +matches were generated. +.TP +\fBcomplete\fP [\fB\-abcdefgjksuv\fP] [\fB\-o\fP \fIcomp-option\fP] [\fB\-DE\fP] [\fB\-A\fP \fIaction\fP] [\fB\-G\fP \fIglobpat\fP] [\fB\-W\fP \fIwordlist\fP] [\fB\-F\fP \fIfunction\fP] [\fB\-C\fP \fIcommand\fP] +.br +[\fB\-X\fP \fIfilterpat\fP] [\fB\-P\fP \fIprefix\fP] [\fB\-S\fP \fIsuffix\fP] \fIname\fP [\fIname ...\fP] +.PD 0 +.TP +\fBcomplete\fP \fB\-pr\fP [\fB\-DE\fP] [\fIname\fP ...] +.PD +Specify how arguments to each \fIname\fP should be completed. +If the \fB\-p\fP option is supplied, or if no options are supplied, +existing completion specifications are printed in a way that allows +them to be reused as input. +The \fB\-r\fP option removes a completion specification for +each \fIname\fP, or, if no \fIname\fPs are supplied, all +completion specifications. +The \fB\-D\fP option indicates that the remaining options and actions should +apply to the ``default'' command completion; that is, completion attempted +on a command for which no completion has previously been defined. +The \fB\-E\fP option indicates that the remaining options and actions should +apply to ``empty'' command completion; that is, completion attempted on a +blank line. +.sp 1 +The process of applying these completion specifications when word completion +is attempted is described above under \fBProgrammable Completion\fP. +.sp 1 +Other options, if specified, have the following meanings. +The arguments to the \fB\-G\fP, \fB\-W\fP, and \fB\-X\fP options +(and, if necessary, the \fB\-P\fP and \fB\-S\fP options) +should be quoted to protect them from expansion before the +.B complete +builtin is invoked. +.RS +.PD 0 +.TP 8 +\fB\-o\fP \fIcomp-option\fP +The \fIcomp-option\fP controls several aspects of the compspec's behavior +beyond the simple generation of completions. +\fIcomp-option\fP may be one of: +.RS +.TP 8 +.B bashdefault +Perform the rest of the default \fBbash\fP completions if the compspec +generates no matches. +.TP 8 +.B default +Use readline's default filename completion if the compspec generates +no matches. +.TP 8 +.B dirnames +Perform directory name completion if the compspec generates no matches. +.TP 8 +.B filenames +Tell readline that the compspec generates filenames, so it can perform any +filename\-specific processing (like adding a slash to directory names, +quoting special characters, or suppressing trailing spaces). +Intended to be used with shell functions. +.TP 8 +.B noquote +Tell readline not to quote the completed words if they are filenames +(quoting filenames is the default). +.TP 8 +.B nospace +Tell readline not to append a space (the default) to words completed at +the end of the line. +.TP 8 +.B plusdirs +After any matches defined by the compspec are generated, +directory name completion is attempted and any +matches are added to the results of the other actions. +.RE +.TP 8 +\fB\-A\fP \fIaction\fP +The \fIaction\fP may be one of the following to generate a list of possible +completions: +.RS +.TP 8 +.B alias +Alias names. May also be specified as \fB\-a\fP. +.TP 8 +.B arrayvar +Array variable names. +.TP 8 +.B binding +\fBReadline\fP key binding names. +.TP 8 +.B builtin +Names of shell builtin commands. May also be specified as \fB\-b\fP. +.TP 8 +.B command +Command names. May also be specified as \fB\-c\fP. +.TP 8 +.B directory +Directory names. May also be specified as \fB\-d\fP. +.TP 8 +.B disabled +Names of disabled shell builtins. +.TP 8 +.B enabled +Names of enabled shell builtins. +.TP 8 +.B export +Names of exported shell variables. May also be specified as \fB\-e\fP. +.TP 8 +.B file +File names. May also be specified as \fB\-f\fP. +.TP 8 +.B function +Names of shell functions. +.TP 8 +.B group +Group names. May also be specified as \fB\-g\fP. +.TP 8 +.B helptopic +Help topics as accepted by the \fBhelp\fP builtin. +.TP 8 +.B hostname +Hostnames, as taken from the file specified by the +.SM +.B HOSTFILE +shell variable. +.TP 8 +.B job +Job names, if job control is active. May also be specified as \fB\-j\fP. +.TP 8 +.B keyword +Shell reserved words. May also be specified as \fB\-k\fP. +.TP 8 +.B running +Names of running jobs, if job control is active. +.TP 8 +.B service +Service names. May also be specified as \fB\-s\fP. +.TP 8 +.B setopt +Valid arguments for the \fB\-o\fP option to the \fBset\fP builtin. +.TP 8 +.B shopt +Shell option names as accepted by the \fBshopt\fP builtin. +.TP 8 +.B signal +Signal names. +.TP 8 +.B stopped +Names of stopped jobs, if job control is active. +.TP 8 +.B user +User names. May also be specified as \fB\-u\fP. +.TP 8 +.B variable +Names of all shell variables. May also be specified as \fB\-v\fP. +.RE +.TP 8 +\fB\-C\fP \fIcommand\fP +\fIcommand\fP is executed in a subshell environment, and its output is +used as the possible completions. +.TP 8 +\fB\-F\fP \fIfunction\fP +The shell function \fIfunction\fP is executed in the current shell +environment. +When the function is executed, +the first argument (\fB$1\fP) is the name of the command whose arguments are +being completed, +the second argument (\fB$2\fP) is the word being completed, +and the third argument (\fB$3\fP) is the word preceding the word being +completed on the current command line. +When it finishes, the possible completions are retrieved from the value +of the +.SM +.B COMPREPLY +array variable. +.TP 8 +\fB\-G\fP \fIglobpat\fP +The pathname expansion pattern \fIglobpat\fP is expanded to generate +the possible completions. +.TP 8 +\fB\-P\fP \fIprefix\fP +\fIprefix\fP is added at the beginning of each possible completion +after all other options have been applied. +.TP 8 +\fB\-S\fP \fIsuffix\fP +\fIsuffix\fP is appended to each possible completion +after all other options have been applied. +.TP 8 +\fB\-W\fP \fIwordlist\fP +The \fIwordlist\fP is split using the characters in the +.SM +.B IFS +special variable as delimiters, and each resultant word is expanded. +The possible completions are the members of the resultant list which +match the word being completed. +.TP 8 +\fB\-X\fP \fIfilterpat\fP +\fIfilterpat\fP is a pattern as used for pathname expansion. +It is applied to the list of possible completions generated by the +preceding options and arguments, and each completion matching +\fIfilterpat\fP is removed from the list. +A leading \fB!\fP in \fIfilterpat\fP negates the pattern; in this +case, any completion not matching \fIfilterpat\fP is removed. +.PD +.PP +The return value is true unless an invalid option is supplied, an option +other than \fB\-p\fP or \fB\-r\fP is supplied without a \fIname\fP +argument, an attempt is made to remove a completion specification for +a \fIname\fP for which no specification exists, or +an error occurs adding a completion specification. +.RE +.TP +\fBcompopt\fP [\fB\-o\fP \fIoption\fP] [\fB\-DE\fP] [\fB+o\fP \fIoption\fP] [\fIname\fP] +Modify completion options for each \fIname\fP according to the +\fIoption\fPs, or for the +currently-executing completion if no \fIname\fPs are supplied. +If no \fIoption\fPs are given, display the completion options for each +\fIname\fP or the current completion. +The possible values of \fIoption\fP are those valid for the \fBcomplete\fP +builtin described above. +The \fB\-D\fP option indicates that the remaining options should +apply to the ``default'' command completion; that is, completion attempted +on a command for which no completion has previously been defined. +The \fB\-E\fP option indicates that the remaining options should +apply to ``empty'' command completion; that is, completion attempted on a +blank line. +.sp 1 +The return value is true unless an invalid option is supplied, an attempt +is made to modify the options for a \fIname\fP for which no completion +specification exists, or an output error occurs. +.TP +\fBcontinue\fP [\fIn\fP] +Resume the next iteration of the enclosing +.BR for , +.BR while , +.BR until , +or +.B select +loop. +If +.I n +is specified, resume at the \fIn\fPth enclosing loop. +.I n +must be \(>= 1. If +.I n +is greater than the number of enclosing loops, the last enclosing loop +(the ``top-level'' loop) is resumed. +The return value is 0 unless \fIn\fP is not greater than or equal to 1. +.TP +\fBdeclare\fP [\fB\-aAfFgilnrtux\fP] [\fB\-p\fP] [\fIname\fP[=\fIvalue\fP] ...] +.PD 0 +.TP +\fBtypeset\fP [\fB\-aAfFgilnrtux\fP] [\fB\-p\fP] [\fIname\fP[=\fIvalue\fP] ...] +.PD +Declare variables and/or give them attributes. +If no \fIname\fPs are given then display the values of variables. +The +.B \-p +option will display the attributes and values of each +.IR name . +When +.B \-p +is used with \fIname\fP arguments, additional options, +other than \fB\-f\fP and \fB\-F\fP, are ignored. +When +.B \-p +is supplied without \fIname\fP arguments, it will display the attributes +and values of all variables having the attributes specified by the +additional options. +If no other options are supplied with \fB\-p\fP, \fBdeclare\fP will display +the attributes and values of all shell variables. The \fB\-f\fP option +will restrict the display to shell functions. +The +.B \-F +option inhibits the display of function definitions; only the +function name and attributes are printed. +If the \fBextdebug\fP shell option is enabled using \fBshopt\fP, +the source file name and line number where the function is defined +are displayed as well. The +.B \-F +option implies +.BR \-f . +The +.B \-g +option forces variables to be created or modified at the global scope, +even when \fBdeclare\fP is executed in a shell function. +It is ignored in all other cases. +The following options can +be used to restrict output to variables with the specified attribute or +to give variables attributes: +.RS +.PD 0 +.TP +.B \-a +Each \fIname\fP is an indexed array variable (see +.B Arrays +above). +.TP +.B \-A +Each \fIname\fP is an associative array variable (see +.B Arrays +above). +.TP +.B \-f +Use function names only. +.TP +.B \-i +The variable is treated as an integer; arithmetic evaluation (see +.SM +.B "ARITHMETIC EVALUATION" +above) is performed when the variable is assigned a value. +.TP +.B \-l +When the variable is assigned a value, all upper-case characters are +converted to lower-case. +The upper-case attribute is disabled. +.TP +.B \-n +Give each \fIname\fP the \fInameref\fP attribute, making +it a name reference to another variable. +That other variable is defined by the value of \fIname\fP. +All references, assignments, and attribute modifications +to \fIname\fP, except for changing the +\fB\-n\fP attribute itself, are performed on the variable referenced by +\fIname\fP's value. +The nameref attribute cannot be applied to array variables. +.TP +.B \-r +Make \fIname\fPs readonly. These names cannot then be assigned values +by subsequent assignment statements or unset. +.TP +.B \-t +Give each \fIname\fP the \fItrace\fP attribute. +Traced functions inherit the \fBDEBUG\fP and \fBRETURN\fP traps from +the calling shell. +The trace attribute has no special meaning for variables. +.TP +.B \-u +When the variable is assigned a value, all lower-case characters are +converted to upper-case. +The lower-case attribute is disabled. +.TP +.B \-x +Mark \fIname\fPs for export to subsequent commands via the environment. +.PD +.PP +Using `+' instead of `\-' +turns off the attribute instead, +with the exceptions that \fB+a\fP +may not be used to destroy an array variable and \fB+r\fP will not +remove the readonly attribute. +When used in a function, +.B declare +and +.B typeset +make each +\fIname\fP local, as with the +.B local +command, +unless the \fB\-g\fP option is supplied. +If a variable name is followed by =\fIvalue\fP, the value of +the variable is set to \fIvalue\fP. +When using \fB\-a\fP or \fB\-A\fP and the compound assignment syntax to +create array variables, additional attributes do not take effect until +subsequent assignments. +The return value is 0 unless an invalid option is encountered, +an attempt is made to define a function using +.if n ``\-f foo=bar'', +.if t \f(CW\-f foo=bar\fP, +an attempt is made to assign a value to a readonly variable, +an attempt is made to assign a value to an array variable without +using the compound assignment syntax (see +.B Arrays +above), one of the \fInames\fP is not a valid shell variable name, +an attempt is made to turn off readonly status for a readonly variable, +an attempt is made to turn off array status for an array variable, +or an attempt is made to display a non-existent function with \fB\-f\fP. +.RE +.TP +.B dirs [\fB\-clpv\fP] [+\fIn\fP] [\-\fIn\fP] +Without options, displays the list of currently remembered directories. +The default display is on a single line with directory names separated +by spaces. +Directories are added to the list with the +.B pushd +command; the +.B popd +command removes entries from the list. +.RS +.PD 0 +.TP +.B \-c +Clears the directory stack by deleting all of the entries. +.TP +.B \-l +Produces a listing using full pathnames; +the default listing format uses a tilde to denote the home directory. +.TP +.B \-p +Print the directory stack with one entry per line. +.TP +.B \-v +Print the directory stack with one entry per line, +prefixing each entry with its index in the stack. +.TP +\fB+\fP\fIn\fP +Displays the \fIn\fPth entry counting from the left of the list +shown by +.B dirs +when invoked without options, starting with zero. +.TP +\fB\-\fP\fIn\fP +Displays the \fIn\fPth entry counting from the right of the list +shown by +.B dirs +when invoked without options, starting with zero. +.PD +.PP +The return value is 0 unless an +invalid option is supplied or \fIn\fP indexes beyond the end +of the directory stack. +.RE +.TP +\fBdisown\fP [\fB\-ar\fP] [\fB\-h\fP] [\fIjobspec\fP ...] +Without options, remove each +.I jobspec +from the table of active jobs. +If +.I jobspec +is not present, and neither the \fB\-a\fP nor the \fB\-r\fP option +is supplied, the \fIcurrent job\fP is used. +If the \fB\-h\fP option is given, each +.I jobspec +is not removed from the table, but is marked so that +.SM +.B SIGHUP +is not sent to the job if the shell receives a +.SM +.BR SIGHUP . +If no +.I jobspec +is supplied, the +.B \-a +option means to remove or mark all jobs; the +.B \-r +option without a +.I jobspec +argument restricts operation to running jobs. +The return value is 0 unless a +.I jobspec +does not specify a valid job. +.TP +\fBecho\fP [\fB\-neE\fP] [\fIarg\fP ...] +Output the \fIarg\fPs, separated by spaces, followed by a newline. +The return status is 0 unless a write error occurs. +If \fB\-n\fP is specified, the trailing newline is +suppressed. If the \fB\-e\fP option is given, interpretation of +the following backslash-escaped characters is enabled. The +.B \-E +option disables the interpretation of these escape characters, +even on systems where they are interpreted by default. +The \fBxpg_echo\fP shell option may be used to +dynamically determine whether or not \fBecho\fP expands these +escape characters by default. +.B echo +does not interpret \fB\-\-\fP to mean the end of options. +.B echo +interprets the following escape sequences: +.RS +.PD 0 +.TP +.B \ea +alert (bell) +.TP +.B \eb +backspace +.TP +.B \ec +suppress further output +.TP +.B \ee +.TP +.B \eE +an escape character +.TP +.B \ef +form feed +.TP +.B \en +new line +.TP +.B \er +carriage return +.TP +.B \et +horizontal tab +.TP +.B \ev +vertical tab +.TP +.B \e\e +backslash +.TP +.B \e0\fInnn\fP +the eight-bit character whose value is the octal value \fInnn\fP +(zero to three octal digits) +.TP +.B \ex\fIHH\fP +the eight-bit character whose value is the hexadecimal value \fIHH\fP +(one or two hex digits) +.TP +.B \eu\fIHHHH\fP +the Unicode (ISO/IEC 10646) character whose value is the hexadecimal value +\fIHHHH\fP (one to four hex digits) +.TP +.B \eU\fIHHHHHHHH\fP +the Unicode (ISO/IEC 10646) character whose value is the hexadecimal value +\fIHHHHHHHH\fP (one to eight hex digits) +.PD +.RE +.TP +\fBenable\fP [\fB\-a\fP] [\fB\-dnps\fP] [\fB\-f\fP \fIfilename\fP] [\fIname\fP ...] +Enable and disable builtin shell commands. +Disabling a builtin allows a disk command which has the same name +as a shell builtin to be executed without specifying a full pathname, +even though the shell normally searches for builtins before disk commands. +If \fB\-n\fP is used, each \fIname\fP +is disabled; otherwise, +\fInames\fP are enabled. For example, to use the +.B test +binary found via the +.SM +.B PATH +instead of the shell builtin version, run +.if t \f(CWenable -n test\fP. +.if n ``enable -n test''. +The +.B \-f +option means to load the new builtin command +.I name +from shared object +.IR filename , +on systems that support dynamic loading. The +.B \-d +option will delete a builtin previously loaded with +.BR \-f . +If no \fIname\fP arguments are given, or if the +.B \-p +option is supplied, a list of shell builtins is printed. +With no other option arguments, the list consists of all enabled +shell builtins. +If \fB\-n\fP is supplied, only disabled builtins are printed. +If \fB\-a\fP is supplied, the list printed includes all builtins, with an +indication of whether or not each is enabled. +If \fB\-s\fP is supplied, the output is restricted to the POSIX +\fIspecial\fP builtins. +The return value is 0 unless a +.I name +is not a shell builtin or there is an error loading a new builtin +from a shared object. +.TP +\fBeval\fP [\fIarg\fP ...] +The \fIarg\fPs are read and concatenated together into a single +command. This command is then read and executed by the shell, and +its exit status is returned as the value of +.BR eval . +If there are no +.IR args , +or only null arguments, +.B eval +returns 0. +.TP +\fBexec\fP [\fB\-cl\fP] [\fB\-a\fP \fIname\fP] [\fIcommand\fP [\fIarguments\fP]] +If +.I command +is specified, it replaces the shell. +No new process is created. The +.I arguments +become the arguments to \fIcommand\fP. +If the +.B \-l +option is supplied, +the shell places a dash at the beginning of the zeroth argument passed to +.IR command . +This is what +.IR login (1) +does. The +.B \-c +option causes +.I command +to be executed with an empty environment. If +.B \-a +is supplied, the shell passes +.I name +as the zeroth argument to the executed command. +If +.I command +cannot be executed for some reason, a non-interactive shell exits, +unless the +.B execfail +shell option +is enabled. In that case, it returns failure. +An interactive shell returns failure if the file cannot be executed. +If +.I command +is not specified, any redirections take effect in the current shell, +and the return status is 0. If there is a redirection error, the +return status is 1. +.TP +\fBexit\fP [\fIn\fP] +Cause the shell to exit +with a status of \fIn\fP. If +.I n +is omitted, the exit status +is that of the last command executed. +A trap on +.SM +.B EXIT +is executed before the shell terminates. +.TP +\fBexport\fP [\fB\-fn\fP\^] [\fIname\fP[=\fIword\fP]] ... +.PD 0 +.TP +.B export \-p +.PD +The supplied +.I names +are marked for automatic export to the environment of +subsequently executed commands. If the +.B \-f +option is given, the +.I names +refer to functions. +If no +.I names +are given, or if the +.B \-p +option is supplied, a list +of names of all exported variables is printed. +The +.B \-n +option causes the export property to be removed from each +\fIname\fP. +If a variable name is followed by =\fIword\fP, the value of +the variable is set to \fIword\fP. +.B export +returns an exit status of 0 unless an invalid option is +encountered, +one of the \fInames\fP is not a valid shell variable name, or +.B \-f +is supplied with a +.I name +that is not a function. +.TP +\fBfc\fP [\fB\-e\fP \fIename\fP] [\fB\-lnr\fP] [\fIfirst\fP] [\fIlast\fP] +.PD 0 +.TP +\fBfc\fP \fB\-s\fP [\fIpat\fP=\fIrep\fP] [\fIcmd\fP] +.PD +The first form selects a range of commands from +.I first +to +.I last +from the history list and displays or edits and re-executes them. +.I First +and +.I last +may be specified as a string (to locate the last command beginning +with that string) or as a number (an index into the history list, +where a negative number is used as an offset from the current +command number). If +.I last +is not specified it is set to +the current command for listing (so that +.if n ``fc \-l \-10'' +.if t \f(CWfc \-l \-10\fP +prints the last 10 commands) and to +.I first +otherwise. +If +.I first +is not specified it is set to the previous +command for editing and \-16 for listing. +.sp 1 +The +.B \-n +option suppresses +the command numbers when listing. The +.B \-r +option reverses the order of +the commands. If the +.B \-l +option is given, +the commands are listed on +standard output. Otherwise, the editor given by +.I ename +is invoked +on a file containing those commands. If +.I ename +is not given, the +value of the +.SM +.B FCEDIT +variable is used, and +the value of +.SM +.B EDITOR +if +.SM +.B FCEDIT +is not set. If neither variable is set, +.FN vi +is used. When editing is complete, the edited commands are +echoed and executed. +.sp 1 +In the second form, \fIcommand\fP is re-executed after each instance +of \fIpat\fP is replaced by \fIrep\fP. +\fICommand\fP is intepreted the same as \fIfirst\fP above. +A useful alias to use with this is +.if n ``r="fc -s"'', +.if t \f(CWr='fc \-s'\fP, +so that typing +.if n ``r cc'' +.if t \f(CWr cc\fP +runs the last command beginning with +.if n ``cc'' +.if t \f(CWcc\fP +and typing +.if n ``r'' +.if t \f(CWr\fP +re-executes the last command. +.sp 1 +If the first form is used, the return value is 0 unless an invalid +option is encountered or +.I first +or +.I last +specify history lines out of range. +If the +.B \-e +option is supplied, the return value is the value of the last +command executed or failure if an error occurs with the temporary +file of commands. If the second form is used, the return status +is that of the command re-executed, unless +.I cmd +does not specify a valid history line, in which case +.B fc +returns failure. +.TP +\fBfg\fP [\fIjobspec\fP] +Resume +.I jobspec +in the foreground, and make it the current job. +If +.I jobspec +is not present, the shell's notion of the \fIcurrent job\fP is used. +The return value is that of the command placed into the foreground, +or failure if run when job control is disabled or, when run with +job control enabled, if +.I jobspec +does not specify a valid job or +.I jobspec +specifies a job that was started without job control. +.TP +\fBgetopts\fP \fIoptstring\fP \fIname\fP [\fIargs\fP] +.B getopts +is used by shell procedures to parse positional parameters. +.I optstring +contains the option characters to be recognized; if a character +is followed by a colon, the option is expected to have an +argument, which should be separated from it by white space. +The colon and question mark characters may not be used as +option characters. +Each time it is invoked, +.B getopts +places the next option in the shell variable +.IR name , +initializing +.I name +if it does not exist, +and the index of the next argument to be processed into the +variable +.SM +.BR OPTIND . +.SM +.B OPTIND +is initialized to 1 each time the shell or a shell script +is invoked. When an option requires an argument, +.B getopts +places that argument into the variable +.SM +.BR OPTARG . +The shell does not reset +.SM +.B OPTIND +automatically; it must be manually reset between multiple +calls to +.B getopts +within the same shell invocation if a new set of parameters +is to be used. +.sp 1 +When the end of options is encountered, \fBgetopts\fP exits with a +return value greater than zero. +.SM +.B OPTIND +is set to the index of the first non-option argument, +and \fIname\fP is set to ?. +.sp 1 +.B getopts +normally parses the positional parameters, but if more arguments are +given in +.IR args , +.B getopts +parses those instead. +.sp 1 +.B getopts +can report errors in two ways. If the first character of +.I optstring +is a colon, +.I silent +error reporting is used. In normal operation, diagnostic messages +are printed when invalid options or missing option arguments are +encountered. +If the variable +.SM +.B OPTERR +is set to 0, no error messages will be displayed, even if the first +character of +.I optstring +is not a colon. +.sp 1 +If an invalid option is seen, +.B getopts +places ? into +.I name +and, if not silent, +prints an error message and unsets +.SM +.BR OPTARG . +If +.B getopts +is silent, +the option character found is placed in +.SM +.B OPTARG +and no diagnostic message is printed. +.sp 1 +If a required argument is not found, and +.B getopts +is not silent, +a question mark (\^\fB?\fP\^) is placed in +.IR name , +.SM +.B OPTARG +is unset, and a diagnostic message is printed. +If +.B getopts +is silent, then a colon (\^\fB:\fP\^) is placed in +.I name +and +.SM +.B OPTARG +is set to the option character found. +.sp 1 +.B getopts +returns true if an option, specified or unspecified, is found. +It returns false if the end of options is encountered or an +error occurs. +.TP +\fBhash\fP [\fB\-lr\fP] [\fB\-p\fP \fIfilename\fP] [\fB\-dt\fP] [\fIname\fP] +Each time \fBhash\fP is invoked, +the full pathname of the command +.I name +is determined by searching +the directories in +.B $PATH +and remembered. Any previously-remembered pathname is discarded. +If the +.B \-p +option is supplied, no path search is performed, and +.I filename +is used as the full filename of the command. +The +.B \-r +option causes the shell to forget all +remembered locations. +The +.B \-d +option causes the shell to forget the remembered location of each \fIname\fP. +If the +.B \-t +option is supplied, the full pathname to which each \fIname\fP corresponds +is printed. If multiple \fIname\fP arguments are supplied with \fB\-t\fP, +the \fIname\fP is printed before the hashed full pathname. +The +.B \-l +option causes output to be displayed in a format that may be reused as input. +If no arguments are given, or if only \fB\-l\fP is supplied, +information about remembered commands is printed. +The return status is true unless a +.I name +is not found or an invalid option is supplied. +.TP +\fBhelp\fP [\fB\-dms\fP] [\fIpattern\fP] +Display helpful information about builtin commands. If +.I pattern +is specified, +.B help +gives detailed help on all commands matching +.IR pattern ; +otherwise help for all the builtins and shell control structures +is printed. +.RS +.PD 0 +.TP +.B \-d +Display a short description of each \fIpattern\fP +.TP +.B \-m +Display the description of each \fIpattern\fP in a manpage-like format +.TP +.B \-s +Display only a short usage synopsis for each \fIpattern\fP +.PD +.PP +The return status is 0 unless no command matches +.IR pattern . +.RE +.TP +\fBhistory [\fIn\fP] +.PD 0 +.TP +\fBhistory\fP \fB\-c\fP +.TP +\fBhistory \-d\fP \fIoffset\fP +.TP +\fBhistory\fP \fB\-anrw\fP [\fIfilename\fP] +.TP +\fBhistory\fP \fB\-p\fP \fIarg\fP [\fIarg ...\fP] +.TP +\fBhistory\fP \fB\-s\fP \fIarg\fP [\fIarg ...\fP] +.PD +With no options, display the command +history list with line numbers. Lines listed +with a +.B * +have been modified. An argument of +.I n +lists only the last +.I n +lines. +If the shell variable +.SM +.B HISTTIMEFORMAT +is set and not null, +it is used as a format string for \fIstrftime\fP(3) to display +the time stamp associated with each displayed history entry. +No intervening blank is printed between the formatted time stamp +and the history line. +If \fIfilename\fP is supplied, it is used as the +name of the history file; if not, the value of +.SM +.B HISTFILE +is used. Options, if supplied, have the following meanings: +.RS +.PD 0 +.TP +.B \-c +Clear the history list by deleting all the entries. +.TP +\fB\-d\fP \fIoffset\fP +Delete the history entry at position \fIoffset\fP. +.TP +.B \-a +Append the ``new'' history lines (history lines entered since the +beginning of the current \fBbash\fP session) to the history file. +.TP +.B \-n +Read the history lines not already read from the history +file into the current history list. These are lines +appended to the history file since the beginning of the +current \fBbash\fP session. +.TP +.B \-r +Read the contents of the history file +and append them to the current history list. +.TP +.B \-w +Write the current history list to the history file, overwriting the +history file's contents. +.TP +.B \-p +Perform history substitution on the following \fIargs\fP and display +the result on the standard output. +Does not store the results in the history list. +Each \fIarg\fP must be quoted to disable normal history expansion. +.TP +.B \-s +Store the +.I args +in the history list as a single entry. The last command in the +history list is removed before the +.I args +are added. +.PD +.PP +If the +.SM +.B HISTTIMEFORMAT +variable is set, the time stamp information +associated with each history entry is written to the history file, +marked with the history comment character. +When the history file is read, lines beginning with the history +comment character followed immediately by a digit are interpreted +as timestamps for the previous history line. +The return value is 0 unless an invalid option is encountered, an +error occurs while reading or writing the history file, an invalid +\fIoffset\fP is supplied as an argument to \fB\-d\fP, or the +history expansion supplied as an argument to \fB\-p\fP fails. +.RE +.TP +\fBjobs\fP [\fB\-lnprs\fP] [ \fIjobspec\fP ... ] +.PD 0 +.TP +\fBjobs\fP \fB\-x\fP \fIcommand\fP [ \fIargs\fP ... ] +.PD +The first form lists the active jobs. The options have the following +meanings: +.RS +.PD 0 +.TP +.B \-l +List process IDs +in addition to the normal information. +.TP +.B \-n +Display information only about jobs that have changed status since +the user was last notified of their status. +.TP +.B \-p +List only the process ID of the job's process group +leader. +.TP +.B \-r +Display only running jobs. +.TP +.B \-s +Display only stopped jobs. +.PD +.PP +If +.I jobspec +is given, output is restricted to information about that job. +The return status is 0 unless an invalid option is encountered +or an invalid +.I jobspec +is supplied. +.PP +If the +.B \-x +option is supplied, +.B jobs +replaces any +.I jobspec +found in +.I command +or +.I args +with the corresponding process group ID, and executes +.I command +passing it +.IR args , +returning its exit status. +.RE +.TP +\fBkill\fP [\fB\-s\fP \fIsigspec\fP | \fB\-n\fP \fIsignum\fP | \fB\-\fP\fIsigspec\fP] [\fIpid\fP | \fIjobspec\fP] ... +.PD 0 +.TP +\fBkill\fP \fB\-l\fP [\fIsigspec\fP | \fIexit_status\fP] +.PD +Send the signal named by +.I sigspec +or +.I signum +to the processes named by +.I pid +or +.IR jobspec . +.I sigspec +is either a case-insensitive signal name such as +.SM +.B SIGKILL +(with or without the +.SM +.B SIG +prefix) or a signal number; +.I signum +is a signal number. +If +.I sigspec +is not present, then +.SM +.B SIGTERM +is assumed. +An argument of +.B \-l +lists the signal names. +If any arguments are supplied when +.B \-l +is given, the names of the signals corresponding to the arguments are +listed, and the return status is 0. +The \fIexit_status\fP argument to +.B \-l +is a number specifying either a signal number or the exit status of +a process terminated by a signal. +.B kill +returns true if at least one signal was successfully sent, or false +if an error occurs or an invalid option is encountered. +.TP +\fBlet\fP \fIarg\fP [\fIarg\fP ...] +Each +.I arg +is an arithmetic expression to be evaluated (see +.SM +.B "ARITHMETIC EVALUATION" +above). +If the last +.I arg +evaluates to 0, +.B let +returns 1; 0 is returned otherwise. +.TP +\fBlocal\fP [\fIoption\fP] [\fIname\fP[=\fIvalue\fP] ...] +For each argument, a local variable named +.I name +is created, and assigned +.IR value . +The \fIoption\fP can be any of the options accepted by \fBdeclare\fP. +When +.B local +is used within a function, it causes the variable +.I name +to have a visible scope restricted to that function and its children. +With no operands, +.B local +writes a list of local variables to the standard output. It is +an error to use +.B local +when not within a function. The return status is 0 unless +.B local +is used outside a function, an invalid +.I name +is supplied, or +\fIname\fP is a readonly variable. +.TP +.B logout +Exit a login shell. +.TP +\fBmapfile\fP [\fB\-d\fP \fIdelim\fP] [\fB\-n\fP \fIcount\fP] [\fB\-O\fP \fIorigin\fP] [\fB\-s\fP \fIcount\fP] [\fB\-t\fP] [\fB\-u\fP \fIfd\fP] [\fB\-C\fP \fIcallback\fP] [\fB\-c\fP \fIquantum\fP] [\fIarray\fP] +.PD 0 +.TP +\fBreadarray\fP [\fB\-d\fP \fIdelim\fP] [\fB\-n\fP \fIcount\fP] [\fB\-O\fP \fIorigin\fP] [\fB\-s\fP \fIcount\fP] [\fB\-t\fP] [\fB\-u\fP \fIfd\fP] [\fB\-C\fP \fIcallback\fP] [\fB\-c\fP \fIquantum\fP] [\fIarray\fP] +.PD +Read lines from the standard input into the indexed array variable +.IR array , +or from file descriptor +.IR fd +if the +.B \-u +option is supplied. +The variable +.SM +.B MAPFILE +is the default \fIarray\fP. +Options, if supplied, have the following meanings: +.RS +.PD 0 +.TP +.B \-d +The first character of \fIdelim\fP is used to terminate each input line, +rather than newline. +.TP +.B \-n +Copy at most +.I count +lines. If \fIcount\fP is 0, all lines are copied. +.TP +.B \-O +Begin assigning to +.I array +at index +.IR origin . +The default index is 0. +.TP +.B \-s +Discard the first \fIcount\fP lines read. +.TP +.B \-t +Remove a trailing newline from each line read. +.TP +.B \-u +Read lines from file descriptor \fIfd\fP instead of the standard input. +.TP +.B \-C +Evaluate +.I callback +each time \fIquantum\fP lines are read. The \fB\-c\fP option specifies +.IR quantum . +.TP +.B \-c +Specify the number of lines read between each call to +.IR callback . +.PD +.PP +If +.B \-C +is specified without +.BR \-c , +the default quantum is 5000. +When \fIcallback\fP is evaluated, it is supplied the index of the next +array element to be assigned and the line to be assigned to that element +as additional arguments. +\fIcallback\fP is evaluated after the line is read but before the +array element is assigned. +.PP +If not supplied with an explicit origin, \fBmapfile\fP will clear \fIarray\fP +before assigning to it. +.PP +\fBmapfile\fP returns successfully unless an invalid option or option +argument is supplied, \fIarray\fP is invalid or unassignable, or if +\fIarray\fP is not an indexed array. +.RE +.TP +\fBpopd\fP [\-\fBn\fP] [+\fIn\fP] [\-\fIn\fP] +Removes entries from the directory stack. With no arguments, +removes the top directory from the stack, and performs a +.B cd +to the new top directory. +Arguments, if supplied, have the following meanings: +.RS +.PD 0 +.TP +.B \-n +Suppresses the normal change of directory when removing directories +from the stack, so that only the stack is manipulated. +.TP +\fB+\fP\fIn\fP +Removes the \fIn\fPth entry counting from the left of the list +shown by +.BR dirs , +starting with zero. For example: +.if n ``popd +0'' +.if t \f(CWpopd +0\fP +removes the first directory, +.if n ``popd +1'' +.if t \f(CWpopd +1\fP +the second. +.TP +\fB\-\fP\fIn\fP +Removes the \fIn\fPth entry counting from the right of the list +shown by +.BR dirs , +starting with zero. For example: +.if n ``popd -0'' +.if t \f(CWpopd -0\fP +removes the last directory, +.if n ``popd -1'' +.if t \f(CWpopd -1\fP +the next to last. +.PD +.PP +If the +.B popd +command is successful, a +.B dirs +is performed as well, and the return status is 0. +.B popd +returns false if an invalid option is encountered, the directory stack +is empty, a non-existent directory stack entry is specified, or the +directory change fails. +.RE +.TP +\fBprintf\fP [\fB\-v\fP \fIvar\fP] \fIformat\fP [\fIarguments\fP] +Write the formatted \fIarguments\fP to the standard output under the +control of the \fIformat\fP. +The \fB\-v\fP option causes the output to be assigned to the variable +\fIvar\fP rather than being printed to the standard output. +.sp 1 +The \fIformat\fP is a character string which contains three types of objects: +plain characters, which are simply copied to standard output, character +escape sequences, which are converted and copied to the standard output, and +format specifications, each of which causes printing of the next successive +\fIargument\fP. +In addition to the standard \fIprintf\fP(1) format specifications, +\fBprintf\fP interprets the following extensions: +.RS +.PD 0 +.TP +.B %b +causes +\fBprintf\fP to expand backslash escape sequences in the corresponding +\fIargument\fP (except that \fB\ec\fP terminates output, backslashes in +\fB\e\(aq\fP, \fB\e"\fP, and \fB\e?\fP are not removed, and octal escapes +beginning with \fB\e0\fP may contain up to four digits). +.TP +.B %q +causes \fBprintf\fP to output the corresponding +\fIargument\fP in a format that can be reused as shell input. +.TP +.B %(\fIdatefmt\fP)T +causes \fBprintf\fP to output the date-time string resulting from using +\fIdatefmt\fP as a format string for \fIstrftime\fP(3). +The corresponding \fIargument\fP is an integer representing the number of +seconds since the epoch. +Two special argument values may be used: -1 represents the current +time, and -2 represents the time the shell was invoked. +If no argument is specified, conversion behaves as if -1 had been given. +This is an exception to the usual \fBprintf\fP behavior. +.PD +.PP +Arguments to non-string format specifiers are treated as C constants, +except that a leading plus or minus sign is allowed, and if the leading +character is a single or double quote, the value is the ASCII value of +the following character. +.PP +The \fIformat\fP is reused as necessary to consume all of the \fIarguments\fP. +If the \fIformat\fP requires more \fIarguments\fP than are supplied, the +extra format specifications behave as if a zero value or null string, as +appropriate, had been supplied. +The return value is zero on success, non-zero on failure. +.RE +.TP +\fBpushd\fP [\fB\-n\fP] [+\fIn\fP] [\-\fIn\fP] +.PD 0 +.TP +\fBpushd\fP [\fB\-n\fP] [\fIdir\fP] +.PD +Adds a directory to the top of the directory stack, or rotates +the stack, making the new top of the stack the current working +directory. With no arguments, exchanges the top two directories +and returns 0, unless the directory stack is empty. +Arguments, if supplied, have the following meanings: +.RS +.PD 0 +.TP +.B \-n +Suppresses the normal change of directory when adding directories +to the stack, so that only the stack is manipulated. +.TP +\fB+\fP\fIn\fP +Rotates the stack so that the \fIn\fPth directory +(counting from the left of the list shown by +.BR dirs , +starting with zero) +is at the top. +.TP +\fB\-\fP\fIn\fP +Rotates the stack so that the \fIn\fPth directory +(counting from the right of the list shown by +.BR dirs , +starting with zero) is at the top. +.TP +.I dir +Adds +.I dir +to the directory stack at the top, making it the +new current working directory as if it had been supplied as the argument +to the \fBcd\fP builtin. +.PD +.PP +If the +.B pushd +command is successful, a +.B dirs +is performed as well. +If the first form is used, +.B pushd +returns 0 unless the cd to +.I dir +fails. With the second form, +.B pushd +returns 0 unless the directory stack is empty, +a non-existent directory stack element is specified, +or the directory change to the specified new current directory +fails. +.RE +.TP +\fBpwd\fP [\fB\-LP\fP] +Print the absolute pathname of the current working directory. +The pathname printed contains no symbolic links if the +.B \-P +option is supplied or the +.B \-o physical +option to the +.B set +builtin command is enabled. +If the +.B \-L +option is used, the pathname printed may contain symbolic links. +The return status is 0 unless an error occurs while +reading the name of the current directory or an +invalid option is supplied. +.TP +\fBread\fP [\fB\-ers\fP] [\fB\-a\fP \fIaname\fP] [\fB\-d\fP \fIdelim\fP] [\fB\-i\fP \fItext\fP] [\fB\-n\fP \fInchars\fP] [\fB\-N\fP \fInchars\fP] [\fB\-p\fP \fIprompt\fP] [\fB\-t\fP \fItimeout\fP] [\fB\-u\fP \fIfd\fP] [\fIname\fP ...] +One line is read from the standard input, or from the file descriptor +\fIfd\fP supplied as an argument to the \fB\-u\fP option, and the first word +is assigned to the first +.IR name , +the second word to the second +.IR name , +and so on, with leftover words and their intervening separators assigned +to the last +.IR name . +If there are fewer words read from the input stream than names, +the remaining names are assigned empty values. +The characters in +.SM +.B IFS +are used to split the line into words using the same rules the shell +uses for expansion (described above under \fBWord Splitting\fP). +The backslash character (\fB\e\fP) may be used to remove any special +meaning for the next character read and for line continuation. +Options, if supplied, have the following meanings: +.RS +.PD 0 +.TP +.B \-a \fIaname\fP +The words are assigned to sequential indices +of the array variable +.IR aname , +starting at 0. +.I aname +is unset before any new values are assigned. +Other \fIname\fP arguments are ignored. +.TP +.B \-d \fIdelim\fP +The first character of \fIdelim\fP is used to terminate the input line, +rather than newline. +.TP +.B \-e +If the standard input +is coming from a terminal, +.B readline +(see +.SM +.B READLINE +above) is used to obtain the line. +Readline uses the current (or default, if line editing was not previously +active) editing settings. +.TP +.B \-i \fItext\fP +If +.B readline +is being used to read the line, \fItext\fP is placed into the editing +buffer before editing begins. +.TP +.B \-n \fInchars\fP +\fBread\fP returns after reading \fInchars\fP characters rather than +waiting for a complete line of input, but honor a delimiter if fewer +than \fInchars\fP characters are read before the delimiter. +.TP +.B \-N \fInchars\fP +\fBread\fP returns after reading exactly \fInchars\fP characters rather +than waiting for a complete line of input, unless EOF is encountered or +\fBread\fP times out. +Delimiter characters encountered in the input are +not treated specially and do not cause \fBread\fP to return until +\fInchars\fP characters are read. +.TP +.B \-p \fIprompt\fP +Display \fIprompt\fP on standard error, without a +trailing newline, before attempting to read any input. The prompt +is displayed only if input is coming from a terminal. +.TP +.B \-r +Backslash does not act as an escape character. +The backslash is considered to be part of the line. +In particular, a backslash-newline pair may not be used as a line +continuation. +.TP +.B \-s +Silent mode. If input is coming from a terminal, characters are +not echoed. +.TP +.B \-t \fItimeout\fP +Cause \fBread\fP to time out and return failure if a complete line of +input (or a specified number of characters) +is not read within \fItimeout\fP seconds. +\fItimeout\fP may be a decimal number with a fractional portion following +the decimal point. +This option is only effective if \fBread\fP is reading input from a +terminal, pipe, or other special file; it has no effect when reading +from regular files. +If \fBread\fP times out, \fBread\fP saves any partial input read into +the specified variable \fIname\fP. +If \fItimeout\fP is 0, \fBread\fP returns immediately, without trying to +read any data. The exit status is 0 if input is available on +the specified file descriptor, non-zero otherwise. +The exit status is greater than 128 if the timeout is exceeded. +.TP +.B \-u \fIfd\fP +Read input from file descriptor \fIfd\fP. +.PD +.PP +If no +.I names +are supplied, the line read is assigned to the variable +.SM +.BR REPLY . +The return code is zero, unless end-of-file is encountered, \fBread\fP +times out (in which case the return code is greater than 128), +a variable assignment error (such as assigning to a readonly variable) occurs, +or an invalid file descriptor is supplied as the argument to \fB\-u\fP. +.RE +.TP +\fBreadonly\fP [\fB\-aAf\fP] [\fB\-p\fP] [\fIname\fP[=\fIword\fP] ...] +.PD +The given +\fInames\fP are marked readonly; the values of these +.I names +may not be changed by subsequent assignment. +If the +.B \-f +option is supplied, the functions corresponding to the +\fInames\fP are so +marked. +The +.B \-a +option restricts the variables to indexed arrays; the +.B \-A +option restricts the variables to associative arrays. +If both options are supplied, +.B \-A +takes precedence. +If no +.I name +arguments are given, or if the +.B \-p +option is supplied, a list of all readonly names is printed. +The other options may be used to restrict the output to a subset of +the set of readonly names. +The +.B \-p +option causes output to be displayed in a format that +may be reused as input. +If a variable name is followed by =\fIword\fP, the value of +the variable is set to \fIword\fP. +The return status is 0 unless an invalid option is encountered, +one of the +.I names +is not a valid shell variable name, or +.B \-f +is supplied with a +.I name +that is not a function. +.TP +\fBreturn\fP [\fIn\fP] +Causes a function to stop executing and return the value specified by +.I n +to its caller. +If +.I n +is omitted, the return status is that of the last command +executed in the function body. +If \fBreturn\fP is executed by a trap handler, the last command used to +determine the status is the last command executed before the trap handler. +if \fBreturn\fP is executed during a \fBDEBUG\fP trap, the last command +used to determine the status is the last command executed by the trap +handler before \fBreturn\fP was invoked. +If +.B return +is used outside a function, +but during execution of a script by the +.B . +(\fBsource\fP) command, it causes the shell to stop executing +that script and return either +.I n +or the exit status of the last command executed within the +script as the exit status of the script. +If \fIn\fP is supplied, the return value is its least significant +8 bits. +The return status is non-zero if +.B return +is supplied a non-numeric argument, or +is used outside a +function and not during execution of a script by \fB.\fP\^ or \fBsource\fP. +Any command associated with the \fBRETURN\fP trap is executed +before execution resumes after the function or script. +.TP +\fBset\fP [\fB\-\-abefhkmnptuvxBCEHPT\fP] [\fB\-o\fP \fIoption\-name\fP] [\fIarg\fP ...] +.PD 0 +.TP +\fBset\fP [\fB+abefhkmnptuvxBCEHPT\fP] [\fB+o\fP \fIoption\-name\fP] [\fIarg\fP ...] +.PD +Without options, the name and value of each shell variable are displayed +in a format that can be reused as input +for setting or resetting the currently-set variables. +Read-only variables cannot be reset. +In \fIposix\fP mode, only shell variables are listed. +The output is sorted according to the current locale. +When options are specified, they set or unset shell attributes. +Any arguments remaining after option processing are treated +as values for the positional parameters and are assigned, in order, to +.BR $1 , +.BR $2 , +.B ... +.BR $\fIn\fP . +Options, if specified, have the following meanings: +.RS +.PD 0 +.TP 8 +.B \-a +Automatically mark variables and functions which are modified or +created for export to the environment of subsequent commands. +.TP 8 +.B \-b +Report the status of terminated background jobs +immediately, rather than before the next primary prompt. This is +effective only when job control is enabled. +.TP 8 +.B \-e +Exit immediately if a +\fIpipeline\fP (which may consist of a single \fIsimple command\fP), +a \fIlist\fP, +or a \fIcompound command\fP +(see +.SM +.B SHELL GRAMMAR +above), exits with a non-zero status. +The shell does not exit if the +command that fails is part of the command list immediately following a +.B while +or +.B until +keyword, +part of the test following the +.B if +or +.B elif +reserved words, part of any command executed in a +.B && +or +.B || +list except the command following the final \fB&&\fP or \fB||\fP, +any command in a pipeline but the last, +or if the command's return value is +being inverted with +.BR ! . +If a compound command other than a subshell +returns a non-zero status because a command failed +while \fB\-e\fP was being ignored, the shell does not exit. +A trap on \fBERR\fP, if set, is executed before the shell exits. +This option applies to the shell environment and each subshell environment +separately (see +.SM +.B "COMMAND EXECUTION ENVIRONMENT" +above), and may cause +subshells to exit before executing all the commands in the subshell. +.if t .sp 0.5 +.if n .sp 1 +If a compound command or shell function executes in a context +where \fB\-e\fP is being ignored, +none of the commands executed within the compound command or function body +will be affected by the \fB\-e\fP setting, even if \fB\-e\fP is set +and a command returns a failure status. +If a compound command or shell function sets \fB\-e\fP while executing in +a context where \fB\-e\fP is ignored, that setting will not have any +effect until the compound command or the command containing the function +call completes. +.TP 8 +.B \-f +Disable pathname expansion. +.TP 8 +.B \-h +Remember the location of commands as they are looked up for execution. +This is enabled by default. +.TP 8 +.B \-k +All arguments in the form of assignment statements +are placed in the environment for a command, not just +those that precede the command name. +.TP 8 +.B \-m +Monitor mode. Job control is enabled. This option is on +by default for interactive shells on systems that support +it (see +.SM +.B JOB CONTROL +above). +All processes run in a separate process group. +When a background job completes, the shell prints a line +containing its exit status. +.TP 8 +.B \-n +Read commands but do not execute them. +This may be used to check a shell script for syntax errors. +This is ignored by interactive shells. +.TP 8 +.B \-o \fIoption\-name\fP +The \fIoption\-name\fP can be one of the following: +.RS +.TP 8 +.B allexport +Same as +.BR \-a . +.TP 8 +.B braceexpand +Same as +.BR \-B . +.TP 8 +.B emacs +Use an emacs-style command line editing interface. This is enabled +by default when the shell is interactive, unless the shell is started +with the +.B \-\-noediting +option. +This also affects the editing interface used for \fBread \-e\fP. +.TP 8 +.B errexit +Same as +.BR \-e . +.TP 8 +.B errtrace +Same as +.BR \-E . +.TP 8 +.B functrace +Same as +.BR \-T . +.TP 8 +.B hashall +Same as +.BR \-h . +.TP 8 +.B histexpand +Same as +.BR \-H . +.TP 8 +.B history +Enable command history, as described above under +.SM +.BR HISTORY . +This option is on by default in interactive shells. +.TP 8 +.B ignoreeof +The effect is as if the shell command +.if t \f(CWIGNOREEOF=10\fP +.if n ``IGNOREEOF=10'' +had been executed +(see +.B Shell Variables +above). +.TP 8 +.B keyword +Same as +.BR \-k . +.TP 8 +.B monitor +Same as +.BR \-m . +.TP 8 +.B noclobber +Same as +.BR \-C . +.TP 8 +.B noexec +Same as +.BR \-n . +.TP 8 +.B noglob +Same as +.BR \-f . +.TP 8 +.B nolog +Currently ignored. +.TP 8 +.B notify +Same as +.BR \-b . +.TP 8 +.B nounset +Same as +.BR \-u . +.TP 8 +.B onecmd +Same as +.BR \-t . +.TP 8 +.B physical +Same as +.BR \-P . +.TP 8 +.B pipefail +If set, the return value of a pipeline is the value of the last +(rightmost) command to exit with a non-zero status, or zero if all +commands in the pipeline exit successfully. +This option is disabled by default. +.TP 8 +.B posix +Change the behavior of +.B bash +where the default operation differs +from the POSIX standard to match the standard (\fIposix mode\fP). +See +.SM +.B "SEE ALSO" +below for a reference to a document that details how posix mode affects +bash's behavior. +.TP 8 +.B privileged +Same as +.BR \-p . +.TP 8 +.B verbose +Same as +.BR \-v . +.TP 8 +.B vi +Use a vi-style command line editing interface. +This also affects the editing interface used for \fBread \-e\fP. +.TP 8 +.B xtrace +Same as +.BR \-x . +.sp .5 +.PP +If +.B \-o +is supplied with no \fIoption\-name\fP, the values of the current options are +printed. +If +.B +o +is supplied with no \fIoption\-name\fP, a series of +.B set +commands to recreate the current option settings is displayed on +the standard output. +.RE +.TP 8 +.B \-p +Turn on +.I privileged +mode. In this mode, the +.SM +.B $ENV +and +.SM +.B $BASH_ENV +files are not processed, shell functions are not inherited from the +environment, and the +.SM +.BR SHELLOPTS , +.SM +.BR BASHOPTS , +.SM +.BR CDPATH , +and +.SM +.B GLOBIGNORE +variables, if they appear in the environment, are ignored. +If the shell is started with the effective user (group) id not equal to the +real user (group) id, and the \fB\-p\fP option is not supplied, these actions +are taken and the effective user id is set to the real user id. +If the \fB\-p\fP option is supplied at startup, the effective user id is +not reset. +Turning this option off causes the effective user +and group ids to be set to the real user and group ids. +.TP 8 +.B \-t +Exit after reading and executing one command. +.TP 8 +.B \-u +Treat unset variables and parameters other than the special +parameters "@" and "*" as an error when performing +parameter expansion. If expansion is attempted on an +unset variable or parameter, the shell prints an error message, and, +if not interactive, exits with a non-zero status. +.TP 8 +.B \-v +Print shell input lines as they are read. +.TP 8 +.B \-x +After expanding each \fIsimple command\fP, +\fBfor\fP command, \fBcase\fP command, \fBselect\fP command, or +arithmetic \fBfor\fP command, display the expanded value of +.SM +.BR PS4 , +followed by the command and its expanded arguments +or associated word list. +.TP 8 +.B \-B +The shell performs brace expansion (see +.B Brace Expansion +above). This is on by default. +.TP 8 +.B \-C +If set, +.B bash +does not overwrite an existing file with the +.BR > , +.BR >& , +and +.B <> +redirection operators. This may be overridden when +creating output files by using the redirection operator +.B >| +instead of +.BR > . +.TP 8 +.B \-E +If set, any trap on \fBERR\fP is inherited by shell functions, command +substitutions, and commands executed in a subshell environment. +The \fBERR\fP trap is normally not inherited in such cases. +.TP 8 +.B \-H +Enable +.B ! +style history substitution. This option is on by +default when the shell is interactive. +.TP 8 +.B \-P +If set, the shell does not resolve symbolic links when executing +commands such as +.B cd +that change the current working directory. It uses the +physical directory structure instead. By default, +.B bash +follows the logical chain of directories when performing commands +which change the current directory. +.TP 8 +.B \-T +If set, any traps on \fBDEBUG\fP and \fBRETURN\fP are inherited by shell +functions, command substitutions, and commands executed in a +subshell environment. +The \fBDEBUG\fP and \fBRETURN\fP traps are normally not inherited +in such cases. +.TP 8 +.B \-\- +If no arguments follow this option, then the positional parameters are +unset. Otherwise, the positional parameters are set to the +\fIarg\fPs, even if some of them begin with a +.BR \- . +.TP 8 +.B \- +Signal the end of options, cause all remaining \fIarg\fPs to be +assigned to the positional parameters. The +.B \-x +and +.B \-v +options are turned off. +If there are no \fIarg\fPs, +the positional parameters remain unchanged. +.PD +.PP +The options are off by default unless otherwise noted. +Using + rather than \- causes these options to be turned off. +The options can also be specified as arguments to an invocation of +the shell. +The current set of options may be found in +.BR $\- . +The return status is always true unless an invalid option is encountered. +.RE +.TP +\fBshift\fP [\fIn\fP] +The positional parameters from \fIn\fP+1 ... are renamed to +.B $1 +.B .... +Parameters represented by the numbers \fB$#\fP +down to \fB$#\fP\-\fIn\fP+1 are unset. +.I n +must be a non-negative number less than or equal to \fB$#\fP. +If +.I n +is 0, no parameters are changed. +If +.I n +is not given, it is assumed to be 1. +If +.I n +is greater than \fB$#\fP, the positional parameters are not changed. +The return status is greater than zero if +.I n +is greater than +.B $# +or less than zero; otherwise 0. +.TP +\fBshopt\fP [\fB\-pqsu\fP] [\fB\-o\fP] [\fIoptname\fP ...] +Toggle the values of settings controlling optional shell behavior. +The settings can be either those listed below, or, if the +.B \-o +option is used, those available with the +.B \-o +option to the \fBset\fP builtin command. +With no options, or with the +.B \-p +option, a list of all settable options is displayed, with +an indication of whether or not each is set. +The \fB\-p\fP option causes output to be displayed in a form that +may be reused as input. +Other options have the following meanings: +.RS +.PD 0 +.TP +.B \-s +Enable (set) each \fIoptname\fP. +.TP +.B \-u +Disable (unset) each \fIoptname\fP. +.TP +.B \-q +Suppresses normal output (quiet mode); the return status indicates +whether the \fIoptname\fP is set or unset. +If multiple \fIoptname\fP arguments are given with +.BR \-q , +the return status is zero if all \fIoptnames\fP are enabled; non-zero +otherwise. +.TP +.B \-o +Restricts the values of \fIoptname\fP to be those defined for the +.B \-o +option to the +.B set +builtin. +.PD +.PP +If either +.B \-s +or +.B \-u +is used with no \fIoptname\fP arguments, +.B shopt +shows only those options which are set or unset, respectively. +Unless otherwise noted, the \fBshopt\fP options are disabled (unset) +by default. +.PP +The return status when listing options is zero if all \fIoptnames\fP +are enabled, non-zero otherwise. When setting or unsetting options, +the return status is zero unless an \fIoptname\fP is not a valid shell +option. +.PP +The list of \fBshopt\fP options is: +.if t .sp .5v +.if n .sp 1v +.PD 0 +.TP 8 +.B autocd +If set, a command name that is the name of a directory is executed as if +it were the argument to the \fBcd\fP command. +This option is only used by interactive shells. +.TP 8 +.B cdable_vars +If set, an argument to the +.B cd +builtin command that +is not a directory is assumed to be the name of a variable whose +value is the directory to change to. +.TP 8 +.B cdspell +If set, minor errors in the spelling of a directory component in a +.B cd +command will be corrected. +The errors checked for are transposed characters, +a missing character, and one character too many. +If a correction is found, the corrected filename is printed, +and the command proceeds. +This option is only used by interactive shells. +.TP 8 +.B checkhash +If set, \fBbash\fP checks that a command found in the hash +table exists before trying to execute it. If a hashed command no +longer exists, a normal path search is performed. +.TP 8 +.B checkjobs +If set, \fBbash\fP lists the status of any stopped and running jobs before +exiting an interactive shell. If any jobs are running, this causes +the exit to be deferred until a second exit is attempted without an +intervening command (see +.SM +.B "JOB CONTROL" +above). The shell always +postpones exiting if any jobs are stopped. +.TP 8 +.B checkwinsize +If set, \fBbash\fP checks the window size after each command +and, if necessary, updates the values of +.SM +.B LINES +and +.SM +.BR COLUMNS . +.TP 8 +.B cmdhist +If set, +.B bash +attempts to save all lines of a multiple-line +command in the same history entry. This allows +easy re-editing of multi-line commands. +.TP 8 +.B compat31 +If set, +.B bash +changes its behavior to that of version 3.1 with respect to quoted +arguments to the \fB[[\fP conditional command's \fB=~\fP operator +and locale-specific string comparison when using the \fB[[\fP +conditional command's \fB<\fP and \fB>\fP operators. +Bash versions prior to bash-4.1 use ASCII collation and +.IR strcmp (3); +bash-4.1 and later use the current locale's collation sequence and +.IR strcoll (3). +.TP 8 +.B compat32 +If set, +.B bash +changes its behavior to that of version 3.2 with respect to +locale-specific string comparison when using the \fB[[\fP +conditional command's \fB<\fP and \fB>\fP operators (see previous item). +.TP 8 +.B compat40 +If set, +.B bash +changes its behavior to that of version 4.0 with respect to locale-specific +string comparison when using the \fB[[\fP +conditional command's \fB<\fP and \fB>\fP operators (see description of +\fBcompat31\fP) +and the effect of interrupting a command list. +Bash versions 4.0 and later interrupt the list as if the shell received the +interrupt; previous versions continue with the next command in the list. +.TP 8 +.B compat41 +If set, +.BR bash , +when in \fIposix\fP mode, treats a single quote in a double-quoted +parameter expansion as a special character. The single quotes must match +(an even number) and the characters between the single quotes are considered +quoted. This is the behavior of posix mode through version 4.1. +The default bash behavior remains as in previous versions. +.TP 8 +.B compat42 +If set, +.B bash +does not process the replacement string in the pattern substitution word +expansion using quote removal. +.TP 8 +.B complete_fullquote +If set, +.B bash +quotes all shell metacharacters in filenames and directory names when +performing completion. +If not set, +.B bash +removes metacharacters such as the dollar sign from the set of +characters that will be quoted in completed filenames +when these metacharacters appear in shell variable references in words to be +completed. +This means that dollar signs in variable names that expand to directories +will not be quoted; +however, any dollar signs appearing in filenames will not be quoted, either. +This is active only when bash is using backslashes to quote completed +filenames. +This variable is set by default, which is the default bash behavior in +versions through 4.2. +.TP 8 +.B direxpand +If set, +.B bash +replaces directory names with the results of word expansion when performing +filename completion. This changes the contents of the readline editing +buffer. +If not set, +.B bash +attempts to preserve what the user typed. +.TP 8 +.B dirspell +If set, +.B bash +attempts spelling correction on directory names during word completion +if the directory name initially supplied does not exist. +.TP 8 +.B dotglob +If set, +.B bash +includes filenames beginning with a `.' in the results of pathname +expansion. +.TP 8 +.B execfail +If set, a non-interactive shell will not exit if +it cannot execute the file specified as an argument to the +.B exec +builtin command. An interactive shell does not exit if +.B exec +fails. +.TP 8 +.B expand_aliases +If set, aliases are expanded as described above under +.SM +.BR ALIASES . +This option is enabled by default for interactive shells. +.TP 8 +.B extdebug +If set, behavior intended for use by debuggers is enabled: +.RS +.TP +.B 1. +The \fB\-F\fP option to the \fBdeclare\fP builtin displays the source +file name and line number corresponding to each function name supplied +as an argument. +.TP +.B 2. +If the command run by the \fBDEBUG\fP trap returns a non-zero value, the +next command is skipped and not executed. +.TP +.B 3. +If the command run by the \fBDEBUG\fP trap returns a value of 2, and the +shell is executing in a subroutine (a shell function or a shell script +executed by the \fB.\fP or \fBsource\fP builtins), the shell simulates +a call to \fBreturn\fP. +.TP +.B 4. +.SM +.B BASH_ARGC +and +.SM +.B BASH_ARGV +are updated as described in their descriptions above. +.TP +.B 5. +Function tracing is enabled: command substitution, shell functions, and +subshells invoked with \fB(\fP \fIcommand\fP \fB)\fP inherit the +\fBDEBUG\fP and \fBRETURN\fP traps. +.TP +.B 6. +Error tracing is enabled: command substitution, shell functions, and +subshells invoked with \fB(\fP \fIcommand\fP \fB)\fP inherit the +\fBERR\fP trap. +.RE +.TP 8 +.B extglob +If set, the extended pattern matching features described above under +\fBPathname Expansion\fP are enabled. +.TP 8 +.B extquote +If set, \fB$\fP\(aq\fIstring\fP\(aq and \fB$\fP"\fIstring\fP" quoting is +performed within \fB${\fP\fIparameter\fP\fB}\fP expansions +enclosed in double quotes. This option is enabled by default. +.TP 8 +.B failglob +If set, patterns which fail to match filenames during pathname expansion +result in an expansion error. +.TP 8 +.B force_fignore +If set, the suffixes specified by the +.SM +.B FIGNORE +shell variable +cause words to be ignored when performing word completion even if +the ignored words are the only possible completions. +See +.SM +\fBSHELL VARIABLES\fP +above for a description of +.SM +.BR FIGNORE . +This option is enabled by default. +.TP 8 +.B globasciiranges +If set, range expressions used in pattern matching bracket expressions (see +.SM +.B Pattern Matching +above) behave as if in the traditional C locale when performing +comparisons. That is, the current locale's collating sequence +is not taken into account, so +.B b +will not collate between +.B A +and +.BR B , +and upper-case and lower-case ASCII characters will collate together. +.TP 8 +.B globstar +If set, the pattern \fB**\fP used in a pathname expansion context will +match all files and zero or more directories and subdirectories. +If the pattern is followed by a \fB/\fP, only directories and +subdirectories match. +.TP 8 +.B gnu_errfmt +If set, shell error messages are written in the standard GNU error +message format. +.TP 8 +.B histappend +If set, the history list is appended to the file named by the value +of the +.SM +.B HISTFILE +variable when the shell exits, rather than overwriting the file. +.TP 8 +.B histreedit +If set, and +.B readline +is being used, a user is given the opportunity to re-edit a +failed history substitution. +.TP 8 +.B histverify +If set, and +.B readline +is being used, the results of history substitution are not immediately +passed to the shell parser. Instead, the resulting line is loaded into +the \fBreadline\fP editing buffer, allowing further modification. +.TP 8 +.B hostcomplete +If set, and +.B readline +is being used, \fBbash\fP will attempt to perform hostname completion when a +word containing a \fB@\fP is being completed (see +.B Completing +under +.SM +.B READLINE +above). +This is enabled by default. +.TP 8 +.B huponexit +If set, \fBbash\fP will send +.SM +.B SIGHUP +to all jobs when an interactive login shell exits. +.TP 8 +.B interactive_comments +If set, allow a word beginning with +.B # +to cause that word and all remaining characters on that +line to be ignored in an interactive shell (see +.SM +.B COMMENTS +above). This option is enabled by default. +.TP 8 +.B lastpipe +If set, and job control is not active, the shell runs the last command of +a pipeline not executed in the background in the current shell environment. +.TP 8 +.B lithist +If set, and the +.B cmdhist +option is enabled, multi-line commands are saved to the history with +embedded newlines rather than using semicolon separators where possible. +.TP 8 +.B login_shell +The shell sets this option if it is started as a login shell (see +.SM +.B "INVOCATION" +above). +The value may not be changed. +.TP 8 +.B mailwarn +If set, and a file that \fBbash\fP is checking for mail has been +accessed since the last time it was checked, the message ``The mail in +\fImailfile\fP has been read'' is displayed. +.TP 8 +.B no_empty_cmd_completion +If set, and +.B readline +is being used, +.B bash +will not attempt to search the +.SM +.B PATH +for possible completions when +completion is attempted on an empty line. +.TP 8 +.B nocaseglob +If set, +.B bash +matches filenames in a case\-insensitive fashion when performing pathname +expansion (see +.B Pathname Expansion +above). +.TP 8 +.B nocasematch +If set, +.B bash +matches patterns in a case\-insensitive fashion when performing matching +while executing \fBcase\fP or \fB[[\fP conditional commands, +when performing pattern substitution word expansions, +or when filtering possible completions as part of programmable completion. +.TP 8 +.B nullglob +If set, +.B bash +allows patterns which match no +files (see +.B Pathname Expansion +above) +to expand to a null string, rather than themselves. +.TP 8 +.B progcomp +If set, the programmable completion facilities (see +\fBProgrammable Completion\fP above) are enabled. +This option is enabled by default. +.TP 8 +.B promptvars +If set, prompt strings undergo +parameter expansion, command substitution, arithmetic +expansion, and quote removal after being expanded as described in +.SM +.B PROMPTING +above. This option is enabled by default. +.TP 8 +.B restricted_shell +The shell sets this option if it is started in restricted mode (see +.SM +.B "RESTRICTED SHELL" +below). +The value may not be changed. +This is not reset when the startup files are executed, allowing +the startup files to discover whether or not a shell is restricted. +.TP 8 +.B shift_verbose +If set, the +.B shift +builtin prints an error message when the shift count exceeds the +number of positional parameters. +.TP 8 +.B sourcepath +If set, the +\fBsource\fP (\fB.\fP) builtin uses the value of +.SM +.B PATH +to find the directory containing the file supplied as an argument. +This option is enabled by default. +.TP 8 +.B xpg_echo +If set, the \fBecho\fP builtin expands backslash-escape sequences +by default. +.RE +.PD +.TP +\fBsuspend\fP [\fB\-f\fP] +Suspend the execution of this shell until it receives a +.SM +.B SIGCONT +signal. A login shell cannot be suspended; the +.B \-f +option can be used to override this and force the suspension. +The return status is 0 unless the shell is a login shell and +.B \-f +is not supplied, or if job control is not enabled. +.TP +\fBtest\fP \fIexpr\fP +.PD 0 +.TP +\fB[\fP \fIexpr\fP \fB]\fP +Return a status of 0 (true) or 1 (false) depending on +the evaluation of the conditional expression +.IR expr . +Each operator and operand must be a separate argument. +Expressions are composed of the primaries described above under +.SM +.BR "CONDITIONAL EXPRESSIONS" . +\fBtest\fP does not accept any options, nor does it accept and ignore +an argument of \fB\-\-\fP as signifying the end of options. +.if t .sp 0.5 +.if n .sp 1 +Expressions may be combined using the following operators, listed +in decreasing order of precedence. +The evaluation depends on the number of arguments; see below. +Operator precedence is used when there are five or more arguments. +.RS +.PD 0 +.TP +.B ! \fIexpr\fP +True if +.I expr +is false. +.TP +.B ( \fIexpr\fP ) +Returns the value of \fIexpr\fP. +This may be used to override the normal precedence of operators. +.TP +\fIexpr1\fP \-\fBa\fP \fIexpr2\fP +True if both +.I expr1 +and +.I expr2 +are true. +.TP +\fIexpr1\fP \-\fBo\fP \fIexpr2\fP +True if either +.I expr1 +or +.I expr2 +is true. +.PD +.PP +\fBtest\fP and \fB[\fP evaluate conditional +expressions using a set of rules based on the number of arguments. +.if t .sp 0.5 +.if n .sp 1 +.PD 0 +.TP +0 arguments +The expression is false. +.TP +1 argument +The expression is true if and only if the argument is not null. +.TP +2 arguments +If the first argument is \fB!\fP, the expression is true if and +only if the second argument is null. +If the first argument is one of the unary conditional operators listed above +under +.SM +.BR "CONDITIONAL EXPRESSIONS" , +the expression is true if the unary test is true. +If the first argument is not a valid unary conditional operator, the expression +is false. +.TP +3 arguments +The following conditions are applied in the order listed. +If the second argument is one of the binary conditional operators listed above +under +.SM +.BR "CONDITIONAL EXPRESSIONS" , +the result of the expression is the result of the binary test using +the first and third arguments as operands. +The \fB\-a\fP and \fB\-o\fP operators are considered binary operators +when there are three arguments. +If the first argument is \fB!\fP, the value is the negation of +the two-argument test using the second and third arguments. +If the first argument is exactly \fB(\fP and the third argument is +exactly \fB)\fP, the result is the one-argument test of the second +argument. +Otherwise, the expression is false. +.TP +4 arguments +If the first argument is \fB!\fP, the result is the negation of +the three-argument expression composed of the remaining arguments. +Otherwise, the expression is parsed and evaluated according to +precedence using the rules listed above. +.TP +5 or more arguments +The expression is parsed and evaluated according to precedence +using the rules listed above. +.if t .sp 0.5 +.if n .sp 1 +.LP +When used with \fBtest\fP or \fB[\fP, the \fB<\fP and \fB>\fP operators +sort lexicographically using ASCII ordering. +.RE +.PD +.TP +.B times +Print the accumulated user and system times for the shell and +for processes run from the shell. The return status is 0. +.TP +\fBtrap\fP [\fB\-lp\fP] [[\fIarg\fP] \fIsigspec\fP ...] +The command +.I arg +is to be read and executed when the shell receives +signal(s) +.IR sigspec . +If +.I arg +is absent (and there is a single \fIsigspec\fP) or +.BR \- , +each specified signal is +reset to its original disposition (the value it had +upon entrance to the shell). +If +.I arg +is the null string the signal specified by each +.I sigspec +is ignored by the shell and by the commands it invokes. +If +.I arg +is not present and +.B \-p +has been supplied, then the trap commands associated with each +.I sigspec +are displayed. +If no arguments are supplied or if only +.B \-p +is given, +.B trap +prints the list of commands associated with each signal. +The +.B \-l +option causes the shell to print a list of signal names and +their corresponding numbers. +Each +.I sigspec +is either +a signal name defined in <\fIsignal.h\fP>, or a signal number. +Signal names are case insensitive and the +.SM +.B SIG +prefix is optional. +.if t .sp 0.5 +.if n .sp 1 +If a +.I sigspec +is +.SM +.B EXIT +(0) the command +.I arg +is executed on exit from the shell. +If a +.I sigspec +is +.SM +.BR DEBUG , +the command +.I arg +is executed before every \fIsimple command\fP, \fIfor\fP command, +\fIcase\fP command, \fIselect\fP command, every arithmetic \fIfor\fP +command, and before the first command executes in a shell function (see +.SM +.B SHELL GRAMMAR +above). +Refer to the description of the \fBextdebug\fP option to the +\fBshopt\fP builtin for details of its effect on the \fBDEBUG\fP trap. +If a +.I sigspec +is +.SM +.BR RETURN , +the command +.I arg +is executed each time a shell function or a script executed with +the \fB.\fP or \fBsource\fP builtins finishes executing. +.if t .sp 0.5 +.if n .sp 1 +If a +.I sigspec +is +.SM +.BR ERR , +the command +.I arg +is executed whenever a +a pipeline (which may consist of a single simple +command), a list, or a compound command returns a +non\-zero exit status, +subject to the following conditions. +The +.SM +.B ERR +trap is not executed if the failed +command is part of the command list immediately following a +.B while +or +.B until +keyword, +part of the test in an +.I if +statement, part of a command executed in a +.B && +or +.B || +list except the command following the final \fB&&\fP or \fB||\fP, +any command in a pipeline but the last, +or if the command's return value is +being inverted using +.BR ! . +These are the same conditions obeyed by the \fBerrexit\fP (\fB\-e\fP) option. +.if t .sp 0.5 +.if n .sp 1 +Signals ignored upon entry to the shell cannot be trapped or reset. +Trapped signals that are not being ignored are reset to their original +values in a subshell or subshell environment when one is created. +The return status is false if any +.I sigspec +is invalid; otherwise +.B trap +returns true. +.TP +\fBtype\fP [\fB\-aftpP\fP] \fIname\fP [\fIname\fP ...] +With no options, +indicate how each +.I name +would be interpreted if used as a command name. +If the +.B \-t +option is used, +.B type +prints a string which is one of +.IR alias , +.IR keyword , +.IR function , +.IR builtin , +or +.I file +if +.I name +is an alias, shell reserved word, function, builtin, or disk file, +respectively. +If the +.I name +is not found, then nothing is printed, and an exit status of false +is returned. +If the +.B \-p +option is used, +.B type +either returns the name of the disk file +that would be executed if +.I name +were specified as a command name, +or nothing if +.if t \f(CWtype -t name\fP +.if n ``type -t name'' +would not return +.IR file . +The +.B \-P +option forces a +.SM +.B PATH +search for each \fIname\fP, even if +.if t \f(CWtype -t name\fP +.if n ``type -t name'' +would not return +.IR file . +If a command is hashed, +.B \-p +and +.B \-P +print the hashed value, which is not necessarily the file that appears +first in +.SM +.BR PATH . +If the +.B \-a +option is used, +.B type +prints all of the places that contain +an executable named +.IR name . +This includes aliases and functions, +if and only if the +.B \-p +option is not also used. +The table of hashed commands is not consulted +when using +.BR \-a . +The +.B \-f +option suppresses shell function lookup, as with the \fBcommand\fP builtin. +.B type +returns true if all of the arguments are found, false if +any are not found. +.TP +\fBulimit\fP [\fB\-HSabcdefiklmnpqrstuvxPT\fP [\fIlimit\fP]] +Provides control over the resources available to the shell and to +processes started by it, on systems that allow such control. +The \fB\-H\fP and \fB\-S\fP options specify that the hard or soft limit is +set for the given resource. +A hard limit cannot be increased by a non-root user once it is set; +a soft limit may be increased up to the value of the hard limit. +If neither \fB\-H\fP nor \fB\-S\fP is specified, both the soft and hard +limits are set. +The value of +.I limit +can be a number in the unit specified for the resource +or one of the special values +.BR hard , +.BR soft , +or +.BR unlimited , +which stand for the current hard limit, the current soft limit, and +no limit, respectively. +If +.I limit +is omitted, the current value of the soft limit of the resource is +printed, unless the \fB\-H\fP option is given. When more than one +resource is specified, the limit name and unit are printed before the value. +Other options are interpreted as follows: +.RS +.PD 0 +.TP +.B \-a +All current limits are reported +.TP +.B \-b +The maximum socket buffer size +.TP +.B \-c +The maximum size of core files created +.TP +.B \-d +The maximum size of a process's data segment +.TP +.B \-e +The maximum scheduling priority ("nice") +.TP +.B \-f +The maximum size of files written by the shell and its children +.TP +.B \-i +The maximum number of pending signals +.TP +.B \-k +The maximum number of kqueues that may be allocated +.TP +.B \-l +The maximum size that may be locked into memory +.TP +.B \-m +The maximum resident set size (many systems do not honor this limit) +.TP +.B \-n +The maximum number of open file descriptors (most systems do not +allow this value to be set) +.TP +.B \-p +The pipe size in 512-byte blocks (this may not be set) +.TP +.B \-q +The maximum number of bytes in POSIX message queues +.TP +.B \-r +The maximum real-time scheduling priority +.TP +.B \-s +The maximum stack size +.TP +.B \-t +The maximum amount of cpu time in seconds +.TP +.B \-u +The maximum number of processes available to a single user +.TP +.B \-v +The maximum amount of virtual memory available to the shell and, on +some systems, to its children +.TP +.B \-x +The maximum number of file locks +.TP +.B \-P +The maximum number of pseudoterminals +.TP +.B \-T +The maximum number of threads +.PD +.PP +If +.I limit +is given, and the +.B \-a +option is not used, +\fIlimit\fP is the new value of the specified resource. +If no option is given, then +.B \-f +is assumed. Values are in 1024-byte increments, except for +.BR \-t , +which is in seconds; +.BR \-p , +which is in units of 512-byte blocks; +and +.BR \-P , +.BR \-T , +.BR \-b , +.BR \-k , +.BR \-n , +and +.BR \-u , +which are unscaled values. +The return status is 0 unless an invalid option or argument is supplied, +or an error occurs while setting a new limit. +.RE +.TP +\fBumask\fP [\fB\-p\fP] [\fB\-S\fP] [\fImode\fP] +The user file-creation mask is set to +.IR mode . +If +.I mode +begins with a digit, it +is interpreted as an octal number; otherwise +it is interpreted as a symbolic mode mask similar +to that accepted by +.IR chmod (1). +If +.I mode +is omitted, the current value of the mask is printed. +The +.B \-S +option causes the mask to be printed in symbolic form; the +default output is an octal number. +If the +.B \-p +option is supplied, and +.I mode +is omitted, the output is in a form that may be reused as input. +The return status is 0 if the mode was successfully changed or if +no \fImode\fP argument was supplied, and false otherwise. +.TP +\fBunalias\fP [\-\fBa\fP] [\fIname\fP ...] +Remove each \fIname\fP from the list of defined aliases. If +.B \-a +is supplied, all alias definitions are removed. The return +value is true unless a supplied +.I name +is not a defined alias. +.TP +\fBunset\fP [\-\fBfv\fP] [\-\fBn\fP] [\fIname\fP ...] +For each +.IR name , +remove the corresponding variable or function. +If the +.B \-v +option is given, each +.I name +refers to a shell variable, and that variable is removed. +Read-only variables may not be unset. +If +.B \-f +is specified, each +.I name +refers to a shell function, and the function definition +is removed. +If the +.B \-n +option is supplied, and \fIname\fP is a variable with the \fInameref\fP +attribute, \fIname\fP will be unset rather than the variable it +references. +\fB\-n\fP has no effect if the \fB\-f\fP option is supplied. +If no options are supplied, each \fIname\fP refers to a variable; if +there is no variable by that name, any function with that name is +unset. +Each unset variable or function is removed from the environment +passed to subsequent commands. +If any of +.SM +.BR COMP_WORDBREAKS , +.SM +.BR RANDOM , +.SM +.BR SECONDS , +.SM +.BR LINENO , +.SM +.BR HISTCMD , +.SM +.BR FUNCNAME , +.SM +.BR GROUPS , +or +.SM +.B DIRSTACK +are unset, they lose their special properties, even if they are +subsequently reset. The exit status is true unless a +.I name +is readonly. +.TP +\fBwait\fP [\fB\-n\fP] [\fIn ...\fP] +Wait for each specified child process and return its termination status. +Each +.I n +may be a process +ID or a job specification; if a job spec is given, all processes +in that job's pipeline are waited for. If +.I n +is not given, all currently active child processes +are waited for, and the return status is zero. +If the \fB\-n\fP option is supplied, \fBwait\fP waits for any job to +terminate and returns its exit status. +If +.I n +specifies a non-existent process or job, the return status is +127. Otherwise, the return status is the exit status of the last +process or job waited for. +.\" bash_builtins +.if \n(zZ=1 .ig zZ +.SH "RESTRICTED SHELL" +.\" rbash.1 +.zY +.PP +If +.B bash +is started with the name +.BR rbash , +or the +.B \-r +option is supplied at invocation, +the shell becomes restricted. +A restricted shell is used to +set up an environment more controlled than the standard shell. +It behaves identically to +.B bash +with the exception that the following are disallowed or not performed: +.IP \(bu +changing directories with \fBcd\fP +.IP \(bu +setting or unsetting the values of +.SM +.BR SHELL , +.SM +.BR PATH , +.SM +.BR ENV , +or +.SM +.B BASH_ENV +.IP \(bu +specifying command names containing +.B / +.IP \(bu +specifying a filename containing a +.B / +as an argument to the +.B . +builtin command +.IP \(bu +specifying a filename containing a slash as an argument to the +.B \-p +option to the +.B hash +builtin command +.IP \(bu +importing function definitions from the shell environment at startup +.IP \(bu +parsing the value of +.SM +.B SHELLOPTS +from the shell environment at startup +.IP \(bu +redirecting output using the >, >|, <>, >&, &>, and >> redirection operators +.IP \(bu +using the +.B exec +builtin command to replace the shell with another command +.IP \(bu +adding or deleting builtin commands with the +.B \-f +and +.B \-d +options to the +.B enable +builtin command +.IP \(bu +using the \fBenable\fP builtin command to enable disabled shell builtins +.IP \(bu +specifying the +.B \-p +option to the +.B command +builtin command +.IP \(bu +turning off restricted mode with +\fBset +r\fP or \fBset +o restricted\fP. +.PP +These restrictions are enforced after any startup files are read. +.PP +.ie \n(zY=1 When a command that is found to be a shell script is executed, +.el \{ When a command that is found to be a shell script is executed +(see +.SM +.B "COMMAND EXECUTION" +above), +\} +.B rbash +turns off any restrictions in the shell spawned to execute the +script. +.\" end of rbash.1 +.if \n(zY=1 .ig zY +.SH "SEE ALSO" +.PD 0 +.TP +\fIBash Reference Manual\fP, Brian Fox and Chet Ramey +.TP +\fIThe Gnu Readline Library\fP, Brian Fox and Chet Ramey +.TP +\fIThe Gnu History Library\fP, Brian Fox and Chet Ramey +.TP +\fIPortable Operating System Interface (POSIX) Part 2: Shell and Utilities\fP, IEEE -- +http://pubs.opengroup.org/onlinepubs/9699919799/ +.TP +http://tiswww.case.edu/~chet/bash/POSIX -- a description of posix mode +.TP +\fIsh\fP(1), \fIksh\fP(1), \fIcsh\fP(1) +.TP +\fIemacs\fP(1), \fIvi\fP(1) +.TP +\fIreadline\fP(3) +.PD +.SH FILES +.PD 0 +.TP +.FN /bin/bash +The \fBbash\fP executable +.TP +.FN /etc/profile +The systemwide initialization file, executed for login shells +.TP +.FN ~/.bash_profile +The personal initialization file, executed for login shells +.TP +.FN ~/.bashrc +The individual per-interactive-shell startup file +.TP +.FN ~/.bash_logout +The individual login shell cleanup file, executed when a login shell exits +.TP +.FN ~/.inputrc +Individual \fIreadline\fP initialization file +.PD +.SH AUTHORS +Brian Fox, Free Software Foundation +.br +bfox@gnu.org +.PP +Chet Ramey, Case Western Reserve University +.br +chet.ramey@case.edu +.SH BUG REPORTS +If you find a bug in +.B bash, +you should report it. But first, you should +make sure that it really is a bug, and that it appears in the latest +version of +.BR bash . +The latest version is always available from +\fIftp://ftp.gnu.org/pub/gnu/bash/\fP. +.PP +Once you have determined that a bug actually exists, use the +.I bashbug +command to submit a bug report. +If you have a fix, you are encouraged to mail that as well! +Suggestions and `philosophical' bug reports may be mailed +to \fIbug-bash@gnu.org\fP or posted to the Usenet +newsgroup +.BR gnu.bash.bug . +.PP +ALL bug reports should include: +.PP +.PD 0 +.TP 20 +The version number of \fBbash\fR +.TP +The hardware and operating system +.TP +The compiler used to compile +.TP +A description of the bug behaviour +.TP +A short script or `recipe' which exercises the bug +.PD +.PP +.I bashbug +inserts the first three items automatically into the template +it provides for filing a bug report. +.PP +Comments and bug reports concerning +this manual page should be directed to +.IR chet.ramey@case.edu . +.SH BUGS +.PP +It's too big and too slow. +.PP +There are some subtle differences between +.B bash +and traditional versions of +.BR sh , +mostly because of the +.SM +.B POSIX +specification. +.PP +Aliases are confusing in some uses. +.PP +Shell builtin commands and functions are not stoppable/restartable. +.PP +Compound commands and command sequences of the form `a ; b ; c' +are not handled gracefully when process suspension is attempted. +When a process is stopped, the shell immediately executes the next +command in the sequence. +It suffices to place the sequence of commands between +parentheses to force it into a subshell, which may be stopped as +a unit. +.PP +Array variables may not (yet) be exported. +.PP +There may be only one active coprocess at a time. +.zZ +.zY diff --git a/doc/bashref.texi b/doc/bashref.texi index 71d468b46..b8429c50e 100644 --- a/doc/bashref.texi +++ b/doc/bashref.texi @@ -1875,12 +1875,16 @@ or when @var{parameter} is followed by a character that is not to be interpreted as part of its name. If the first character of @var{parameter} is an exclamation point (!), +and @var{parameter} is not a @var{nameref}, it introduces a level of variable indirection. Bash uses the value of the variable formed from the rest of @var{parameter} as the name of the variable; this variable is then expanded and that value is used in the rest of the substitution, rather than the value of @var{parameter} itself. This is known as @code{indirect expansion}. +If @var{parameter} is a nameref, this expands to the name of the +variable referenced by @var{parameter} instead of performing the +complete indirect expansion. The exceptions to this are the expansions of $@{!@var{prefix}*@} and $@{!@var{name}[@@]@} described below. diff --git a/doc/bashref.texi~ b/doc/bashref.texi~ new file mode 100644 index 000000000..71d468b46 --- /dev/null +++ b/doc/bashref.texi~ @@ -0,0 +1,8824 @@ +\input texinfo.tex @c -*- texinfo -*- +@c %**start of header +@setfilename bashref.info +@settitle Bash Reference Manual + +@include version.texi +@c %**end of header + +@copying +This text is a brief description of the features that are present in +the Bash shell (version @value{VERSION}, @value{UPDATED}). + +This is Edition @value{EDITION}, last updated @value{UPDATED}, +of @cite{The GNU Bash Reference Manual}, +for @code{Bash}, Version @value{VERSION}. + +Copyright @copyright{} 1988--2014 Free Software Foundation, Inc. + +@quotation +Permission is granted to copy, distribute and/or modify this document +under the terms of the GNU Free Documentation License, Version 1.3 or +any later version published by the Free Software Foundation; with no +Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. +A copy of the license is included in the section entitled +``GNU Free Documentation License''. +@end quotation +@end copying + +@defcodeindex bt +@defcodeindex rw +@set BashFeatures + +@dircategory Basics +@direntry +* Bash: (bash). The GNU Bourne-Again SHell. +@end direntry + +@finalout + +@titlepage +@title Bash Reference Manual +@subtitle Reference Documentation for Bash +@subtitle Edition @value{EDITION}, for @code{Bash} Version @value{VERSION}. +@subtitle @value{UPDATED-MONTH} +@author Chet Ramey, Case Western Reserve University +@author Brian Fox, Free Software Foundation + +@page +@vskip 0pt plus 1filll +@insertcopying + +@end titlepage + +@contents + +@ifnottex +@node Top, Introduction, (dir), (dir) +@top Bash Features + +This text is a brief description of the features that are present in +the Bash shell (version @value{VERSION}, @value{UPDATED}). +The Bash home page is @url{http://www.gnu.org/software/bash/}. + +This is Edition @value{EDITION}, last updated @value{UPDATED}, +of @cite{The GNU Bash Reference Manual}, +for @code{Bash}, Version @value{VERSION}. + +Bash contains features that appear in other popular shells, and some +features that only appear in Bash. Some of the shells that Bash has +borrowed concepts from are the Bourne Shell (@file{sh}), the Korn Shell +(@file{ksh}), and the C-shell (@file{csh} and its successor, +@file{tcsh}). The following menu breaks the features up into +categories, noting which features were inspired by other shells and +which are specific to Bash. + +This manual is meant as a brief introduction to features found in +Bash. The Bash manual page should be used as the definitive +reference on shell behavior. + +@menu +* Introduction:: An introduction to the shell. +* Definitions:: Some definitions used in the rest of this + manual. +* Basic Shell Features:: The shell "building blocks". +* Shell Builtin Commands:: Commands that are a part of the shell. +* Shell Variables:: Variables used or set by Bash. +* Bash Features:: Features found only in Bash. +* Job Control:: What job control is and how Bash allows you + to use it. +* Command Line Editing:: Chapter describing the command line + editing features. +* Using History Interactively:: Command History Expansion +* Installing Bash:: How to build and install Bash on your system. +* Reporting Bugs:: How to report bugs in Bash. +* Major Differences From The Bourne Shell:: A terse list of the differences + between Bash and historical + versions of /bin/sh. +* GNU Free Documentation License:: Copying and sharing this documentation. +* Indexes:: Various indexes for this manual. +@end menu +@end ifnottex + +@node Introduction +@chapter Introduction +@menu +* What is Bash?:: A short description of Bash. +* What is a shell?:: A brief introduction to shells. +@end menu + +@node What is Bash? +@section What is Bash? + +Bash is the shell, or command language interpreter, +for the @sc{gnu} operating system. +The name is an acronym for the @samp{Bourne-Again SHell}, +a pun on Stephen Bourne, the author of the direct ancestor of +the current Unix shell @code{sh}, +which appeared in the Seventh Edition Bell Labs Research version +of Unix. + +Bash is largely compatible with @code{sh} and incorporates useful +features from the Korn shell @code{ksh} and the C shell @code{csh}. +It is intended to be a conformant implementation of the @sc{ieee} +@sc{posix} Shell and Tools portion of the @sc{ieee} @sc{posix} +specification (@sc{ieee} Standard 1003.1). +It offers functional improvements over @code{sh} for both interactive and +programming use. + +While the @sc{gnu} operating system provides other shells, including +a version of @code{csh}, Bash is the default shell. +Like other @sc{gnu} software, Bash is quite portable. It currently runs +on nearly every version of Unix and a few other operating systems @minus{} +independently-supported ports exist for @sc{ms-dos}, @sc{os/2}, +and Windows platforms. + +@node What is a shell? +@section What is a shell? + +At its base, a shell is simply a macro processor that executes +commands. The term macro processor means functionality where text +and symbols are expanded to create larger expressions. + +A Unix shell is both a command interpreter and a programming +language. As a command interpreter, the shell provides the user +interface to the rich set of @sc{gnu} utilities. The programming +language features allow these utilities to be combined. +Files containing commands can be created, and become +commands themselves. These new commands have the same status as +system commands in directories such as @file{/bin}, allowing users +or groups to establish custom environments to automate their common +tasks. + +Shells may be used interactively or non-interactively. In +interactive mode, they accept input typed from the keyboard. +When executing non-interactively, shells execute commands read +from a file. + +A shell allows execution of @sc{gnu} commands, both synchronously and +asynchronously. +The shell waits for synchronous commands to complete before accepting +more input; asynchronous commands continue to execute in parallel +with the shell while it reads and executes additional commands. +The @dfn{redirection} constructs permit +fine-grained control of the input and output of those commands. +Moreover, the shell allows control over the contents of commands' +environments. + +Shells also provide a small set of built-in +commands (@dfn{builtins}) implementing functionality impossible +or inconvenient to obtain via separate utilities. +For example, @code{cd}, @code{break}, @code{continue}, and +@code{exec} cannot be implemented outside of the shell because +they directly manipulate the shell itself. +The @code{history}, @code{getopts}, @code{kill}, or @code{pwd} +builtins, among others, could be implemented in separate utilities, +but they are more convenient to use as builtin commands. +All of the shell builtins are described in +subsequent sections. + +While executing commands is essential, most of the power (and +complexity) of shells is due to their embedded programming +languages. Like any high-level language, the shell provides +variables, flow control constructs, quoting, and functions. + +Shells offer features geared specifically for +interactive use rather than to augment the programming language. +These interactive features include job control, command line +editing, command history and aliases. Each of these features is +described in this manual. + +@node Definitions +@chapter Definitions +These definitions are used throughout the remainder of this manual. + +@table @code + +@item POSIX +@cindex POSIX +A family of open system standards based on Unix. Bash +is primarily concerned with the Shell and Utilities portion of the +@sc{posix} 1003.1 standard. + +@item blank +A space or tab character. + +@item builtin +@cindex builtin +A command that is implemented internally by the shell itself, rather +than by an executable program somewhere in the file system. + +@item control operator +@cindex control operator +A @code{token} that performs a control function. It is a @code{newline} +or one of the following: +@samp{||}, @samp{&&}, @samp{&}, @samp{;}, @samp{;;}, +@samp{|}, @samp{|&}, @samp{(}, or @samp{)}. + +@item exit status +@cindex exit status +The value returned by a command to its caller. The value is restricted +to eight bits, so the maximum value is 255. + +@item field +@cindex field +A unit of text that is the result of one of the shell expansions. After +expansion, when executing a command, the resulting fields are used as +the command name and arguments. + +@item filename +@cindex filename +A string of characters used to identify a file. + +@item job +@cindex job +A set of processes comprising a pipeline, and any processes descended +from it, that are all in the same process group. + +@item job control +@cindex job control +A mechanism by which users can selectively stop (suspend) and restart +(resume) execution of processes. + +@item metacharacter +@cindex metacharacter +A character that, when unquoted, separates words. A metacharacter is +a @code{blank} or one of the following characters: +@samp{|}, @samp{&}, @samp{;}, @samp{(}, @samp{)}, @samp{<}, or +@samp{>}. + +@item name +@cindex name +@cindex identifier +A @code{word} consisting solely of letters, numbers, and underscores, +and beginning with a letter or underscore. @code{Name}s are used as +shell variable and function names. +Also referred to as an @code{identifier}. + +@item operator +@cindex operator, shell +A @code{control operator} or a @code{redirection operator}. +@xref{Redirections}, for a list of redirection operators. +Operators contain at least one unquoted @code{metacharacter}. + +@item process group +@cindex process group +A collection of related processes each having the same process +group @sc{id}. + +@item process group ID +@cindex process group ID +A unique identifier that represents a @code{process group} +during its lifetime. + +@item reserved word +@cindex reserved word +A @code{word} that has a special meaning to the shell. Most reserved +words introduce shell flow control constructs, such as @code{for} and +@code{while}. + +@item return status +@cindex return status +A synonym for @code{exit status}. + +@item signal +@cindex signal +A mechanism by which a process may be notified by the kernel +of an event occurring in the system. + +@item special builtin +@cindex special builtin +A shell builtin command that has been classified as special by the +@sc{posix} standard. + +@item token +@cindex token +A sequence of characters considered a single unit by the shell. +It is either a @code{word} or an @code{operator}. + +@item word +@cindex word +A sequence of characters treated as a unit by the shell. +Words may not include unquoted @code{metacharacters}. +@end table + +@node Basic Shell Features +@chapter Basic Shell Features +@cindex Bourne shell + +Bash is an acronym for @samp{Bourne-Again SHell}. +The Bourne shell is +the traditional Unix shell originally written by Stephen Bourne. +All of the Bourne shell builtin commands are available in Bash, +The rules for evaluation and quoting are taken from the @sc{posix} +specification for the `standard' Unix shell. + +This chapter briefly summarizes the shell's `building blocks': +commands, control structures, shell functions, shell @i{parameters}, +shell expansions, +@i{redirections}, which are a way to direct input and output from +and to named files, and how the shell executes commands. + +@menu +* Shell Syntax:: What your input means to the shell. +* Shell Commands:: The types of commands you can use. +* Shell Functions:: Grouping commands by name. +* Shell Parameters:: How the shell stores values. +* Shell Expansions:: How Bash expands parameters and the various + expansions available. +* Redirections:: A way to control where input and output go. +* Executing Commands:: What happens when you run a command. +* Shell Scripts:: Executing files of shell commands. +@end menu + +@node Shell Syntax +@section Shell Syntax +@menu +* Shell Operation:: The basic operation of the shell. +* Quoting:: How to remove the special meaning from characters. +* Comments:: How to specify comments. +@end menu + +When the shell reads input, it proceeds through a +sequence of operations. If the input indicates the beginning of a +comment, the shell ignores the comment symbol (@samp{#}), and the rest +of that line. + +Otherwise, roughly speaking, the shell reads its input and +divides the input into words and operators, employing the quoting rules +to select which meanings to assign various words and characters. + +The shell then parses these tokens into commands and other constructs, +removes the special meaning of certain words or characters, expands +others, redirects input and output as needed, executes the specified +command, waits for the command's exit status, and makes that exit status +available for further inspection or processing. + +@node Shell Operation +@subsection Shell Operation + +The following is a brief description of the shell's operation when it +reads and executes a command. Basically, the shell does the +following: + +@enumerate +@item +Reads its input from a file (@pxref{Shell Scripts}), from a string +supplied as an argument to the @option{-c} invocation option +(@pxref{Invoking Bash}), or from the user's terminal. + +@item +Breaks the input into words and operators, obeying the quoting rules +described in @ref{Quoting}. These tokens are separated by +@code{metacharacters}. Alias expansion is performed by this step +(@pxref{Aliases}). + +@item +Parses the tokens into simple and compound commands +(@pxref{Shell Commands}). + +@item +Performs the various shell expansions (@pxref{Shell Expansions}), breaking +the expanded tokens into lists of filenames (@pxref{Filename Expansion}) +and commands and arguments. + +@item +Performs any necessary redirections (@pxref{Redirections}) and removes +the redirection operators and their operands from the argument list. + +@item +Executes the command (@pxref{Executing Commands}). + +@item +Optionally waits for the command to complete and collects its exit +status (@pxref{Exit Status}). + +@end enumerate + +@node Quoting +@subsection Quoting +@cindex quoting +@menu +* Escape Character:: How to remove the special meaning from a single + character. +* Single Quotes:: How to inhibit all interpretation of a sequence + of characters. +* Double Quotes:: How to suppress most of the interpretation of a + sequence of characters. +* ANSI-C Quoting:: How to expand ANSI-C sequences in quoted strings. +* Locale Translation:: How to translate strings into different languages. +@end menu + +Quoting is used to remove the special meaning of certain +characters or words to the shell. Quoting can be used to +disable special treatment for special characters, to prevent +reserved words from being recognized as such, and to prevent +parameter expansion. + +Each of the shell metacharacters (@pxref{Definitions}) +has special meaning to the shell and must be quoted if it is to +represent itself. +When the command history expansion facilities are being used +(@pxref{History Interaction}), the +@var{history expansion} character, usually @samp{!}, must be quoted +to prevent history expansion. @xref{Bash History Facilities}, for +more details concerning history expansion. + +There are three quoting mechanisms: the +@var{escape character}, single quotes, and double quotes. + +@node Escape Character +@subsubsection Escape Character +A non-quoted backslash @samp{\} is the Bash escape character. +It preserves the literal value of the next character that follows, +with the exception of @code{newline}. If a @code{\newline} pair +appears, and the backslash itself is not quoted, the @code{\newline} +is treated as a line continuation (that is, it is removed from +the input stream and effectively ignored). + +@node Single Quotes +@subsubsection Single Quotes + +Enclosing characters in single quotes (@samp{'}) preserves the literal value +of each character within the quotes. A single quote may not occur +between single quotes, even when preceded by a backslash. + +@node Double Quotes +@subsubsection Double Quotes + +Enclosing characters in double quotes (@samp{"}) preserves the literal value +of all characters within the quotes, with the exception of +@samp{$}, @samp{`}, @samp{\}, +and, when history expansion is enabled, @samp{!}. +The characters @samp{$} and @samp{`} +retain their special meaning within double quotes (@pxref{Shell Expansions}). +The backslash retains its special meaning only when followed by one of +the following characters: +@samp{$}, @samp{`}, @samp{"}, @samp{\}, or @code{newline}. +Within double quotes, backslashes that are followed by one of these +characters are removed. Backslashes preceding characters without a +special meaning are left unmodified. +A double quote may be quoted within double quotes by preceding it with +a backslash. +If enabled, history expansion will be performed unless an @samp{!} +appearing in double quotes is escaped using a backslash. +The backslash preceding the @samp{!} is not removed. + +The special parameters @samp{*} and @samp{@@} have special meaning +when in double quotes (@pxref{Shell Parameter Expansion}). + +@node ANSI-C Quoting +@subsubsection ANSI-C Quoting +@cindex quoting, ANSI + +Words of the form @code{$'@var{string}'} are treated specially. The +word expands to @var{string}, with backslash-escaped characters replaced +as specified by the ANSI C standard. Backslash escape sequences, if +present, are decoded as follows: + +@table @code +@item \a +alert (bell) +@item \b +backspace +@item \e +@itemx \E +an escape character (not ANSI C) +@item \f +form feed +@item \n +newline +@item \r +carriage return +@item \t +horizontal tab +@item \v +vertical tab +@item \\ +backslash +@item \' +single quote +@item \" +double quote +@item \@var{nnn} +the eight-bit character whose value is the octal value @var{nnn} +(one to three digits) +@item \x@var{HH} +the eight-bit character whose value is the hexadecimal value @var{HH} +(one or two hex digits) +@item \u@var{HHHH} +the Unicode (ISO/IEC 10646) character whose value is the hexadecimal value +@var{HHHH} (one to four hex digits) +@item \U@var{HHHHHHHH} +the Unicode (ISO/IEC 10646) character whose value is the hexadecimal value +@var{HHHHHHHH} (one to eight hex digits) +@item \c@var{x} +a control-@var{x} character +@end table + +@noindent +The expanded result is single-quoted, as if the dollar sign had not +been present. + +@node Locale Translation +@subsubsection Locale-Specific Translation +@cindex localization +@cindex internationalization +@cindex native languages +@cindex translation, native languages + +A double-quoted string preceded by a dollar sign (@samp{$}) will cause +the string to be translated according to the current locale. +If the current locale is @code{C} or @code{POSIX}, the dollar sign +is ignored. +If the string is translated and replaced, the replacement is +double-quoted. + +@vindex LC_MESSAGES +@vindex TEXTDOMAIN +@vindex TEXTDOMAINDIR +Some systems use the message catalog selected by the @env{LC_MESSAGES} +shell variable. Others create the name of the message catalog from the +value of the @env{TEXTDOMAIN} shell variable, possibly adding a +suffix of @samp{.mo}. If you use the @env{TEXTDOMAIN} variable, you +may need to set the @env{TEXTDOMAINDIR} variable to the location of +the message catalog files. Still others use both variables in this +fashion: +@env{TEXTDOMAINDIR}/@env{LC_MESSAGES}/LC_MESSAGES/@env{TEXTDOMAIN}.mo. + +@node Comments +@subsection Comments +@cindex comments, shell + +In a non-interactive shell, or an interactive shell in which the +@code{interactive_comments} option to the @code{shopt} +builtin is enabled (@pxref{The Shopt Builtin}), +a word beginning with @samp{#} +causes that word and all remaining characters on that line to +be ignored. An interactive shell without the @code{interactive_comments} +option enabled does not allow comments. The @code{interactive_comments} +option is on by default in interactive shells. +@xref{Interactive Shells}, for a description of what makes +a shell interactive. + +@node Shell Commands +@section Shell Commands +@cindex commands, shell + +A simple shell command such as @code{echo a b c} consists of the command +itself followed by arguments, separated by spaces. + +More complex shell commands are composed of simple commands arranged together +in a variety of ways: in a pipeline in which the output of one command +becomes the input of a second, in a loop or conditional construct, or in +some other grouping. + +@menu +* Simple Commands:: The most common type of command. +* Pipelines:: Connecting the input and output of several + commands. +* Lists:: How to execute commands sequentially. +* Compound Commands:: Shell commands for control flow. +* Coprocesses:: Two-way communication between commands. +* GNU Parallel:: Running commands in parallel. +@end menu + +@node Simple Commands +@subsection Simple Commands +@cindex commands, simple + +A simple command is the kind of command encountered most often. +It's just a sequence of words separated by @code{blank}s, terminated +by one of the shell's control operators (@pxref{Definitions}). The +first word generally specifies a command to be executed, with the +rest of the words being that command's arguments. + +The return status (@pxref{Exit Status}) of a simple command is +its exit status as provided +by the @sc{posix} 1003.1 @code{waitpid} function, or 128+@var{n} if +the command was terminated by signal @var{n}. + +@node Pipelines +@subsection Pipelines +@cindex pipeline +@cindex commands, pipelines + +A @code{pipeline} is a sequence of one or more commands separated by +one of the control operators @samp{|} or @samp{|&}. + +@rwindex time +@rwindex ! +@cindex command timing +The format for a pipeline is +@example +[time [-p]] [!] @var{command1} [ | or |& @var{command2} ] @dots{} +@end example + +@noindent +The output of each command in the pipeline is connected via a pipe +to the input of the next command. +That is, each command reads the previous command's output. This +connection is performed before any redirections specified by the +command. + +If @samp{|&} is used, @var{command1}'s standard error, in addition to +its standard output, is connected to +@var{command2}'s standard input through the pipe; +it is shorthand for @code{2>&1 |}. +This implicit redirection of the standard error to the standard output is +performed after any redirections specified by the command. + +The reserved word @code{time} causes timing statistics +to be printed for the pipeline once it finishes. +The statistics currently consist of elapsed (wall-clock) time and +user and system time consumed by the command's execution. +The @option{-p} option changes the output format to that specified +by @sc{posix}. +When the shell is in @sc{posix} mode (@pxref{Bash POSIX Mode}), +it does not recognize @code{time} as a reserved word if the next +token begins with a @samp{-}. +The @env{TIMEFORMAT} variable may be set to a format string that +specifies how the timing information should be displayed. +@xref{Bash Variables}, for a description of the available formats. +The use of @code{time} as a reserved word permits the timing of +shell builtins, shell functions, and pipelines. An external +@code{time} command cannot time these easily. + +When the shell is in @sc{posix} mode (@pxref{Bash POSIX Mode}), @code{time} +may be followed by a newline. In this case, the shell displays the +total user and system time consumed by the shell and its children. +The @env{TIMEFORMAT} variable may be used to specify the format of +the time information. + +If the pipeline is not executed asynchronously (@pxref{Lists}), the +shell waits for all commands in the pipeline to complete. + +Each command in a pipeline is executed in its own subshell +(@pxref{Command Execution Environment}). The exit +status of a pipeline is the exit status of the last command in the +pipeline, unless the @code{pipefail} option is enabled +(@pxref{The Set Builtin}). +If @code{pipefail} is enabled, the pipeline's return status is the +value of the last (rightmost) command to exit with a non-zero status, +or zero if all commands exit successfully. +If the reserved word @samp{!} precedes the pipeline, the +exit status is the logical negation of the exit status as described +above. +The shell waits for all commands in the pipeline to terminate before +returning a value. + +@node Lists +@subsection Lists of Commands +@cindex commands, lists + +A @code{list} is a sequence of one or more pipelines separated by one +of the operators @samp{;}, @samp{&}, @samp{&&}, or @samp{||}, +and optionally terminated by one of @samp{;}, @samp{&}, or a +@code{newline}. + +Of these list operators, @samp{&&} and @samp{||} +have equal precedence, followed by @samp{;} and @samp{&}, +which have equal precedence. + +A sequence of one or more newlines may appear in a @code{list} +to delimit commands, equivalent to a semicolon. + +If a command is terminated by the control operator @samp{&}, +the shell executes the command asynchronously in a subshell. +This is known as executing the command in the @var{background}. +The shell does not wait for the command to finish, and the return +status is 0 (true). +When job control is not active (@pxref{Job Control}), +the standard input for asynchronous commands, in the absence of any +explicit redirections, is redirected from @code{/dev/null}. + +Commands separated by a @samp{;} are executed sequentially; the shell +waits for each command to terminate in turn. The return status is the +exit status of the last command executed. + +@sc{and} and @sc{or} lists are sequences of one or more pipelines +separated by the control operators @samp{&&} and @samp{||}, +respectively. @sc{and} and @sc{or} lists are executed with left +associativity. + +An @sc{and} list has the form +@example +@var{command1} && @var{command2} +@end example + +@noindent +@var{command2} is executed if, and only if, @var{command1} +returns an exit status of zero. + +An @sc{or} list has the form +@example +@var{command1} || @var{command2} +@end example + +@noindent +@var{command2} is executed if, and only if, @var{command1} +returns a non-zero exit status. + +The return status of +@sc{and} and @sc{or} lists is the exit status of the last command +executed in the list. + +@node Compound Commands +@subsection Compound Commands +@cindex commands, compound + +@menu +* Looping Constructs:: Shell commands for iterative action. +* Conditional Constructs:: Shell commands for conditional execution. +* Command Grouping:: Ways to group commands. +@end menu + +Compound commands are the shell programming constructs. +Each construct begins with a reserved word or control operator and is +terminated by a corresponding reserved word or operator. +Any redirections (@pxref{Redirections}) associated with a compound command +apply to all commands within that compound command unless explicitly overridden. + +In most cases a list of commands in a compound command's description may be +separated from the rest of the command by one or more newlines, and may be +followed by a newline in place of a semicolon. + +Bash provides looping constructs, conditional commands, and mechanisms +to group commands and execute them as a unit. + +@node Looping Constructs +@subsubsection Looping Constructs +@cindex commands, looping + +Bash supports the following looping constructs. + +Note that wherever a @samp{;} appears in the description of a +command's syntax, it may be replaced with one or more newlines. + +@table @code +@item until +@rwindex until +@rwindex do +@rwindex done +The syntax of the @code{until} command is: + +@example +until @var{test-commands}; do @var{consequent-commands}; done +@end example + +Execute @var{consequent-commands} as long as +@var{test-commands} has an exit status which is not zero. +The return status is the exit status of the last command executed +in @var{consequent-commands}, or zero if none was executed. + +@item while +@rwindex while +The syntax of the @code{while} command is: + +@example +while @var{test-commands}; do @var{consequent-commands}; done +@end example + +Execute @var{consequent-commands} as long as +@var{test-commands} has an exit status of zero. +The return status is the exit status of the last command executed +in @var{consequent-commands}, or zero if none was executed. + +@item for +@rwindex for +The syntax of the @code{for} command is: + +@example +for @var{name} [ [in [@var{words} @dots{}] ] ; ] do @var{commands}; done +@end example + +Expand @var{words}, and execute @var{commands} once for each member +in the resultant list, with @var{name} bound to the current member. +If @samp{in @var{words}} is not present, the @code{for} command +executes the @var{commands} once for each positional parameter that is +set, as if @samp{in "$@@"} had been specified +(@pxref{Special Parameters}). +The return status is the exit status of the last command that executes. +If there are no items in the expansion of @var{words}, no commands are +executed, and the return status is zero. + +An alternate form of the @code{for} command is also supported: + +@example +for (( @var{expr1} ; @var{expr2} ; @var{expr3} )) ; do @var{commands} ; done +@end example + +First, the arithmetic expression @var{expr1} is evaluated according +to the rules described below (@pxref{Shell Arithmetic}). +The arithmetic expression @var{expr2} is then evaluated repeatedly +until it evaluates to zero. +Each time @var{expr2} evaluates to a non-zero value, @var{commands} are +executed and the arithmetic expression @var{expr3} is evaluated. +If any expression is omitted, it behaves as if it evaluates to 1. +The return value is the exit status of the last command in @var{commands} +that is executed, or false if any of the expressions is invalid. +@end table + +The @code{break} and @code{continue} builtins (@pxref{Bourne Shell Builtins}) +may be used to control loop execution. + +@node Conditional Constructs +@subsubsection Conditional Constructs +@cindex commands, conditional + +@table @code +@item if +@rwindex if +@rwindex then +@rwindex else +@rwindex elif +@rwindex fi +The syntax of the @code{if} command is: + +@example +if @var{test-commands}; then + @var{consequent-commands}; +[elif @var{more-test-commands}; then + @var{more-consequents};] +[else @var{alternate-consequents};] +fi +@end example + +The @var{test-commands} list is executed, and if its return status is zero, +the @var{consequent-commands} list is executed. +If @var{test-commands} returns a non-zero status, each @code{elif} list +is executed in turn, and if its exit status is zero, +the corresponding @var{more-consequents} is executed and the +command completes. +If @samp{else @var{alternate-consequents}} is present, and +the final command in the final @code{if} or @code{elif} clause +has a non-zero exit status, then @var{alternate-consequents} is executed. +The return status is the exit status of the last command executed, or +zero if no condition tested true. + +@item case +@rwindex case +@rwindex in +@rwindex esac +The syntax of the @code{case} command is: + +@example +case @var{word} in [ [(] @var{pattern} [| @var{pattern}]@dots{}) @var{command-list} ;;]@dots{} esac +@end example + +@code{case} will selectively execute the @var{command-list} corresponding to +the first @var{pattern} that matches @var{word}. +If the @code{nocasematch} shell option +(see the description of @code{shopt} in @ref{The Shopt Builtin}) +is enabled, the match is performed without regard to the case +of alphabetic characters. +The @samp{|} is used to separate multiple patterns, and the @samp{)} +operator terminates a pattern list. +A list of patterns and an associated command-list is known +as a @var{clause}. + +Each clause must be terminated with @samp{;;}, @samp{;&}, or @samp{;;&}. +The @var{word} undergoes tilde expansion, parameter expansion, command +substitution, arithmetic expansion, and quote removal before matching is +attempted. Each @var{pattern} undergoes tilde expansion, parameter +expansion, command substitution, and arithmetic expansion. + +There may be an arbitrary number of @code{case} clauses, each terminated +by a @samp{;;}, @samp{;&}, or @samp{;;&}. +The first pattern that matches determines the +command-list that is executed. +It's a common idiom to use @samp{*} as the final pattern to define the +default case, since that pattern will always match. + +Here is an example using @code{case} in a script that could be used to +describe one interesting feature of an animal: + +@example +echo -n "Enter the name of an animal: " +read ANIMAL +echo -n "The $ANIMAL has " +case $ANIMAL in + horse | dog | cat) echo -n "four";; + man | kangaroo ) echo -n "two";; + *) echo -n "an unknown number of";; +esac +echo " legs." +@end example + +@noindent + +If the @samp{;;} operator is used, no subsequent matches are attempted after +the first pattern match. +Using @samp{;&} in place of @samp{;;} causes execution to continue with +the @var{command-list} associated with the next clause, if any. +Using @samp{;;&} in place of @samp{;;} causes the shell to test the patterns +in the next clause, if any, and execute any associated @var{command-list} +on a successful match. + +The return status is zero if no @var{pattern} is matched. Otherwise, the +return status is the exit status of the @var{command-list} executed. + +@item select +@rwindex select + +The @code{select} construct allows the easy generation of menus. +It has almost the same syntax as the @code{for} command: + +@example +select @var{name} [in @var{words} @dots{}]; do @var{commands}; done +@end example + +The list of words following @code{in} is expanded, generating a list +of items. The set of expanded words is printed on the standard +error output stream, each preceded by a number. If the +@samp{in @var{words}} is omitted, the positional parameters are printed, +as if @samp{in "$@@"} had been specified. +The @env{PS3} prompt is then displayed and a line is read from the +standard input. +If the line consists of a number corresponding to one of the displayed +words, then the value of @var{name} is set to that word. +If the line is empty, the words and prompt are displayed again. +If @code{EOF} is read, the @code{select} command completes. +Any other value read causes @var{name} to be set to null. +The line read is saved in the variable @env{REPLY}. + +The @var{commands} are executed after each selection until a +@code{break} command is executed, at which +point the @code{select} command completes. + +Here is an example that allows the user to pick a filename from the +current directory, and displays the name and index of the file +selected. + +@example +select fname in *; +do + echo you picked $fname \($REPLY\) + break; +done +@end example + +@item ((@dots{})) +@example +(( @var{expression} )) +@end example + +The arithmetic @var{expression} is evaluated according to the rules +described below (@pxref{Shell Arithmetic}). +If the value of the expression is non-zero, the return status is 0; +otherwise the return status is 1. This is exactly equivalent to +@example +let "@var{expression}" +@end example +@noindent +@xref{Bash Builtins}, for a full description of the @code{let} builtin. + +@item [[@dots{}]] +@rwindex [[ +@rwindex ]] +@example +[[ @var{expression} ]] +@end example + +Return a status of 0 or 1 depending on the evaluation of +the conditional expression @var{expression}. +Expressions are composed of the primaries described below in +@ref{Bash Conditional Expressions}. +Word splitting and filename expansion are not performed on the words +between the @code{[[} and @code{]]}; tilde expansion, parameter and +variable expansion, arithmetic expansion, command substitution, process +substitution, and quote removal are performed. +Conditional operators such as @samp{-f} must be unquoted to be recognized +as primaries. + +When used with @code{[[}, the @samp{<} and @samp{>} operators sort +lexicographically using the current locale. + +When the @samp{==} and @samp{!=} operators are used, the string to the +right of the operator is considered a pattern and matched according +to the rules described below in @ref{Pattern Matching}, +as if the @code{extglob} shell option were enabled. +The @samp{=} operator is identical to @samp{==}. +If the @code{nocasematch} shell option +(see the description of @code{shopt} in @ref{The Shopt Builtin}) +is enabled, the match is performed without regard to the case +of alphabetic characters. +The return value is 0 if the string matches (@samp{==}) or does not +match (@samp{!=})the pattern, and 1 otherwise. +Any part of the pattern may be quoted to force the quoted portion +to be matched as a string. + +An additional binary operator, @samp{=~}, is available, with the same +precedence as @samp{==} and @samp{!=}. +When it is used, the string to the right of the operator is considered +an extended regular expression and matched accordingly (as in @i{regex}3)). +The return value is 0 if the string matches +the pattern, and 1 otherwise. +If the regular expression is syntactically incorrect, the conditional +expression's return value is 2. +If the @code{nocasematch} shell option +(see the description of @code{shopt} in @ref{The Shopt Builtin}) +is enabled, the match is performed without regard to the case +of alphabetic characters. +Any part of the pattern may be quoted to force the quoted portion +to be matched as a string. +Bracket expressions in regular expressions must be treated carefully, +since normal quoting characters lose their meanings between brackets. +If the pattern is stored in a shell variable, quoting the variable +expansion forces the entire pattern to be matched as a string. +Substrings matched by parenthesized subexpressions within the regular +expression are saved in the array variable @code{BASH_REMATCH}. +The element of @code{BASH_REMATCH} with index 0 is the portion of the string +matching the entire regular expression. +The element of @code{BASH_REMATCH} with index @var{n} is the portion of the +string matching the @var{n}th parenthesized subexpression. + +For example, the following will match a line +(stored in the shell variable @var{line}) +if there is a sequence of characters in the value consisting of +any number, including zero, of +space characters, zero or one instances of @samp{a}, then a @samp{b}: +@example +[[ $line =~ [[:space:]]*(a)?b ]] +@end example + +@noindent +That means values like @samp{aab} and @samp{ aaaaaab} will match, as +will a line containing a @samp{b} anywhere in its value. + +Storing the regular expression in a shell variable is often a useful +way to avoid problems with quoting characters that are special to the +shell. +It is sometimes difficult to specify a regular expression literally +without using quotes, or to keep track of the quoting used by regular +expressions while paying attention to the shell's quote removal. +Using a shell variable to store the pattern decreases these problems. +For example, the following is equivalent to the above: +@example +pattern='[[:space:]]*(a)?b' +[[ $line =~ $pattern ]] +@end example + +@noindent +If you want to match a character that's special to the regular expression +grammar, it has to be quoted to remove its special meaning. +This means that in the pattern @samp{xxx.txt}, the @samp{.} matches any +character in the string (its usual regular expression meaning), but in the +pattern @samp{"xxx.txt"} it can only match a literal @samp{.}. +Shell programmers should take special care with backslashes, since backslashes +are used both by the shell and regular expressions to remove the special +meaning from the following character. +The following two sets of commands are @emph{not} equivalent: +@example +pattern='\.' + +[[ . =~ $pattern ]] +[[ . =~ \. ]] + +[[ . =~ "$pattern" ]] +[[ . =~ '\.' ]] +@end example + +@noindent +The first two matches will succeed, but the second two will not, because +in the second two the backslash will be part of the pattern to be matched. +In the first two examples, the backslash removes the special meaning from +@samp{.}, so the literal @samp{.} matches. +If the string in the first examples were anything other than @samp{.}, say +@samp{a}, the pattern would not match, because the quoted @samp{.} in the +pattern loses its special meaning of matching any single character. + +Expressions may be combined using the following operators, listed +in decreasing order of precedence: + +@table @code +@item ( @var{expression} ) +Returns the value of @var{expression}. +This may be used to override the normal precedence of operators. + +@item ! @var{expression} +True if @var{expression} is false. + +@item @var{expression1} && @var{expression2} +True if both @var{expression1} and @var{expression2} are true. + +@item @var{expression1} || @var{expression2} +True if either @var{expression1} or @var{expression2} is true. +@end table + +@noindent +The @code{&&} and @code{||} operators do not evaluate @var{expression2} if the +value of @var{expression1} is sufficient to determine the return +value of the entire conditional expression. +@end table + +@node Command Grouping +@subsubsection Grouping Commands +@cindex commands, grouping + +Bash provides two ways to group a list of commands to be executed +as a unit. When commands are grouped, redirections may be applied +to the entire command list. For example, the output of all the +commands in the list may be redirected to a single stream. + +@table @code +@item () +@example +( @var{list} ) +@end example + +Placing a list of commands between parentheses causes a subshell +environment to be created (@pxref{Command Execution Environment}), and each +of the commands in @var{list} to be executed in that subshell. Since the +@var{list} is executed in a subshell, variable assignments do not remain in +effect after the subshell completes. + +@item @{@} +@rwindex @{ +@rwindex @} +@example +@{ @var{list}; @} +@end example + +Placing a list of commands between curly braces causes the list to +be executed in the current shell context. No subshell is created. +The semicolon (or newline) following @var{list} is required. +@end table + +In addition to the creation of a subshell, there is a subtle difference +between these two constructs due to historical reasons. The braces +are @code{reserved words}, so they must be separated from the @var{list} +by @code{blank}s or other shell metacharacters. +The parentheses are @code{operators}, and are +recognized as separate tokens by the shell even if they are not separated +from the @var{list} by whitespace. + +The exit status of both of these constructs is the exit status of +@var{list}. + +@node Coprocesses +@subsection Coprocesses +@cindex coprocess + +A @code{coprocess} is a shell command preceded by the @code{coproc} +reserved word. +A coprocess is executed asynchronously in a subshell, as if the command +had been terminated with the @samp{&} control operator, with a two-way pipe +established between the executing shell and the coprocess. + +The format for a coprocess is: +@example +coproc [@var{NAME}] @var{command} [@var{redirections}] +@end example + +@noindent +This creates a coprocess named @var{NAME}. +If @var{NAME} is not supplied, the default name is @var{COPROC}. +@var{NAME} must not be supplied if @var{command} is a simple +command (@pxref{Simple Commands}); otherwise, it is interpreted as +the first word of the simple command. + +When the coprocess is executed, the shell creates an array variable +(@pxref{Arrays}) +named @env{NAME} in the context of the executing shell. +The standard output of @var{command} +is connected via a pipe to a file descriptor in the executing shell, +and that file descriptor is assigned to @env{NAME}[0]. +The standard input of @var{command} +is connected via a pipe to a file descriptor in the executing shell, +and that file descriptor is assigned to @env{NAME}[1]. +This pipe is established before any redirections specified by the +command (@pxref{Redirections}). +The file descriptors can be utilized as arguments to shell commands +and redirections using standard word expansions. +The file descriptors are not available in subshells. + +The process ID of the shell spawned to execute the coprocess is +available as the value of the variable @env{NAME}_PID. +The @code{wait} +builtin command may be used to wait for the coprocess to terminate. + +Since the coprocess is created as an asynchronous command, +the @code{coproc} command always returns success. +The return status of a coprocess is the exit status of @var{command}. + +@node GNU Parallel +@subsection GNU Parallel + +There are ways to run commands in parallel that are not built into Bash. +GNU Parallel is a tool to do just that. + +GNU Parallel, as its name suggests, can be used to build and run commands +in parallel. You may run the same command with different arguments, whether +they are filenames, usernames, hostnames, or lines read from files. GNU +Parallel provides shorthand references to many of the most common operations +(input lines, various portions of the input line, different ways to specify +the input source, and so on). Parallel can replace @code{xargs} or feed +commands from its input sources to several different instances of Bash. + +For a complete description, refer to the GNU Parallel documentation. A few +examples should provide a brief introduction to its use. + +For example, it is easy to replace @code{xargs} to gzip all html files in the +current directory and its subdirectories: +@example +find . -type f -name '*.html' -print | parallel gzip +@end example +@noindent +If you need to protect special characters such as newlines in file names, +use find's @option{-print0} option and parallel's @option{-0} option. + +You can use Parallel to move files from the current directory when the +number of files is too large to process with one @code{mv} invocation: +@example +ls | parallel mv @{@} destdir +@end example + +As you can see, the @{@} is replaced with each line read from standard input. +While using @code{ls} will work in most instances, it is not sufficient to +deal with all filenames. +If you need to accommodate special characters in filenames, you can use + +@example +find . -depth 1 \! -name '.*' -print0 | parallel -0 mv @{@} destdir +@end example + +@noindent +as alluded to above. + +This will run as many @code{mv} commands as there are files in the current +directory. +You can emulate a parallel @code{xargs} by adding the @option{-X} option: +@example +find . -depth 1 \! -name '.*' -print0 | parallel -0 -X mv @{@} destdir +@end example + +GNU Parallel can replace certain common idioms that operate on lines read +from a file (in this case, filenames listed one per line): +@example + while IFS= read -r x; do + do-something1 "$x" "config-$x" + do-something2 < "$x" + done < file | process-output +@end example + +@noindent +with a more compact syntax reminiscent of lambdas: +@example +cat list | parallel "do-something1 @{@} config-@{@} ; do-something2 < @{@}" | process-output +@end example + +Parallel provides a built-in mechanism to remove filename extensions, which +lends itself to batch file transformations or renaming: +@example +ls *.gz | parallel -j+0 "zcat @{@} | bzip2 >@{.@}.bz2 && rm @{@}" +@end example +@noindent +This will recompress all files in the current directory with names ending +in .gz using bzip2, running one job per CPU (-j+0) in parallel. +(We use @code{ls} for brevity here; using @code{find} as above is more +robust in the face of filenames containing unexpected characters.) +Parallel can take arguments from the command line; the above can also be +written as + +@example +parallel "zcat @{@} | bzip2 >@{.@}.bz2 && rm @{@}" ::: *.gz +@end example + +If a command generates output, you may want to preserve the input order in +the output. For instance, the following command +@example +@{ echo foss.org.my ; echo debian.org; echo freenetproject.org; @} | parallel traceroute +@end example +@noindent +will display as output the traceroute invocation that finishes first. +Adding the @option{-k} option +@example +@{ echo foss.org.my ; echo debian.org; echo freenetproject.org; @} | parallel -k traceroute +@end example +@noindent +will ensure that the output of @code{traceroute foss.org.my} is displayed first. + +Finally, Parallel can be used to run a sequence of shell commands in parallel, +similar to @samp{cat file | bash}. +It is not uncommon to take a list of filenames, create a series of shell +commands to operate on them, and feed that list of commnds to a shell. +Parallel can speed this up. Assuming that @file{file} contains a list of +shell commands, one per line, + +@example +parallel -j 10 < file +@end example + +@noindent +will evaluate the commands using the shell (since no explicit command is +supplied as an argument), in blocks of ten shell jobs at a time. + +@node Shell Functions +@section Shell Functions +@cindex shell function +@cindex functions, shell + +Shell functions are a way to group commands for later execution +using a single name for the group. They are executed just like +a "regular" command. +When the name of a shell function is used as a simple command name, +the list of commands associated with that function name is executed. +Shell functions are executed in the current +shell context; no new process is created to interpret them. + +Functions are declared using this syntax: +@rwindex function +@example +@var{name} () @var{compound-command} [ @var{redirections} ] +@end example + +or + +@example +function @var{name} [()] @var{compound-command} [ @var{redirections} ] +@end example + +This defines a shell function named @var{name}. The reserved +word @code{function} is optional. +If the @code{function} reserved +word is supplied, the parentheses are optional. +The @var{body} of the function is the compound command +@var{compound-command} (@pxref{Compound Commands}). +That command is usually a @var{list} enclosed between @{ and @}, but +may be any compound command listed above, +with one exception: If the @code{function} reserved word is used, but the +parentheses are not supplied, the braces are required. +@var{compound-command} is executed whenever @var{name} is specified as the +name of a command. +When the shell is in @sc{posix} mode (@pxref{Bash POSIX Mode}), +@var{name} may not be the same as one of the special builtins +(@pxref{Special Builtins}). +Any redirections (@pxref{Redirections}) associated with the shell function +are performed when the function is executed. + +A function definition may be deleted using the @option{-f} option to the +@code{unset} builtin (@pxref{Bourne Shell Builtins}). + +The exit status of a function definition is zero unless a syntax error +occurs or a readonly function with the same name already exists. +When executed, the exit status of a function is the exit status of the +last command executed in the body. + +Note that for historical reasons, in the most common usage the curly braces +that surround the body of the function must be separated from the body by +@code{blank}s or newlines. +This is because the braces are reserved words and are only recognized +as such when they are separated from the command list +by whitespace or another shell metacharacter. +Also, when using the braces, the @var{list} must be terminated by a semicolon, +a @samp{&}, or a newline. + +When a function is executed, the arguments to the +function become the positional parameters +during its execution (@pxref{Positional Parameters}). +The special parameter @samp{#} that expands to the number of +positional parameters is updated to reflect the change. +Special parameter @code{0} is unchanged. +The first element of the @env{FUNCNAME} variable is set to the +name of the function while the function is executing. + +All other aspects of the shell execution +environment are identical between a function and its caller +with these exceptions: +the @env{DEBUG} and @env{RETURN} traps +are not inherited unless the function has been given the +@code{trace} attribute using the @code{declare} builtin or +the @code{-o functrace} option has been enabled with +the @code{set} builtin, +(in which case all functions inherit the @env{DEBUG} and @env{RETURN} traps), +and the @env{ERR} trap is not inherited unless the @code{-o errtrace} +shell option has been enabled. +@xref{Bourne Shell Builtins}, for the description of the +@code{trap} builtin. + +The @env{FUNCNEST} variable, if set to a numeric value greater +than 0, defines a maximum function nesting level. Function +invocations that exceed the limit cause the entire command to +abort. + +If the builtin command @code{return} +is executed in a function, the function completes and +execution resumes with the next command after the function +call. +Any command associated with the @code{RETURN} trap is executed +before execution resumes. +When a function completes, the values of the +positional parameters and the special parameter @samp{#} +are restored to the values they had prior to the function's +execution. If a numeric argument is given to @code{return}, +that is the function's return status; otherwise the function's +return status is the exit status of the last command executed +before the @code{return}. + +Variables local to the function may be declared with the +@code{local} builtin. These variables are visible only to +the function and the commands it invokes. + +Function names and definitions may be listed with the +@option{-f} option to the @code{declare} (@code{typeset}) +builtin command (@pxref{Bash Builtins}). +The @option{-F} option to @code{declare} or @code{typeset} +will list the function names only +(and optionally the source file and line number, if the @code{extdebug} +shell option is enabled). +Functions may be exported so that subshells +automatically have them defined with the +@option{-f} option to the @code{export} builtin +(@pxref{Bourne Shell Builtins}). +Note that shell functions and variables with the same name may result +in multiple identically-named entries in the environment passed to the +shell's children. +Care should be taken in cases where this may cause a problem. + +Functions may be recursive. +The @code{FUNCNEST} variable may be used to limit the depth of the +function call stack and restrict the number of function invocations. +By default, no limit is placed on the number of recursive calls. + +@node Shell Parameters +@section Shell Parameters +@cindex parameters +@cindex variable, shell +@cindex shell variable + +@menu +* Positional Parameters:: The shell's command-line arguments. +* Special Parameters:: Parameters denoted by special characters. +@end menu + +A @var{parameter} is an entity that stores values. +It can be a @code{name}, a number, or one of the special characters +listed below. +A @var{variable} is a parameter denoted by a @code{name}. +A variable has a @var{value} and zero or more @var{attributes}. +Attributes are assigned using the @code{declare} builtin command +(see the description of the @code{declare} builtin in @ref{Bash Builtins}). + +A parameter is set if it has been assigned a value. The null string is +a valid value. Once a variable is set, it may be unset only by using +the @code{unset} builtin command. + +A variable may be assigned to by a statement of the form +@example +@var{name}=[@var{value}] +@end example +@noindent +If @var{value} +is not given, the variable is assigned the null string. All +@var{value}s undergo tilde expansion, parameter and variable expansion, +command substitution, arithmetic expansion, and quote +removal (detailed below). If the variable has its @code{integer} +attribute set, then @var{value} +is evaluated as an arithmetic expression even if the @code{$((@dots{}))} +expansion is not used (@pxref{Arithmetic Expansion}). +Word splitting is not performed, with the exception +of @code{"$@@"} as explained below. +Filename expansion is not performed. +Assignment statements may also appear as arguments to the +@code{alias}, +@code{declare}, @code{typeset}, @code{export}, @code{readonly}, +and @code{local} builtin commands (@var{declaration} commands). +When in @sc{posix} mode (@pxref{Bash POSIX Mode}), these builtins may appear +in a command after one or more instances of the @code{command} builtin +and retain these assignment statement properties. + +In the context where an assignment statement is assigning a value +to a shell variable or array index (@pxref{Arrays}), the @samp{+=} +operator can be used to +append to or add to the variable's previous value. +This includes arguments to builtin commands such as @code{declare} that +accept assignment statements (@var{declaration} commands). +When @samp{+=} is applied to a variable for which the @var{integer} attribute +has been set, @var{value} is evaluated as an arithmetic expression and +added to the variable's current value, which is also evaluated. +When @samp{+=} is applied to an array variable using compound assignment +(@pxref{Arrays}), the +variable's value is not unset (as it is when using @samp{=}), and new +values are appended to the array beginning at one greater than the array's +maximum index (for indexed arrays), or added as additional key-value pairs +in an associative array. +When applied to a string-valued variable, @var{value} is expanded and +appended to the variable's value. + +A variable can be assigned the @var{nameref} attribute using the +@option{-n} option to the \fBdeclare\fP or \fBlocal\fP builtin commands +(@pxref{Bash Builtins}) +to create a @var{nameref}, or a reference to another variable. +This allows variables to be manipulated indirectly. +Whenever the nameref variable is referenced, assigned to, unset, or has +its attributes modified (other than the nameref attribute itself), the +operation is actually performed on the variable specified by the nameref +variable's value. +A nameref is commonly used within shell functions to refer to a variable +whose name is passed as an argument to the function. +For instance, if a variable name is passed to a shell function as its first +argument, running +@example +declare -n ref=$1 +@end example +@noindent +inside the function creates a nameref variable @var{ref} whose value is +the variable name passed as the first argument. +References and assignments to @var{ref}, and changes to its attributes, +are treated as references, assignments, and attribute modifications +to the variable whose name was passed as @code{$1}. + +If the control variable in a @code{for} loop has the nameref attribute, +the list of words can be a list of shell variables, and a name reference +will be established for each word in the list, in turn, when the loop is +executed. +Array variables cannot be given the nameref attribute. +However, nameref variables can reference array variables and subscripted +array variables. +Namerefs can be unset using the @option{-n} option to the @code{unset} builtin +(@pxref{Bourne Shell Builtins}). +Otherwise, if @code{unset} is executed with the name of a nameref variable +as an argument, the variable referenced by the nameref variable will be unset. + +@node Positional Parameters +@subsection Positional Parameters +@cindex parameters, positional + +A @var{positional parameter} is a parameter denoted by one or more +digits, other than the single digit @code{0}. Positional parameters are +assigned from the shell's arguments when it is invoked, +and may be reassigned using the @code{set} builtin command. +Positional parameter @code{N} may be referenced as @code{$@{N@}}, or +as @code{$N} when @code{N} consists of a single digit. +Positional parameters may not be assigned to with assignment statements. +The @code{set} and @code{shift} builtins are used to set and +unset them (@pxref{Shell Builtin Commands}). +The positional parameters are +temporarily replaced when a shell function is executed +(@pxref{Shell Functions}). + +When a positional parameter consisting of more than a single +digit is expanded, it must be enclosed in braces. + +@node Special Parameters +@subsection Special Parameters +@cindex parameters, special + +The shell treats several parameters specially. These parameters may +only be referenced; assignment to them is not allowed. + +@vtable @code + +@item * +@vindex $* +($*) Expands to the positional parameters, starting from one. +When the expansion is not within double quotes, each positional parameter +expands to a separate word. +In contexts where it is performed, those words +are subject to further word splitting and pathname expansion. +When the expansion occurs within double quotes, it expands to a single word +with the value of each parameter separated by the first character of the +@env{IFS} special variable. That is, @code{"$*"} is equivalent +to @code{"$1@var{c}$2@var{c}@dots{}"}, where @var{c} +is the first character of the value of the @code{IFS} +variable. +If @env{IFS} is unset, the parameters are separated by spaces. +If @env{IFS} is null, the parameters are joined without intervening +separators. + +@item @@ +@vindex $@@ +($@@) Expands to the positional parameters, starting from one. When the +expansion occurs within double quotes, each parameter expands to a +separate word. That is, @code{"$@@"} is equivalent to +@code{"$1" "$2" @dots{}}. +If the double-quoted expansion occurs within a word, the expansion of +the first parameter is joined with the beginning part of the original +word, and the expansion of the last parameter is joined with the last +part of the original word. +When there are no positional parameters, @code{"$@@"} and +@code{$@@} +expand to nothing (i.e., they are removed). + +@item # +@vindex $# +($#) Expands to the number of positional parameters in decimal. + +@item ? +@vindex $? +($?) Expands to the exit status of the most recently executed foreground +pipeline. + +@item - +@vindex $- +($-, a hyphen.) Expands to the current option flags as specified upon +invocation, by the @code{set} +builtin command, or those set by the shell itself +(such as the @option{-i} option). + +@item $ +@vindex $$ +($$) Expands to the process @sc{id} of the shell. In a @code{()} subshell, it +expands to the process @sc{id} of the invoking shell, not the subshell. + +@item ! +@vindex $! +($!) Expands to the process @sc{id} of the job most recently placed into the +background, whether executed as an asynchronous command or using +the @code{bg} builtin (@pxref{Job Control Builtins}). + +@item 0 +@vindex $0 +($0) Expands to the name of the shell or shell script. This is set at +shell initialization. If Bash is invoked with a file of commands +(@pxref{Shell Scripts}), @code{$0} is set to the name of that file. +If Bash is started with the @option{-c} option (@pxref{Invoking Bash}), +then @code{$0} is set to the first argument after the string to be +executed, if one is present. Otherwise, it is set +to the filename used to invoke Bash, as given by argument zero. + +@item _ +@vindex $_ +($_, an underscore.) +At shell startup, set to the absolute pathname used to invoke the +shell or shell script being executed as passed in the environment +or argument list. +Subsequently, expands to the last argument to the previous command, +after expansion. +Also set to the full pathname used to invoke each command executed +and placed in the environment exported to that command. +When checking mail, this parameter holds the name of the mail file. +@end vtable + +@node Shell Expansions +@section Shell Expansions +@cindex expansion + +Expansion is performed on the command line after it has been split into +@code{token}s. There are seven kinds of expansion performed: + +@itemize @bullet +@item brace expansion +@item tilde expansion +@item parameter and variable expansion +@item command substitution +@item arithmetic expansion +@item word splitting +@item filename expansion +@end itemize + +@menu +* Brace Expansion:: Expansion of expressions within braces. +* Tilde Expansion:: Expansion of the ~ character. +* Shell Parameter Expansion:: How Bash expands variables to their values. +* Command Substitution:: Using the output of a command as an argument. +* Arithmetic Expansion:: How to use arithmetic in shell expansions. +* Process Substitution:: A way to write and read to and from a + command. +* Word Splitting:: How the results of expansion are split into separate + arguments. +* Filename Expansion:: A shorthand for specifying filenames matching patterns. +* Quote Removal:: How and when quote characters are removed from + words. +@end menu + +The order of expansions is: +brace expansion; +tilde expansion, parameter and variable expansion, arithmetic expansion, +and command substitution (done in a left-to-right fashion); +word splitting; +and filename expansion. + +On systems that can support it, there is an additional expansion +available: @var{process substitution}. +This is performed at the +same time as tilde, parameter, variable, and arithmetic expansion and +command substitution. + +Only brace expansion, word splitting, and filename expansion +can change the number of words of the expansion; other expansions +expand a single word to a single word. +The only exceptions to this are the expansions of +@code{"$@@"} (@pxref{Special Parameters}) and @code{"$@{@var{name}[@@]@}"} +(@pxref{Arrays}). + +After all expansions, @code{quote removal} (@pxref{Quote Removal}) +is performed. + +@node Brace Expansion +@subsection Brace Expansion +@cindex brace expansion +@cindex expansion, brace + +Brace expansion is a mechanism by which arbitrary strings may be generated. +This mechanism is similar to +@var{filename expansion} (@pxref{Filename Expansion}), +but the filenames generated need not exist. +Patterns to be brace expanded take the form of an optional @var{preamble}, +followed by either a series of comma-separated strings or a sequence expression +between a pair of braces, +followed by an optional @var{postscript}. +The preamble is prefixed to each string contained within the braces, and +the postscript is then appended to each resulting string, expanding left +to right. + +Brace expansions may be nested. +The results of each expanded string are not sorted; left to right order +is preserved. +For example, +@example +bash$ echo a@{d,c,b@}e +ade ace abe +@end example + +A sequence expression takes the form @code{@{@var{x}..@var{y}[..@var{incr}]@}}, +where @var{x} and @var{y} are either integers or single characters, +and @var{incr}, an optional increment, is an integer. +When integers are supplied, the expression expands to each number between +@var{x} and @var{y}, inclusive. +Supplied integers may be prefixed with @samp{0} to force each term to have the +same width. +When either @var{x} or @var{y} begins with a zero, the shell +attempts to force all generated terms to contain the same number of digits, +zero-padding where necessary. +When characters are supplied, the expression expands to each character +lexicographically between @var{x} and @var{y}, inclusive, +using the default C locale. +Note that both @var{x} and @var{y} must be of the same type. +When the increment is supplied, it is used as the difference between +each term. The default increment is 1 or -1 as appropriate. + +Brace expansion is performed before any other expansions, +and any characters special to other expansions are preserved +in the result. It is strictly textual. Bash +does not apply any syntactic interpretation to the context of the +expansion or the text between the braces. +To avoid conflicts with parameter expansion, the string @samp{$@{} +is not considered eligible for brace expansion. + +A correctly-formed brace expansion must contain unquoted opening +and closing braces, and at least one unquoted comma or a valid +sequence expression. +Any incorrectly formed brace expansion is left unchanged. + +A @{ or @samp{,} may be quoted with a backslash to prevent its +being considered part of a brace expression. +To avoid conflicts with parameter expansion, the string @samp{$@{} +is not considered eligible for brace expansion. + +This construct is typically used as shorthand when the common +prefix of the strings to be generated is longer than in the +above example: +@example +mkdir /usr/local/src/bash/@{old,new,dist,bugs@} +@end example +or +@example +chown root /usr/@{ucb/@{ex,edit@},lib/@{ex?.?*,how_ex@}@} +@end example + +@node Tilde Expansion +@subsection Tilde Expansion +@cindex tilde expansion +@cindex expansion, tilde + +If a word begins with an unquoted tilde character (@samp{~}), all of the +characters up to the first unquoted slash (or all characters, +if there is no unquoted slash) are considered a @var{tilde-prefix}. +If none of the characters in the tilde-prefix are quoted, the +characters in the tilde-prefix following the tilde are treated as a +possible @var{login name}. +If this login name is the null string, the tilde is replaced with the +value of the @env{HOME} shell variable. +If @env{HOME} is unset, the home directory of the user executing the +shell is substituted instead. +Otherwise, the tilde-prefix is replaced with the home directory +associated with the specified login name. + +If the tilde-prefix is @samp{~+}, the value of +the shell variable @env{PWD} replaces the tilde-prefix. +If the tilde-prefix is @samp{~-}, the value of the shell variable +@env{OLDPWD}, if it is set, is substituted. + +If the characters following the tilde in the tilde-prefix consist of a +number @var{N}, optionally prefixed by a @samp{+} or a @samp{-}, +the tilde-prefix is replaced with the +corresponding element from the directory stack, as it would be displayed +by the @code{dirs} builtin invoked with the characters following tilde +in the tilde-prefix as an argument (@pxref{The Directory Stack}). +If the tilde-prefix, sans the tilde, consists of a number without a +leading @samp{+} or @samp{-}, @samp{+} is assumed. + +If the login name is invalid, or the tilde expansion fails, the word is +left unchanged. + +Each variable assignment is checked for unquoted tilde-prefixes immediately +following a @samp{:} or the first @samp{=}. +In these cases, tilde expansion is also performed. +Consequently, one may use filenames with tildes in assignments to +@env{PATH}, @env{MAILPATH}, and @env{CDPATH}, +and the shell assigns the expanded value. + +The following table shows how Bash treats unquoted tilde-prefixes: + +@table @code +@item ~ +The value of @code{$HOME} +@item ~/foo +@file{$HOME/foo} + +@item ~fred/foo +The subdirectory @code{foo} of the home directory of the user +@code{fred} + +@item ~+/foo +@file{$PWD/foo} + +@item ~-/foo +@file{$@{OLDPWD-'~-'@}/foo} + +@item ~@var{N} +The string that would be displayed by @samp{dirs +@var{N}} + +@item ~+@var{N} +The string that would be displayed by @samp{dirs +@var{N}} + +@item ~-@var{N} +The string that would be displayed by @samp{dirs -@var{N}} +@end table + +@node Shell Parameter Expansion +@subsection Shell Parameter Expansion +@cindex parameter expansion +@cindex expansion, parameter + +The @samp{$} character introduces parameter expansion, +command substitution, or arithmetic expansion. The parameter name +or symbol to be expanded may be enclosed in braces, which +are optional but serve to protect the variable to be expanded from +characters immediately following it which could be +interpreted as part of the name. + +When braces are used, the matching ending brace is the first @samp{@}} +not escaped by a backslash or within a quoted string, and not within an +embedded arithmetic expansion, command substitution, or parameter +expansion. + +The basic form of parameter expansion is $@{@var{parameter}@}. +The value of @var{parameter} is substituted. +The @var{parameter} is a shell parameter as described above +(@pxref{Shell Parameters}) or an array reference (@pxref{Arrays}). +The braces are required when @var{parameter} +is a positional parameter with more than one digit, +or when @var{parameter} is followed by a character that is not to be +interpreted as part of its name. + +If the first character of @var{parameter} is an exclamation point (!), +it introduces a level of variable indirection. +Bash uses the value of the variable formed from the rest of +@var{parameter} as the name of the variable; this variable is then +expanded and that value is used in the rest of the substitution, rather +than the value of @var{parameter} itself. +This is known as @code{indirect expansion}. +The exceptions to this are the expansions of $@{!@var{prefix}*@} +and $@{!@var{name}[@@]@} +described below. +The exclamation point must immediately follow the left brace in order to +introduce indirection. + +In each of the cases below, @var{word} is subject to tilde expansion, +parameter expansion, command substitution, and arithmetic expansion. + +When not performing substring expansion, using the form described +below (e.g., @samp{:-}), Bash tests for a parameter that is unset or null. +Omitting the colon results in a test only for a parameter that is unset. +Put another way, if the colon is included, +the operator tests for both @var{parameter}'s existence and that its value +is not null; if the colon is omitted, the operator tests only for existence. + +@table @code + +@item $@{@var{parameter}:@minus{}@var{word}@} +If @var{parameter} is unset or null, the expansion of +@var{word} is substituted. Otherwise, the value of +@var{parameter} is substituted. + +@item $@{@var{parameter}:=@var{word}@} +If @var{parameter} +is unset or null, the expansion of @var{word} +is assigned to @var{parameter}. +The value of @var{parameter} is then substituted. +Positional parameters and special parameters may not be assigned to +in this way. + +@item $@{@var{parameter}:?@var{word}@} +If @var{parameter} +is null or unset, the expansion of @var{word} (or a message +to that effect if @var{word} +is not present) is written to the standard error and the shell, if it +is not interactive, exits. Otherwise, the value of @var{parameter} is +substituted. + +@item $@{@var{parameter}:+@var{word}@} +If @var{parameter} +is null or unset, nothing is substituted, otherwise the expansion of +@var{word} is substituted. + +@item $@{@var{parameter}:@var{offset}@} +@itemx $@{@var{parameter}:@var{offset}:@var{length}@} +This is referred to as Substring Expansion. +It expands to up to @var{length} characters of the value of @var{parameter} +starting at the character specified by @var{offset}. +If @var{parameter} is @samp{@@}, an indexed array subscripted by +@samp{@@} or @samp{*}, or an associative array name, the results differ as +described below. +If @var{length} is omitted, it expands to the substring of the value of +@var{parameter} starting at the character specified by @var{offset} +and extending to the end of the value. +@var{length} and @var{offset} are arithmetic expressions +(@pxref{Shell Arithmetic}). + +If @var{offset} evaluates to a number less than zero, the value +is used as an offset in characters +from the end of the value of @var{parameter}. +If @var{length} evaluates to a number less than zero, +it is interpreted as an offset in characters +from the end of the value of @var{parameter} rather than +a number of characters, and the expansion is the characters between +@var{offset} and that result. +Note that a negative offset must be separated from the colon by at least +one space to avoid being confused with the @samp{:-} expansion. + +Here are some examples illustrating substring expansion on parameters and +subscripted arrays: + +@verbatim +$ string=01234567890abcdefgh +$ echo ${string:7} +7890abcdefgh +$ echo ${string:7:0} + +$ echo ${string:7:2} +78 +$ echo ${string:7:-2} +7890abcdef +$ echo ${string: -7} +bcdefgh +$ echo ${string: -7:0} + +$ echo ${string: -7:2} +bc +$ echo ${string: -7:-2} +bcdef +$ set -- 01234567890abcdefgh +$ echo ${1:7} +7890abcdefgh +$ echo ${1:7:0} + +$ echo ${1:7:2} +78 +$ echo ${1:7:-2} +7890abcdef +$ echo ${1: -7} +bcdefgh +$ echo ${1: -7:0} + +$ echo ${1: -7:2} +bc +$ echo ${1: -7:-2} +bcdef +$ array[0]=01234567890abcdefgh +$ echo ${array[0]:7} +7890abcdefgh +$ echo ${array[0]:7:0} + +$ echo ${array[0]:7:2} +78 +$ echo ${array[0]:7:-2} +7890abcdef +$ echo ${array[0]: -7} +bcdefgh +$ echo ${array[0]: -7:0} + +$ echo ${array[0]: -7:2} +bc +$ echo ${array[0]: -7:-2} +bcdef +@end verbatim + +If @var{parameter} is @samp{@@}, the result is @var{length} positional +parameters beginning at @var{offset}. +A negative @var{offset} is taken relative to one greater than the greatest +positional parameter, so an offset of -1 evaluates to the last positional +parameter. +It is an expansion error if @var{length} evaluates to a number less than zero. + +The following examples illustrate substring expansion using positional +parameters: + +@verbatim +$ set -- 1 2 3 4 5 6 7 8 9 0 a b c d e f g h +$ echo ${@:7} +7 8 9 0 a b c d e f g h +$ echo ${@:7:0} + +$ echo ${@:7:2} +7 8 +$ echo ${@:7:-2} +bash: -2: substring expression < 0 +$ echo ${@: -7:2} +b c +$ echo ${@:0} +./bash 1 2 3 4 5 6 7 8 9 0 a b c d e f g h +$ echo ${@:0:2} +./bash 1 +$ echo ${@: -7:0} + +@end verbatim + +If @var{parameter} is an indexed array name subscripted +by @samp{@@} or @samp{*}, the result is the @var{length} +members of the array beginning with @code{$@{@var{parameter}[@var{offset}]@}}. +A negative @var{offset} is taken relative to one greater than the maximum +index of the specified array. +It is an expansion error if @var{length} evaluates to a number less than zero. + +These examples show how you can use substring expansion with indexed +arrays: + +@verbatim +$ array=(0 1 2 3 4 5 6 7 8 9 0 a b c d e f g h) +$ echo ${array[@]:7} +7 8 9 0 a b c d e f g h +$ echo ${array[@]:7:2} +7 8 +$ echo ${array[@]: -7:2} +b c +$ echo ${array[@]: -7:-2} +bash: -2: substring expression < 0 +$ echo ${array[@]:0} +0 1 2 3 4 5 6 7 8 9 0 a b c d e f g h +$ echo ${array[@]:0:2} +0 1 +$ echo ${array[@]: -7:0} + +@end verbatim + +Substring expansion applied to an associative array produces undefined +results. + +Substring indexing is zero-based unless the positional parameters +are used, in which case the indexing starts at 1 by default. +If @var{offset} is 0, and the positional parameters are used, @code{$@@} is +prefixed to the list. + +@item $@{!@var{prefix}*@} +@itemx $@{!@var{prefix}@@@} +Expands to the names of variables whose names begin with @var{prefix}, +separated by the first character of the @env{IFS} special variable. +When @samp{@@} is used and the expansion appears within double quotes, each +variable name expands to a separate word. + +@item $@{!@var{name}[@@]@} +@itemx $@{!@var{name}[*]@} +If @var{name} is an array variable, expands to the list of array indices +(keys) assigned in @var{name}. +If @var{name} is not an array, expands to 0 if @var{name} is set and null +otherwise. +When @samp{@@} is used and the expansion appears within double quotes, each +key expands to a separate word. + +@item $@{#@var{parameter}@} +The length in characters of the expanded value of @var{parameter} is +substituted. +If @var{parameter} is @samp{*} or @samp{@@}, the value substituted +is the number of positional parameters. +If @var{parameter} is an array name subscripted by @samp{*} or @samp{@@}, +the value substituted is the number of elements in the array. +If @var{parameter} +is an indexed array name subscripted by a negative number, that number is +interpreted as relative to one greater than the maximum index of +@var{parameter}, so negative indices count back from the end of the +array, and an index of -1 references the last element. + +@item $@{@var{parameter}#@var{word}@} +@itemx $@{@var{parameter}##@var{word}@} +The @var{word} +is expanded to produce a pattern just as in filename +expansion (@pxref{Filename Expansion}). If the pattern matches +the beginning of the expanded value of @var{parameter}, +then the result of the expansion is the expanded value of @var{parameter} +with the shortest matching pattern (the @samp{#} case) or the +longest matching pattern (the @samp{##} case) deleted. +If @var{parameter} is @samp{@@} or @samp{*}, +the pattern removal operation is applied to each positional +parameter in turn, and the expansion is the resultant list. +If @var{parameter} is an array variable subscripted with +@samp{@@} or @samp{*}, +the pattern removal operation is applied to each member of the +array in turn, and the expansion is the resultant list. + +@item $@{@var{parameter}%@var{word}@} +@itemx $@{@var{parameter}%%@var{word}@} +The @var{word} is expanded to produce a pattern just as in +filename expansion. +If the pattern matches a trailing portion of the expanded value of +@var{parameter}, then the result of the expansion is the value of +@var{parameter} with the shortest matching pattern (the @samp{%} case) +or the longest matching pattern (the @samp{%%} case) deleted. +If @var{parameter} is @samp{@@} or @samp{*}, +the pattern removal operation is applied to each positional +parameter in turn, and the expansion is the resultant list. +If @var{parameter} +is an array variable subscripted with @samp{@@} or @samp{*}, +the pattern removal operation is applied to each member of the +array in turn, and the expansion is the resultant list. + +@item $@{@var{parameter}/@var{pattern}/@var{string}@} + +The @var{pattern} is expanded to produce a pattern just as in +filename expansion. +@var{Parameter} is expanded and the longest match of @var{pattern} +against its value is replaced with @var{string}. +If @var{pattern} begins with @samp{/}, all matches of @var{pattern} are +replaced with @var{string}. Normally only the first match is replaced. +If @var{pattern} begins with @samp{#}, it must match at the beginning +of the expanded value of @var{parameter}. +If @var{pattern} begins with @samp{%}, it must match at the end +of the expanded value of @var{parameter}. +If @var{string} is null, matches of @var{pattern} are deleted +and the @code{/} following @var{pattern} may be omitted. +If the @code{nocasematch} shell option +(see the description of @code{shopt} in @ref{The Shopt Builtin}) +is enabled, the match is performed without regard to the case +of alphabetic characters. +If @var{parameter} is @samp{@@} or @samp{*}, +the substitution operation is applied to each positional +parameter in turn, and the expansion is the resultant list. +If @var{parameter} +is an array variable subscripted with @samp{@@} or @samp{*}, +the substitution operation is applied to each member of the +array in turn, and the expansion is the resultant list. + +@item $@{@var{parameter}^@var{pattern}@} +@itemx $@{@var{parameter}^^@var{pattern}@} +@itemx $@{@var{parameter},@var{pattern}@} +@itemx $@{@var{parameter},,@var{pattern}@} +This expansion modifies the case of alphabetic characters in @var{parameter}. +The @var{pattern} is expanded to produce a pattern just as in +filename expansion. +Each character in the expanded value of @var{parameter} is tested against +@var{pattern}, and, if it matches the pattern, its case is converted. +The pattern should not attempt to match more than one character. +The @samp{^} operator converts lowercase letters matching @var{pattern} +to uppercase; the @samp{,} operator converts matching uppercase letters +to lowercase. +The @samp{^^} and @samp{,,} expansions convert each matched character in the +expanded value; the @samp{^} and @samp{,} expansions match and convert only +the first character in the expanded value. +If @var{pattern} is omitted, it is treated like a @samp{?}, which matches +every character. +If @var{parameter} is @samp{@@} or @samp{*}, +the case modification operation is applied to each positional +parameter in turn, and the expansion is the resultant list. +If @var{parameter} +is an array variable subscripted with @samp{@@} or @samp{*}, +the case modification operation is applied to each member of the +array in turn, and the expansion is the resultant list. + +@item $@{@var{parameter}@@@var{operator}@} +The expansion is either a transformation of the value of @var{parameter} +or information about @var{parameter} itself, depending on the value of +@var{operator}. Each @var{operator} is a single letter: + +@table @code +@item Q +The expansion is a string that is the value of @var{parameter} quoted in a +format that can be reused as input. +@item E +The expansion is a string that is the value of @var{parameter} with backslash +escape sequences expanded as with the @code{$'@dots{}'} quoting mechansim. +@item P +The expansion is a string that is the result of expanding the value of +@var{parameter} as if it were a prompt string (@pxref{Controlling the Prompt}). +@item A +The expansion is a string in the form of a @code{declare} command that, if +evaluated, will recreate @var{parameter} with its attributes and value. +@item a +The expansion is a string consisting of flag values representing +@var{parameter}'s attributes. +@end table + +If @var{parameter} is @samp{@@} or @samp{*}, +the operation is applied to each positional +parameter in turn, and the expansion is the resultant list. +If @var{parameter} +is an array variable subscripted with @samp{@@} or @samp{*}, +the operation is applied to each member of the +array in turn, and the expansion is the resultant list. + +The result of the expansion is subject to word splitting and pathname +expansion as described below. +@end table + +@node Command Substitution +@subsection Command Substitution +@cindex command substitution + +Command substitution allows the output of a command to replace +the command itself. +Command substitution occurs when a command is enclosed as follows: +@example +$(@var{command}) +@end example +@noindent +or +@example +`@var{command}` +@end example + +@noindent +Bash performs the expansion by executing @var{command} and +replacing the command substitution with the standard output of the +command, with any trailing newlines deleted. +Embedded newlines are not deleted, but they may be removed during +word splitting. +The command substitution @code{$(cat @var{file})} can be +replaced by the equivalent but faster @code{$(< @var{file})}. + +When the old-style backquote form of substitution is used, +backslash retains its literal meaning except when followed by +@samp{$}, @samp{`}, or @samp{\}. +The first backquote not preceded by a backslash terminates the +command substitution. +When using the @code{$(@var{command})} form, all characters between +the parentheses make up the command; none are treated specially. + +Command substitutions may be nested. To nest when using the backquoted +form, escape the inner backquotes with backslashes. + +If the substitution appears within double quotes, word splitting and +filename expansion are not performed on the results. + +@node Arithmetic Expansion +@subsection Arithmetic Expansion +@cindex expansion, arithmetic +@cindex arithmetic expansion + +Arithmetic expansion allows the evaluation of an arithmetic expression +and the substitution of the result. The format for arithmetic expansion is: + +@example +$(( @var{expression} )) +@end example + +The expression is treated as if it were within double quotes, but +a double quote inside the parentheses is not treated specially. +All tokens in the expression undergo parameter and variable expansion, +command substitution, and quote removal. +The result is treated as the arithmetic expression to be evaluated. +Arithmetic expansions may be nested. + +The evaluation is performed according to the rules listed below +(@pxref{Shell Arithmetic}). +If the expression is invalid, Bash prints a message indicating +failure to the standard error and no substitution occurs. + +@node Process Substitution +@subsection Process Substitution +@cindex process substitution + +Process substitution is supported on systems that support named +pipes (@sc{fifo}s) or the @file{/dev/fd} method of naming open files. +It takes the form of +@example +<(@var{list}) +@end example +@noindent +or +@example +>(@var{list}) +@end example +@noindent +The process @var{list} is run with its input or output connected to a +@sc{fifo} or some file in @file{/dev/fd}. The name of this file is +passed as an argument to the current command as the result of the +expansion. If the @code{>(@var{list})} form is used, writing to +the file will provide input for @var{list}. If the +@code{<(@var{list})} form is used, the file passed as an +argument should be read to obtain the output of @var{list}. +Note that no space may appear between the @code{<} or @code{>} +and the left parenthesis, otherwise the construct would be interpreted +as a redirection. + +When available, process substitution is performed simultaneously with +parameter and variable expansion, command substitution, and arithmetic +expansion. + +@node Word Splitting +@subsection Word Splitting +@cindex word splitting + +The shell scans the results of parameter expansion, command substitution, +and arithmetic expansion that did not occur within double quotes for +word splitting. + +The shell treats each character of @env{$IFS} as a delimiter, and splits +the results of the other expansions into words using these characters +as field terminators. +If @env{IFS} is unset, or its value is exactly @code{}, +the default, then sequences of +@code{ }, @code{}, and @code{} +at the beginning and end of the results of the previous +expansions are ignored, and any sequence of @env{IFS} +characters not at the beginning or end serves to delimit words. +If @env{IFS} has a value other than the default, then sequences of +the whitespace characters @code{space} and @code{tab} +are ignored at the beginning and end of the +word, as long as the whitespace character is in the +value of @env{IFS} (an @env{IFS} whitespace character). +Any character in @env{IFS} that is not @env{IFS} +whitespace, along with any adjacent @env{IFS} +whitespace characters, delimits a field. A sequence of @env{IFS} +whitespace characters is also treated as a delimiter. +If the value of @env{IFS} is null, no word splitting occurs. + +Explicit null arguments (@code{""} or @code{''}) are retained. +Unquoted implicit null arguments, resulting from the expansion of +parameters that have no values, are removed. +If a parameter with no value is expanded within double quotes, a +null argument results and is retained. + +Note that if no expansion occurs, no splitting +is performed. + +@node Filename Expansion +@subsection Filename Expansion +@menu +* Pattern Matching:: How the shell matches patterns. +@end menu +@cindex expansion, filename +@cindex expansion, pathname +@cindex filename expansion +@cindex pathname expansion + +After word splitting, unless the @option{-f} option has been set +(@pxref{The Set Builtin}), Bash scans each word for the characters +@samp{*}, @samp{?}, and @samp{[}. +If one of these characters appears, then the word is +regarded as a @var{pattern}, +and replaced with an alphabetically sorted list of +filenames matching the pattern (@pxref{Pattern Matching}). +If no matching filenames are found, +and the shell option @code{nullglob} is disabled, the word is left +unchanged. +If the @code{nullglob} option is set, and no matches are found, the word +is removed. +If the @code{failglob} shell option is set, and no matches are found, +an error message is printed and the command is not executed. +If the shell option @code{nocaseglob} is enabled, the match is performed +without regard to the case of alphabetic characters. + +When a pattern is used for filename expansion, the character @samp{.} +at the start of a filename or immediately following a slash +must be matched explicitly, unless the shell option @code{dotglob} is set. +When matching a filename, the slash character must always be +matched explicitly. +In other cases, the @samp{.} character is not treated specially. + +See the description of @code{shopt} in @ref{The Shopt Builtin}, +for a description of the @code{nocaseglob}, @code{nullglob}, +@code{failglob}, and @code{dotglob} options. + +The @env{GLOBIGNORE} +shell variable may be used to restrict the set of filenames matching a +pattern. If @env{GLOBIGNORE} +is set, each matching filename that also matches one of the patterns in +@env{GLOBIGNORE} is removed from the list of matches. +If the @code{nocaseglob} option is set, the matching against the patterns in +@env{GLOBIGNORE} is performed without regard to case. +The filenames +@file{.} and @file{..} +are always ignored when @env{GLOBIGNORE} +is set and not null. +However, setting @env{GLOBIGNORE} to a non-null value has the effect of +enabling the @code{dotglob} +shell option, so all other filenames beginning with a +@samp{.} will match. +To get the old behavior of ignoring filenames beginning with a +@samp{.}, make @samp{.*} one of the patterns in @env{GLOBIGNORE}. +The @code{dotglob} option is disabled when @env{GLOBIGNORE} +is unset. + +@node Pattern Matching +@subsubsection Pattern Matching +@cindex pattern matching +@cindex matching, pattern + +Any character that appears in a pattern, other than the special pattern +characters described below, matches itself. +The @sc{nul} character may not occur in a pattern. +A backslash escapes the following character; the +escaping backslash is discarded when matching. +The special pattern characters must be quoted if they are to be matched +literally. + +The special pattern characters have the following meanings: +@table @code +@item * +Matches any string, including the null string. +When the @code{globstar} shell option is enabled, and @samp{*} is used in +a filename expansion context, two adjacent @samp{*}s used as a single +pattern will match all files and zero or more directories and +subdirectories. +If followed by a @samp{/}, two adjacent @samp{*}s will match only +directories and subdirectories. +@item ? +Matches any single character. +@item [@dots{}] +Matches any one of the enclosed characters. A pair of characters +separated by a hyphen denotes a @var{range expression}; +any character that falls between those two characters, inclusive, +using the current locale's collating sequence and character set, +is matched. If the first character following the +@samp{[} is a @samp{!} or a @samp{^} +then any character not enclosed is matched. A @samp{@minus{}} +may be matched by including it as the first or last character +in the set. A @samp{]} may be matched by including it as the first +character in the set. +The sorting order of characters in range expressions is determined by +the current locale and the values of the +@env{LC_COLLATE} and @env{LC_ALL} shell variables, if set. + +For example, in the default C locale, @samp{[a-dx-z]} is equivalent to +@samp{[abcdxyz]}. Many locales sort characters in dictionary order, and in +these locales @samp{[a-dx-z]} is typically not equivalent to @samp{[abcdxyz]}; +it might be equivalent to @samp{[aBbCcDdxXyYz]}, for example. To obtain +the traditional interpretation of ranges in bracket expressions, you can +force the use of the C locale by setting the @env{LC_COLLATE} or +@env{LC_ALL} environment variable to the value @samp{C}, or enable the +@code{globasciiranges} shell option. + +Within @samp{[} and @samp{]}, @var{character classes} can be specified +using the syntax +@code{[:}@var{class}@code{:]}, where @var{class} is one of the +following classes defined in the @sc{posix} standard: +@example +alnum alpha ascii blank cntrl digit graph lower +print punct space upper word xdigit +@end example +@noindent +A character class matches any character belonging to that class. +The @code{word} character class matches letters, digits, and the character +@samp{_}. + +Within @samp{[} and @samp{]}, an @var{equivalence class} can be +specified using the syntax @code{[=}@var{c}@code{=]}, which +matches all characters with the same collation weight (as defined +by the current locale) as the character @var{c}. + +Within @samp{[} and @samp{]}, the syntax @code{[.}@var{symbol}@code{.]} +matches the collating symbol @var{symbol}. +@end table + +If the @code{extglob} shell option is enabled using the @code{shopt} +builtin, several extended pattern matching operators are recognized. +In the following description, a @var{pattern-list} is a list of one +or more patterns separated by a @samp{|}. +Composite patterns may be formed using one or more of the following +sub-patterns: + +@table @code +@item ?(@var{pattern-list}) +Matches zero or one occurrence of the given patterns. + +@item *(@var{pattern-list}) +Matches zero or more occurrences of the given patterns. + +@item +(@var{pattern-list}) +Matches one or more occurrences of the given patterns. + +@item @@(@var{pattern-list}) +Matches one of the given patterns. + +@item !(@var{pattern-list}) +Matches anything except one of the given patterns. +@end table + +@node Quote Removal +@subsection Quote Removal + +After the preceding expansions, all unquoted occurrences of the +characters @samp{\}, @samp{'}, and @samp{"} that did not +result from one of the above expansions are removed. + +@node Redirections +@section Redirections +@cindex redirection + +Before a command is executed, its input and output +may be @var{redirected} +using a special notation interpreted by the shell. +Redirection allows commands' file handles to be +duplicated, opened, closed, +made to refer to different files, +and can change the files the command reads from and writes to. +Redirection may also be used to modify file handles in the +current shell execution environment. The following redirection +operators may precede or appear anywhere within a +simple command or may follow a command. +Redirections are processed in the order they appear, from +left to right. + +Each redirection that may be preceded by a file descriptor number +may instead be preceded by a word of the form @{@var{varname}@}. +In this case, for each redirection operator except +>&- and <&-, the shell will allocate a file descriptor greater +than 10 and assign it to @{@var{varname}@}. If >&- or <&- is preceded +by @{@var{varname}@}, the value of @var{varname} defines the file +descriptor to close. + +In the following descriptions, if the file descriptor number is +omitted, and the first character of the redirection operator is +@samp{<}, the redirection refers to the standard input (file +descriptor 0). If the first character of the redirection operator +is @samp{>}, the redirection refers to the standard output (file +descriptor 1). + +The word following the redirection operator in the following +descriptions, unless otherwise noted, is subjected to brace expansion, +tilde expansion, parameter expansion, command substitution, arithmetic +expansion, quote removal, filename expansion, and word splitting. +If it expands to more than one word, Bash reports an error. + +Note that the order of redirections is significant. For example, +the command +@example +ls > @var{dirlist} 2>&1 +@end example +@noindent +directs both standard output (file descriptor 1) and standard error +(file descriptor 2) to the file @var{dirlist}, while the command +@example +ls 2>&1 > @var{dirlist} +@end example +@noindent +directs only the standard output to file @var{dirlist}, +because the standard error was made a copy of the standard output +before the standard output was redirected to @var{dirlist}. + +Bash handles several filenames specially when they are used in +redirections, as described in the following table: + +@table @code +@item /dev/fd/@var{fd} +If @var{fd} is a valid integer, file descriptor @var{fd} is duplicated. + +@item /dev/stdin +File descriptor 0 is duplicated. + +@item /dev/stdout +File descriptor 1 is duplicated. + +@item /dev/stderr +File descriptor 2 is duplicated. + +@item /dev/tcp/@var{host}/@var{port} +If @var{host} is a valid hostname or Internet address, and @var{port} +is an integer port number or service name, Bash attempts to open +the corresponding TCP socket. + +@item /dev/udp/@var{host}/@var{port} +If @var{host} is a valid hostname or Internet address, and @var{port} +is an integer port number or service name, Bash attempts to open +the corresponding UDP socket. +@end table + +A failure to open or create a file causes the redirection to fail. + +Redirections using file descriptors greater than 9 should be used with +care, as they may conflict with file descriptors the shell uses +internally. + +@subsection Redirecting Input +Redirection of input causes the file whose name results from +the expansion of @var{word} +to be opened for reading on file descriptor @code{n}, +or the standard input (file descriptor 0) if @code{n} +is not specified. + +The general format for redirecting input is: +@example +[@var{n}]<@var{word} +@end example + +@subsection Redirecting Output +Redirection of output causes the file whose name results from +the expansion of @var{word} +to be opened for writing on file descriptor @var{n}, +or the standard output (file descriptor 1) if @var{n} +is not specified. If the file does not exist it is created; +if it does exist it is truncated to zero size. + +The general format for redirecting output is: +@example +[@var{n}]>[|]@var{word} +@end example + +If the redirection operator is @samp{>}, and the @code{noclobber} +option to the @code{set} builtin has been enabled, the redirection +will fail if the file whose name results from the expansion of +@var{word} exists and is a regular file. +If the redirection operator is @samp{>|}, or the redirection operator is +@samp{>} and the @code{noclobber} option is not enabled, the redirection +is attempted even if the file named by @var{word} exists. + +@subsection Appending Redirected Output +Redirection of output in this fashion +causes the file whose name results from +the expansion of @var{word} +to be opened for appending on file descriptor @var{n}, +or the standard output (file descriptor 1) if @var{n} +is not specified. If the file does not exist it is created. + +The general format for appending output is: +@example +[@var{n}]>>@var{word} +@end example + +@subsection Redirecting Standard Output and Standard Error +This construct allows both the +standard output (file descriptor 1) and +the standard error output (file descriptor 2) +to be redirected to the file whose name is the +expansion of @var{word}. + +There are two formats for redirecting standard output and +standard error: +@example +&>@var{word} +@end example +@noindent +and +@example +>&@var{word} +@end example +@noindent +Of the two forms, the first is preferred. +This is semantically equivalent to +@example +>@var{word} 2>&1 +@end example +When using the second form, @var{word} may not expand to a number or +@samp{-}. If it does, other redirection operators apply +(see Duplicating File Descriptors below) for compatibility reasons. + +@subsection Appending Standard Output and Standard Error +This construct allows both the +standard output (file descriptor 1) and +the standard error output (file descriptor 2) +to be appended to the file whose name is the +expansion of @var{word}. + +The format for appending standard output and standard error is: +@example +&>>@var{word} +@end example +@noindent +This is semantically equivalent to +@example +>>@var{word} 2>&1 +@end example +(see Duplicating File Descriptors below). + +@subsection Here Documents +This type of redirection instructs the shell to read input from the +current source until a line containing only @var{word} +(with no trailing blanks) is seen. All of +the lines read up to that point are then used as the standard +input (or file descriptor @var{n} if @var{n} is specified) for a command. + +The format of here-documents is: +@example +[@var{n}]<<[@minus{}]@var{word} + @var{here-document} +@var{delimiter} +@end example + +No parameter and variable expansion, command substitution, +arithmetic expansion, or filename expansion is performed on +@var{word}. If any characters in @var{word} are quoted, the +@var{delimiter} is the result of quote removal on @var{word}, +and the lines in the here-document are not expanded. +If @var{word} is unquoted, +all lines of the here-document are subjected to +parameter expansion, command substitution, and arithmetic expansion, +the character sequence @code{\newline} is ignored, and @samp{\} +must be used to quote the characters +@samp{\}, @samp{$}, and @samp{`}. + +If the redirection operator is @samp{<<-}, +then all leading tab characters are stripped from input lines and the +line containing @var{delimiter}. +This allows here-documents within shell scripts to be indented in a +natural fashion. + +@subsection Here Strings +A variant of here documents, the format is: +@example +[@var{n}]<<< @var{word} +@end example + +The @var{word} undergoes +brace expansion, tilde expansion, parameter and variable expansion, +command substitution, arithmetic expansion, and quote removal. +Pathname expansion and word splitting are not performed. +The result is supplied as a single string to the command on its +standard input (or file descriptor @var{n} if @var{n} is specified). + +@subsection Duplicating File Descriptors +The redirection operator +@example +[@var{n}]<&@var{word} +@end example +@noindent +is used to duplicate input file descriptors. +If @var{word} +expands to one or more digits, the file descriptor denoted by @var{n} +is made to be a copy of that file descriptor. +If the digits in @var{word} do not specify a file descriptor open for +input, a redirection error occurs. +If @var{word} +evaluates to @samp{-}, file descriptor @var{n} is closed. +If @var{n} is not specified, the standard input (file descriptor 0) is used. + +The operator +@example +[@var{n}]>&@var{word} +@end example +@noindent +is used similarly to duplicate output file descriptors. If +@var{n} is not specified, the standard output (file descriptor 1) is used. +If the digits in @var{word} do not specify a file descriptor open for +output, a redirection error occurs. +If @var{word} +evaluates to @samp{-}, file descriptor @var{n} is closed. +As a special case, if @var{n} is omitted, and @var{word} does not +expand to one or more digits or @samp{-}, the standard output and standard +error are redirected as described previously. + +@subsection Moving File Descriptors +The redirection operator +@example +[@var{n}]<&@var{digit}- +@end example +@noindent +moves the file descriptor @var{digit} to file descriptor @var{n}, +or the standard input (file descriptor 0) if @var{n} is not specified. +@var{digit} is closed after being duplicated to @var{n}. + +Similarly, the redirection operator +@example +[@var{n}]>&@var{digit}- +@end example +@noindent +moves the file descriptor @var{digit} to file descriptor @var{n}, +or the standard output (file descriptor 1) if @var{n} is not specified. + +@subsection Opening File Descriptors for Reading and Writing +The redirection operator +@example +[@var{n}]<>@var{word} +@end example +@noindent +causes the file whose name is the expansion of @var{word} +to be opened for both reading and writing on file descriptor +@var{n}, or on file descriptor 0 if @var{n} +is not specified. If the file does not exist, it is created. + +@node Executing Commands +@section Executing Commands + +@menu +* Simple Command Expansion:: How Bash expands simple commands before + executing them. +* Command Search and Execution:: How Bash finds commands and runs them. +* Command Execution Environment:: The environment in which Bash + executes commands that are not + shell builtins. +* Environment:: The environment given to a command. +* Exit Status:: The status returned by commands and how Bash + interprets it. +* Signals:: What happens when Bash or a command it runs + receives a signal. +@end menu + +@node Simple Command Expansion +@subsection Simple Command Expansion +@cindex command expansion + +When a simple command is executed, the shell performs the following +expansions, assignments, and redirections, from left to right. + +@enumerate +@item +The words that the parser has marked as variable assignments (those +preceding the command name) and redirections are saved for later +processing. + +@item +The words that are not variable assignments or redirections are +expanded (@pxref{Shell Expansions}). +If any words remain after expansion, the first word +is taken to be the name of the command and the remaining words are +the arguments. + +@item +Redirections are performed as described above (@pxref{Redirections}). + +@item +The text after the @samp{=} in each variable assignment undergoes tilde +expansion, parameter expansion, command substitution, arithmetic expansion, +and quote removal before being assigned to the variable. +@end enumerate + +If no command name results, the variable assignments affect the current +shell environment. Otherwise, the variables are added to the environment +of the executed command and do not affect the current shell environment. +If any of the assignments attempts to assign a value to a readonly variable, +an error occurs, and the command exits with a non-zero status. + +If no command name results, redirections are performed, but do not +affect the current shell environment. A redirection error causes the +command to exit with a non-zero status. + +If there is a command name left after expansion, execution proceeds as +described below. Otherwise, the command exits. If one of the expansions +contained a command substitution, the exit status of the command is +the exit status of the last command substitution performed. If there +were no command substitutions, the command exits with a status of zero. + +@node Command Search and Execution +@subsection Command Search and Execution +@cindex command execution +@cindex command search + +After a command has been split into words, if it results in a +simple command and an optional list of arguments, the following +actions are taken. + +@enumerate +@item +If the command name contains no slashes, the shell attempts to +locate it. If there exists a shell function by that name, that +function is invoked as described in @ref{Shell Functions}. + +@item +If the name does not match a function, the shell searches for +it in the list of shell builtins. If a match is found, that +builtin is invoked. + +@item +If the name is neither a shell function nor a builtin, +and contains no slashes, Bash searches each element of +@env{$PATH} for a directory containing an executable file +by that name. Bash uses a hash table to remember the full +pathnames of executable files to avoid multiple @env{PATH} searches +(see the description of @code{hash} in @ref{Bourne Shell Builtins}). +A full search of the directories in @env{$PATH} +is performed only if the command is not found in the hash table. +If the search is unsuccessful, the shell searches for a defined shell +function named @code{command_not_found_handle}. +If that function exists, it is invoked with the original command and +the original command's arguments as its arguments, and the function's +exit status becomes the exit status of the shell. +If that function is not defined, the shell prints an error +message and returns an exit status of 127. + +@item +If the search is successful, or if the command name contains +one or more slashes, the shell executes the named program in +a separate execution environment. +Argument 0 is set to the name given, and the remaining arguments +to the command are set to the arguments supplied, if any. + +@item +If this execution fails because the file is not in executable +format, and the file is not a directory, it is assumed to be a +@var{shell script} and the shell executes it as described in +@ref{Shell Scripts}. + +@item +If the command was not begun asynchronously, the shell waits for +the command to complete and collects its exit status. + +@end enumerate + +@node Command Execution Environment +@subsection Command Execution Environment +@cindex execution environment + +The shell has an @var{execution environment}, which consists of the +following: + +@itemize @bullet +@item +open files inherited by the shell at invocation, as modified by +redirections supplied to the @code{exec} builtin + +@item +the current working directory as set by @code{cd}, @code{pushd}, or +@code{popd}, or inherited by the shell at invocation + +@item +the file creation mode mask as set by @code{umask} or inherited from +the shell's parent + +@item +current traps set by @code{trap} + +@item +shell parameters that are set by variable assignment or with @code{set} +or inherited from the shell's parent in the environment + +@item +shell functions defined during execution or inherited from the shell's +parent in the environment + +@item +options enabled at invocation (either by default or with command-line +arguments) or by @code{set} + +@item +options enabled by @code{shopt} (@pxref{The Shopt Builtin}) + +@item +shell aliases defined with @code{alias} (@pxref{Aliases}) + +@item +various process @sc{id}s, including those of background jobs +(@pxref{Lists}), the value of @code{$$}, and the value of +@env{$PPID} + +@end itemize + +When a simple command other than a builtin or shell function +is to be executed, it +is invoked in a separate execution environment that consists of +the following. Unless otherwise noted, the values are inherited +from the shell. + +@itemize @bullet +@item +the shell's open files, plus any modifications and additions specified +by redirections to the command + +@item +the current working directory + +@item +the file creation mode mask + +@item +shell variables and functions marked for export, along with variables +exported for the command, passed in the environment (@pxref{Environment}) + +@item +traps caught by the shell are reset to the values inherited from the +shell's parent, and traps ignored by the shell are ignored + +@end itemize + +A command invoked in this separate environment cannot affect the +shell's execution environment. + +Command substitution, commands grouped with parentheses, +and asynchronous commands are invoked in a +subshell environment that is a duplicate of the shell environment, +except that traps caught by the shell are reset to the values +that the shell inherited from its parent at invocation. Builtin +commands that are invoked as part of a pipeline are also executed +in a subshell environment. Changes made to the subshell environment +cannot affect the shell's execution environment. + +Subshells spawned to execute command substitutions inherit the value of +the @option{-e} option from the parent shell. When not in @sc{posix} mode, +Bash clears the @option{-e} option in such subshells. + +If a command is followed by a @samp{&} and job control is not active, the +default standard input for the command is the empty file @file{/dev/null}. +Otherwise, the invoked command inherits the file descriptors of the calling +shell as modified by redirections. + +@node Environment +@subsection Environment +@cindex environment + +When a program is invoked it is given an array of strings +called the @var{environment}. +This is a list of name-value pairs, of the form @code{name=value}. + +Bash provides several ways to manipulate the environment. +On invocation, the shell scans its own environment and +creates a parameter for each name found, automatically marking +it for @var{export} +to child processes. Executed commands inherit the environment. +The @code{export} and @samp{declare -x} +commands allow parameters and functions to be added to and +deleted from the environment. If the value of a parameter +in the environment is modified, the new value becomes part +of the environment, replacing the old. The environment +inherited by any executed command consists of the shell's +initial environment, whose values may be modified in the shell, +less any pairs removed by the @code{unset} and @samp{export -n} +commands, plus any additions via the @code{export} and +@samp{declare -x} commands. + +The environment for any simple command +or function may be augmented temporarily by prefixing it with +parameter assignments, as described in @ref{Shell Parameters}. +These assignment statements affect only the environment seen +by that command. + +If the @option{-k} option is set (@pxref{The Set Builtin}), then all +parameter assignments are placed in the environment for a command, +not just those that precede the command name. + +When Bash invokes an external command, the variable @samp{$_} +is set to the full pathname of the command and passed to that +command in its environment. + +@node Exit Status +@subsection Exit Status +@cindex exit status + +The exit status of an executed command is the value returned by the +@var{waitpid} system call or equivalent function. Exit statuses +fall between 0 and 255, though, as explained below, the shell may +use values above 125 specially. Exit statuses from shell builtins and +compound commands are also limited to this range. Under certain +circumstances, the shell will use special values to indicate specific +failure modes. + +For the shell's purposes, a command which exits with a +zero exit status has succeeded. +A non-zero exit status indicates failure. +This seemingly counter-intuitive scheme is used so there +is one well-defined way to indicate success and a variety of +ways to indicate various failure modes. +When a command terminates on a fatal signal whose number is @var{N}, +Bash uses the value 128+@var{N} as the exit status. + +If a command is not found, the child process created to +execute it returns a status of 127. If a command is found +but is not executable, the return status is 126. + +If a command fails because of an error during expansion or redirection, +the exit status is greater than zero. + +The exit status is used by the Bash conditional commands +(@pxref{Conditional Constructs}) and some of the list +constructs (@pxref{Lists}). + +All of the Bash builtins return an exit status of zero if they succeed +and a non-zero status on failure, so they may be used by the +conditional and list constructs. +All builtins return an exit status of 2 to indicate incorrect usage, +generally invalid options or missing arguments. + +@node Signals +@subsection Signals +@cindex signal handling + +When Bash is interactive, in the absence of any traps, it ignores +@code{SIGTERM} (so that @samp{kill 0} does not kill an interactive shell), +and @code{SIGINT} +is caught and handled (so that the @code{wait} builtin is interruptible). +When Bash receives a @code{SIGINT}, it breaks out of any executing loops. +In all cases, Bash ignores @code{SIGQUIT}. +If job control is in effect (@pxref{Job Control}), Bash +ignores @code{SIGTTIN}, @code{SIGTTOU}, and @code{SIGTSTP}. + +Non-builtin commands started by Bash have signal handlers set to the +values inherited by the shell from its parent. +When job control is not in effect, asynchronous commands +ignore @code{SIGINT} and @code{SIGQUIT} in addition to these inherited +handlers. +Commands run as a result of +command substitution ignore the keyboard-generated job control signals +@code{SIGTTIN}, @code{SIGTTOU}, and @code{SIGTSTP}. + +The shell exits by default upon receipt of a @code{SIGHUP}. +Before exiting, an interactive shell resends the @code{SIGHUP} to +all jobs, running or stopped. +Stopped jobs are sent @code{SIGCONT} to ensure that they receive +the @code{SIGHUP}. +To prevent the shell from sending the @code{SIGHUP} signal to a +particular job, it should be removed +from the jobs table with the @code{disown} +builtin (@pxref{Job Control Builtins}) or marked +to not receive @code{SIGHUP} using @code{disown -h}. + +If the @code{huponexit} shell option has been set with @code{shopt} +(@pxref{The Shopt Builtin}), Bash sends a @code{SIGHUP} to all jobs when +an interactive login shell exits. + +If Bash is waiting for a command to complete and receives a signal +for which a trap has been set, the trap will not be executed until +the command completes. +When Bash is waiting for an asynchronous +command via the @code{wait} builtin, the reception of a signal for +which a trap has been set will cause the @code{wait} builtin to return +immediately with an exit status greater than 128, immediately after +which the trap is executed. + +@node Shell Scripts +@section Shell Scripts +@cindex shell script + +A shell script is a text file containing shell commands. When such +a file is used as the first non-option argument when invoking Bash, +and neither the @option{-c} nor @option{-s} option is supplied +(@pxref{Invoking Bash}), +Bash reads and executes commands from the file, then exits. This +mode of operation creates a non-interactive shell. The shell first +searches for the file in the current directory, and looks in the +directories in @env{$PATH} if not found there. + +When Bash runs +a shell script, it sets the special parameter @code{0} to the name +of the file, rather than the name of the shell, and the positional +parameters are set to the remaining arguments, if any are given. +If no additional arguments are supplied, the positional parameters +are unset. + +A shell script may be made executable by using the @code{chmod} command +to turn on the execute bit. When Bash finds such a file while +searching the @env{$PATH} for a command, it spawns a subshell to +execute it. In other words, executing +@example +filename @var{arguments} +@end example +@noindent +is equivalent to executing +@example +bash filename @var{arguments} +@end example + +@noindent +if @code{filename} is an executable shell script. +This subshell reinitializes itself, so that the effect is as if a +new shell had been invoked to interpret the script, with the +exception that the locations of commands remembered by the parent +(see the description of @code{hash} in @ref{Bourne Shell Builtins}) +are retained by the child. + +Most versions of Unix make this a part of the operating system's command +execution mechanism. If the first line of a script begins with +the two characters @samp{#!}, the remainder of the line specifies +an interpreter for the program. +Thus, you can specify Bash, @code{awk}, Perl, or some other +interpreter and write the rest of the script file in that language. + +The arguments to the interpreter +consist of a single optional argument following the interpreter +name on the first line of the script file, followed by the name of +the script file, followed by the rest of the arguments. Bash +will perform this action on operating systems that do not handle it +themselves. Note that some older versions of Unix limit the interpreter +name and argument to a maximum of 32 characters. + +Bash scripts often begin with @code{#! /bin/bash} (assuming that +Bash has been installed in @file{/bin}), since this ensures that +Bash will be used to interpret the script, even if it is executed +under another shell. + +@node Shell Builtin Commands +@chapter Shell Builtin Commands + +@menu +* Bourne Shell Builtins:: Builtin commands inherited from the Bourne + Shell. +* Bash Builtins:: Table of builtins specific to Bash. +* Modifying Shell Behavior:: Builtins to modify shell attributes and + optional behavior. +* Special Builtins:: Builtin commands classified specially by + POSIX. +@end menu + +Builtin commands are contained within the shell itself. +When the name of a builtin command is used as the first word of +a simple command (@pxref{Simple Commands}), the shell executes +the command directly, without invoking another program. +Builtin commands are necessary to implement functionality impossible +or inconvenient to obtain with separate utilities. + +This section briefly describes the builtins which Bash inherits from +the Bourne Shell, as well as the builtin commands which are unique +to or have been extended in Bash. + +Several builtin commands are described in other chapters: builtin +commands which provide the Bash interface to the job control +facilities (@pxref{Job Control Builtins}), the directory stack +(@pxref{Directory Stack Builtins}), the command history +(@pxref{Bash History Builtins}), and the programmable completion +facilities (@pxref{Programmable Completion Builtins}). + +Many of the builtins have been extended by @sc{posix} or Bash. + +Unless otherwise noted, each builtin command documented as accepting +options preceded by @samp{-} accepts @samp{--} +to signify the end of the options. +The @code{:}, @code{true}, @code{false}, and @code{test} +builtins do not accept options and do not treat @samp{--} specially. +The @code{exit}, @code{logout}, @code{break}, @code{continue}, @code{let}, +and @code{shift} builtins accept and process arguments beginning +with @samp{-} without requiring @samp{--}. +Other builtins that accept arguments but are not specified as accepting +options interpret arguments beginning with @samp{-} as invalid options and +require @samp{--} to prevent this interpretation. + +@node Bourne Shell Builtins +@section Bourne Shell Builtins + +The following shell builtin commands are inherited from the Bourne Shell. +These commands are implemented as specified by the @sc{posix} standard. + +@table @code +@item : @r{(a colon)} +@btindex : +@example +: [@var{arguments}] +@end example + +Do nothing beyond expanding @var{arguments} and performing redirections. +The return status is zero. + +@item . @r{(a period)} +@btindex . +@example +. @var{filename} [@var{arguments}] +@end example + +Read and execute commands from the @var{filename} argument in the +current shell context. If @var{filename} does not contain a slash, +the @env{PATH} variable is used to find @var{filename}. +When Bash is not in @sc{posix} mode, the current directory is searched +if @var{filename} is not found in @env{$PATH}. +If any @var{arguments} are supplied, they become the positional +parameters when @var{filename} is executed. Otherwise the positional +parameters are unchanged. +The return status is the exit status of the last command executed, or +zero if no commands are executed. If @var{filename} is not found, or +cannot be read, the return status is non-zero. +This builtin is equivalent to @code{source}. + +@item break +@btindex break +@example +break [@var{n}] +@end example + +Exit from a @code{for}, @code{while}, @code{until}, or @code{select} loop. +If @var{n} is supplied, the @var{n}th enclosing loop is exited. +@var{n} must be greater than or equal to 1. +The return status is zero unless @var{n} is not greater than or equal to 1. + +@item cd +@btindex cd +@example +cd [-L|[-P [-e]] [-@@] [@var{directory}] +@end example + +Change the current working directory to @var{directory}. +If @var{directory} is not supplied, the value of the @env{HOME} +shell variable is used. +Any additional arguments following @var{directory} are ignored. +If the shell variable +@env{CDPATH} exists, it is used as a search path: +each directory name in @env{CDPATH} is searched for +@var{directory}, with alternative directory names in @env{CDPATH} +separated by a colon (@samp{:}). +If @var{directory} begins with a slash, @env{CDPATH} is not used. + +The @option{-P} option means to not follow symbolic links: symbolic links +are resolved while @code{cd} is traversing @var{directory} and before +processing an instance of @samp{..} in @var{directory}. + +By default, or when the @option{-L} option is supplied, symbolic links +in @var{directory} are resolved after @code{cd} processes an instance +of @samp{..} in @var{directory}. + +If @samp{..} appears in @var{directory}, it is processed by removing the +immediately preceding pathname component, back to a slash or the beginning +of @var{directory}. + +If the @option{-e} option is supplied with @option{-P} +and the current working directory cannot be successfully determined +after a successful directory change, @code{cd} will return an unsuccessful +status. + +On systems that support it, the @option{-@@} option presents the extended +attributes associated with a file as a directory. + +If @var{directory} is @samp{-}, it is converted to @env{$OLDPWD} +before the directory change is attempted. + +If a non-empty directory name from @env{CDPATH} is used, or if +@samp{-} is the first argument, and the directory change is +successful, the absolute pathname of the new working directory is +written to the standard output. + +The return status is zero if the directory is successfully changed, +non-zero otherwise. + +@item continue +@btindex continue +@example +continue [@var{n}] +@end example + +Resume the next iteration of an enclosing @code{for}, @code{while}, +@code{until}, or @code{select} loop. +If @var{n} is supplied, the execution of the @var{n}th enclosing loop +is resumed. +@var{n} must be greater than or equal to 1. +The return status is zero unless @var{n} is not greater than or equal to 1. + +@item eval +@btindex eval +@example +eval [@var{arguments}] +@end example + +The arguments are concatenated together into a single command, which is +then read and executed, and its exit status returned as the exit status +of @code{eval}. +If there are no arguments or only empty arguments, the return status is +zero. + +@item exec +@btindex exec +@example +exec [-cl] [-a @var{name}] [@var{command} [@var{arguments}]] +@end example + +If @var{command} +is supplied, it replaces the shell without creating a new process. +If the @option{-l} option is supplied, the shell places a dash at the +beginning of the zeroth argument passed to @var{command}. +This is what the @code{login} program does. +The @option{-c} option causes @var{command} to be executed with an empty +environment. +If @option{-a} is supplied, the shell passes @var{name} as the zeroth +argument to @var{command}. +If @var{command} +cannot be executed for some reason, a non-interactive shell exits, +unless the @code{execfail} shell option +is enabled. In that case, it returns failure. +An interactive shell returns failure if the file cannot be executed. +If no @var{command} is specified, redirections may be used to affect +the current shell environment. If there are no redirection errors, the +return status is zero; otherwise the return status is non-zero. + +@item exit +@btindex exit +@example +exit [@var{n}] +@end example + +Exit the shell, returning a status of @var{n} to the shell's parent. +If @var{n} is omitted, the exit status is that of the last command executed. +Any trap on @code{EXIT} is executed before the shell terminates. + +@item export +@btindex export +@example +export [-fn] [-p] [@var{name}[=@var{value}]] +@end example + +Mark each @var{name} to be passed to child processes +in the environment. If the @option{-f} option is supplied, the @var{name}s +refer to shell functions; otherwise the names refer to shell variables. +The @option{-n} option means to no longer mark each @var{name} for export. +If no @var{names} are supplied, or if the @option{-p} option is given, a +list of names of all exported variables is displayed. +The @option{-p} option displays output in a form that may be reused as input. +If a variable name is followed by =@var{value}, the value of +the variable is set to @var{value}. + +The return status is zero unless an invalid option is supplied, one of +the names is not a valid shell variable name, or @option{-f} is supplied +with a name that is not a shell function. + +@item getopts +@btindex getopts +@example +getopts @var{optstring} @var{name} [@var{args}] +@end example + +@code{getopts} is used by shell scripts to parse positional parameters. +@var{optstring} contains the option characters to be recognized; if a +character is followed by a colon, the option is expected to have an +argument, which should be separated from it by whitespace. +The colon (@samp{:}) and question mark (@samp{?}) may not be +used as option characters. +Each time it is invoked, @code{getopts} +places the next option in the shell variable @var{name}, initializing +@var{name} if it does not exist, +and the index of the next argument to be processed into the +variable @env{OPTIND}. +@env{OPTIND} is initialized to 1 each time the shell or a shell script +is invoked. +When an option requires an argument, +@code{getopts} places that argument into the variable @env{OPTARG}. +The shell does not reset @env{OPTIND} automatically; it must be manually +reset between multiple calls to @code{getopts} within the same shell +invocation if a new set of parameters is to be used. + +When the end of options is encountered, @code{getopts} exits with a +return value greater than zero. +@env{OPTIND} is set to the index of the first non-option argument, +and @var{name} is set to @samp{?}. + +@code{getopts} +normally parses the positional parameters, but if more arguments are +given in @var{args}, @code{getopts} parses those instead. + +@code{getopts} can report errors in two ways. If the first character of +@var{optstring} is a colon, @var{silent} +error reporting is used. In normal operation, diagnostic messages +are printed when invalid options or missing option arguments are +encountered. +If the variable @env{OPTERR} +is set to 0, no error messages will be displayed, even if the first +character of @code{optstring} is not a colon. + +If an invalid option is seen, +@code{getopts} places @samp{?} into @var{name} and, if not silent, +prints an error message and unsets @env{OPTARG}. +If @code{getopts} is silent, the option character found is placed in +@env{OPTARG} and no diagnostic message is printed. + +If a required argument is not found, and @code{getopts} +is not silent, a question mark (@samp{?}) is placed in @var{name}, +@code{OPTARG} is unset, and a diagnostic message is printed. +If @code{getopts} is silent, then a colon (@samp{:}) is placed in +@var{name} and @env{OPTARG} is set to the option character found. + +@item hash +@btindex hash +@example +hash [-r] [-p @var{filename}] [-dt] [@var{name}] +@end example + +Each time @code{hash} is invoked, it remembers the full pathnames of the +commands specified as @var{name} arguments, +so they need not be searched for on subsequent invocations. +The commands are found by searching through the directories listed in +@env{$PATH}. +Any previously-remembered pathname is discarded. +The @option{-p} option inhibits the path search, and @var{filename} is +used as the location of @var{name}. +The @option{-r} option causes the shell to forget all remembered locations. +The @option{-d} option causes the shell to forget the remembered location +of each @var{name}. +If the @option{-t} option is supplied, the full pathname to which each +@var{name} corresponds is printed. If multiple @var{name} arguments are +supplied with @option{-t} the @var{name} is printed before the hashed +full pathname. +The @option{-l} option causes output to be displayed in a format +that may be reused as input. +If no arguments are given, or if only @option{-l} is supplied, +information about remembered commands is printed. +The return status is zero unless a @var{name} is not found or an invalid +option is supplied. + +@item pwd +@btindex pwd +@example +pwd [-LP] +@end example + +Print the absolute pathname of the current working directory. +If the @option{-P} option is supplied, the pathname printed will not +contain symbolic links. +If the @option{-L} option is supplied, the pathname printed may contain +symbolic links. +The return status is zero unless an error is encountered while +determining the name of the current directory or an invalid option +is supplied. + +@item readonly +@btindex readonly +@example +readonly [-aAf] [-p] [@var{name}[=@var{value}]] @dots{} +@end example + +Mark each @var{name} as readonly. +The values of these names may not be changed by subsequent assignment. +If the @option{-f} option is supplied, each @var{name} refers to a shell +function. +The @option{-a} option means each @var{name} refers to an indexed +array variable; the @option{-A} option means each @var{name} refers +to an associative array variable. +If both options are supplied, @option{-A} takes precedence. +If no @var{name} arguments are given, or if the @option{-p} +option is supplied, a list of all readonly names is printed. +The other options may be used to restrict the output to a subset of +the set of readonly names. +The @option{-p} option causes output to be displayed in a format that +may be reused as input. +If a variable name is followed by =@var{value}, the value of +the variable is set to @var{value}. +The return status is zero unless an invalid option is supplied, one of +the @var{name} arguments is not a valid shell variable or function name, +or the @option{-f} option is supplied with a name that is not a shell function. + +@item return +@btindex return +@example +return [@var{n}] +@end example + +Cause a shell function to stop executing and return the value @var{n} +to its caller. +If @var{n} is not supplied, the return value is the exit status of the +last command executed in the function. +If @code{return} is executed by a trap handler, the last command used to +determine the status is the last command executed before the trap handler. +if @code{return} is executed during a @code{DEBUG} trap, the last command +used to determine the status is the last command executed by the trap +handler before @code{return} was invoked. +@code{return} may also be used to terminate execution of a script +being executed with the @code{.} (@code{source}) builtin, +returning either @var{n} or +the exit status of the last command executed within the script as the exit +status of the script. +If @var{n} is supplied, the return value is its least significant +8 bits. +Any command associated with the @code{RETURN} trap is executed +before execution resumes after the function or script. +The return status is non-zero if @code{return} is supplied a non-numeric +argument or is used outside a function +and not during the execution of a script by @code{.} or @code{source}. + +@item shift +@btindex shift +@example +shift [@var{n}] +@end example + +Shift the positional parameters to the left by @var{n}. +The positional parameters from @var{n}+1 @dots{} @code{$#} are +renamed to @code{$1} @dots{} @code{$#}-@var{n}. +Parameters represented by the numbers @code{$#} to @code{$#}-@var{n}+1 +are unset. +@var{n} must be a non-negative number less than or equal to @code{$#}. +If @var{n} is zero or greater than @code{$#}, the positional parameters +are not changed. +If @var{n} is not supplied, it is assumed to be 1. +The return status is zero unless @var{n} is greater than @code{$#} or +less than zero, non-zero otherwise. + +@item test +@itemx [ +@btindex test +@btindex [ +@example +test @var{expr} +@end example + +Evaluate a conditional express +ion @var{expr} and return a status of 0 +(true) or 1 (false). +Each operator and operand must be a separate argument. +Expressions are composed of the primaries described below in +@ref{Bash Conditional Expressions}. +@code{test} does not accept any options, nor does it accept and ignore +an argument of @option{--} as signifying the end of options. + +When the @code{[} form is used, the last argument to the command must +be a @code{]}. + +Expressions may be combined using the following operators, listed in +decreasing order of precedence. +The evaluation depends on the number of arguments; see below. +Operator precedence is used when there are five or more arguments. + +@table @code +@item ! @var{expr} +True if @var{expr} is false. + +@item ( @var{expr} ) +Returns the value of @var{expr}. +This may be used to override the normal precedence of operators. + +@item @var{expr1} -a @var{expr2} +True if both @var{expr1} and @var{expr2} are true. + +@item @var{expr1} -o @var{expr2} +True if either @var{expr1} or @var{expr2} is true. +@end table + +The @code{test} and @code{[} builtins evaluate conditional +expressions using a set of rules based on the number of arguments. + +@table @asis +@item 0 arguments +The expression is false. + +@item 1 argument +The expression is true if and only if the argument is not null. + +@item 2 arguments +If the first argument is @samp{!}, the expression is true if and +only if the second argument is null. +If the first argument is one of the unary conditional operators +(@pxref{Bash Conditional Expressions}), the expression +is true if the unary test is true. +If the first argument is not a valid unary operator, the expression is +false. + +@item 3 arguments +The following conditions are applied in the order listed. +If the second argument is one of the binary conditional +operators (@pxref{Bash Conditional Expressions}), the +result of the expression is the result of the binary test using the +first and third arguments as operands. +The @samp{-a} and @samp{-o} operators are considered binary operators +when there are three arguments. +If the first argument is @samp{!}, the value is the negation of +the two-argument test using the second and third arguments. +If the first argument is exactly @samp{(} and the third argument is +exactly @samp{)}, the result is the one-argument test of the second +argument. +Otherwise, the expression is false. + +@item 4 arguments +If the first argument is @samp{!}, the result is the negation of +the three-argument expression composed of the remaining arguments. +Otherwise, the expression is parsed and evaluated according to +precedence using the rules listed above. + +@item 5 or more arguments +The expression is parsed and evaluated according to precedence +using the rules listed above. +@end table + +When used with @code{test} or @samp{[}, the @samp{<} and @samp{>} +operators sort lexicographically using ASCII ordering. + +@item times +@btindex times +@example +times +@end example + +Print out the user and system times used by the shell and its children. +The return status is zero. + +@item trap +@btindex trap +@example +trap [-lp] [@var{arg}] [@var{sigspec} @dots{}] +@end example + +The commands in @var{arg} are to be read and executed when the +shell receives signal @var{sigspec}. If @var{arg} is absent (and +there is a single @var{sigspec}) or +equal to @samp{-}, each specified signal's disposition is reset +to the value it had when the shell was started. +If @var{arg} is the null string, then the signal specified by +each @var{sigspec} is ignored by the shell and commands it invokes. +If @var{arg} is not present and @option{-p} has been supplied, +the shell displays the trap commands associated with each @var{sigspec}. +If no arguments are supplied, or +only @option{-p} is given, @code{trap} prints the list of commands +associated with each signal number in a form that may be reused as +shell input. +The @option{-l} option causes the shell to print a list of signal names +and their corresponding numbers. +Each @var{sigspec} is either a signal name or a signal number. +Signal names are case insensitive and the @code{SIG} prefix is optional. + +If a @var{sigspec} +is @code{0} or @code{EXIT}, @var{arg} is executed when the shell exits. +If a @var{sigspec} is @code{DEBUG}, the command @var{arg} is executed +before every simple command, @code{for} command, @code{case} command, +@code{select} command, every arithmetic @code{for} command, and before +the first command executes in a shell function. +Refer to the description of the @code{extdebug} option to the +@code{shopt} builtin (@pxref{The Shopt Builtin}) for details of its +effect on the @code{DEBUG} trap. +If a @var{sigspec} is @code{RETURN}, the command @var{arg} is executed +each time a shell function or a script executed with the @code{.} or +@code{source} builtins finishes executing. + +If a @var{sigspec} is @code{ERR}, the command @var{arg} +is executed whenever +a pipeline (which may consist of a single simple +command), a list, or a compound command returns a +non-zero exit status, +subject to the following conditions. +The @code{ERR} trap is not executed if the failed command is part of the +command list immediately following an @code{until} or @code{while} keyword, +part of the test following the @code{if} or @code{elif} reserved words, +part of a command executed in a @code{&&} or @code{||} list +except the command following the final @code{&&} or @code{||}, +any command in a pipeline but the last, +or if the command's return +status is being inverted using @code{!}. +These are the same conditions obeyed by the @code{errexit} (@option{-e}) +option. + +Signals ignored upon entry to the shell cannot be trapped or reset. +Trapped signals that are not being ignored are reset to their original +values in a subshell or subshell environment when one is created. + +The return status is zero unless a @var{sigspec} does not specify a +valid signal. + +@item umask +@btindex umask +@example +umask [-p] [-S] [@var{mode}] +@end example + +Set the shell process's file creation mask to @var{mode}. If +@var{mode} begins with a digit, it is interpreted as an octal number; +if not, it is interpreted as a symbolic mode mask similar +to that accepted by the @code{chmod} command. If @var{mode} is +omitted, the current value of the mask is printed. If the @option{-S} +option is supplied without a @var{mode} argument, the mask is printed +in a symbolic format. +If the @option{-p} option is supplied, and @var{mode} +is omitted, the output is in a form that may be reused as input. +The return status is zero if the mode is successfully changed or if +no @var{mode} argument is supplied, and non-zero otherwise. + +Note that when the mode is interpreted as an octal number, each number +of the umask is subtracted from @code{7}. Thus, a umask of @code{022} +results in permissions of @code{755}. + +@item unset +@btindex unset +@example +unset [-fnv] [@var{name}] +@end example + +Remove each variable or function @var{name}. +If the @option{-v} option is given, each +@var{name} refers to a shell variable and that variable is remvoved. +If the @option{-f} option is given, the @var{name}s refer to shell +functions, and the function definition is removed. +If the @option{-n} option is supplied, and @var{name} is a variable with +the @var{nameref} attribute, @var{name} will be unset rather than the +variable it references. +@option{-n} has no effect if the @option{-f} option is supplied. +If no options are supplied, each @var{name} refers to a variable; if +there is no variable by that name, any function with that name is +unset. +Readonly variables and functions may not be unset. +The return status is zero unless a @var{name} is readonly. +@end table + +@node Bash Builtins +@section Bash Builtin Commands + +This section describes builtin commands which are unique to +or have been extended in Bash. +Some of these commands are specified in the @sc{posix} standard. + +@table @code + +@item alias +@btindex alias +@example +alias [-p] [@var{name}[=@var{value}] @dots{}] +@end example + +Without arguments or with the @option{-p} option, @code{alias} prints +the list of aliases on the standard output in a form that allows +them to be reused as input. +If arguments are supplied, an alias is defined for each @var{name} +whose @var{value} is given. If no @var{value} is given, the name +and value of the alias is printed. +Aliases are described in @ref{Aliases}. + +@item bind +@btindex bind +@example +bind [-m @var{keymap}] [-lpsvPSVX] +bind [-m @var{keymap}] [-q @var{function}] [-u @var{function}] [-r @var{keyseq}] +bind [-m @var{keymap}] -f @var{filename} +bind [-m @var{keymap}] -x @var{keyseq:shell-command} +bind [-m @var{keymap}] @var{keyseq:function-name} +bind [-m @var{keymap}] @var{keyseq:readline-command} +@end example + +Display current Readline (@pxref{Command Line Editing}) +key and function bindings, +bind a key sequence to a Readline function or macro, +or set a Readline variable. +Each non-option argument is a command as it would appear in a +Readline initialization file (@pxref{Readline Init File}), +but each binding or command must be passed as a separate argument; e.g., +@samp{"\C-x\C-r":re-read-init-file}. + +Options, if supplied, have the following meanings: + +@table @code +@item -m @var{keymap} +Use @var{keymap} as the keymap to be affected by +the subsequent bindings. Acceptable @var{keymap} +names are +@code{emacs}, +@code{emacs-standard}, +@code{emacs-meta}, +@code{emacs-ctlx}, +@code{vi}, +@code{vi-move}, +@code{vi-command}, and +@code{vi-insert}. +@code{vi} is equivalent to @code{vi-command}; +@code{emacs} is equivalent to @code{emacs-standard}. + +@item -l +List the names of all Readline functions. + +@item -p +Display Readline function names and bindings in such a way that they +can be used as input or in a Readline initialization file. + +@item -P +List current Readline function names and bindings. + +@item -v +Display Readline variable names and values in such a way that they +can be used as input or in a Readline initialization file. + +@item -V +List current Readline variable names and values. + +@item -s +Display Readline key sequences bound to macros and the strings they output +in such a way that they can be used as input or in a Readline +initialization file. + +@item -S +Display Readline key sequences bound to macros and the strings they output. + +@item -f @var{filename} +Read key bindings from @var{filename}. + +@item -q @var{function} +Query about which keys invoke the named @var{function}. + +@item -u @var{function} +Unbind all keys bound to the named @var{function}. + +@item -r @var{keyseq} +Remove any current binding for @var{keyseq}. + +@item -x @var{keyseq:shell-command} +Cause @var{shell-command} to be executed whenever @var{keyseq} is +entered. +When @var{shell-command} is executed, the shell sets the +@code{READLINE_LINE} variable to the contents of the Readline line +buffer and the @code{READLINE_POINT} variable to the current location +of the insertion point. +If the executed command changes the value of @code{READLINE_LINE} or +@code{READLINE_POINT}, those new values will be reflected in the +editing state. + +@item -X +List all key sequences bound to shell commands and the associated commands +in a format that can be reused as input. +@end table + +@noindent +The return status is zero unless an invalid option is supplied or an +error occurs. + +@item builtin +@btindex builtin +@example +builtin [@var{shell-builtin} [@var{args}]] +@end example + +Run a shell builtin, passing it @var{args}, and return its exit status. +This is useful when defining a shell function with the same +name as a shell builtin, retaining the functionality of the builtin within +the function. +The return status is non-zero if @var{shell-builtin} is not a shell +builtin command. + +@item caller +@btindex caller +@example +caller [@var{expr}] +@end example + +Returns the context of any active subroutine call (a shell function or +a script executed with the @code{.} or @code{source} builtins). + +Without @var{expr}, @code{caller} displays the line number and source +filename of the current subroutine call. +If a non-negative integer is supplied as @var{expr}, @code{caller} +displays the line number, subroutine name, and source file corresponding +to that position in the current execution call stack. This extra +information may be used, for example, to print a stack trace. The +current frame is frame 0. + +The return value is 0 unless the shell is not executing a subroutine +call or @var{expr} does not correspond to a valid position in the +call stack. + +@item command +@btindex command +@example +command [-pVv] @var{command} [@var{arguments} @dots{}] +@end example + +Runs @var{command} with @var{arguments} ignoring any shell function +named @var{command}. +Only shell builtin commands or commands found by searching the +@env{PATH} are executed. +If there is a shell function named @code{ls}, running @samp{command ls} +within the function will execute the external command @code{ls} +instead of calling the function recursively. +The @option{-p} option means to use a default value for @env{PATH} +that is guaranteed to find all of the standard utilities. +The return status in this case is 127 if @var{command} cannot be +found or an error occurred, and the exit status of @var{command} +otherwise. + +If either the @option{-V} or @option{-v} option is supplied, a +description of @var{command} is printed. The @option{-v} option +causes a single word indicating the command or file name used to +invoke @var{command} to be displayed; the @option{-V} option produces +a more verbose description. In this case, the return status is +zero if @var{command} is found, and non-zero if not. + +@item declare +@btindex declare +@example +declare [-aAfFgilnrtux] [-p] [@var{name}[=@var{value}] @dots{}] +@end example + +Declare variables and give them attributes. If no @var{name}s +are given, then display the values of variables instead. + +The @option{-p} option will display the attributes and values of each +@var{name}. +When @option{-p} is used with @var{name} arguments, additional options, +other than @option{-f} and @option{-F}, are ignored. + +When @option{-p} is supplied without @var{name} arguments, @code{declare} +will display the attributes and values of all variables having the +attributes specified by the additional options. +If no other options are supplied with @option{-p}, @code{declare} will +display the attributes and values of all shell variables. The @option{-f} +option will restrict the display to shell functions. + +The @option{-F} option inhibits the display of function definitions; +only the function name and attributes are printed. +If the @code{extdebug} shell option is enabled using @code{shopt} +(@pxref{The Shopt Builtin}), the source file name and line number where +the function is defined are displayed as well. +@option{-F} implies @option{-f}. + +The @option{-g} option forces variables to be created or modified at +the global scope, even when @code{declare} is executed in a shell function. +It is ignored in all other cases. + +The following options can be used to restrict output to variables with +the specified attributes or to give variables attributes: + +@table @code +@item -a +Each @var{name} is an indexed array variable (@pxref{Arrays}). + +@item -A +Each @var{name} is an associative array variable (@pxref{Arrays}). + +@item -f +Use function names only. + +@item -i +The variable is to be treated as +an integer; arithmetic evaluation (@pxref{Shell Arithmetic}) is +performed when the variable is assigned a value. + +@item -l +When the variable is assigned a value, all upper-case characters are +converted to lower-case. +The upper-case attribute is disabled. + +@item -n +Give each @var{name} the @var{nameref} attribute, making +it a name reference to another variable. +That other variable is defined by the value of @var{name}. +All references, assignments, and attribute modifications +to @var{name}, except for changing the +@option{-n} attribute itself, are performed on the variable referenced by +@var{name}'s value. +The nameref attribute cannot be applied to array variables. + +@item -r +Make @var{name}s readonly. These names cannot then be assigned values +by subsequent assignment statements or unset. + +@item -t +Give each @var{name} the @code{trace} attribute. +Traced functions inherit the @code{DEBUG} and @code{RETURN} traps from +the calling shell. +The trace attribute has no special meaning for variables. + +@item -u +When the variable is assigned a value, all lower-case characters are +converted to upper-case. +The lower-case attribute is disabled. + +@item -x +Mark each @var{name} for export to subsequent commands via +the environment. +@end table + +Using @samp{+} instead of @samp{-} turns off the attribute instead, +with the exceptions that @samp{+a} +may not be used to destroy an array variable and @samp{+r} will not +remove the readonly attribute. +When used in a function, @code{declare} makes each @var{name} local, +as with the @code{local} command, unless the @option{-g} option is used. +If a variable name is followed by =@var{value}, the value of the variable +is set to @var{value}. + +When using @option{-a} or @option{-A} and the compound assignment syntax to +create array variables, additional attributes do not take effect until +subsequent assignments. + +The return status is zero unless an invalid option is encountered, +an attempt is made to define a function using @samp{-f foo=bar}, +an attempt is made to assign a value to a readonly variable, +an attempt is made to assign a value to an array variable without +using the compound assignment syntax (@pxref{Arrays}), +one of the @var{names} is not a valid shell variable name, +an attempt is made to turn off readonly status for a readonly variable, +an attempt is made to turn off array status for an array variable, +or an attempt is made to display a non-existent function with @option{-f}. + +@item echo +@btindex echo +@example +echo [-neE] [@var{arg} @dots{}] +@end example + +Output the @var{arg}s, separated by spaces, terminated with a +newline. +The return status is 0 unless a write error occurs. +If @option{-n} is specified, the trailing newline is suppressed. +If the @option{-e} option is given, interpretation of the following +backslash-escaped characters is enabled. +The @option{-E} option disables the interpretation of these escape characters, +even on systems where they are interpreted by default. +The @code{xpg_echo} shell option may be used to +dynamically determine whether or not @code{echo} expands these +escape characters by default. +@code{echo} does not interpret @option{--} to mean the end of options. + +@code{echo} interprets the following escape sequences: +@table @code +@item \a +alert (bell) +@item \b +backspace +@item \c +suppress further output +@item \e +@itemx \E +escape +@item \f +form feed +@item \n +new line +@item \r +carriage return +@item \t +horizontal tab +@item \v +vertical tab +@item \\ +backslash +@item \0@var{nnn} +the eight-bit character whose value is the octal value @var{nnn} +(zero to three octal digits) +@item \x@var{HH} +the eight-bit character whose value is the hexadecimal value @var{HH} +(one or two hex digits) +@item \u@var{HHHH} +the Unicode (ISO/IEC 10646) character whose value is the hexadecimal value +@var{HHHH} (one to four hex digits) +@item \U@var{HHHHHHHH} +the Unicode (ISO/IEC 10646) character whose value is the hexadecimal value +@var{HHHHHHHH} (one to eight hex digits) +@end table + +@item enable +@btindex enable +@example +enable [-a] [-dnps] [-f @var{filename}] [@var{name} @dots{}] +@end example + +Enable and disable builtin shell commands. +Disabling a builtin allows a disk command which has the same name +as a shell builtin to be executed without specifying a full pathname, +even though the shell normally searches for builtins before disk commands. +If @option{-n} is used, the @var{name}s become disabled. Otherwise +@var{name}s are enabled. For example, to use the @code{test} binary +found via @env{$PATH} instead of the shell builtin version, type +@samp{enable -n test}. + +If the @option{-p} option is supplied, or no @var{name} arguments appear, +a list of shell builtins is printed. With no other arguments, the list +consists of all enabled shell builtins. +The @option{-a} option means to list +each builtin with an indication of whether or not it is enabled. + +The @option{-f} option means to load the new builtin command @var{name} +from shared object @var{filename}, on systems that support dynamic loading. +The @option{-d} option will delete a builtin loaded with @option{-f}. + +If there are no options, a list of the shell builtins is displayed. +The @option{-s} option restricts @code{enable} to the @sc{posix} special +builtins. If @option{-s} is used with @option{-f}, the new builtin becomes +a special builtin (@pxref{Special Builtins}). + +The return status is zero unless a @var{name} is not a shell builtin +or there is an error loading a new builtin from a shared object. + +@item help +@btindex help +@example +help [-dms] [@var{pattern}] +@end example + +Display helpful information about builtin commands. +If @var{pattern} is specified, @code{help} gives detailed help +on all commands matching @var{pattern}, otherwise a list of +the builtins is printed. + +Options, if supplied, have the following meanings: + +@table @code +@item -d +Display a short description of each @var{pattern} +@item -m +Display the description of each @var{pattern} in a manpage-like format +@item -s +Display only a short usage synopsis for each @var{pattern} +@end table + +The return status is zero unless no command matches @var{pattern}. + +@item let +@btindex let +@example +let @var{expression} [@var{expression} @dots{}] +@end example + +The @code{let} builtin allows arithmetic to be performed on shell +variables. Each @var{expression} is evaluated according to the +rules given below in @ref{Shell Arithmetic}. If the +last @var{expression} evaluates to 0, @code{let} returns 1; +otherwise 0 is returned. + +@item local +@btindex local +@example +local [@var{option}] @var{name}[=@var{value}] @dots{} +@end example + +For each argument, a local variable named @var{name} is created, +and assigned @var{value}. +The @var{option} can be any of the options accepted by @code{declare}. +@code{local} can only be used within a function; it makes the variable +@var{name} have a visible scope restricted to that function and its +children. The return status is zero unless @code{local} is used outside +a function, an invalid @var{name} is supplied, or @var{name} is a +readonly variable. + +@item logout +@btindex logout +@example +logout [@var{n}] +@end example + +Exit a login shell, returning a status of @var{n} to the shell's +parent. + +@item mapfile +@btindex mapfile +@example +mapfile [-d @var{delim}] [-n @var{count}] [-O @var{origin}] [-s @var{count}] [-t] [-u @var{fd}] + [-C @var{callback}] [-c @var{quantum}] [@var{array}] +@end example + +Read lines from the standard input into the indexed array variable @var{array}, +or from file descriptor @var{fd} +if the @option{-u} option is supplied. +The variable @code{MAPFILE} is the default @var{array}. +Options, if supplied, have the following meanings: + +@table @code + +@item -d +The first character of @var{delim} is used to terminate each input line, +rather than newline. +@item -n +Copy at most @var{count} lines. If @var{count} is 0, all lines are copied. +@item -O +Begin assigning to @var{array} at index @var{origin}. +The default index is 0. +@item -s +Discard the first @var{count} lines read. +@item -t +Remove a trailing newline from each line read. +@item -u +Read lines from file descriptor @var{fd} instead of the standard input. +@item -C +Evaluate @var{callback} each time @var{quantum}P lines are read. +The @option{-c} option specifies @var{quantum}. +@item -c +Specify the number of lines read between each call to @var{callback}. +@end table + +If @option{-C} is specified without @option{-c}, +the default quantum is 5000. +When @var{callback} is evaluated, it is supplied the index of the next +array element to be assigned and the line to be assigned to that element +as additional arguments. +@var{callback} is evaluated after the line is read but before the +array element is assigned. + +If not supplied with an explicit origin, @code{mapfile} will clear @var{array} +before assigning to it. + +@code{mapfile} returns successfully unless an invalid option or option +argument is supplied, @var{array} is invalid or unassignable, or @var{array} +is not an indexed array. + +@item printf +@btindex printf +@example +printf [-v @var{var}] @var{format} [@var{arguments}] +@end example + +Write the formatted @var{arguments} to the standard output under the +control of the @var{format}. +The @option{-v} option causes the output to be assigned to the variable +@var{var} rather than being printed to the standard output. + +The @var{format} is a character string which contains three types of objects: +plain characters, which are simply copied to standard output, character +escape sequences, which are converted and copied to the standard output, and +format specifications, each of which causes printing of the next successive +@var{argument}. +In addition to the standard @code{printf(1)} formats, @code{printf} +interprets the following extensions: + +@table @code +@item %b +Causes @code{printf} to expand backslash escape sequences in the +corresponding @var{argument}, +except that @samp{\c} terminates output, backslashes in +@samp{\'}, @samp{\"}, and @samp{\?} are not removed, and octal escapes +beginning with @samp{\0} may contain up to four digits. +@item %q +Causes @code{printf} to output the +corresponding @var{argument} in a format that can be reused as shell input. +@item %(@var{datefmt})T +Causes @code{printf} to output the date-time string resulting from using +@var{datefmt} as a format string for @code{strftime}(3). +The corresponding @var{argument} is an integer representing the number of +seconds since the epoch. +Two special argument values may be used: -1 represents the current +time, and -2 represents the time the shell was invoked. +If no argument is specified, conversion behaves as if -1 had been given. +This is an exception to the usual @code{printf} behavior. +@end table + +@noindent +Arguments to non-string format specifiers are treated as C language constants, +except that a leading plus or minus sign is allowed, and if the leading +character is a single or double quote, the value is the ASCII value of +the following character. + +The @var{format} is reused as necessary to consume all of the @var{arguments}. +If the @var{format} requires more @var{arguments} than are supplied, the +extra format specifications behave as if a zero value or null string, as +appropriate, had been supplied. The return value is zero on success, +non-zero on failure. + +@item read +@btindex read +@example +read [-ers] [-a @var{aname}] [-d @var{delim}] [-i @var{text}] [-n @var{nchars}] + [-N @var{nchars}] [-p @var{prompt}] [-t @var{timeout}] [-u @var{fd}] [@var{name} @dots{}] +@end example + +One line is read from the standard input, or from the file descriptor +@var{fd} supplied as an argument to the @option{-u} option, and the first word +is assigned to the first @var{name}, the second word to the second @var{name}, +and so on, with leftover words and their intervening separators assigned +to the last @var{name}. +If there are fewer words read from the input stream than names, +the remaining names are assigned empty values. +The characters in the value of the @env{IFS} variable +are used to split the line into words using the same rules the shell +uses for expansion (described above in @ref{Word Splitting}). +The backslash character @samp{\} may be used to remove any special +meaning for the next character read and for line continuation. +If no names are supplied, the line read is assigned to the +variable @env{REPLY}. +The return code is zero, unless end-of-file is encountered, @code{read} +times out (in which case the return code is greater than 128), +a variable assignment error (such as assigning to a readonly variable) occurs, +or an invalid file descriptor is supplied as the argument to @option{-u}. + +Options, if supplied, have the following meanings: + +@table @code +@item -a @var{aname} +The words are assigned to sequential indices of the array variable +@var{aname}, starting at 0. +All elements are removed from @var{aname} before the assignment. +Other @var{name} arguments are ignored. + +@item -d @var{delim} +The first character of @var{delim} is used to terminate the input line, +rather than newline. + +@item -e +Readline (@pxref{Command Line Editing}) is used to obtain the line. +Readline uses the current (or default, if line editing was not previously +active) editing settings. + +@item -i @var{text} +If Readline is being used to read the line, @var{text} is placed into +the editing buffer before editing begins. + +@item -n @var{nchars} +@code{read} returns after reading @var{nchars} characters rather than +waiting for a complete line of input, but honor a delimiter if fewer +than @var{nchars} characters are read before the delimiter. + +@item -N @var{nchars} +@code{read} returns after reading exactly @var{nchars} characters rather +than waiting for a complete line of input, unless EOF is encountered or +@code{read} times out. +Delimiter characters encountered in the input are +not treated specially and do not cause @code{read} to return until +@var{nchars} characters are read. + +@item -p @var{prompt} +Display @var{prompt}, without a trailing newline, before attempting +to read any input. +The prompt is displayed only if input is coming from a terminal. + +@item -r +If this option is given, backslash does not act as an escape character. +The backslash is considered to be part of the line. +In particular, a backslash-newline pair may not be used as a line +continuation. + +@item -s +Silent mode. If input is coming from a terminal, characters are +not echoed. + +@item -t @var{timeout} +Cause @code{read} to time out and return failure if a complete line of +input (or a specified number of characters) +is not read within @var{timeout} seconds. +@var{timeout} may be a decimal number with a fractional portion following +the decimal point. +This option is only effective if @code{read} is reading input from a +terminal, pipe, or other special file; it has no effect when reading +from regular files. +If @code{read} times out, @code{read} saves any partial input read into +the specified variable @var{name}. +If @var{timeout} is 0, @code{read} returns immediately, without trying to +read and data. The exit status is 0 if input is available on +the specified file descriptor, non-zero otherwise. +The exit status is greater than 128 if the timeout is exceeded. + +@item -u @var{fd} +Read input from file descriptor @var{fd}. +@end table + +@item readarray +@btindex readarray +@example +readarray [-d @var{delim}] [-n @var{count}] [-O @var{origin}] [-s @var{count}] [-t] [-u @var{fd}] + [-C @var{callback}] [-c @var{quantum}] [@var{array}] +@end example + +Read lines from the standard input into the indexed array variable @var{array}, +or from file descriptor @var{fd} +if the @option{-u} option is supplied. + +A synonym for @code{mapfile}. + +@item source +@btindex source +@example +source @var{filename} +@end example + +A synonym for @code{.} (@pxref{Bourne Shell Builtins}). + +@item type +@btindex type +@example +type [-afptP] [@var{name} @dots{}] +@end example + +For each @var{name}, indicate how it would be interpreted if used as a +command name. + +If the @option{-t} option is used, @code{type} prints a single word +which is one of @samp{alias}, @samp{function}, @samp{builtin}, +@samp{file} or @samp{keyword}, +if @var{name} is an alias, shell function, shell builtin, +disk file, or shell reserved word, respectively. +If the @var{name} is not found, then nothing is printed, and +@code{type} returns a failure status. + +If the @option{-p} option is used, @code{type} either returns the name +of the disk file that would be executed, or nothing if @option{-t} +would not return @samp{file}. + +The @option{-P} option forces a path search for each @var{name}, even if +@option{-t} would not return @samp{file}. + +If a command is hashed, @option{-p} and @option{-P} print the hashed value, +which is not necessarily the file that appears first in @code{$PATH}. + +If the @option{-a} option is used, @code{type} returns all of the places +that contain an executable named @var{file}. +This includes aliases and functions, if and only if the @option{-p} option +is not also used. + +If the @option{-f} option is used, @code{type} does not attempt to find +shell functions, as with the @code{command} builtin. + +The return status is zero if all of the @var{names} are found, non-zero +if any are not found. + +@item typeset +@btindex typeset +@example +typeset [-afFgrxilnrtux] [-p] [@var{name}[=@var{value}] @dots{}] +@end example + +The @code{typeset} command is supplied for compatibility with the Korn +shell. +It is a synonym for the @code{declare} builtin command. + +@item ulimit +@btindex ulimit +@example +ulimit [-HSabcdefiklmnpqrstuvxPT] [@var{limit}] +@end example + +@code{ulimit} provides control over the resources available to processes +started by the shell, on systems that allow such control. If an +option is given, it is interpreted as follows: + +@table @code +@item -S +Change and report the soft limit associated with a resource. + +@item -H +Change and report the hard limit associated with a resource. + +@item -a +All current limits are reported. + +@item -b +The maximum socket buffer size. + +@item -c +The maximum size of core files created. + +@item -d +The maximum size of a process's data segment. + +@item -e +The maximum scheduling priority ("nice"). + +@item -f +The maximum size of files written by the shell and its children. + +@item -i +The maximum number of pending signals. + +@item -k +The maximum number of kqueues that may be allocated. + +@item -l +The maximum size that may be locked into memory. + +@item -m +The maximum resident set size (many systems do not honor this limit). + +@item -n +The maximum number of open file descriptors (most systems do not +allow this value to be set). + +@item -p +The pipe buffer size. + +@item -q +The maximum number of bytes in POSIX message queues. + +@item -r +The maximum real-time scheduling priority. + +@item -s +The maximum stack size. + +@item -t +The maximum amount of cpu time in seconds. + +@item -u +The maximum number of processes available to a single user. + +@item -v +The maximum amount of virtual memory available to the shell, and, on +some systems, to its children. + +@item -x +The maximum number of file locks. + +@item -P +The maximum number of pseudoterminals. + +@item -T +The maximum number of threads. +@end table + +If @var{limit} is given, and the @option{-a} option is not used, +@var{limit} is the new value of the specified resource. +The special @var{limit} values @code{hard}, @code{soft}, and +@code{unlimited} stand for the current hard limit, the current soft limit, +and no limit, respectively. +A hard limit cannot be increased by a non-root user once it is set; +a soft limit may be increased up to the value of the hard limit. +Otherwise, the current value of the soft limit for the specified resource +is printed, unless the @option{-H} option is supplied. +When setting new limits, if neither @option{-H} nor @option{-S} is supplied, +both the hard and soft limits are set. +If no option is given, then @option{-f} is assumed. Values are in 1024-byte +increments, except for @option{-t}, which is in seconds; @option{-p}, +which is in units of 512-byte blocks; and @option{-P}, @option{-T}, +@option{-b}, +@option{-k}, @option{-n} and @option{-u}, which are unscaled values. + +The return status is zero unless an invalid option or argument is supplied, +or an error occurs while setting a new limit. + +@item unalias +@btindex unalias +@example +unalias [-a] [@var{name} @dots{} ] +@end example + +Remove each @var{name} from the list of aliases. If @option{-a} is +supplied, all aliases are removed. +Aliases are described in @ref{Aliases}. +@end table + +@node Modifying Shell Behavior +@section Modifying Shell Behavior + +@menu +* The Set Builtin:: Change the values of shell attributes and + positional parameters. +* The Shopt Builtin:: Modify shell optional behavior. +@end menu + +@node The Set Builtin +@subsection The Set Builtin + +This builtin is so complicated that it deserves its own section. @code{set} +allows you to change the values of shell options and set the positional +parameters, or to display the names and values of shell variables. + +@table @code +@item set +@btindex set +@example +set [--abefhkmnptuvxBCEHPT] [-o @var{option-name}] [@var{argument} @dots{}] +set [+abefhkmnptuvxBCEHPT] [+o @var{option-name}] [@var{argument} @dots{}] +@end example + +If no options or arguments are supplied, @code{set} displays the names +and values of all shell variables and functions, sorted according to the +current locale, in a format that may be reused as input +for setting or resetting the currently-set variables. +Read-only variables cannot be reset. +In @sc{posix} mode, only shell variables are listed. + +When options are supplied, they set or unset shell attributes. +Options, if specified, have the following meanings: + +@table @code +@item -a +Mark variables and function which are modified or created for export +to the environment of subsequent commands. + +@item -b +Cause the status of terminated background jobs to be reported +immediately, rather than before printing the next primary prompt. + +@item -e +Exit immediately if +a pipeline (@pxref{Pipelines}), which may consist of a single simple command +(@pxref{Simple Commands}), +a list (@pxref{Lists}), +or a compound command (@pxref{Compound Commands}) +returns a non-zero status. +The shell does not exit if the command that fails is part of the +command list immediately following a @code{while} or @code{until} keyword, +part of the test in an @code{if} statement, +part of any command executed in a @code{&&} or @code{||} list except +the command following the final @code{&&} or @code{||}, +any command in a pipeline but the last, +or if the command's return status is being inverted with @code{!}. +If a compound command other than a subshell +returns a non-zero status because a command failed +while @option{-e} was being ignored, the shell does not exit. +A trap on @code{ERR}, if set, is executed before the shell exits. + +This option applies to the shell environment and each subshell environment +separately (@pxref{Command Execution Environment}), and may cause +subshells to exit before executing all the commands in the subshell. + +If a compound command or shell function executes in a context where +@option{-e} is being ignored, +none of the commands executed within the compound command or function body +will be affected by the @option{-e} setting, even if @option{-e} is set +and a command returns a failure status. +If a compound command or shell function sets @option{-e} while executing in +a context where @option{-e} is ignored, that setting will not have any +effect until the compound command or the command containing the function +call completes. + +@item -f +Disable filename expansion (globbing). + +@item -h +Locate and remember (hash) commands as they are looked up for execution. +This option is enabled by default. + +@item -k +All arguments in the form of assignment statements are placed +in the environment for a command, not just those that precede +the command name. + +@item -m +Job control is enabled (@pxref{Job Control}). +All processes run in a separate process group. +When a background job completes, the shell prints a line +containing its exit status. + +@item -n +Read commands but do not execute them. +This may be used to check a script for syntax errors. +This option is ignored by interactive shells. + +@item -o @var{option-name} + +Set the option corresponding to @var{option-name}: + +@table @code +@item allexport +Same as @code{-a}. + +@item braceexpand +Same as @code{-B}. + +@item emacs +Use an @code{emacs}-style line editing interface (@pxref{Command Line Editing}). +This also affects the editing interface used for @code{read -e}. + +@item errexit +Same as @code{-e}. + +@item errtrace +Same as @code{-E}. + +@item functrace +Same as @code{-T}. + +@item hashall +Same as @code{-h}. + +@item histexpand +Same as @code{-H}. + +@item history +Enable command history, as described in @ref{Bash History Facilities}. +This option is on by default in interactive shells. + +@item ignoreeof +An interactive shell will not exit upon reading EOF. + +@item keyword +Same as @code{-k}. + +@item monitor +Same as @code{-m}. + +@item noclobber +Same as @code{-C}. + +@item noexec +Same as @code{-n}. + +@item noglob +Same as @code{-f}. + +@item nolog +Currently ignored. + +@item notify +Same as @code{-b}. + +@item nounset +Same as @code{-u}. + +@item onecmd +Same as @code{-t}. + +@item physical +Same as @code{-P}. + +@item pipefail +If set, the return value of a pipeline is the value of the last +(rightmost) command to exit with a non-zero status, or zero if all +commands in the pipeline exit successfully. +This option is disabled by default. + +@item posix +Change the behavior of Bash where the default operation differs +from the @sc{posix} standard to match the standard +(@pxref{Bash POSIX Mode}). +This is intended to make Bash behave as a strict superset of that +standard. + +@item privileged +Same as @code{-p}. + +@item verbose +Same as @code{-v}. + +@item vi +Use a @code{vi}-style line editing interface. +This also affects the editing interface used for @code{read -e}. + +@item xtrace +Same as @code{-x}. +@end table + +@item -p +Turn on privileged mode. +In this mode, the @env{$BASH_ENV} and @env{$ENV} files are not +processed, shell functions are not inherited from the environment, +and the @env{SHELLOPTS}, @env{BASHOPTS}, @env{CDPATH} and @env{GLOBIGNORE} +variables, if they appear in the environment, are ignored. +If the shell is started with the effective user (group) id not equal to the +real user (group) id, and the @option{-p} option is not supplied, these actions +are taken and the effective user id is set to the real user id. +If the @option{-p} option is supplied at startup, the effective user id is +not reset. +Turning this option off causes the effective user +and group ids to be set to the real user and group ids. + +@item -t +Exit after reading and executing one command. + +@item -u +Treat unset variables and parameters other than the special parameters +@samp{@@} or @samp{*} as an error when performing parameter expansion. +An error message will be written to the standard error, and a non-interactive +shell will exit. + +@item -v +Print shell input lines as they are read. + +@item -x +Print a trace of simple commands, @code{for} commands, @code{case} +commands, @code{select} commands, and arithmetic @code{for} commands +and their arguments or associated word lists after they are +expanded and before they are executed. The value of the @env{PS4} +variable is expanded and the resultant value is printed before +the command and its expanded arguments. + +@item -B +The shell will perform brace expansion (@pxref{Brace Expansion}). +This option is on by default. + +@item -C +Prevent output redirection using @samp{>}, @samp{>&}, and @samp{<>} +from overwriting existing files. + +@item -E +If set, any trap on @code{ERR} is inherited by shell functions, command +substitutions, and commands executed in a subshell environment. +The @code{ERR} trap is normally not inherited in such cases. + +@item -H +Enable @samp{!} style history substitution (@pxref{History Interaction}). +This option is on by default for interactive shells. + +@item -P +If set, do not resolve symbolic links when performing commands such as +@code{cd} which change the current directory. The physical directory +is used instead. By default, Bash follows +the logical chain of directories when performing commands +which change the current directory. + +For example, if @file{/usr/sys} is a symbolic link to @file{/usr/local/sys} +then: +@example +$ cd /usr/sys; echo $PWD +/usr/sys +$ cd ..; pwd +/usr +@end example + +@noindent +If @code{set -P} is on, then: +@example +$ cd /usr/sys; echo $PWD +/usr/local/sys +$ cd ..; pwd +/usr/local +@end example + +@item -T +If set, any trap on @code{DEBUG} and @code{RETURN} are inherited by +shell functions, command substitutions, and commands executed +in a subshell environment. +The @code{DEBUG} and @code{RETURN} traps are normally not inherited +in such cases. + +@item -- +If no arguments follow this option, then the positional parameters are +unset. Otherwise, the positional parameters are set to the +@var{arguments}, even if some of them begin with a @samp{-}. + +@item - +Signal the end of options, cause all remaining @var{arguments} +to be assigned to the positional parameters. The @option{-x} +and @option{-v} options are turned off. +If there are no arguments, the positional parameters remain unchanged. +@end table + +Using @samp{+} rather than @samp{-} causes these options to be +turned off. The options can also be used upon invocation of the +shell. The current set of options may be found in @code{$-}. + +The remaining N @var{arguments} are positional parameters and are +assigned, in order, to @code{$1}, @code{$2}, @dots{} @code{$N}. +The special parameter @code{#} is set to N. + +The return status is always zero unless an invalid option is supplied. +@end table + +@node The Shopt Builtin +@subsection The Shopt Builtin + +This builtin allows you to change additional shell optional behavior. + +@table @code + +@item shopt +@btindex shopt +@example +shopt [-pqsu] [-o] [@var{optname} @dots{}] +@end example + +Toggle the values of settings controlling optional shell behavior. +The settings can be either those listed below, or, if the +@option{-o} option is used, those available with the @option{-o} +option to the @code{set} builtin command (@pxref{The Set Builtin}). +With no options, or with the @option{-p} option, a list of all settable +options is displayed, with an indication of whether or not each is set. +The @option{-p} option causes output to be displayed in a form that +may be reused as input. +Other options have the following meanings: + +@table @code +@item -s +Enable (set) each @var{optname}. + +@item -u +Disable (unset) each @var{optname}. + +@item -q +Suppresses normal output; the return status +indicates whether the @var{optname} is set or unset. +If multiple @var{optname} arguments are given with @option{-q}, +the return status is zero if all @var{optnames} are enabled; +non-zero otherwise. + +@item -o +Restricts the values of +@var{optname} to be those defined for the @option{-o} option to the +@code{set} builtin (@pxref{The Set Builtin}). +@end table + +If either @option{-s} or @option{-u} +is used with no @var{optname} arguments, @code{shopt} shows only +those options which are set or unset, respectively. + +Unless otherwise noted, the @code{shopt} options are disabled (off) +by default. + +The return status when listing options is zero if all @var{optnames} +are enabled, non-zero otherwise. When setting or unsetting options, +the return status is zero unless an @var{optname} is not a valid shell +option. + +The list of @code{shopt} options is: +@table @code + +@item autocd +If set, a command name that is the name of a directory is executed as if +it were the argument to the @code{cd} command. +This option is only used by interactive shells. + +@item cdable_vars +If this is set, an argument to the @code{cd} builtin command that +is not a directory is assumed to be the name of a variable whose +value is the directory to change to. + +@item cdspell +If set, minor errors in the spelling of a directory component in a +@code{cd} command will be corrected. +The errors checked for are transposed characters, +a missing character, and a character too many. +If a correction is found, the corrected path is printed, +and the command proceeds. +This option is only used by interactive shells. + +@item checkhash +If this is set, Bash checks that a command found in the hash +table exists before trying to execute it. If a hashed command no +longer exists, a normal path search is performed. + +@item checkjobs +If set, Bash lists the status of any stopped and running jobs before +exiting an interactive shell. If any jobs are running, this causes +the exit to be deferred until a second exit is attempted without an +intervening command (@pxref{Job Control}). +The shell always postpones exiting if any jobs are stopped. + +@item checkwinsize +If set, Bash checks the window size after each command + and, if necessary, updates the values of +@env{LINES} and @env{COLUMNS}. + +@item cmdhist +If set, Bash +attempts to save all lines of a multiple-line +command in the same history entry. This allows +easy re-editing of multi-line commands. + +@item compat31 +If set, Bash +changes its behavior to that of version 3.1 with respect to quoted +arguments to the conditional command's @samp{=~} operator +and with respect to locale-specific +string comparison when using the @code{[[} +conditional command's @samp{<} and @samp{>} operators. +Bash versions prior to bash-4.1 use ASCII collation and strcmp(3); +bash-4.1 and later use the current locale's collation sequence and strcoll(3). + +@item compat32 +If set, Bash +changes its behavior to that of version 3.2 with respect to locale-specific +string comparison when using the @code{[[} +conditional command's @samp{<} and @samp{>} operators (see previous item). + +@item compat40 +If set, Bash +changes its behavior to that of version 4.0 with respect to locale-specific +string comparison when using the @code{[[} +conditional command's @samp{<} and @samp{>} operators (see description +of @code{compat31}) +and the effect of interrupting a command list. +Bash versions 4.0 and later interrupt the list as if the shell received the +interrupt; previous versions continue with the next command in the list. + +@item compat41 +If set, Bash, when in @sc{posix} mode, treats a single quote in a double-quoted +parameter expansion as a special character. The single quotes must match +(an even number) and the characters between the single quotes are considered +quoted. This is the behavior of @sc{posix} mode through version 4.1. +The default Bash behavior remains as in previous versions. + +@item compat42 +If set, Bash +does not process the replacement string in the pattern substitution word +expansion using quote removal. + +@item complete_fullquote +If set, Bash +quotes all shell metacharacters in filenames and directory names when +performing completion. +If not set, Bash +removes metacharacters such as the dollar sign from the set of +characters that will be quoted in completed filenames +when these metacharacters appear in shell variable references in words to be +completed. +This means that dollar signs in variable names that expand to directories +will not be quoted; +however, any dollar signs appearing in filenames will not be quoted, either. +This is active only when bash is using backslashes to quote completed +filenames. +This variable is set by default, which is the default Bash behavior in +versions through 4.2. + +@item direxpand +If set, Bash +replaces directory names with the results of word expansion when performing +filename completion. This changes the contents of the readline editing +buffer. +If not set, Bash attempts to preserve what the user typed. + +@item dirspell +If set, Bash +attempts spelling correction on directory names during word completion +if the directory name initially supplied does not exist. + +@item dotglob +If set, Bash includes filenames beginning with a `.' in +the results of filename expansion. + +@item execfail +If this is set, a non-interactive shell will not exit if +it cannot execute the file specified as an argument to the @code{exec} +builtin command. An interactive shell does not exit if @code{exec} +fails. + +@item expand_aliases +If set, aliases are expanded as described below under Aliases, +@ref{Aliases}. +This option is enabled by default for interactive shells. + +@item extdebug +If set, behavior intended for use by debuggers is enabled: + +@enumerate +@item +The @option{-F} option to the @code{declare} builtin (@pxref{Bash Builtins}) +displays the source file name and line number corresponding to each function +name supplied as an argument. + +@item +If the command run by the @code{DEBUG} trap returns a non-zero value, the +next command is skipped and not executed. + +@item +If the command run by the @code{DEBUG} trap returns a value of 2, and the +shell is executing in a subroutine (a shell function or a shell script +executed by the @code{.} or @code{source} builtins), the shell simulates +a call to @code{return}. + +@item +@code{BASH_ARGC} and @code{BASH_ARGV} are updated as described in their +descriptions (@pxref{Bash Variables}). + +@item +Function tracing is enabled: command substitution, shell functions, and +subshells invoked with @code{( @var{command} )} inherit the +@code{DEBUG} and @code{RETURN} traps. + +@item +Error tracing is enabled: command substitution, shell functions, and +subshells invoked with @code{( @var{command} )} inherit the +@code{ERR} trap. +@end enumerate + +@item extglob +If set, the extended pattern matching features described above +(@pxref{Pattern Matching}) are enabled. + +@item extquote +If set, @code{$'@var{string}'} and @code{$"@var{string}"} quoting is +performed within @code{$@{@var{parameter}@}} expansions +enclosed in double quotes. This option is enabled by default. + +@item failglob +If set, patterns which fail to match filenames during filename expansion +result in an expansion error. + +@item force_fignore +If set, the suffixes specified by the @env{FIGNORE} shell variable +cause words to be ignored when performing word completion even if +the ignored words are the only possible completions. +@xref{Bash Variables}, for a description of @env{FIGNORE}. +This option is enabled by default. + +@item globasciiranges +If set, range expressions used in pattern matching bracket expressions +(@pxref{Pattern Matching}) +behave as if in the traditional C locale when performing +comparisons. That is, the current locale's collating sequence +is not taken into account, so +@samp{b} will not collate between @samp{A} and @samp{B}, +and upper-case and lower-case ASCII characters will collate together. + +@item globstar +If set, the pattern @samp{**} used in a filename expansion context will +match all files and zero or more directories and subdirectories. +If the pattern is followed by a @samp{/}, only directories and +subdirectories match. + +@item gnu_errfmt +If set, shell error messages are written in the standard @sc{gnu} error +message format. + +@item histappend +If set, the history list is appended to the file named by the value +of the @env{HISTFILE} +variable when the shell exits, rather than overwriting the file. + +@item histreedit +If set, and Readline +is being used, a user is given the opportunity to re-edit a +failed history substitution. + +@item histverify +If set, and Readline +is being used, the results of history substitution are not immediately +passed to the shell parser. Instead, the resulting line is loaded into +the Readline editing buffer, allowing further modification. + +@item hostcomplete +If set, and Readline is being used, Bash will attempt to perform +hostname completion when a word containing a @samp{@@} is being +completed (@pxref{Commands For Completion}). This option is enabled +by default. + +@item huponexit +If set, Bash will send @code{SIGHUP} to all jobs when an interactive +login shell exits (@pxref{Signals}). + +@item interactive_comments +Allow a word beginning with @samp{#} +to cause that word and all remaining characters on that +line to be ignored in an interactive shell. +This option is enabled by default. + +@item lastpipe +If set, and job control is not active, the shell runs the last command of +a pipeline not executed in the background in the current shell environment. + +@item lithist +If enabled, and the @code{cmdhist} +option is enabled, multi-line commands are saved to the history with +embedded newlines rather than using semicolon separators where possible. + +@item login_shell +The shell sets this option if it is started as a login shell +(@pxref{Invoking Bash}). +The value may not be changed. + +@item mailwarn +If set, and a file that Bash is checking for mail has been +accessed since the last time it was checked, the message +@code{"The mail in @var{mailfile} has been read"} is displayed. + +@item no_empty_cmd_completion +If set, and Readline is being used, Bash will not attempt to search +the @env{PATH} for possible completions when completion is attempted +on an empty line. + +@item nocaseglob +If set, Bash matches filenames in a case-insensitive fashion when +performing filename expansion. + +@item nocasematch +If set, Bash matches patterns in a case-insensitive fashion when +performing matching while executing @code{case} or @code{[[} +conditional commands, +when performing pattern substitution word expansions, +or when filtering possible completions as part of programmable completion. + +@item nullglob +If set, Bash allows filename patterns which match no +files to expand to a null string, rather than themselves. + +@item progcomp +If set, the programmable completion facilities +(@pxref{Programmable Completion}) are enabled. +This option is enabled by default. + +@item promptvars +If set, prompt strings undergo +parameter expansion, command substitution, arithmetic +expansion, and quote removal after being expanded +as described below (@pxref{Controlling the Prompt}). +This option is enabled by default. + +@item restricted_shell +The shell sets this option if it is started in restricted mode +(@pxref{The Restricted Shell}). +The value may not be changed. +This is not reset when the startup files are executed, allowing +the startup files to discover whether or not a shell is restricted. + +@item shift_verbose +If this is set, the @code{shift} +builtin prints an error message when the shift count exceeds the +number of positional parameters. + +@item sourcepath +If set, the @code{source} builtin uses the value of @env{PATH} +to find the directory containing the file supplied as an argument. +This option is enabled by default. + +@item xpg_echo +If set, the @code{echo} builtin expands backslash-escape sequences +by default. + +@end table + +@noindent +The return status when listing options is zero if all @var{optnames} +are enabled, non-zero otherwise. +When setting or unsetting options, the return status is zero unless an +@var{optname} is not a valid shell option. +@end table + +@node Special Builtins +@section Special Builtins +@cindex special builtin + +For historical reasons, the @sc{posix} standard has classified +several builtin commands as @emph{special}. +When Bash is executing in @sc{posix} mode, the special builtins +differ from other builtin commands in three respects: + +@enumerate +@item +Special builtins are found before shell functions during command lookup. + +@item +If a special builtin returns an error status, a non-interactive shell exits. + +@item +Assignment statements preceding the command stay in effect in the shell +environment after the command completes. +@end enumerate + +When Bash is not executing in @sc{posix} mode, these builtins behave no +differently than the rest of the Bash builtin commands. +The Bash @sc{posix} mode is described in @ref{Bash POSIX Mode}. + +These are the @sc{posix} special builtins: +@example +@w{break : . continue eval exec exit export readonly return set} +@w{shift trap unset} +@end example + +@node Shell Variables +@chapter Shell Variables + +@menu +* Bourne Shell Variables:: Variables which Bash uses in the same way + as the Bourne Shell. +* Bash Variables:: List of variables that exist in Bash. +@end menu + +This chapter describes the shell variables that Bash uses. +Bash automatically assigns default values to a number of variables. + +@node Bourne Shell Variables +@section Bourne Shell Variables + +Bash uses certain shell variables in the same way as the Bourne shell. +In some cases, Bash assigns a default value to the variable. + +@vtable @code + +@item CDPATH +A colon-separated list of directories used as a search path for +the @code{cd} builtin command. + +@item HOME +The current user's home directory; the default for the @code{cd} builtin +command. +The value of this variable is also used by tilde expansion +(@pxref{Tilde Expansion}). + +@item IFS +A list of characters that separate fields; used when the shell splits +words as part of expansion. + +@item MAIL +If this parameter is set to a filename or directory name +and the @env{MAILPATH} variable +is not set, Bash informs the user of the arrival of mail in +the specified file or Maildir-format directory. + +@item MAILPATH +A colon-separated list of filenames which the shell periodically checks +for new mail. +Each list entry can specify the message that is printed when new mail +arrives in the mail file by separating the filename from the message with +a @samp{?}. +When used in the text of the message, @code{$_} expands to the name of +the current mail file. + +@item OPTARG +The value of the last option argument processed by the @code{getopts} builtin. + +@item OPTIND +The index of the last option argument processed by the @code{getopts} builtin. + +@item PATH +A colon-separated list of directories in which the shell looks for +commands. +A zero-length (null) directory name in the value of @code{PATH} indicates the +current directory. +A null directory name may appear as two adjacent colons, or as an initial +or trailing colon. + + +@item PS1 +The primary prompt string. The default value is @samp{\s-\v\$ }. +@xref{Controlling the Prompt}, for the complete list of escape +sequences that are expanded before @env{PS1} is displayed. + +@item PS2 +The secondary prompt string. The default value is @samp{> }. + +@end vtable + +@node Bash Variables +@section Bash Variables + +These variables are set or used by Bash, but other shells +do not normally treat them specially. + +A few variables used by Bash are described in different chapters: +variables for controlling the job control facilities +(@pxref{Job Control Variables}). + +@vtable @code + +@item BASH +The full pathname used to execute the current instance of Bash. + +@item BASHOPTS +A colon-separated list of enabled shell options. Each word in +the list is a valid argument for the @option{-s} option to the +@code{shopt} builtin command (@pxref{The Shopt Builtin}). +The options appearing in @env{BASHOPTS} are those reported +as @samp{on} by @samp{shopt}. +If this variable is in the environment when Bash +starts up, each shell option in the list will be enabled before +reading any startup files. This variable is readonly. + +@item BASHPID +Expands to the process ID of the current Bash process. +This differs from @code{$$} under certain circumstances, such as subshells +that do not require Bash to be re-initialized. + +@item BASH_ALIASES +An associative array variable whose members correspond to the internal +list of aliases as maintained by the @code{alias} builtin. +(@pxref{Bourne Shell Builtins}). +Elements added to this array appear in the alias list; unsetting array +elements cause aliases to be removed from the alias list. + +@item BASH_ARGC +An array variable whose values are the number of parameters in each +frame of the current bash execution call stack. The number of +parameters to the current subroutine (shell function or script executed +with @code{.} or @code{source}) is at the top of the stack. When a +subroutine is executed, the number of parameters passed is pushed onto +@code{BASH_ARGC}. +The shell sets @code{BASH_ARGC} only when in extended debugging mode +(see @ref{The Shopt Builtin} +for a description of the @code{extdebug} option to the @code{shopt} +builtin). + +@item BASH_ARGV +An array variable containing all of the parameters in the current bash +execution call stack. The final parameter of the last subroutine call +is at the top of the stack; the first parameter of the initial call is +at the bottom. When a subroutine is executed, the parameters supplied +are pushed onto @code{BASH_ARGV}. +The shell sets @code{BASH_ARGV} only when in extended debugging mode +(see @ref{The Shopt Builtin} +for a description of the @code{extdebug} option to the @code{shopt} +builtin). + +@item BASH_CMDS +An associative array variable whose members correspond to the internal +hash table of commands as maintained by the @code{hash} builtin +(@pxref{Bourne Shell Builtins}). +Elements added to this array appear in the hash table; unsetting array +elements cause commands to be removed from the hash table. + +@item BASH_COMMAND +The command currently being executed or about to be executed, unless the +shell is executing a command as the result of a trap, +in which case it is the command executing at the time of the trap. + +@item BASH_COMPAT +The value is used to set the shell's compatibility level. +@xref{The Shopt Builtin}, for a description of the various compatibility +levels and their effects. +The value may be a decimal number (e.g., 4.2) or an integer (e.g., 42) +corresponding to the desired compatibility level. +If @code{BASH_COMPAT} is unset or set to the empty string, the compatibility +level is set to the default for the current version. +If @code{BASH_COMPAT} is set to a value that is not one of the valid +compatibility levels, the shell prints an error message and sets the +compatibility level to the default for the current version. +The valid compatibility levels correspond to the compatibility options +accepted by the @code{shopt} builtin described above (for example, +@var{compat42} means that 4.2 and 42 are valid values). +The current version is also a valid value. + +@item BASH_ENV +If this variable is set when Bash is invoked to execute a shell +script, its value is expanded and used as the name of a startup file +to read before executing the script. @xref{Bash Startup Files}. + +@item BASH_EXECUTION_STRING +The command argument to the @option{-c} invocation option. + +@item BASH_LINENO +An array variable whose members are the line numbers in source files +where each corresponding member of @var{FUNCNAME} was invoked. +@code{$@{BASH_LINENO[$i]@}} is the line number in the source file +(@code{$@{BASH_SOURCE[$i+1]@}}) where +@code{$@{FUNCNAME[$i]@}} was called (or @code{$@{BASH_LINENO[$i-1]@}} if +referenced within another shell function). +Use @code{LINENO} to obtain the current line number. + +@item BASH_REMATCH +An array variable whose members are assigned by the @samp{=~} binary +operator to the @code{[[} conditional command +(@pxref{Conditional Constructs}). +The element with index 0 is the portion of the string +matching the entire regular expression. +The element with index @var{n} is the portion of the +string matching the @var{n}th parenthesized subexpression. +This variable is read-only. + +@item BASH_SOURCE +An array variable whose members are the source filenames where the +corresponding shell function names in the @code{FUNCNAME} array +variable are defined. +The shell function @code{$@{FUNCNAME[$i]@}} is defined in the file +@code{$@{BASH_SOURCE[$i]@}} and called from @code{$@{BASH_SOURCE[$i+1]@}} + +@item BASH_SUBSHELL +Incremented by one within each subshell or subshell environment when +the shell begins executing in that environment. +The initial value is 0. + +@item BASH_VERSINFO +A readonly array variable (@pxref{Arrays}) +whose members hold version information for this instance of Bash. +The values assigned to the array members are as follows: + +@table @code + +@item BASH_VERSINFO[0] +The major version number (the @var{release}). + +@item BASH_VERSINFO[1] +The minor version number (the @var{version}). + +@item BASH_VERSINFO[2] +The patch level. + +@item BASH_VERSINFO[3] +The build version. + +@item BASH_VERSINFO[4] +The release status (e.g., @var{beta1}). + +@item BASH_VERSINFO[5] +The value of @env{MACHTYPE}. +@end table + +@item BASH_VERSION +The version number of the current instance of Bash. + +@item BASH_XTRACEFD +If set to an integer corresponding to a valid file descriptor, Bash +will write the trace output generated when @samp{set -x} +is enabled to that file descriptor. +This allows tracing output to be separated from diagnostic and error +messages. +The file descriptor is closed when @code{BASH_XTRACEFD} is unset or assigned +a new value. +Unsetting @code{BASH_XTRACEFD} or assigning it the empty string causes the +trace output to be sent to the standard error. +Note that setting @code{BASH_XTRACEFD} to 2 (the standard error file +descriptor) and then unsetting it will result in the standard error +being closed. + +@item CHILD_MAX +Set the number of exited child status values for the shell to remember. +Bash will not allow this value to be decreased below a @sc{posix}-mandated +minimum, and there is a maximum value (currently 8192) that this may +not exceed. +The minimum value is system-dependent. + +@item COLUMNS +Used by the @code{select} command to determine the terminal width +when printing selection lists. +Automatically set if the @code{checkwinsize} option is enabled +(@pxref{The Shopt Builtin}), or in an interactive shell upon receipt of a +@code{SIGWINCH}. + +@item COMP_CWORD +An index into @env{$@{COMP_WORDS@}} of the word containing the current +cursor position. +This variable is available only in shell functions invoked by the +programmable completion facilities (@pxref{Programmable Completion}). + +@item COMP_LINE +The current command line. +This variable is available only in shell functions and external +commands invoked by the +programmable completion facilities (@pxref{Programmable Completion}). + +@item COMP_POINT +The index of the current cursor position relative to the beginning of +the current command. +If the current cursor position is at the end of the current command, +the value of this variable is equal to @code{$@{#COMP_LINE@}}. +This variable is available only in shell functions and external +commands invoked by the +programmable completion facilities (@pxref{Programmable Completion}). + +@item COMP_TYPE +Set to an integer value corresponding to the type of completion attempted +that caused a completion function to be called: +@var{TAB}, for normal completion, +@samp{?}, for listing completions after successive tabs, +@samp{!}, for listing alternatives on partial word completion, +@samp{@@}, to list completions if the word is not unmodified, +or +@samp{%}, for menu completion. +This variable is available only in shell functions and external +commands invoked by the +programmable completion facilities (@pxref{Programmable Completion}). + +@item COMP_KEY +The key (or final key of a key sequence) used to invoke the current +completion function. + +@item COMP_WORDBREAKS +The set of characters that the Readline library treats as word +separators when performing word completion. +If @code{COMP_WORDBREAKS} is unset, it loses its special properties, +even if it is subsequently reset. + +@item COMP_WORDS +An array variable consisting of the individual +words in the current command line. +The line is split into words as Readline would split it, using +@code{COMP_WORDBREAKS} as described above. +This variable is available only in shell functions invoked by the +programmable completion facilities (@pxref{Programmable Completion}). + +@item COMPREPLY +An array variable from which Bash reads the possible completions +generated by a shell function invoked by the programmable completion +facility (@pxref{Programmable Completion}). +Each array element contains one possible completion. + +@item COPROC +An array variable created to hold the file descriptors +for output from and input to an unnamed coprocess (@pxref{Coprocesses}). + +@item DIRSTACK +An array variable containing the current contents of the directory stack. +Directories appear in the stack in the order they are displayed by the +@code{dirs} builtin. +Assigning to members of this array variable may be used to modify +directories already in the stack, but the @code{pushd} and @code{popd} +builtins must be used to add and remove directories. +Assignment to this variable will not change the current directory. +If @env{DIRSTACK} is unset, it loses its special properties, even if +it is subsequently reset. + +@item EMACS +If Bash finds this variable in the environment when the shell +starts with value @samp{t}, it assumes that the shell is running in an +Emacs shell buffer and disables line editing. + +@item ENV +Similar to @code{BASH_ENV}; used when the shell is invoked in +@sc{posix} Mode (@pxref{Bash POSIX Mode}). + +@item EUID +The numeric effective user id of the current user. This variable +is readonly. + +@item FCEDIT +The editor used as a default by the @option{-e} option to the @code{fc} +builtin command. + +@item FIGNORE +A colon-separated list of suffixes to ignore when performing +filename completion. +A filename whose suffix matches one of the entries in +@env{FIGNORE} +is excluded from the list of matched filenames. A sample +value is @samp{.o:~} + +@item FUNCNAME +An array variable containing the names of all shell functions +currently in the execution call stack. +The element with index 0 is the name of any currently-executing +shell function. +The bottom-most element (the one with the highest index) +is @code{"main"}. +This variable exists only when a shell function is executing. +Assignments to @env{FUNCNAME} have no effect and return an error status. +If @env{FUNCNAME} is unset, it loses its special properties, even if +it is subsequently reset. + +This variable can be used with @code{BASH_LINENO} and @code{BASH_SOURCE}. +Each element of @code{FUNCNAME} has corresponding elements in +@code{BASH_LINENO} and @code{BASH_SOURCE} to describe the call stack. +For instance, @code{$@{FUNCNAME[$i]@}} was called from the file +@code{$@{BASH_SOURCE[$i+1]@}} at line number @code{$@{BASH_LINENO[$i]@}}. +The @code{caller} builtin displays the current call stack using this +information. + +@item FUNCNEST +If set to a numeric value greater than 0, defines a maximum function +nesting level. Function invocations that exceed this nesting level +will cause the current command to abort. + +@item GLOBIGNORE +A colon-separated list of patterns defining the set of filenames to +be ignored by filename expansion. +If a filename matched by a filename expansion pattern also matches one +of the patterns in @env{GLOBIGNORE}, it is removed from the list +of matches. + +@item GROUPS +An array variable containing the list of groups of which the current +user is a member. +Assignments to @env{GROUPS} have no effect and return an error status. +If @env{GROUPS} is unset, it loses its special properties, even if it is +subsequently reset. + +@item histchars +Up to three characters which control history expansion, quick +substitution, and tokenization (@pxref{History Interaction}). +The first character is the +@var{history expansion} character, that is, the character which signifies the +start of a history expansion, normally @samp{!}. The second character is the +character which signifies `quick substitution' when seen as the first +character on a line, normally @samp{^}. The optional third character is the +character which indicates that the remainder of the line is a comment when +found as the first character of a word, usually @samp{#}. The history +comment character causes history substitution to be skipped for the +remaining words on the line. It does not necessarily cause the shell +parser to treat the rest of the line as a comment. + +@item HISTCMD +The history number, or index in the history list, of the current +command. If @env{HISTCMD} is unset, it loses its special properties, +even if it is subsequently reset. + +@item HISTCONTROL +A colon-separated list of values controlling how commands are saved on +the history list. +If the list of values includes @samp{ignorespace}, lines which begin +with a space character are not saved in the history list. +A value of @samp{ignoredups} causes lines which match the previous +history entry to not be saved. +A value of @samp{ignoreboth} is shorthand for +@samp{ignorespace} and @samp{ignoredups}. +A value of @samp{erasedups} causes all previous lines matching the +current line to be removed from the history list before that line +is saved. +Any value not in the above list is ignored. +If @env{HISTCONTROL} is unset, or does not include a valid value, +all lines read by the shell parser are saved on the history list, +subject to the value of @env{HISTIGNORE}. +The second and subsequent lines of a multi-line compound command are +not tested, and are added to the history regardless of the value of +@env{HISTCONTROL}. + +@item HISTFILE +The name of the file to which the command history is saved. The +default value is @file{~/.bash_history}. + +@item HISTFILESIZE +The maximum number of lines contained in the history file. +When this variable is assigned a value, the history file is truncated, +if necessary, to contain no more than that number of lines +by removing the oldest entries. +The history file is also truncated to this size after +writing it when a shell exits. +If the value is 0, the history file is truncated to zero size. +Non-numeric values and numeric values less than zero inhibit truncation. +The shell sets the default value to the value of @env{HISTSIZE} +after reading any startup files. + +@item HISTIGNORE +A colon-separated list of patterns used to decide which command +lines should be saved on the history list. Each pattern is +anchored at the beginning of the line and must match the complete +line (no implicit @samp{*} is appended). Each pattern is tested +against the line after the checks specified by @env{HISTCONTROL} +are applied. In addition to the normal shell pattern matching +characters, @samp{&} matches the previous history line. @samp{&} +may be escaped using a backslash; the backslash is removed +before attempting a match. +The second and subsequent lines of a multi-line compound command are +not tested, and are added to the history regardless of the value of +@env{HISTIGNORE}. + +@env{HISTIGNORE} subsumes the function of @env{HISTCONTROL}. A +pattern of @samp{&} is identical to @code{ignoredups}, and a +pattern of @samp{[ ]*} is identical to @code{ignorespace}. +Combining these two patterns, separating them with a colon, +provides the functionality of @code{ignoreboth}. + +@item HISTSIZE +The maximum number of commands to remember on the history list. +If the value is 0, commands are not saved in the history list. +Numeric values less than zero result in every command being saved +on the history list (there is no limit). +The shell sets the default value to 500 after reading any startup files. + +@item HISTTIMEFORMAT +If this variable is set and not null, its value is used as a format string +for @var{strftime} to print the time stamp associated with each history +entry displayed by the @code{history} builtin. +If this variable is set, time stamps are written to the history file so +they may be preserved across shell sessions. +This uses the history comment character to distinguish timestamps from +other history lines. + +@item HOSTFILE +Contains the name of a file in the same format as @file{/etc/hosts} that +should be read when the shell needs to complete a hostname. +The list of possible hostname completions may be changed while the shell +is running; +the next time hostname completion is attempted after the +value is changed, Bash adds the contents of the new file to the +existing list. +If @env{HOSTFILE} is set, but has no value, or does not name a readable file, +Bash attempts to read +@file{/etc/hosts} to obtain the list of possible hostname completions. +When @env{HOSTFILE} is unset, the hostname list is cleared. + +@item HOSTNAME +The name of the current host. + +@item HOSTTYPE +A string describing the machine Bash is running on. + +@item IGNOREEOF +Controls the action of the shell on receipt of an @code{EOF} character +as the sole input. If set, the value denotes the number +of consecutive @code{EOF} characters that can be read as the +first character on an input line +before the shell will exit. If the variable exists but does not +have a numeric value (or has no value) then the default is 10. +If the variable does not exist, then @code{EOF} signifies the end of +input to the shell. This is only in effect for interactive shells. + +@item INPUTRC +The name of the Readline initialization file, overriding the default +of @file{~/.inputrc}. + +@item LANG +Used to determine the locale category for any category not specifically +selected with a variable starting with @code{LC_}. + +@item LC_ALL +This variable overrides the value of @env{LANG} and any other +@code{LC_} variable specifying a locale category. + +@item LC_COLLATE +This variable determines the collation order used when sorting the +results of filename expansion, and +determines the behavior of range expressions, equivalence classes, +and collating sequences within filename expansion and pattern matching +(@pxref{Filename Expansion}). + +@item LC_CTYPE +This variable determines the interpretation of characters and the +behavior of character classes within filename expansion and pattern +matching (@pxref{Filename Expansion}). + +@item LC_MESSAGES +This variable determines the locale used to translate double-quoted +strings preceded by a @samp{$} (@pxref{Locale Translation}). + +@item LC_NUMERIC +This variable determines the locale category used for number formatting. + +@item LINENO +The line number in the script or shell function currently executing. + +@item LINES +Used by the @code{select} command to determine the column length +for printing selection lists. +Automatically set if the @code{checkwinsize} option is enabled +(@pxref{The Shopt Builtin}), or in an interactive shell upon receipt of a +@code{SIGWINCH}. + +@item MACHTYPE +A string that fully describes the system type on which Bash +is executing, in the standard @sc{gnu} @var{cpu-company-system} format. + +@item MAILCHECK +How often (in seconds) that the shell should check for mail in the +files specified in the @env{MAILPATH} or @env{MAIL} variables. +The default is 60 seconds. When it is time to check +for mail, the shell does so before displaying the primary prompt. +If this variable is unset, or set to a value that is not a number +greater than or equal to zero, the shell disables mail checking. + +@item MAPFILE +An array variable created to hold the text read by the +@code{mapfile} builtin when no variable name is supplied. + +@item OLDPWD +The previous working directory as set by the @code{cd} builtin. + +@item OPTERR +If set to the value 1, Bash displays error messages +generated by the @code{getopts} builtin command. + +@item OSTYPE +A string describing the operating system Bash is running on. + +@item PIPESTATUS +An array variable (@pxref{Arrays}) +containing a list of exit status values from the processes +in the most-recently-executed foreground pipeline (which may +contain only a single command). + +@item POSIXLY_CORRECT +If this variable is in the environment when Bash starts, the shell +enters @sc{posix} mode (@pxref{Bash POSIX Mode}) before reading the +startup files, as if the @option{--posix} invocation option had been supplied. +If it is set while the shell is running, Bash enables @sc{posix} mode, +as if the command +@example +@code{set -o posix} +@end example +@noindent +had been executed. + +@item PPID +The process @sc{id} of the shell's parent process. This variable +is readonly. + +@item PROMPT_COMMAND +If set, the value is interpreted as a command to execute +before the printing of each primary prompt (@env{$PS1}). + +@item PROMPT_DIRTRIM +If set to a number greater than zero, the value is used as the number of +trailing directory components to retain when expanding the @code{\w} and +@code{\W} prompt string escapes (@pxref{Controlling the Prompt}). +Characters removed are replaced with an ellipsis. + +@item PS3 +The value of this variable is used as the prompt for the +@code{select} command. If this variable is not set, the +@code{select} command prompts with @samp{#? } + +@item PS4 +The value is the prompt printed before the command line is echoed +when the @option{-x} option is set (@pxref{The Set Builtin}). +The first character of @env{PS4} is replicated multiple times, as +necessary, to indicate multiple levels of indirection. +The default is @samp{+ }. + +@item PWD +The current working directory as set by the @code{cd} builtin. + +@item RANDOM +Each time this parameter is referenced, a random integer +between 0 and 32767 is generated. Assigning a value to this +variable seeds the random number generator. + +@item READLINE_LINE +The contents of the Readline line buffer, for use +with @samp{bind -x} (@pxref{Bash Builtins}). + +@item READLINE_POINT +The position of the insertion point in the Readline line buffer, for use +with @samp{bind -x} (@pxref{Bash Builtins}). + +@item REPLY +The default variable for the @code{read} builtin. + +@item SECONDS +This variable expands to the number of seconds since the +shell was started. Assignment to this variable resets +the count to the value assigned, and the expanded value +becomes the value assigned plus the number of seconds +since the assignment. + +@item SHELL +The full pathname to the shell is kept in this environment variable. +If it is not set when the shell starts, +Bash assigns to it the full pathname of the current user's login shell. + +@item SHELLOPTS +A colon-separated list of enabled shell options. Each word in +the list is a valid argument for the @option{-o} option to the +@code{set} builtin command (@pxref{The Set Builtin}). +The options appearing in @env{SHELLOPTS} are those reported +as @samp{on} by @samp{set -o}. +If this variable is in the environment when Bash +starts up, each shell option in the list will be enabled before +reading any startup files. This variable is readonly. + +@item SHLVL +Incremented by one each time a new instance of Bash is started. This is +intended to be a count of how deeply your Bash shells are nested. + +@item TIMEFORMAT +The value of this parameter is used as a format string specifying +how the timing information for pipelines prefixed with the @code{time} +reserved word should be displayed. +The @samp{%} character introduces an +escape sequence that is expanded to a time value or other +information. +The escape sequences and their meanings are as +follows; the braces denote optional portions. + +@table @code + +@item %% +A literal @samp{%}. + +@item %[@var{p}][l]R +The elapsed time in seconds. + +@item %[@var{p}][l]U +The number of CPU seconds spent in user mode. + +@item %[@var{p}][l]S +The number of CPU seconds spent in system mode. + +@item %P +The CPU percentage, computed as (%U + %S) / %R. +@end table + +The optional @var{p} is a digit specifying the precision, the number of +fractional digits after a decimal point. +A value of 0 causes no decimal point or fraction to be output. +At most three places after the decimal point may be specified; values +of @var{p} greater than 3 are changed to 3. +If @var{p} is not specified, the value 3 is used. + +The optional @code{l} specifies a longer format, including minutes, of +the form @var{MM}m@var{SS}.@var{FF}s. +The value of @var{p} determines whether or not the fraction is included. + +If this variable is not set, Bash acts as if it had the value +@example +@code{$'\nreal\t%3lR\nuser\t%3lU\nsys\t%3lS'} +@end example +If the value is null, no timing information is displayed. +A trailing newline is added when the format string is displayed. + +@item TMOUT +If set to a value greater than zero, @code{TMOUT} is treated as the +default timeout for the @code{read} builtin (@pxref{Bash Builtins}). +The @code{select} command (@pxref{Conditional Constructs}) terminates +if input does not arrive after @code{TMOUT} seconds when input is coming +from a terminal. + +In an interactive shell, the value is interpreted as +the number of seconds to wait for a line of input after issuing +the primary prompt. +Bash +terminates after waiting for that number of seconds if a complete +line of input does not arrive. + +@item TMPDIR +If set, Bash uses its value as the name of a directory in which +Bash creates temporary files for the shell's use. + +@item UID +The numeric real user id of the current user. This variable is readonly. + +@end vtable + +@node Bash Features +@chapter Bash Features + +This chapter describes features unique to Bash. + +@menu +* Invoking Bash:: Command line options that you can give + to Bash. +* Bash Startup Files:: When and how Bash executes scripts. +* Interactive Shells:: What an interactive shell is. +* Bash Conditional Expressions:: Primitives used in composing expressions for + the @code{test} builtin. +* Shell Arithmetic:: Arithmetic on shell variables. +* Aliases:: Substituting one command for another. +* Arrays:: Array Variables. +* The Directory Stack:: History of visited directories. +* Controlling the Prompt:: Customizing the various prompt strings. +* The Restricted Shell:: A more controlled mode of shell execution. +* Bash POSIX Mode:: Making Bash behave more closely to what + the POSIX standard specifies. +@end menu + +@node Invoking Bash +@section Invoking Bash + +@example +bash [long-opt] [-ir] [-abefhkmnptuvxdBCDHP] [-o @var{option}] [-O @var{shopt_option}] [@var{argument} @dots{}] +bash [long-opt] [-abefhkmnptuvxdBCDHP] [-o @var{option}] [-O @var{shopt_option}] -c @var{string} [@var{argument} @dots{}] +bash [long-opt] -s [-abefhkmnptuvxdBCDHP] [-o @var{option}] [-O @var{shopt_option}] [@var{argument} @dots{}] +@end example + +All of the single-character options used with the @code{set} builtin +(@pxref{The Set Builtin}) can be used as options when the shell is invoked. +In addition, there are several multi-character +options that you can use. These options must appear on the command +line before the single-character options to be recognized. + +@table @code +@item --debugger +Arrange for the debugger profile to be executed before the shell +starts. Turns on extended debugging mode (see @ref{The Shopt Builtin} +for a description of the @code{extdebug} option to the @code{shopt} +builtin). + +@item --dump-po-strings +A list of all double-quoted strings preceded by @samp{$} +is printed on the standard output +in the @sc{gnu} @code{gettext} PO (portable object) file format. +Equivalent to @option{-D} except for the output format. + +@item --dump-strings +Equivalent to @option{-D}. + +@item --help +Display a usage message on standard output and exit successfully. + +@item --init-file @var{filename} +@itemx --rcfile @var{filename} +Execute commands from @var{filename} (instead of @file{~/.bashrc}) +in an interactive shell. + +@item --login +Equivalent to @option{-l}. + +@item --noediting +Do not use the @sc{gnu} Readline library (@pxref{Command Line Editing}) +to read command lines when the shell is interactive. + +@item --noprofile +Don't load the system-wide startup file @file{/etc/profile} +or any of the personal initialization files +@file{~/.bash_profile}, @file{~/.bash_login}, or @file{~/.profile} +when Bash is invoked as a login shell. + +@item --norc +Don't read the @file{~/.bashrc} initialization file in an +interactive shell. This is on by default if the shell is +invoked as @code{sh}. + +@item --posix +Change the behavior of Bash where the default operation differs +from the @sc{posix} standard to match the standard. This +is intended to make Bash behave as a strict superset of that +standard. @xref{Bash POSIX Mode}, for a description of the Bash +@sc{posix} mode. + +@item --restricted +Make the shell a restricted shell (@pxref{The Restricted Shell}). + +@item --verbose +Equivalent to @option{-v}. Print shell input lines as they're read. + +@item --version +Show version information for this instance of +Bash on the standard output and exit successfully. +@end table + +There are several single-character options that may be supplied at +invocation which are not available with the @code{set} builtin. + +@table @code +@item -c +Read and execute commands from the first non-option argument +@var{command_string}, then exit. +If there are arguments after the @var{command_string}, +the first argument is assigned to @code{$0} +and any remaining arguments are assigned to the positional parameters. +The assignment to @code{$0} sets the name of the shell, which is used +in warning and error messages. + +@item -i +Force the shell to run interactively. Interactive shells are +described in @ref{Interactive Shells}. + +@item -l +Make this shell act as if it had been directly invoked by login. +When the shell is interactive, this is equivalent to starting a +login shell with @samp{exec -l bash}. +When the shell is not interactive, the login shell startup files will +be executed. +@samp{exec bash -l} or @samp{exec bash --login} +will replace the current shell with a Bash login shell. +@xref{Bash Startup Files}, for a description of the special behavior +of a login shell. + +@item -r +Make the shell a restricted shell (@pxref{The Restricted Shell}). + +@item -s +If this option is present, or if no arguments remain after option +processing, then commands are read from the standard input. +This option allows the positional parameters to be set +when invoking an interactive shell. + +@item -D +A list of all double-quoted strings preceded by @samp{$} +is printed on the standard output. +These are the strings that +are subject to language translation when the current locale +is not @code{C} or @code{POSIX} (@pxref{Locale Translation}). +This implies the @option{-n} option; no commands will be executed. + +@item [-+]O [@var{shopt_option}] +@var{shopt_option} is one of the shell options accepted by the +@code{shopt} builtin (@pxref{The Shopt Builtin}). +If @var{shopt_option} is present, @option{-O} sets the value of that option; +@option{+O} unsets it. +If @var{shopt_option} is not supplied, the names and values of the shell +options accepted by @code{shopt} are printed on the standard output. +If the invocation option is @option{+O}, the output is displayed in a format +that may be reused as input. + +@item -- +A @code{--} signals the end of options and disables further option +processing. +Any arguments after the @code{--} are treated as filenames and arguments. +@end table + +@cindex login shell +A @emph{login} shell is one whose first character of argument zero is +@samp{-}, or one invoked with the @option{--login} option. + +@cindex interactive shell +An @emph{interactive} shell is one started without non-option arguments, +unless @option{-s} is specified, +without specifying the @option{-c} option, and whose input and output are both +connected to terminals (as determined by @code{isatty(3)}), or one +started with the @option{-i} option. @xref{Interactive Shells}, for more +information. + +If arguments remain after option processing, and neither the +@option{-c} nor the @option{-s} +option has been supplied, the first argument is assumed to +be the name of a file containing shell commands (@pxref{Shell Scripts}). +When Bash is invoked in this fashion, @code{$0} +is set to the name of the file, and the positional parameters +are set to the remaining arguments. +Bash reads and executes commands from this file, then exits. +Bash's exit status is the exit status of the last command executed +in the script. If no commands are executed, the exit status is 0. + +@node Bash Startup Files +@section Bash Startup Files +@cindex startup files + +This section describes how Bash executes its startup files. +If any of the files exist but cannot be read, Bash reports an error. +Tildes are expanded in filenames as described above under +Tilde Expansion (@pxref{Tilde Expansion}). + +Interactive shells are described in @ref{Interactive Shells}. + +@subsubheading Invoked as an interactive login shell, or with @option{--login} + +When Bash is invoked as an interactive login shell, or as a +non-interactive shell with the @option{--login} option, it first reads and +executes commands from the file @file{/etc/profile}, if that file exists. +After reading that file, it looks for @file{~/.bash_profile}, +@file{~/.bash_login}, and @file{~/.profile}, in that order, and reads +and executes commands from the first one that exists and is readable. +The @option{--noprofile} option may be used when the shell is started to +inhibit this behavior. + +When a login shell exits, Bash reads and executes commands from +the file @file{~/.bash_logout}, if it exists. + +@subsubheading Invoked as an interactive non-login shell + +When an interactive shell that is not a login shell is started, Bash +reads and executes commands from @file{~/.bashrc}, if that file exists. +This may be inhibited by using the @option{--norc} option. +The @option{--rcfile @var{file}} option will force Bash to read and +execute commands from @var{file} instead of @file{~/.bashrc}. + +So, typically, your @file{~/.bash_profile} contains the line +@example +@code{if [ -f ~/.bashrc ]; then . ~/.bashrc; fi} +@end example +@noindent +after (or before) any login-specific initializations. + +@subsubheading Invoked non-interactively + +When Bash is started non-interactively, to run a shell script, +for example, it looks for the variable @env{BASH_ENV} in the environment, +expands its value if it appears there, and uses the expanded value as +the name of a file to read and execute. Bash behaves as if the +following command were executed: +@example +@code{if [ -n "$BASH_ENV" ]; then . "$BASH_ENV"; fi} +@end example +@noindent +but the value of the @env{PATH} variable is not used to search for the +filename. + +As noted above, if a non-interactive shell is invoked with the +@option{--login} option, Bash attempts to read and execute commands from the +login shell startup files. + +@subsubheading Invoked with name @code{sh} + +If Bash is invoked with the name @code{sh}, it tries to mimic the +startup behavior of historical versions of @code{sh} as closely as +possible, while conforming to the @sc{posix} standard as well. + +When invoked as an interactive login shell, or as a non-interactive +shell with the @option{--login} option, it first attempts to read +and execute commands from @file{/etc/profile} and @file{~/.profile}, in +that order. +The @option{--noprofile} option may be used to inhibit this behavior. +When invoked as an interactive shell with the name @code{sh}, Bash +looks for the variable @env{ENV}, expands its value if it is defined, +and uses the expanded value as the name of a file to read and execute. +Since a shell invoked as @code{sh} does not attempt to read and execute +commands from any other startup files, the @option{--rcfile} option has +no effect. +A non-interactive shell invoked with the name @code{sh} does not attempt +to read any other startup files. + +When invoked as @code{sh}, Bash enters @sc{posix} mode after +the startup files are read. + +@subsubheading Invoked in @sc{posix} mode + +When Bash is started in @sc{posix} mode, as with the +@option{--posix} command line option, it follows the @sc{posix} standard +for startup files. +In this mode, interactive shells expand the @env{ENV} variable +and commands are read and executed from the file whose name is the +expanded value. +No other startup files are read. + +@subsubheading Invoked by remote shell daemon + +Bash attempts to determine when it is being run with its standard input +connected to a network connection, as when executed by the remote shell +daemon, usually @code{rshd}, or the secure shell daemon @code{sshd}. +If Bash determines it is being run in +this fashion, it reads and executes commands from @file{~/.bashrc}, if that +file exists and is readable. +It will not do this if invoked as @code{sh}. +The @option{--norc} option may be used to inhibit this behavior, and the +@option{--rcfile} option may be used to force another file to be read, but +neither @code{rshd} nor @code{sshd} generally invoke the shell with those +options or allow them to be specified. + +@subsubheading Invoked with unequal effective and real @sc{uid/gid}s + +If Bash is started with the effective user (group) id not equal to the +real user (group) id, and the @option{-p} option is not supplied, no startup +files are read, shell functions are not inherited from the environment, +the @env{SHELLOPTS}, @env{BASHOPTS}, @env{CDPATH}, and @env{GLOBIGNORE} +variables, if they appear in the environment, are ignored, and the effective +user id is set to the real user id. +If the @option{-p} option is supplied at invocation, the startup behavior is +the same, but the effective user id is not reset. + +@node Interactive Shells +@section Interactive Shells +@cindex interactive shell +@cindex shell, interactive + +@menu +* What is an Interactive Shell?:: What determines whether a shell is Interactive. +* Is this Shell Interactive?:: How to tell if a shell is interactive. +* Interactive Shell Behavior:: What changes in a interactive shell? +@end menu + +@node What is an Interactive Shell? +@subsection What is an Interactive Shell? + +An interactive shell +is one started without non-option arguments, unless @option{-s} is +specified, without specifying the @option{-c} option, and +whose input and error output are both +connected to terminals (as determined by @code{isatty(3)}), +or one started with the @option{-i} option. + +An interactive shell generally reads from and writes to a user's +terminal. + +The @option{-s} invocation option may be used to set the positional parameters +when an interactive shell is started. + +@node Is this Shell Interactive? +@subsection Is this Shell Interactive? + +To determine within a startup script whether or not Bash is +running interactively, +test the value of the @samp{-} special parameter. +It contains @code{i} when the shell is interactive. For example: + +@example +case "$-" in +*i*) echo This shell is interactive ;; +*) echo This shell is not interactive ;; +esac +@end example + +Alternatively, startup scripts may examine the variable +@env{PS1}; it is unset in non-interactive shells, and set in +interactive shells. Thus: + +@example +if [ -z "$PS1" ]; then + echo This shell is not interactive +else + echo This shell is interactive +fi +@end example + +@node Interactive Shell Behavior +@subsection Interactive Shell Behavior + +When the shell is running interactively, it changes its behavior in +several ways. + +@enumerate +@item +Startup files are read and executed as described in @ref{Bash Startup Files}. + +@item +Job Control (@pxref{Job Control}) is enabled by default. When job +control is in effect, Bash ignores the keyboard-generated job control +signals @code{SIGTTIN}, @code{SIGTTOU}, and @code{SIGTSTP}. + +@item +Bash expands and displays @env{PS1} before reading the first line +of a command, and expands and displays @env{PS2} before reading the +second and subsequent lines of a multi-line command. + +@item +Bash executes the value of the @env{PROMPT_COMMAND} variable as a command +before printing the primary prompt, @env{$PS1} +(@pxref{Bash Variables}). + +@item +Readline (@pxref{Command Line Editing}) is used to read commands from +the user's terminal. + +@item +Bash inspects the value of the @code{ignoreeof} option to @code{set -o} +instead of exiting immediately when it receives an @code{EOF} on its +standard input when reading a command (@pxref{The Set Builtin}). + +@item +Command history (@pxref{Bash History Facilities}) +and history expansion (@pxref{History Interaction}) +are enabled by default. +Bash will save the command history to the file named by @env{$HISTFILE} +when a shell with history enabled exits. + +@item +Alias expansion (@pxref{Aliases}) is performed by default. + +@item +In the absence of any traps, Bash ignores @code{SIGTERM} +(@pxref{Signals}). + +@item +In the absence of any traps, @code{SIGINT} is caught and handled +((@pxref{Signals}). +@code{SIGINT} will interrupt some shell builtins. + +@item +An interactive login shell sends a @code{SIGHUP} to all jobs on exit +if the @code{huponexit} shell option has been enabled (@pxref{Signals}). + +@item +The @option{-n} invocation option is ignored, and @samp{set -n} has +no effect (@pxref{The Set Builtin}). + +@item +Bash will check for mail periodically, depending on the values of the +@env{MAIL}, @env{MAILPATH}, and @env{MAILCHECK} shell variables +(@pxref{Bash Variables}). + +@item +Expansion errors due to references to unbound shell variables after +@samp{set -u} has been enabled will not cause the shell to exit +(@pxref{The Set Builtin}). + +@item +The shell will not exit on expansion errors caused by @var{var} being unset +or null in @code{$@{@var{var}:?@var{word}@}} expansions +(@pxref{Shell Parameter Expansion}). + +@item +Redirection errors encountered by shell builtins will not cause the +shell to exit. + +@item +When running in @sc{posix} mode, a special builtin returning an error +status will not cause the shell to exit (@pxref{Bash POSIX Mode}). + +@item +A failed @code{exec} will not cause the shell to exit +(@pxref{Bourne Shell Builtins}). + +@item +Parser syntax errors will not cause the shell to exit. + +@item +Simple spelling correction for directory arguments to the @code{cd} +builtin is enabled by default (see the description of the @code{cdspell} +option to the @code{shopt} builtin in @ref{The Shopt Builtin}). + +@item +The shell will check the value of the @env{TMOUT} variable and exit +if a command is not read within the specified number of seconds after +printing @env{$PS1} (@pxref{Bash Variables}). + +@end enumerate + +@node Bash Conditional Expressions +@section Bash Conditional Expressions +@cindex expressions, conditional + +Conditional expressions are used by the @code{[[} compound command +and the @code{test} and @code{[} builtin commands. + +Expressions may be unary or binary. +Unary expressions are often used to examine the status of a file. +There are string operators and numeric comparison operators as well. +If the @var{file} argument to one of the primaries is of the form +@file{/dev/fd/@var{N}}, then file descriptor @var{N} is checked. +If the @var{file} argument to one of the primaries is one of +@file{/dev/stdin}, @file{/dev/stdout}, or @file{/dev/stderr}, file +descriptor 0, 1, or 2, respectively, is checked. + +When used with @code{[[}, the @samp{<} and @samp{>} operators sort +lexicographically using the current locale. +The @code{test} command uses ASCII ordering. + +Unless otherwise specified, primaries that operate on files follow symbolic +links and operate on the target of the link, rather than the link itself. + +@table @code +@item -a @var{file} +True if @var{file} exists. + +@item -b @var{file} +True if @var{file} exists and is a block special file. + +@item -c @var{file} +True if @var{file} exists and is a character special file. + +@item -d @var{file} +True if @var{file} exists and is a directory. + +@item -e @var{file} +True if @var{file} exists. + +@item -f @var{file} +True if @var{file} exists and is a regular file. + +@item -g @var{file} +True if @var{file} exists and its set-group-id bit is set. + +@item -h @var{file} +True if @var{file} exists and is a symbolic link. + +@item -k @var{file} +True if @var{file} exists and its "sticky" bit is set. + +@item -p @var{file} +True if @var{file} exists and is a named pipe (FIFO). + +@item -r @var{file} +True if @var{file} exists and is readable. + +@item -s @var{file} +True if @var{file} exists and has a size greater than zero. + +@item -t @var{fd} +True if file descriptor @var{fd} is open and refers to a terminal. + +@item -u @var{file} +True if @var{file} exists and its set-user-id bit is set. + +@item -w @var{file} +True if @var{file} exists and is writable. + +@item -x @var{file} +True if @var{file} exists and is executable. + +@item -G @var{file} +True if @var{file} exists and is owned by the effective group id. + +@item -L @var{file} +True if @var{file} exists and is a symbolic link. + +@item -N @var{file} +True if @var{file} exists and has been modified since it was last read. + +@item -O @var{file} +True if @var{file} exists and is owned by the effective user id. + +@item -S @var{file} +True if @var{file} exists and is a socket. + +@item @var{file1} -ef @var{file2} +True if @var{file1} and @var{file2} refer to the same device and +inode numbers. + +@item @var{file1} -nt @var{file2} +True if @var{file1} is newer (according to modification date) +than @var{file2}, or if @var{file1} exists and @var{file2} does not. + +@item @var{file1} -ot @var{file2} +True if @var{file1} is older than @var{file2}, +or if @var{file2} exists and @var{file1} does not. + +@item -o @var{optname} +True if the shell option @var{optname} is enabled. +The list of options appears in the description of the @option{-o} +option to the @code{set} builtin (@pxref{The Set Builtin}). + +@item -v @var{varname} +True if the shell variable @var{varname} is set (has been assigned a value). + +@item -R @var{varname} +True if the shell variable @var{varname} is set and is a name reference. + +@item -z @var{string} +True if the length of @var{string} is zero. + +@item -n @var{string} +@itemx @var{string} +True if the length of @var{string} is non-zero. + +@item @var{string1} == @var{string2} +@itemx @var{string1} = @var{string2} +True if the strings are equal. +When used with the @code{[[} command, this performs pattern matching as +described above (@pxref{Conditional Constructs}). + +@samp{=} should be used with the @code{test} command for @sc{posix} conformance. + +@item @var{string1} != @var{string2} +True if the strings are not equal. + +@item @var{string1} < @var{string2} +True if @var{string1} sorts before @var{string2} lexicographically. + +@item @var{string1} > @var{string2} +True if @var{string1} sorts after @var{string2} lexicographically. + +@item @var{arg1} OP @var{arg2} +@code{OP} is one of +@samp{-eq}, @samp{-ne}, @samp{-lt}, @samp{-le}, @samp{-gt}, or @samp{-ge}. +These arithmetic binary operators return true if @var{arg1} +is equal to, not equal to, less than, less than or equal to, +greater than, or greater than or equal to @var{arg2}, +respectively. @var{Arg1} and @var{arg2} +may be positive or negative integers. +@end table + +@node Shell Arithmetic +@section Shell Arithmetic +@cindex arithmetic, shell +@cindex shell arithmetic +@cindex expressions, arithmetic +@cindex evaluation, arithmetic +@cindex arithmetic evaluation + +The shell allows arithmetic expressions to be evaluated, as one of +the shell expansions or by the @code{let} and the @option{-i} option +to the @code{declare} builtins. + +Evaluation is done in fixed-width integers with no check for overflow, +though division by 0 is trapped and flagged as an error. +The operators and their precedence, associativity, and values +are the same as in the C language. +The following list of operators is grouped into levels of +equal-precedence operators. +The levels are listed in order of decreasing precedence. + +@table @code + +@item @var{id}++ @var{id}-- +variable post-increment and post-decrement + +@item ++@var{id} --@var{id} +variable pre-increment and pre-decrement + +@item - + +unary minus and plus + +@item ! ~ +logical and bitwise negation + +@item ** +exponentiation + +@item * / % +multiplication, division, remainder + +@item + - +addition, subtraction + +@item << >> +left and right bitwise shifts + +@item <= >= < > +comparison + +@item == != +equality and inequality + +@item & +bitwise AND + +@item ^ +bitwise exclusive OR + +@item | +bitwise OR + +@item && +logical AND + +@item || +logical OR + +@item expr ? expr : expr +conditional operator + +@item = *= /= %= += -= <<= >>= &= ^= |= +assignment + +@item expr1 , expr2 +comma +@end table + +Shell variables are allowed as operands; parameter expansion is +performed before the expression is evaluated. +Within an expression, shell variables may also be referenced by name +without using the parameter expansion syntax. +A shell variable that is null or unset evaluates to 0 when referenced +by name without using the parameter expansion syntax. +The value of a variable is evaluated as an arithmetic expression +when it is referenced, or when a variable which has been given the +@var{integer} attribute using @samp{declare -i} is assigned a value. +A null value evaluates to 0. +A shell variable need not have its @var{integer} attribute turned on +to be used in an expression. + +Constants with a leading 0 are interpreted as octal numbers. +A leading @samp{0x} or @samp{0X} denotes hexadecimal. Otherwise, +numbers take the form [@var{base}@code{#}]@var{n}, where the optional @var{base} +is a decimal number between 2 and 64 representing the arithmetic +base, and @var{n} is a number in that base. +If @var{base}@code{#} is omitted, then base 10 is used. +When specifying @var{n}, +he digits greater than 9 are represented by the lowercase letters, +the uppercase letters, @samp{@@}, and @samp{_}, in that order. +If @var{base} is less than or equal to 36, lowercase and uppercase +letters may be used interchangeably to represent numbers between 10 +and 35. + +Operators are evaluated in order of precedence. Sub-expressions in +parentheses are evaluated first and may override the precedence +rules above. + +@node Aliases +@section Aliases +@cindex alias expansion + +@var{Aliases} allow a string to be substituted for a word when it is used +as the first word of a simple command. +The shell maintains a list of aliases that may be set and unset with +the @code{alias} and @code{unalias} builtin commands. + +The first word of each simple command, if unquoted, is checked to see +if it has an alias. +If so, that word is replaced by the text of the alias. +The characters @samp{/}, @samp{$}, @samp{`}, @samp{=} and any of the +shell metacharacters or quoting characters listed above may not appear +in an alias name. +The replacement text may contain any valid +shell input, including shell metacharacters. +The first word of the replacement text is tested for +aliases, but a word that is identical to an alias being expanded +is not expanded a second time. +This means that one may alias @code{ls} to @code{"ls -F"}, +for instance, and Bash does not try to recursively expand the +replacement text. +If the last character of the alias value is a +@var{blank}, then the next command word following the +alias is also checked for alias expansion. + +Aliases are created and listed with the @code{alias} +command, and removed with the @code{unalias} command. + +There is no mechanism for using arguments in the replacement text, +as in @code{csh}. +If arguments are needed, a shell function should be used +(@pxref{Shell Functions}). + +Aliases are not expanded when the shell is not interactive, +unless the @code{expand_aliases} shell option is set using +@code{shopt} (@pxref{The Shopt Builtin}). + +The rules concerning the definition and use of aliases are +somewhat confusing. Bash +always reads at least one complete line +of input before executing any +of the commands on that line. Aliases are expanded when a +command is read, not when it is executed. Therefore, an +alias definition appearing on the same line as another +command does not take effect until the next line of input is read. +The commands following the alias definition +on that line are not affected by the new alias. +This behavior is also an issue when functions are executed. +Aliases are expanded when a function definition is read, +not when the function is executed, because a function definition +is itself a command. As a consequence, aliases +defined in a function are not available until after that +function is executed. To be safe, always put +alias definitions on a separate line, and do not use @code{alias} +in compound commands. + +For almost every purpose, shell functions are preferred over aliases. + +@node Arrays +@section Arrays +@cindex arrays + +Bash provides one-dimensional indexed and associative array variables. +Any variable may be used as an indexed array; +the @code{declare} builtin will explicitly declare an array. +There is no maximum +limit on the size of an array, nor any requirement that members +be indexed or assigned contiguously. +Indexed arrays are referenced using integers (including arithmetic +expressions (@pxref{Shell Arithmetic})) and are zero-based; +associative arrays use arbitrary strings. +Unless otherwise noted, indexed array indices must be non-negative integers. + +An indexed array is created automatically if any variable is assigned to +using the syntax +@example +@var{name}[@var{subscript}]=@var{value} +@end example + +@noindent +The @var{subscript} +is treated as an arithmetic expression that must evaluate to a number. +To explicitly declare an array, use +@example +declare -a @var{name} +@end example +@noindent +The syntax +@example +declare -a @var{name}[@var{subscript}] +@end example +@noindent +is also accepted; the @var{subscript} is ignored. + +@noindent +Associative arrays are created using +@example +declare -A @var{name}. +@end example + +Attributes may be +specified for an array variable using the @code{declare} and +@code{readonly} builtins. Each attribute applies to all members of +an array. + +Arrays are assigned to using compound assignments of the form +@example +@var{name}=(@var{value1} @var{value2} @dots{} ) +@end example +@noindent +where each +@var{value} is of the form @code{[@var{subscript}]=}@var{string}. +Indexed array assignments do not require anything but @var{string}. +When assigning to indexed arrays, if +the optional subscript is supplied, that index is assigned to; +otherwise the index of the element assigned is the last index assigned +to by the statement plus one. Indexing starts at zero. + +When assigning to an associative array, the subscript is required. + +This syntax is also accepted by the @code{declare} +builtin. Individual array elements may be assigned to using the +@code{@var{name}[@var{subscript}]=@var{value}} syntax introduced above. + +When assigning to an indexed array, if @var{name} +is subscripted by a negative number, that number is +interpreted as relative to one greater than the maximum index of +@var{name}, so negative indices count back from the end of the +array, and an index of -1 references the last element. + +Any element of an array may be referenced using +@code{$@{@var{name}[@var{subscript}]@}}. +The braces are required to avoid +conflicts with the shell's filename expansion operators. If the +@var{subscript} is @samp{@@} or @samp{*}, the word expands to all members +of the array @var{name}. These subscripts differ only when the word +appears within double quotes. +If the word is double-quoted, +@code{$@{@var{name}[*]@}} expands to a single word with +the value of each array member separated by the first character of the +@env{IFS} variable, and @code{$@{@var{name}[@@]@}} expands each element of +@var{name} to a separate word. When there are no array members, +@code{$@{@var{name}[@@]@}} expands to nothing. +If the double-quoted expansion occurs within a word, the expansion of +the first parameter is joined with the beginning part of the original +word, and the expansion of the last parameter is joined with the last +part of the original word. +This is analogous to the +expansion of the special parameters @samp{@@} and @samp{*}. +@code{$@{#@var{name}[@var{subscript}]@}} expands to the length of +@code{$@{@var{name}[@var{subscript}]@}}. +If @var{subscript} is @samp{@@} or +@samp{*}, the expansion is the number of elements in the array. +If the @var{subscript} +used to reference an element of an indexed array +evaluates to a number less than zero, it is +interpreted as relative to one greater than the maximum index of the array, +so negative indices count back from the end of the array, +and an index of -1 refers to the last element. + +Referencing an array variable without a subscript is equivalent to +referencing with a subscript of 0. +Any reference to a variable using a valid subscript is legal, and +@code{bash} will create an array if necessary. + +An array variable is considered set if a subscript has been assigned a +value. The null string is a valid value. + +It is possible to obtain the keys (indices) of an array as well as the values. +$@{!@var{name}[@@]@} and $@{!@var{name}[*]@} expand to the indices +assigned in array variable @var{name}. +The treatment when in double quotes is similar to the expansion of the +special parameters @samp{@@} and @samp{*} within double quotes. + +The @code{unset} builtin is used to destroy arrays. +@code{unset @var{name}[@var{subscript}]} +destroys the array element at index @var{subscript}. +Negative subscripts to indexed arrays are interpreted as described above. +Care must be taken to avoid unwanted side effects caused by filename +expansion. +@code{unset @var{name}}, where @var{name} is an array, removes the +entire array. A subscript of @samp{*} or @samp{@@} also removes the +entire array. + +The @code{declare}, @code{local}, and @code{readonly} +builtins each accept a @option{-a} option to specify an indexed +array and a @option{-A} option to specify an associative array. +If both options are supplied, @option{-A} takes precedence. +The @code{read} builtin accepts a @option{-a} +option to assign a list of words read from the standard input +to an array, and can read values from the standard input into +individual array elements. The @code{set} and @code{declare} +builtins display array values in a way that allows them to be +reused as input. + +@node The Directory Stack +@section The Directory Stack +@cindex directory stack + +@menu +* Directory Stack Builtins:: Bash builtin commands to manipulate + the directory stack. +@end menu + +The directory stack is a list of recently-visited directories. The +@code{pushd} builtin adds directories to the stack as it changes +the current directory, and the @code{popd} builtin removes specified +directories from the stack and changes the current directory to +the directory removed. The @code{dirs} builtin displays the contents +of the directory stack. + +The contents of the directory stack are also visible +as the value of the @env{DIRSTACK} shell variable. + +@node Directory Stack Builtins +@subsection Directory Stack Builtins + +@table @code + +@item dirs +@btindex dirs +@example +dirs [-clpv] [+@var{N} | -@var{N}] +@end example + +Display the list of currently remembered directories. Directories +are added to the list with the @code{pushd} command; the +@code{popd} command removes directories from the list. + +@table @code +@item -c +Clears the directory stack by deleting all of the elements. +@item -l +Produces a listing using full pathnames; +the default listing format uses a tilde to denote the home directory. +@item -p +Causes @code{dirs} to print the directory stack with one entry per +line. +@item -v +Causes @code{dirs} to print the directory stack with one entry per +line, prefixing each entry with its index in the stack. +@item +@var{N} +Displays the @var{N}th directory (counting from the left of the +list printed by @code{dirs} when invoked without options), starting +with zero. +@item -@var{N} +Displays the @var{N}th directory (counting from the right of the +list printed by @code{dirs} when invoked without options), starting +with zero. +@end table + +@item popd +@btindex popd +@example +popd [-n] [+@var{N} | -@var{N}] +@end example + +Remove the top entry from the directory stack, and @code{cd} +to the new top directory. +When no arguments are given, @code{popd} +removes the top directory from the stack and +performs a @code{cd} to the new top directory. The +elements are numbered from 0 starting at the first directory listed with +@code{dirs}; that is, @code{popd} is equivalent to @code{popd +0}. + +@table @code +@item -n +Suppresses the normal change of directory when removing directories +from the stack, so that only the stack is manipulated. +@item +@var{N} +Removes the @var{N}th directory (counting from the left of the +list printed by @code{dirs}), starting with zero. +@item -@var{N} +Removes the @var{N}th directory (counting from the right of the +list printed by @code{dirs}), starting with zero. +@end table + +@btindex pushd +@item pushd +@example +pushd [-n] [@var{+N} | @var{-N} | @var{dir}] +@end example + +Save the current directory on the top of the directory stack +and then @code{cd} to @var{dir}. +With no arguments, @code{pushd} exchanges the top two directories. + +@table @code +@item -n +Suppresses the normal change of directory when adding directories +to the stack, so that only the stack is manipulated. +@item +@var{N} +Brings the @var{N}th directory (counting from the left of the +list printed by @code{dirs}, starting with zero) to the top of +the list by rotating the stack. +@item -@var{N} +Brings the @var{N}th directory (counting from the right of the +list printed by @code{dirs}, starting with zero) to the top of +the list by rotating the stack. +@item @var{dir} +Makes the current working directory be the top of the stack, making +it the new current directory as if it had been supplied as an argument +to the @code{cd} builtin. +@end table +@end table + +@node Controlling the Prompt +@section Controlling the Prompt +@cindex prompting + +The value of the variable @env{PROMPT_COMMAND} is examined just before +Bash prints each primary prompt. If @env{PROMPT_COMMAND} is set and +has a non-null value, then the +value is executed just as if it had been typed on the command line. + +In addition, the following table describes the special characters which +can appear in the prompt variables @env{PS1} to @env{PS4}: + +@table @code +@item \a +A bell character. +@item \d +The date, in "Weekday Month Date" format (e.g., "Tue May 26"). +@item \D@{@var{format}@} +The @var{format} is passed to @code{strftime}(3) and the result is inserted +into the prompt string; an empty @var{format} results in a locale-specific +time representation. The braces are required. +@item \e +An escape character. +@item \h +The hostname, up to the first `.'. +@item \H +The hostname. +@item \j +The number of jobs currently managed by the shell. +@item \l +The basename of the shell's terminal device name. +@item \n +A newline. +@item \r +A carriage return. +@item \s +The name of the shell, the basename of @code{$0} (the portion +following the final slash). +@item \t +The time, in 24-hour HH:MM:SS format. +@item \T +The time, in 12-hour HH:MM:SS format. +@item \@@ +The time, in 12-hour am/pm format. +@item \A +The time, in 24-hour HH:MM format. +@item \u +The username of the current user. +@item \v +The version of Bash (e.g., 2.00) +@item \V +The release of Bash, version + patchlevel (e.g., 2.00.0) +@item \w +The current working directory, with @env{$HOME} abbreviated with a tilde +(uses the @env{$PROMPT_DIRTRIM} variable). +@item \W +The basename of @env{$PWD}, with @env{$HOME} abbreviated with a tilde. +@item \! +The history number of this command. +@item \# +The command number of this command. +@item \$ +If the effective uid is 0, @code{#}, otherwise @code{$}. +@item \@var{nnn} +The character whose ASCII code is the octal value @var{nnn}. +@item \\ +A backslash. +@item \[ +Begin a sequence of non-printing characters. This could be used to +embed a terminal control sequence into the prompt. +@item \] +End a sequence of non-printing characters. +@end table + +The command number and the history number are usually different: +the history number of a command is its position in the history +list, which may include commands restored from the history file +(@pxref{Bash History Facilities}), while the command number is +the position in the sequence of commands executed during the current +shell session. + +After the string is decoded, it is expanded via +parameter expansion, command substitution, arithmetic +expansion, and quote removal, subject to the value of the +@code{promptvars} shell option (@pxref{Bash Builtins}). + +@node The Restricted Shell +@section The Restricted Shell +@cindex restricted shell + +If Bash is started with the name @code{rbash}, or the +@option{--restricted} +or +@option{-r} +option is supplied at invocation, the shell becomes restricted. +A restricted shell is used to +set up an environment more controlled than the standard shell. +A restricted shell behaves identically to @code{bash} +with the exception that the following are disallowed or not performed: + +@itemize @bullet +@item +Changing directories with the @code{cd} builtin. +@item +Setting or unsetting the values of the @env{SHELL}, @env{PATH}, +@env{ENV}, or @env{BASH_ENV} variables. +@item +Specifying command names containing slashes. +@item +Specifying a filename containing a slash as an argument to the @code{.} +builtin command. +@item +Specifying a filename containing a slash as an argument to the @option{-p} +option to the @code{hash} builtin command. +@item +Importing function definitions from the shell environment at startup. +@item +Parsing the value of @env{SHELLOPTS} from the shell environment at startup. +@item +Redirecting output using the @samp{>}, @samp{>|}, @samp{<>}, @samp{>&}, +@samp{&>}, and @samp{>>} redirection operators. +@item +Using the @code{exec} builtin to replace the shell with another command. +@item +Adding or deleting builtin commands with the +@option{-f} and @option{-d} options to the @code{enable} builtin. +@item +Using the @code{enable} builtin command to enable disabled shell builtins. +@item +Specifying the @option{-p} option to the @code{command} builtin. +@item +Turning off restricted mode with @samp{set +r} or @samp{set +o restricted}. +@end itemize + +These restrictions are enforced after any startup files are read. + +When a command that is found to be a shell script is executed +(@pxref{Shell Scripts}), @code{rbash} turns off any restrictions in +the shell spawned to execute the script. + +@node Bash POSIX Mode +@section Bash POSIX Mode +@cindex POSIX Mode + +Starting Bash with the @option{--posix} command-line option or executing +@samp{set -o posix} while Bash is running will cause Bash to conform more +closely to the @sc{posix} standard by changing the behavior to +match that specified by @sc{posix} in areas where the Bash default differs. + +When invoked as @code{sh}, Bash enters @sc{posix} mode after reading the +startup files. + +The following list is what's changed when `@sc{posix} mode' is in effect: + +@enumerate +@item +When a command in the hash table no longer exists, Bash will re-search +@env{$PATH} to find the new location. This is also available with +@samp{shopt -s checkhash}. + +@item +The message printed by the job control code and builtins when a job +exits with a non-zero status is `Done(status)'. + +@item +The message printed by the job control code and builtins when a job +is stopped is `Stopped(@var{signame})', where @var{signame} is, for +example, @code{SIGTSTP}. + +@item +The @code{bg} builtin uses the required format to describe each job placed +in the background, which does not include an indication of whether the job +is the current or previous job. + +@item +Reserved words appearing in a context where reserved words are recognized +do not undergo alias expansion. + +@item +The @sc{posix} @env{PS1} and @env{PS2} expansions of @samp{!} to +the history number and @samp{!!} to @samp{!} are enabled, +and parameter expansion is performed on the values of @env{PS1} and +@env{PS2} regardless of the setting of the @code{promptvars} option. + +@item +The @sc{posix} startup files are executed (@env{$ENV}) rather than +the normal Bash files. + +@item +Tilde expansion is only performed on assignments preceding a command +name, rather than on all assignment statements on the line. + +@item +The @code{command} builtin does not prevent builtins that take assignment +statements as arguments from expanding them as assignment statements; +when not in @sc{posix} mode, assignment builtins lose their assignment +statement expansion properties when preceded by @code{command}. + +@item +The default history file is @file{~/.sh_history} (this is the +default value of @env{$HISTFILE}). + +@item +The output of @samp{kill -l} prints all the signal names on a single line, +separated by spaces, without the @samp{SIG} prefix. + +@item +The @code{kill} builtin does not accept signal names with a @samp{SIG} +prefix. + +@item +Non-interactive shells exit if @var{filename} in @code{.} @var{filename} +is not found. + +@item +Non-interactive shells exit if a syntax error in an arithmetic expansion +results in an invalid expression. + +@item +Non-interactive shells exit if there is a syntax error in a script read +with the @code{.} or @code{source} builtins, or in a string processed by +the @code{eval} builtin. + +@item +Redirection operators do not perform filename expansion on the word +in the redirection unless the shell is interactive. + +@item +Redirection operators do not perform word splitting on the word in the +redirection. + +@item +Function names must be valid shell @code{name}s. That is, they may not +contain characters other than letters, digits, and underscores, and +may not start with a digit. Declaring a function with an invalid name +causes a fatal syntax error in non-interactive shells. + +@item +Function names may not be the same as one of the @sc{posix} special +builtins. + +@item +@sc{posix} special builtins are found before shell functions +during command lookup. + +@item +Literal tildes that appear as the first character in elements of +the @env{PATH} variable are not expanded as described above +under @ref{Tilde Expansion}. + +@item +The @code{time} reserved word may be used by itself as a command. When +used in this way, it displays timing statistics for the shell and its +completed children. The @env{TIMEFORMAT} variable controls the format +of the timing information. + +@item +When parsing and expanding a $@{@dots{}@} expansion that appears within +double quotes, single quotes are no longer special and cannot be used to +quote a closing brace or other special character, unless the operator is +one of those defined to perform pattern removal. In this case, they do +not have to appear as matched pairs. + +@item +The parser does not recognize @code{time} as a reserved word if the next +token begins with a @samp{-}. + +@item +If a @sc{posix} special builtin returns an error status, a +non-interactive shell exits. The fatal errors are those listed in +the @sc{posix} standard, and include things like passing incorrect options, +redirection errors, variable assignment errors for assignments preceding +the command name, and so on. + +@item +A non-interactive shell exits with an error status if a variable +assignment error occurs when no command name follows the assignment +statements. +A variable assignment error occurs, for example, when trying to assign +a value to a readonly variable. + +@item +A non-interactive shell exits with an error status if a variable +assignment error occurs in an assignment statement preceding a special +builtin, but not with any other simple command. + +@item +A non-interactive shell exits with an error status if the iteration +variable in a @code{for} statement or the selection variable in a +@code{select} statement is a readonly variable. + +@item +Process substitution is not available. + +@item +While variable indirection is available, it may not be applied to the +@samp{#} and @samp{?} special parameters. + +@item +Assignment statements preceding @sc{posix} special builtins +persist in the shell environment after the builtin completes. + +@item +Assignment statements preceding shell function calls persist in the +shell environment after the function returns, as if a @sc{posix} +special builtin command had been executed. + +@item +The @code{export} and @code{readonly} builtin commands display their +output in the format required by @sc{posix}. + +@item +The @code{trap} builtin displays signal names without the leading +@code{SIG}. + +@item +The @code{trap} builtin doesn't check the first argument for a possible +signal specification and revert the signal handling to the original +disposition if it is, unless that argument consists solely of digits and +is a valid signal number. If users want to reset the handler for a given +signal to the original disposition, they should use @samp{-} as the +first argument. + +@item +The @code{.} and @code{source} builtins do not search the current directory +for the filename argument if it is not found by searching @env{PATH}. + +@item +Subshells spawned to execute command substitutions inherit the value of +the @option{-e} option from the parent shell. When not in @sc{posix} mode, +Bash clears the @option{-e} option in such subshells. + +@item +Alias expansion is always enabled, even in non-interactive shells. + +@item +When the @code{alias} builtin displays alias definitions, it does not +display them with a leading @samp{alias } unless the @option{-p} option +is supplied. + +@item +When the @code{set} builtin is invoked without options, it does not display +shell function names and definitions. + +@item +When the @code{set} builtin is invoked without options, it displays +variable values without quotes, unless they contain shell metacharacters, +even if the result contains nonprinting characters. + +@item +When the @code{cd} builtin is invoked in @var{logical} mode, and the pathname +constructed from @code{$PWD} and the directory name supplied as an argument +does not refer to an existing directory, @code{cd} will fail instead of +falling back to @var{physical} mode. + +@item +The @code{pwd} builtin verifies that the value it prints is the same as the +current directory, even if it is not asked to check the file system with the +@option{-P} option. + +@item +When listing the history, the @code{fc} builtin does not include an +indication of whether or not a history entry has been modified. + +@item +The default editor used by @code{fc} is @code{ed}. + +@item +The @code{type} and @code{command} builtins will not report a non-executable +file as having been found, though the shell will attempt to execute such a +file if it is the only so-named file found in @code{$PATH}. + +@item +The @code{vi} editing mode will invoke the @code{vi} editor directly when +the @samp{v} command is run, instead of checking @code{$VISUAL} and +@code{$EDITOR}. + +@item +When the @code{xpg_echo} option is enabled, Bash does not attempt to interpret +any arguments to @code{echo} as options. Each argument is displayed, after +escape characters are converted. + +@item +The @code{ulimit} builtin uses a block size of 512 bytes for the @option{-c} +and @option{-f} options. + +@item +The arrival of @code{SIGCHLD} when a trap is set on @code{SIGCHLD} does +not interrupt the @code{wait} builtin and cause it to return immediately. +The trap command is run once for each child that exits. + +@item +The @code{read} builtin may be interrupted by a signal for which a trap +has been set. +If Bash receives a trapped signal while executing @code{read}, the trap +handler executes and @code{read} returns an exit status greater than 128. + +@end enumerate + +There is other @sc{posix} behavior that Bash does not implement by +default even when in @sc{posix} mode. +Specifically: + +@enumerate + +@item +The @code{fc} builtin checks @code{$EDITOR} as a program to edit history +entries if @code{FCEDIT} is unset, rather than defaulting directly to +@code{ed}. @code{fc} uses @code{ed} if @code{EDITOR} is unset. + +@item +As noted above, Bash requires the @code{xpg_echo} option to be enabled for +the @code{echo} builtin to be fully conformant. + +@end enumerate + +Bash can be configured to be @sc{posix}-conformant by default, by specifying +the @option{--enable-strict-posix-default} to @code{configure} when building +(@pxref{Optional Features}). + +@node Job Control +@chapter Job Control + +This chapter discusses what job control is, how it works, and how +Bash allows you to access its facilities. + +@menu +* Job Control Basics:: How job control works. +* Job Control Builtins:: Bash builtin commands used to interact + with job control. +* Job Control Variables:: Variables Bash uses to customize job + control. +@end menu + +@node Job Control Basics +@section Job Control Basics +@cindex job control +@cindex foreground +@cindex background +@cindex suspending jobs + +Job control +refers to the ability to selectively stop (suspend) +the execution of processes and continue (resume) +their execution at a later point. A user typically employs +this facility via an interactive interface supplied jointly +by the operating system kernel's terminal driver and Bash. + +The shell associates a @var{job} with each pipeline. It keeps a +table of currently executing jobs, which may be listed with the +@code{jobs} command. When Bash starts a job +asynchronously, it prints a line that looks +like: +@example +[1] 25647 +@end example +@noindent +indicating that this job is job number 1 and that the process @sc{id} +of the last process in the pipeline associated with this job is +25647. All of the processes in a single pipeline are members of +the same job. Bash uses the @var{job} abstraction as the +basis for job control. + +To facilitate the implementation of the user interface to job +control, the operating system maintains the notion of a current terminal +process group @sc{id}. Members of this process group (processes whose +process group @sc{id} is equal to the current terminal process group +@sc{id}) receive keyboard-generated signals such as @code{SIGINT}. +These processes are said to be in the foreground. Background +processes are those whose process group @sc{id} differs from the +terminal's; such processes are immune to keyboard-generated +signals. Only foreground processes are allowed to read from or, if +the user so specifies with @code{stty tostop}, write to the terminal. +Background processes which attempt to +read from (write to when @code{stty tostop} is in effect) the +terminal are sent a @code{SIGTTIN} (@code{SIGTTOU}) +signal by the kernel's terminal driver, +which, unless caught, suspends the process. + +If the operating system on which Bash is running supports +job control, Bash contains facilities to use it. Typing the +@var{suspend} character (typically @samp{^Z}, Control-Z) while a +process is running causes that process to be stopped and returns +control to Bash. Typing the @var{delayed suspend} character +(typically @samp{^Y}, Control-Y) causes the process to be stopped +when it attempts to read input from the terminal, and control to +be returned to Bash. The user then manipulates the state of +this job, using the @code{bg} command to continue it in the +background, the @code{fg} command to continue it in the +foreground, or the @code{kill} command to kill it. A @samp{^Z} +takes effect immediately, and has the additional side effect of +causing pending output and typeahead to be discarded. + +There are a number of ways to refer to a job in the shell. The +character @samp{%} introduces a job specification (@var{jobspec}). + +Job number @code{n} may be referred to as @samp{%n}. +The symbols @samp{%%} and @samp{%+} refer to the shell's notion of the +current job, which is the last job stopped while it was in the foreground +or started in the background. +A single @samp{%} (with no accompanying job specification) also refers +to the current job. +The previous job may be referenced using @samp{%-}. +If there is only a single job, @samp{%+} and @samp{%-} can both be used +to refer to that job. +In output pertaining to jobs (e.g., the output of the @code{jobs} +command), the current job is always flagged with a @samp{+}, and the +previous job with a @samp{-}. + +A job may also be referred to +using a prefix of the name used to start it, or using a substring +that appears in its command line. For example, @samp{%ce} refers +to a stopped @code{ce} job. Using @samp{%?ce}, on the +other hand, refers to any job containing the string @samp{ce} in +its command line. If the prefix or substring matches more than one job, +Bash reports an error. + +Simply naming a job can be used to bring it into the foreground: +@samp{%1} is a synonym for @samp{fg %1}, bringing job 1 from the +background into the foreground. Similarly, @samp{%1 &} resumes +job 1 in the background, equivalent to @samp{bg %1} + +The shell learns immediately whenever a job changes state. +Normally, Bash waits until it is about to print a prompt +before reporting changes in a job's status so as to not interrupt +any other output. +If the @option{-b} option to the @code{set} builtin is enabled, +Bash reports such changes immediately (@pxref{The Set Builtin}). +Any trap on @code{SIGCHLD} is executed for each child process +that exits. + +If an attempt to exit Bash is made while jobs are stopped, (or running, if +the @code{checkjobs} option is enabled -- see @ref{The Shopt Builtin}), the +shell prints a warning message, and if the @code{checkjobs} option is +enabled, lists the jobs and their statuses. +The @code{jobs} command may then be used to inspect their status. +If a second attempt to exit is made without an intervening command, +Bash does not print another warning, and any stopped jobs are terminated. + +@node Job Control Builtins +@section Job Control Builtins + +@table @code + +@item bg +@btindex bg +@example +bg [@var{jobspec} @dots{}] +@end example + +Resume each suspended job @var{jobspec} in the background, as if it +had been started with @samp{&}. +If @var{jobspec} is not supplied, the current job is used. +The return status is zero unless it is run when job control is not +enabled, or, when run with job control enabled, any +@var{jobspec} was not found or specifies a job +that was started without job control. + +@item fg +@btindex fg +@example +fg [@var{jobspec}] +@end example + +Resume the job @var{jobspec} in the foreground and make it the current job. +If @var{jobspec} is not supplied, the current job is used. +The return status is that of the command placed into the foreground, +or non-zero if run when job control is disabled or, when run with +job control enabled, @var{jobspec} does not specify a valid job or +@var{jobspec} specifies a job that was started without job control. + +@item jobs +@btindex jobs +@example +jobs [-lnprs] [@var{jobspec}] +jobs -x @var{command} [@var{arguments}] +@end example + +The first form lists the active jobs. The options have the +following meanings: + +@table @code +@item -l +List process @sc{id}s in addition to the normal information. + +@item -n +Display information only about jobs that have changed status since +the user was last notified of their status. + +@item -p +List only the process @sc{id} of the job's process group leader. + +@item -r +Display only running jobs. + +@item -s +Display only stopped jobs. +@end table + +If @var{jobspec} is given, +output is restricted to information about that job. +If @var{jobspec} is not supplied, the status of all jobs is +listed. + +If the @option{-x} option is supplied, @code{jobs} replaces any +@var{jobspec} found in @var{command} or @var{arguments} with the +corresponding process group @sc{id}, and executes @var{command}, +passing it @var{argument}s, returning its exit status. + +@item kill +@btindex kill +@example +kill [-s @var{sigspec}] [-n @var{signum}] [-@var{sigspec}] @var{jobspec} or @var{pid} +kill -l [@var{exit_status}] +@end example + +Send a signal specified by @var{sigspec} or @var{signum} to the process +named by job specification @var{jobspec} or process @sc{id} @var{pid}. +@var{sigspec} is either a case-insensitive signal name such as +@code{SIGINT} (with or without the @code{SIG} prefix) +or a signal number; @var{signum} is a signal number. +If @var{sigspec} and @var{signum} are not present, @code{SIGTERM} is used. +The @option{-l} option lists the signal names. +If any arguments are supplied when @option{-l} is given, the names of the +signals corresponding to the arguments are listed, and the return status +is zero. +@var{exit_status} is a number specifying a signal number or the exit +status of a process terminated by a signal. +The return status is zero if at least one signal was successfully sent, +or non-zero if an error occurs or an invalid option is encountered. + +@item wait +@btindex wait +@example +wait [-n] [@var{jobspec} or @var{pid} @dots{}] +@end example + +Wait until the child process specified by each process @sc{id} @var{pid} +or job specification @var{jobspec} exits and return the exit status of the +last command waited for. +If a job spec is given, all processes in the job are waited for. +If no arguments are given, all currently active child processes are +waited for, and the return status is zero. +If the @option{-n} option is supplied, @code{wait} waits for any job to +terminate and returns its exit status. +If neither @var{jobspec} nor @var{pid} specifies an active child process +of the shell, the return status is 127. + +@item disown +@btindex disown +@example +disown [-ar] [-h] [@var{jobspec} @dots{}] +@end example + +Without options, remove each @var{jobspec} from the table of +active jobs. +If the @option{-h} option is given, the job is not removed from the table, +but is marked so that @code{SIGHUP} is not sent to the job if the shell +receives a @code{SIGHUP}. +If @var{jobspec} is not present, and neither the @option{-a} nor the +@option{-r} option is supplied, the current job is used. +If no @var{jobspec} is supplied, the @option{-a} option means to remove or +mark all jobs; the @option{-r} option without a @var{jobspec} +argument restricts operation to running jobs. + +@item suspend +@btindex suspend +@example +suspend [-f] +@end example + +Suspend the execution of this shell until it receives a +@code{SIGCONT} signal. +A login shell cannot be suspended; the @option{-f} +option can be used to override this and force the suspension. +@end table + +When job control is not active, the @code{kill} and @code{wait} +builtins do not accept @var{jobspec} arguments. They must be +supplied process @sc{id}s. + +@node Job Control Variables +@section Job Control Variables + +@vtable @code + +@item auto_resume +This variable controls how the shell interacts with the user and +job control. If this variable exists then single word simple +commands without redirections are treated as candidates for resumption +of an existing job. There is no ambiguity allowed; if there is +more than one job beginning with the string typed, then +the most recently accessed job will be selected. +The name of a stopped job, in this context, is the command line +used to start it. If this variable is set to the value @samp{exact}, +the string supplied must match the name of a stopped job exactly; +if set to @samp{substring}, +the string supplied needs to match a substring of the name of a +stopped job. The @samp{substring} value provides functionality +analogous to the @samp{%?} job @sc{id} (@pxref{Job Control Basics}). +If set to any other value, the supplied string must +be a prefix of a stopped job's name; this provides functionality +analogous to the @samp{%} job @sc{id}. + +@end vtable + +@set readline-appendix +@set history-appendix +@cindex Readline, how to use +@include rluser.texi +@cindex History, how to use +@include hsuser.texi +@clear readline-appendix +@clear history-appendix + +@node Installing Bash +@chapter Installing Bash + +This chapter provides basic instructions for installing Bash on +the various supported platforms. The distribution supports the +@sc{gnu} operating systems, nearly every version of Unix, and several +non-Unix systems such as BeOS and Interix. +Other independent ports exist for +@sc{ms-dos}, @sc{os/2}, and Windows platforms. + +@menu +* Basic Installation:: Installation instructions. +* Compilers and Options:: How to set special options for various + systems. +* Compiling For Multiple Architectures:: How to compile Bash for more + than one kind of system from + the same source tree. +* Installation Names:: How to set the various paths used by the installation. +* Specifying the System Type:: How to configure Bash for a particular system. +* Sharing Defaults:: How to share default configuration values among GNU + programs. +* Operation Controls:: Options recognized by the configuration program. +* Optional Features:: How to enable and disable optional features when + building Bash. +@end menu + +@node Basic Installation +@section Basic Installation +@cindex installation +@cindex configuration +@cindex Bash installation +@cindex Bash configuration + +These are installation instructions for Bash. + +The simplest way to compile Bash is: + +@enumerate +@item +@code{cd} to the directory containing the source code and type +@samp{./configure} to configure Bash for your system. If you're +using @code{csh} on an old version of System V, you might need to +type @samp{sh ./configure} instead to prevent @code{csh} from trying +to execute @code{configure} itself. + +Running @code{configure} takes some time. +While running, it prints messages telling which features it is +checking for. + +@item +Type @samp{make} to compile Bash and build the @code{bashbug} bug +reporting script. + +@item +Optionally, type @samp{make tests} to run the Bash test suite. + +@item +Type @samp{make install} to install @code{bash} and @code{bashbug}. +This will also install the manual pages and Info file. + +@end enumerate + +The @code{configure} shell script attempts to guess correct +values for various system-dependent variables used during +compilation. It uses those values to create a @file{Makefile} in +each directory of the package (the top directory, the +@file{builtins}, @file{doc}, and @file{support} directories, +each directory under @file{lib}, and several others). It also creates a +@file{config.h} file containing system-dependent definitions. +Finally, it creates a shell script named @code{config.status} that you +can run in the future to recreate the current configuration, a +file @file{config.cache} that saves the results of its tests to +speed up reconfiguring, and a file @file{config.log} containing +compiler output (useful mainly for debugging @code{configure}). +If at some point +@file{config.cache} contains results you don't want to keep, you +may remove or edit it. + +To find out more about the options and arguments that the +@code{configure} script understands, type + +@example +bash-2.04$ ./configure --help +@end example + +@noindent +at the Bash prompt in your Bash source directory. + +If you need to do unusual things to compile Bash, please +try to figure out how @code{configure} could check whether or not +to do them, and mail diffs or instructions to +@email{bash-maintainers@@gnu.org} so they can be +considered for the next release. + +The file @file{configure.ac} is used to create @code{configure} +by a program called Autoconf. You only need +@file{configure.ac} if you want to change it or regenerate +@code{configure} using a newer version of Autoconf. If +you do this, make sure you are using Autoconf version 2.50 or +newer. + +You can remove the program binaries and object files from the +source code directory by typing @samp{make clean}. To also remove the +files that @code{configure} created (so you can compile Bash for +a different kind of computer), type @samp{make distclean}. + +@node Compilers and Options +@section Compilers and Options + +Some systems require unusual options for compilation or linking +that the @code{configure} script does not know about. You can +give @code{configure} initial values for variables by setting +them in the environment. Using a Bourne-compatible shell, you +can do that on the command line like this: + +@example +CC=c89 CFLAGS=-O2 LIBS=-lposix ./configure +@end example + +On systems that have the @code{env} program, you can do it like this: + +@example +env CPPFLAGS=-I/usr/local/include LDFLAGS=-s ./configure +@end example + +The configuration process uses GCC to build Bash if it +is available. + +@node Compiling For Multiple Architectures +@section Compiling For Multiple Architectures + +You can compile Bash for more than one kind of computer at the +same time, by placing the object files for each architecture in their +own directory. To do this, you must use a version of @code{make} that +supports the @code{VPATH} variable, such as GNU @code{make}. +@code{cd} to the +directory where you want the object files and executables to go and run +the @code{configure} script from the source directory. You may need to +supply the @option{--srcdir=PATH} argument to tell @code{configure} where the +source files are. @code{configure} automatically checks for the +source code in the directory that @code{configure} is in and in `..'. + +If you have to use a @code{make} that does not supports the @code{VPATH} +variable, you can compile Bash for one architecture at a +time in the source code directory. After you have installed +Bash for one architecture, use @samp{make distclean} before +reconfiguring for another architecture. + +Alternatively, if your system supports symbolic links, you can use the +@file{support/mkclone} script to create a build tree which has +symbolic links back to each file in the source directory. Here's an +example that creates a build directory in the current directory from a +source directory @file{/usr/gnu/src/bash-2.0}: + +@example +bash /usr/gnu/src/bash-2.0/support/mkclone -s /usr/gnu/src/bash-2.0 . +@end example + +@noindent +The @code{mkclone} script requires Bash, so you must have already built +Bash for at least one architecture before you can create build +directories for other architectures. + +@node Installation Names +@section Installation Names + +By default, @samp{make install} will install into +@file{/usr/local/bin}, @file{/usr/local/man}, etc. You can +specify an installation prefix other than @file{/usr/local} by +giving @code{configure} the option @option{--prefix=@var{PATH}}, +or by specifying a value for the @code{DESTDIR} @samp{make} +variable when running @samp{make install}. + +You can specify separate installation prefixes for +architecture-specific files and architecture-independent files. +If you give @code{configure} the option +@option{--exec-prefix=@var{PATH}}, @samp{make install} will use +@var{PATH} as the prefix for installing programs and libraries. +Documentation and other data files will still use the regular prefix. + +@node Specifying the System Type +@section Specifying the System Type + +There may be some features @code{configure} can not figure out +automatically, but need to determine by the type of host Bash +will run on. Usually @code{configure} can figure that +out, but if it prints a message saying it can not guess the host +type, give it the @option{--host=TYPE} option. @samp{TYPE} can +either be a short name for the system type, such as @samp{sun4}, +or a canonical name with three fields: @samp{CPU-COMPANY-SYSTEM} +(e.g., @samp{i386-unknown-freebsd4.2}). + +See the file @file{support/config.sub} for the possible +values of each field. + +@node Sharing Defaults +@section Sharing Defaults + +If you want to set default values for @code{configure} scripts to +share, you can create a site shell script called +@code{config.site} that gives default values for variables like +@code{CC}, @code{cache_file}, and @code{prefix}. @code{configure} +looks for @file{PREFIX/share/config.site} if it exists, then +@file{PREFIX/etc/config.site} if it exists. Or, you can set the +@code{CONFIG_SITE} environment variable to the location of the site +script. A warning: the Bash @code{configure} looks for a site script, +but not all @code{configure} scripts do. + +@node Operation Controls +@section Operation Controls + +@code{configure} recognizes the following options to control how it +operates. + +@table @code + +@item --cache-file=@var{file} +Use and save the results of the tests in +@var{file} instead of @file{./config.cache}. Set @var{file} to +@file{/dev/null} to disable caching, for debugging +@code{configure}. + +@item --help +Print a summary of the options to @code{configure}, and exit. + +@item --quiet +@itemx --silent +@itemx -q +Do not print messages saying which checks are being made. + +@item --srcdir=@var{dir} +Look for the Bash source code in directory @var{dir}. Usually +@code{configure} can determine that directory automatically. + +@item --version +Print the version of Autoconf used to generate the @code{configure} +script, and exit. +@end table + +@code{configure} also accepts some other, not widely used, boilerplate +options. @samp{configure --help} prints the complete list. + +@node Optional Features +@section Optional Features + +The Bash @code{configure} has a number of @option{--enable-@var{feature}} +options, where @var{feature} indicates an optional part of Bash. +There are also several @option{--with-@var{package}} options, +where @var{package} is something like @samp{bash-malloc} or @samp{purify}. +To turn off the default use of a package, use +@option{--without-@var{package}}. To configure Bash without a feature +that is enabled by default, use @option{--disable-@var{feature}}. + +Here is a complete list of the @option{--enable-} and +@option{--with-} options that the Bash @code{configure} recognizes. + +@table @code +@item --with-afs +Define if you are using the Andrew File System from Transarc. + +@item --with-bash-malloc +Use the Bash version of +@code{malloc} in the directory @file{lib/malloc}. This is not the same +@code{malloc} that appears in @sc{gnu} libc, but an older version +originally derived from the 4.2 @sc{bsd} @code{malloc}. This @code{malloc} +is very fast, but wastes some space on each allocation. +This option is enabled by default. +The @file{NOTES} file contains a list of systems for +which this should be turned off, and @code{configure} disables this +option automatically for a number of systems. + +@item --with-curses +Use the curses library instead of the termcap library. This should +be supplied if your system has an inadequate or incomplete termcap +database. + +@item --with-gnu-malloc +A synonym for @code{--with-bash-malloc}. + +@item --with-installed-readline[=@var{PREFIX}] +Define this to make Bash link with a locally-installed version of Readline +rather than the version in @file{lib/readline}. This works only with +Readline 5.0 and later versions. If @var{PREFIX} is @code{yes} or not +supplied, @code{configure} uses the values of the make variables +@code{includedir} and @code{libdir}, which are subdirectories of @code{prefix} +by default, to find the installed version of Readline if it is not in +the standard system include and library directories. +If @var{PREFIX} is @code{no}, Bash links with the version in +@file{lib/readline}. +If @var{PREFIX} is set to any other value, @code{configure} treats it as +a directory pathname and looks for +the installed version of Readline in subdirectories of that directory +(include files in @var{PREFIX}/@code{include} and the library in +@var{PREFIX}/@code{lib}). + +@item --with-purify +Define this to use the Purify memory allocation checker from Rational +Software. + +@item --enable-minimal-config +This produces a shell with minimal features, close to the historical +Bourne shell. +@end table + +There are several @option{--enable-} options that alter how Bash is +compiled and linked, rather than changing run-time features. + +@table @code +@item --enable-largefile +Enable support for @uref{http://www.sas.com/standards/large_file/x_open.20Mar96.html, +large files} if the operating system requires special compiler options +to build programs which can access large files. This is enabled by +default, if the operating system provides large file support. + +@item --enable-profiling +This builds a Bash binary that produces profiling information to be +processed by @code{gprof} each time it is executed. + +@item --enable-static-link +This causes Bash to be linked statically, if @code{gcc} is being used. +This could be used to build a version to use as root's shell. +@end table + +The @samp{minimal-config} option can be used to disable all of +the following options, but it is processed first, so individual +options may be enabled using @samp{enable-@var{feature}}. + +All of the following options except for @samp{disabled-builtins}, +@samp{direxpand-default}, and +@samp{xpg-echo-default} are +enabled by default, unless the operating system does not provide the +necessary support. + +@table @code +@item --enable-alias +Allow alias expansion and include the @code{alias} and @code{unalias} +builtins (@pxref{Aliases}). + +@item --enable-arith-for-command +Include support for the alternate form of the @code{for} command +that behaves like the C language @code{for} statement +(@pxref{Looping Constructs}). + +@item --enable-array-variables +Include support for one-dimensional array shell variables +(@pxref{Arrays}). + +@item --enable-bang-history +Include support for @code{csh}-like history substitution +(@pxref{History Interaction}). + +@item --enable-brace-expansion +Include @code{csh}-like brace expansion +( @code{b@{a,b@}c} @expansion{} @code{bac bbc} ). +See @ref{Brace Expansion}, for a complete description. + +@item --enable-casemod-attributes +Include support for case-modifying attributes in the @code{declare} builtin +and assignment statements. Variables with the @var{uppercase} attribute, +for example, will have their values converted to uppercase upon assignment. + +@item --enable-casemod-expansion +Include support for case-modifying word expansions. + +@item --enable-command-timing +Include support for recognizing @code{time} as a reserved word and for +displaying timing statistics for the pipeline following @code{time} +(@pxref{Pipelines}). +This allows pipelines as well as shell builtins and functions to be timed. + +@item --enable-cond-command +Include support for the @code{[[} conditional command. +(@pxref{Conditional Constructs}). + +@item --enable-cond-regexp +Include support for matching @sc{posix} regular expressions using the +@samp{=~} binary operator in the @code{[[} conditional command. +(@pxref{Conditional Constructs}). + +@item --enable-coprocesses +Include support for coprocesses and the @code{coproc} reserved word +(@pxref{Pipelines}). + +@item --enable-debugger +Include support for the bash debugger (distributed separately). + +@item --enable-direxpand-default +Cause the @code{direxpand} shell option (@pxref{The Shopt Builtin}) +to be enabled by default when the shell starts. +It is normally disabled by default. + +@item --enable-directory-stack +Include support for a @code{csh}-like directory stack and the +@code{pushd}, @code{popd}, and @code{dirs} builtins +(@pxref{The Directory Stack}). + +@item --enable-disabled-builtins +Allow builtin commands to be invoked via @samp{builtin xxx} +even after @code{xxx} has been disabled using @samp{enable -n xxx}. +See @ref{Bash Builtins}, for details of the @code{builtin} and +@code{enable} builtin commands. + +@item --enable-dparen-arithmetic +Include support for the @code{((@dots{}))} command +(@pxref{Conditional Constructs}). + +@item --enable-extended-glob +Include support for the extended pattern matching features described +above under @ref{Pattern Matching}. + +@item --enable-extended-glob-default +Set the default value of the @var{extglob} shell option described +above under @ref{The Shopt Builtin} to be enabled. + +@item --enable-function-import +Include support for importing function definitions exported by another +instance of the shell from the environment. This option is enabled by +default. + +@item --enable-glob-asciirange-default +Set the default value of the @var{globasciiranges} shell option described +above under @ref{The Shopt Builtin} to be enabled. +This controls the behavior of character ranges when used in pattern matching +bracket expressions. + +@item --enable-help-builtin +Include the @code{help} builtin, which displays help on shell builtins and +variables (@pxref{Bash Builtins}). + +@item --enable-history +Include command history and the @code{fc} and @code{history} +builtin commands (@pxref{Bash History Facilities}). + +@item --enable-job-control +This enables the job control features (@pxref{Job Control}), +if the operating system supports them. + +@item --enable-multibyte +This enables support for multibyte characters if the operating +system provides the necessary support. + +@item --enable-net-redirections +This enables the special handling of filenames of the form +@code{/dev/tcp/@var{host}/@var{port}} and +@code{/dev/udp/@var{host}/@var{port}} +when used in redirections (@pxref{Redirections}). + +@item --enable-process-substitution +This enables process substitution (@pxref{Process Substitution}) if +the operating system provides the necessary support. + +@item --enable-progcomp +Enable the programmable completion facilities +(@pxref{Programmable Completion}). +If Readline is not enabled, this option has no effect. + +@item --enable-prompt-string-decoding +Turn on the interpretation of a number of backslash-escaped characters +in the @env{$PS1}, @env{$PS2}, @env{$PS3}, and @env{$PS4} prompt +strings. See @ref{Controlling the Prompt}, for a complete list of prompt +string escape sequences. + +@item --enable-readline +Include support for command-line editing and history with the Bash +version of the Readline library (@pxref{Command Line Editing}). + +@item --enable-restricted +Include support for a @dfn{restricted shell}. If this is enabled, Bash, +when called as @code{rbash}, enters a restricted mode. See +@ref{The Restricted Shell}, for a description of restricted mode. + +@item --enable-select +Include the @code{select} compound command, which allows the generation of +simple menus (@pxref{Conditional Constructs}). + +@item --enable-separate-helpfiles +Use external files for the documentation displayed by the @code{help} builtin +instead of storing the text internally. + +@item --enable-single-help-strings +Store the text displayed by the @code{help} builtin as a single string for +each help topic. This aids in translating the text to different languages. +You may need to disable this if your compiler cannot handle very long string +literals. + +@item --enable-strict-posix-default +Make Bash @sc{posix}-conformant by default (@pxref{Bash POSIX Mode}). + +@item --enable-usg-echo-default +A synonym for @code{--enable-xpg-echo-default}. + +@item --enable-xpg-echo-default +Make the @code{echo} builtin expand backslash-escaped characters by default, +without requiring the @option{-e} option. +This sets the default value of the @code{xpg_echo} shell option to @code{on}, +which makes the Bash @code{echo} behave more like the version specified in +the Single Unix Specification, version 3. +@xref{Bash Builtins}, for a description of the escape sequences that +@code{echo} recognizes. +@end table + +The file @file{config-top.h} contains C Preprocessor +@samp{#define} statements for options which are not settable from +@code{configure}. +Some of these are not meant to be changed; beware of the consequences if +you do. +Read the comments associated with each definition for more +information about its effect. + +@node Reporting Bugs +@appendix Reporting Bugs + +Please report all bugs you find in Bash. +But first, you should +make sure that it really is a bug, and that it appears in the latest +version of Bash. +The latest version of Bash is always available for FTP from +@uref{ftp://ftp.gnu.org/pub/gnu/bash/}. + +Once you have determined that a bug actually exists, use the +@code{bashbug} command to submit a bug report. +If you have a fix, you are encouraged to mail that as well! +Suggestions and `philosophical' bug reports may be mailed +to @email{bug-bash@@gnu.org} or posted to the Usenet +newsgroup @code{gnu.bash.bug}. + +All bug reports should include: +@itemize @bullet +@item +The version number of Bash. +@item +The hardware and operating system. +@item +The compiler used to compile Bash. +@item +A description of the bug behaviour. +@item +A short script or `recipe' which exercises the bug and may be used +to reproduce it. +@end itemize + +@noindent +@code{bashbug} inserts the first three items automatically into +the template it provides for filing a bug report. + +Please send all reports concerning this manual to +@email{bug-bash@@gnu.org}. + +@node Major Differences From The Bourne Shell +@appendix Major Differences From The Bourne Shell + +Bash implements essentially the same grammar, parameter and +variable expansion, redirection, and quoting as the Bourne Shell. +Bash uses the @sc{posix} standard as the specification of +how these features are to be implemented. There are some +differences between the traditional Bourne shell and Bash; this +section quickly details the differences of significance. A +number of these differences are explained in greater depth in +previous sections. +This section uses the version of @code{sh} included in SVR4.2 (the +last version of the historical Bourne shell) as the baseline reference. + +@itemize @bullet + +@item +Bash is @sc{posix}-conformant, even where the @sc{posix} specification +differs from traditional @code{sh} behavior (@pxref{Bash POSIX Mode}). + +@item +Bash has multi-character invocation options (@pxref{Invoking Bash}). + +@item +Bash has command-line editing (@pxref{Command Line Editing}) and +the @code{bind} builtin. + +@item +Bash provides a programmable word completion mechanism +(@pxref{Programmable Completion}), and builtin commands +@code{complete}, @code{compgen}, and @code{compopt}, to +manipulate it. + +@item +Bash has command history (@pxref{Bash History Facilities}) and the +@code{history} and @code{fc} builtins to manipulate it. +The Bash history list maintains timestamp information and uses the +value of the @code{HISTTIMEFORMAT} variable to display it. + +@item +Bash implements @code{csh}-like history expansion +(@pxref{History Interaction}). + +@item +Bash has one-dimensional array variables (@pxref{Arrays}), and the +appropriate variable expansions and assignment syntax to use them. +Several of the Bash builtins take options to act on arrays. +Bash provides a number of built-in array variables. + +@item +The @code{$'@dots{}'} quoting syntax, which expands ANSI-C +backslash-escaped characters in the text between the single quotes, +is supported (@pxref{ANSI-C Quoting}). + +@item +Bash supports the @code{$"@dots{}"} quoting syntax to do +locale-specific translation of the characters between the double +quotes. The @option{-D}, @option{--dump-strings}, and @option{--dump-po-strings} +invocation options list the translatable strings found in a script +(@pxref{Locale Translation}). + +@item +Bash implements the @code{!} keyword to negate the return value of +a pipeline (@pxref{Pipelines}). +Very useful when an @code{if} statement needs to act only if a test fails. +The Bash @samp{-o pipefail} option to @code{set} will cause a pipeline to +return a failure status if any command fails. + +@item +Bash has the @code{time} reserved word and command timing (@pxref{Pipelines}). +The display of the timing statistics may be controlled with the +@env{TIMEFORMAT} variable. + +@item +Bash implements the @code{for (( @var{expr1} ; @var{expr2} ; @var{expr3} ))} +arithmetic for command, similar to the C language (@pxref{Looping Constructs}). + +@item +Bash includes the @code{select} compound command, which allows the +generation of simple menus (@pxref{Conditional Constructs}). + +@item +Bash includes the @code{[[} compound command, which makes conditional +testing part of the shell grammar (@pxref{Conditional Constructs}), including +optional regular expression matching. + +@item +Bash provides optional case-insensitive matching for the @code{case} and +@code{[[} constructs. + +@item +Bash includes brace expansion (@pxref{Brace Expansion}) and tilde +expansion (@pxref{Tilde Expansion}). + +@item +Bash implements command aliases and the @code{alias} and @code{unalias} +builtins (@pxref{Aliases}). + +@item +Bash provides shell arithmetic, the @code{((} compound command +(@pxref{Conditional Constructs}), +and arithmetic expansion (@pxref{Shell Arithmetic}). + +@item +Variables present in the shell's initial environment are automatically +exported to child processes. The Bourne shell does not normally do +this unless the variables are explicitly marked using the @code{export} +command. + +@item +Bash supports the @samp{+=} assignment operator, which appends to the value +of the variable named on the left hand side. + +@item +Bash includes the @sc{posix} pattern removal @samp{%}, @samp{#}, @samp{%%} +and @samp{##} expansions to remove leading or trailing substrings from +variable values (@pxref{Shell Parameter Expansion}). + +@item +The expansion @code{$@{#xx@}}, which returns the length of @code{$@{xx@}}, +is supported (@pxref{Shell Parameter Expansion}). + +@item +The expansion @code{$@{var:}@var{offset}@code{[:}@var{length}@code{]@}}, +which expands to the substring of @code{var}'s value of length +@var{length}, beginning at @var{offset}, is present +(@pxref{Shell Parameter Expansion}). + +@item +The expansion +@code{$@{var/[/]}@var{pattern}@code{[/}@var{replacement}@code{]@}}, +which matches @var{pattern} and replaces it with @var{replacement} in +the value of @code{var}, is available (@pxref{Shell Parameter Expansion}). + +@item +The expansion @code{$@{!@var{prefix}*@}} expansion, which expands to +the names of all shell variables whose names begin with @var{prefix}, +is available (@pxref{Shell Parameter Expansion}). + +@item +Bash has @var{indirect} variable expansion using @code{$@{!word@}} +(@pxref{Shell Parameter Expansion}). + +@item +Bash can expand positional parameters beyond @code{$9} using +@code{$@{@var{num}@}}. + +@item +The @sc{posix} @code{$()} form of command substitution +is implemented (@pxref{Command Substitution}), +and preferred to the Bourne shell's @code{``} (which +is also implemented for backwards compatibility). + +@item +Bash has process substitution (@pxref{Process Substitution}). + +@item +Bash automatically assigns variables that provide information about the +current user (@env{UID}, @env{EUID}, and @env{GROUPS}), the current host +(@env{HOSTTYPE}, @env{OSTYPE}, @env{MACHTYPE}, and @env{HOSTNAME}), +and the instance of Bash that is running (@env{BASH}, +@env{BASH_VERSION}, and @env{BASH_VERSINFO}). @xref{Bash Variables}, +for details. + +@item +The @env{IFS} variable is used to split only the results of expansion, +not all words (@pxref{Word Splitting}). +This closes a longstanding shell security hole. + +@item +The filename expansion bracket expression code uses @samp{!} and @samp{^} +to negate the set of characters between the brackets. +The Bourne shell uses only @samp{!}. + +@item +Bash implements the full set of @sc{posix} filename expansion operators, +including @var{character classes}, @var{equivalence classes}, and +@var{collating symbols} (@pxref{Filename Expansion}). + +@item +Bash implements extended pattern matching features when the @code{extglob} +shell option is enabled (@pxref{Pattern Matching}). + +@item +It is possible to have a variable and a function with the same name; +@code{sh} does not separate the two name spaces. + +@item +Bash functions are permitted to have local variables using the +@code{local} builtin, and thus useful recursive functions may be written +(@pxref{Bash Builtins}). + +@item +Variable assignments preceding commands affect only that command, even +builtins and functions (@pxref{Environment}). +In @code{sh}, all variable assignments +preceding commands are global unless the command is executed from the +file system. + +@item +Bash performs filename expansion on filenames specified as operands +to input and output redirection operators (@pxref{Redirections}). + +@item +Bash contains the @samp{<>} redirection operator, allowing a file to be +opened for both reading and writing, and the @samp{&>} redirection +operator, for directing standard output and standard error to the same +file (@pxref{Redirections}). + +@item +Bash includes the @samp{<<<} redirection operator, allowing a string to +be used as the standard input to a command. + +@item +Bash implements the @samp{[n]<&@var{word}} and @samp{[n]>&@var{word}} +redirection operators, which move one file descriptor to another. + +@item +Bash treats a number of filenames specially when they are +used in redirection operators (@pxref{Redirections}). + +@item +Bash can open network connections to arbitrary machines and services +with the redirection operators (@pxref{Redirections}). + +@item +The @code{noclobber} option is available to avoid overwriting existing +files with output redirection (@pxref{The Set Builtin}). +The @samp{>|} redirection operator may be used to override @code{noclobber}. + +@item +The Bash @code{cd} and @code{pwd} builtins (@pxref{Bourne Shell Builtins}) +each take @option{-L} and @option{-P} options to switch between logical and +physical modes. + +@item +Bash allows a function to override a builtin with the same name, and provides +access to that builtin's functionality within the function via the +@code{builtin} and @code{command} builtins (@pxref{Bash Builtins}). + +@item +The @code{command} builtin allows selective disabling of functions +when command lookup is performed (@pxref{Bash Builtins}). + +@item +Individual builtins may be enabled or disabled using the @code{enable} +builtin (@pxref{Bash Builtins}). + +@item +The Bash @code{exec} builtin takes additional options that allow users +to control the contents of the environment passed to the executed +command, and what the zeroth argument to the command is to be +(@pxref{Bourne Shell Builtins}). + +@item +Shell functions may be exported to children via the environment +using @code{export -f} (@pxref{Shell Functions}). + +@item +The Bash @code{export}, @code{readonly}, and @code{declare} builtins can +take a @option{-f} option to act on shell functions, a @option{-p} option to +display variables with various attributes set in a format that can be +used as shell input, a @option{-n} option to remove various variable +attributes, and @samp{name=value} arguments to set variable attributes +and values simultaneously. + +@item +The Bash @code{hash} builtin allows a name to be associated with +an arbitrary filename, even when that filename cannot be found by +searching the @env{$PATH}, using @samp{hash -p} +(@pxref{Bourne Shell Builtins}). + +@item +Bash includes a @code{help} builtin for quick reference to shell +facilities (@pxref{Bash Builtins}). + +@item +The @code{printf} builtin is available to display formatted output +(@pxref{Bash Builtins}). + +@item +The Bash @code{read} builtin (@pxref{Bash Builtins}) +will read a line ending in @samp{\} with +the @option{-r} option, and will use the @env{REPLY} variable as a +default if no non-option arguments are supplied. +The Bash @code{read} builtin +also accepts a prompt string with the @option{-p} option and will use +Readline to obtain the line when given the @option{-e} option. +The @code{read} builtin also has additional options to control input: +the @option{-s} option will turn off echoing of input characters as +they are read, the @option{-t} option will allow @code{read} to time out +if input does not arrive within a specified number of seconds, the +@option{-n} option will allow reading only a specified number of +characters rather than a full line, and the @option{-d} option will read +until a particular character rather than newline. + +@item +The @code{return} builtin may be used to abort execution of scripts +executed with the @code{.} or @code{source} builtins +(@pxref{Bourne Shell Builtins}). + +@item +Bash includes the @code{shopt} builtin, for finer control of shell +optional capabilities (@pxref{The Shopt Builtin}), and allows these options +to be set and unset at shell invocation (@pxref{Invoking Bash}). + +@item +Bash has much more optional behavior controllable with the @code{set} +builtin (@pxref{The Set Builtin}). + +@item +The @samp{-x} (@option{xtrace}) option displays commands other than +simple commands when performing an execution trace +(@pxref{The Set Builtin}). + +@item +The @code{test} builtin (@pxref{Bourne Shell Builtins}) +is slightly different, as it implements the @sc{posix} algorithm, +which specifies the behavior based on the number of arguments. + +@item +Bash includes the @code{caller} builtin, which displays the context of +any active subroutine call (a shell function or a script executed with +the @code{.} or @code{source} builtins). This supports the bash +debugger. + +@item +The @code{trap} builtin (@pxref{Bourne Shell Builtins}) allows a +@code{DEBUG} pseudo-signal specification, similar to @code{EXIT}. +Commands specified with a @code{DEBUG} trap are executed before every +simple command, @code{for} command, @code{case} command, +@code{select} command, every arithmetic @code{for} command, and before +the first command executes in a shell function. +The @code{DEBUG} trap is not inherited by shell functions unless the +function has been given the @code{trace} attribute or the +@code{functrace} option has been enabled using the @code{shopt} builtin. +The @code{extdebug} shell option has additional effects on the +@code{DEBUG} trap. + +The @code{trap} builtin (@pxref{Bourne Shell Builtins}) allows an +@code{ERR} pseudo-signal specification, similar to @code{EXIT} and @code{DEBUG}. +Commands specified with an @code{ERR} trap are executed after a simple +command fails, with a few exceptions. +The @code{ERR} trap is not inherited by shell functions unless the +@code{-o errtrace} option to the @code{set} builtin is enabled. + +The @code{trap} builtin (@pxref{Bourne Shell Builtins}) allows a +@code{RETURN} pseudo-signal specification, similar to +@code{EXIT} and @code{DEBUG}. +Commands specified with an @code{RETURN} trap are executed before +execution resumes after a shell function or a shell script executed with +@code{.} or @code{source} returns. +The @code{RETURN} trap is not inherited by shell functions unless the +function has been given the @code{trace} attribute or the +@code{functrace} option has been enabled using the @code{shopt} builtin. + +@item +The Bash @code{type} builtin is more extensive and gives more information +about the names it finds (@pxref{Bash Builtins}). + +@item +The Bash @code{umask} builtin permits a @option{-p} option to cause +the output to be displayed in the form of a @code{umask} command +that may be reused as input (@pxref{Bourne Shell Builtins}). + +@item +Bash implements a @code{csh}-like directory stack, and provides the +@code{pushd}, @code{popd}, and @code{dirs} builtins to manipulate it +(@pxref{The Directory Stack}). +Bash also makes the directory stack visible as the value of the +@env{DIRSTACK} shell variable. + +@item +Bash interprets special backslash-escaped characters in the prompt +strings when interactive (@pxref{Controlling the Prompt}). + +@item +The Bash restricted mode is more useful (@pxref{The Restricted Shell}); +the SVR4.2 shell restricted mode is too limited. + +@item +The @code{disown} builtin can remove a job from the internal shell +job table (@pxref{Job Control Builtins}) or suppress the sending +of @code{SIGHUP} to a job when the shell exits as the result of a +@code{SIGHUP}. + +@item +Bash includes a number of features to support a separate debugger for +shell scripts. + +@item +The SVR4.2 shell has two privilege-related builtins +(@code{mldmode} and @code{priv}) not present in Bash. + +@item +Bash does not have the @code{stop} or @code{newgrp} builtins. + +@item +Bash does not use the @env{SHACCT} variable or perform shell accounting. + +@item +The SVR4.2 @code{sh} uses a @env{TIMEOUT} variable like Bash uses +@env{TMOUT}. + +@end itemize + +@noindent +More features unique to Bash may be found in @ref{Bash Features}. + + +@appendixsec Implementation Differences From The SVR4.2 Shell + +Since Bash is a completely new implementation, it does not suffer from +many of the limitations of the SVR4.2 shell. For instance: + +@itemize @bullet + +@item +Bash does not fork a subshell when redirecting into or out of +a shell control structure such as an @code{if} or @code{while} +statement. + +@item +Bash does not allow unbalanced quotes. The SVR4.2 shell will silently +insert a needed closing quote at @code{EOF} under certain circumstances. +This can be the cause of some hard-to-find errors. + +@item +The SVR4.2 shell uses a baroque memory management scheme based on +trapping @code{SIGSEGV}. If the shell is started from a process with +@code{SIGSEGV} blocked (e.g., by using the @code{system()} C library +function call), it misbehaves badly. + +@item +In a questionable attempt at security, the SVR4.2 shell, +when invoked without the @option{-p} option, will alter its real +and effective @sc{uid} and @sc{gid} if they are less than some +magic threshold value, commonly 100. +This can lead to unexpected results. + +@item +The SVR4.2 shell does not allow users to trap @code{SIGSEGV}, +@code{SIGALRM}, or @code{SIGCHLD}. + +@item +The SVR4.2 shell does not allow the @env{IFS}, @env{MAILCHECK}, +@env{PATH}, @env{PS1}, or @env{PS2} variables to be unset. + +@item +The SVR4.2 shell treats @samp{^} as the undocumented equivalent of +@samp{|}. + +@item +Bash allows multiple option arguments when it is invoked (@code{-x -v}); +the SVR4.2 shell allows only one option argument (@code{-xv}). In +fact, some versions of the shell dump core if the second argument begins +with a @samp{-}. + +@item +The SVR4.2 shell exits a script if any builtin fails; Bash exits +a script only if one of the @sc{posix} special builtins fails, and +only for certain failures, as enumerated in the @sc{posix} standard. + +@item +The SVR4.2 shell behaves differently when invoked as @code{jsh} +(it turns on job control). +@end itemize + +@node GNU Free Documentation License +@appendix GNU Free Documentation License + +@include fdl.texi + +@node Indexes +@appendix Indexes + +@menu +* Builtin Index:: Index of Bash builtin commands. +* Reserved Word Index:: Index of Bash reserved words. +* Variable Index:: Quick reference helps you find the + variable you want. +* Function Index:: Index of bindable Readline functions. +* Concept Index:: General index for concepts described in + this manual. +@end menu + +@node Builtin Index +@appendixsec Index of Shell Builtin Commands +@printindex bt + +@node Reserved Word Index +@appendixsec Index of Shell Reserved Words +@printindex rw + +@node Variable Index +@appendixsec Parameter and Variable Index +@printindex vr + +@node Function Index +@appendixsec Function Index +@printindex fn + +@node Concept Index +@appendixsec Concept Index +@printindex cp + +@bye diff --git a/doc/version.texi b/doc/version.texi index 587db9047..5208b0a9f 100644 --- a/doc/version.texi +++ b/doc/version.texi @@ -2,10 +2,10 @@ Copyright (C) 1988-2014 Free Software Foundation, Inc. @end ignore -@set LASTCHANGE Fri Nov 28 18:36:44 EST 2014 +@set LASTCHANGE Sat Dec 20 13:52:20 EST 2014 @set EDITION 4.3 @set VERSION 4.3 -@set UPDATED 28 November 2014 -@set UPDATED-MONTH November 2014 +@set UPDATED 20 December 2014 +@set UPDATED-MONTH December 2014 diff --git a/doc/version.texi~ b/doc/version.texi~ new file mode 100644 index 000000000..587db9047 --- /dev/null +++ b/doc/version.texi~ @@ -0,0 +1,11 @@ +@ignore +Copyright (C) 1988-2014 Free Software Foundation, Inc. +@end ignore + +@set LASTCHANGE Fri Nov 28 18:36:44 EST 2014 + +@set EDITION 4.3 +@set VERSION 4.3 + +@set UPDATED 28 November 2014 +@set UPDATED-MONTH November 2014 diff --git a/examples/loadables/Makefile.in.save b/examples/loadables/Makefile.in.save new file mode 100644 index 000000000..f6208f5cc --- /dev/null +++ b/examples/loadables/Makefile.in.save @@ -0,0 +1,238 @@ +# +# Simple makefile for the sample loadable builtins +# +# Copyright (C) 1996 Free Software Foundation, Inc. + +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2, or (at your option) +# any later version. + +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. + +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111 USA. + +# Include some boilerplate Gnu makefile definitions. +prefix = @prefix@ + +exec_prefix = @exec_prefix@ +bindir = @bindir@ +libdir = @libdir@ +infodir = @infodir@ +includedir = @includedir@ + +topdir = @top_srcdir@ +BUILD_DIR = @BUILD_DIR@ +srcdir = @srcdir@ +VPATH = .:@srcdir@ + +@SET_MAKE@ +CC = @CC@ +RM = rm -f + +SHELL = @MAKE_SHELL@ + +host_os = @host_os@ +host_cpu = @host_cpu@ +host_vendor = @host_vendor@ + +CFLAGS = @CFLAGS@ +LOCAL_CFLAGS = @LOCAL_CFLAGS@ +DEFS = @DEFS@ +LOCAL_DEFS = @LOCAL_DEFS@ + +CPPFLAGS = @CPPFLAGS@ + +BASHINCDIR = ${topdir}/include + +LIBBUILD = ${BUILD_DIR}/lib + +INTL_LIBSRC = ${topdir}/lib/intl +INTL_BUILDDIR = ${LIBBUILD}/intl +INTL_INC = @INTL_INC@ +LIBINTL_H = @LIBINTL_H@ + +CCFLAGS = $(DEFS) $(LOCAL_DEFS) $(LOCAL_CFLAGS) $(CFLAGS) + +# +# These values are generated for configure by ${topdir}/support/shobj-conf. +# If your system is not supported by that script, but includes facilities for +# dynamic loading of shared objects, please update the script and send the +# changes to bash-maintainers@gnu.org. +# +SHOBJ_CC = @SHOBJ_CC@ +SHOBJ_CFLAGS = @SHOBJ_CFLAGS@ +SHOBJ_LD = @SHOBJ_LD@ +SHOBJ_LDFLAGS = @SHOBJ_LDFLAGS@ +SHOBJ_XLDFLAGS = @SHOBJ_XLDFLAGS@ +SHOBJ_LIBS = @SHOBJ_LIBS@ +SHOBJ_STATUS = @SHOBJ_STATUS@ + +INC = -I. -I.. -I$(topdir) -I$(topdir)/lib -I$(topdir)/builtins \ + -I$(BASHINCDIR) -I$(BUILD_DIR) -I$(LIBBUILD) \ + -I$(BUILD_DIR)/builtins $(INTL_INC) + +.c.o: + $(SHOBJ_CC) $(SHOBJ_CFLAGS) $(CCFLAGS) $(INC) -c -o $@ $< + + +ALLPROG = print truefalse sleep pushd finfo logname basename dirname \ + tty pathchk tee head mkdir rmdir printenv id whoami \ + uname sync push ln unlink cut realpath getconf strftime +OTHERPROG = necho hello cat + +all: $(SHOBJ_STATUS) + +supported: $(ALLPROG) +others: $(OTHERPROG) + +unsupported: + @echo "Your system (${host_os}) is not supported by the" + @echo "${topdir}/support/shobj-conf script." + @echo "If your operating system provides facilities for dynamic" + @echo "loading of shared objects using the dlopen(3) interface," + @echo "please update the script and re-run configure. + @echo "Please send the changes you made to bash-maintainers@gnu.org" + @echo "for inclusion in future bash releases." + +everything: supported others + +print: print.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ print.o $(SHOBJ_LIBS) + +necho: necho.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ necho.o $(SHOBJ_LIBS) + +getconf: getconf.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ getconf.o $(SHOBJ_LIBS) + +hello: hello.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ hello.o $(SHOBJ_LIBS) + +truefalse: truefalse.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ truefalse.o $(SHOBJ_LIBS) + +sleep: sleep.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ sleep.o $(SHOBJ_LIBS) + +finfo: finfo.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ finfo.o $(SHOBJ_LIBS) + +cat: cat.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ cat.o $(SHOBJ_LIBS) + +logname: logname.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ logname.o $(SHOBJ_LIBS) + +basename: basename.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ basename.o $(SHOBJ_LIBS) + +dirname: dirname.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ dirname.o $(SHOBJ_LIBS) + +tty: tty.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ tty.o $(SHOBJ_LIBS) + +pathchk: pathchk.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ pathchk.o $(SHOBJ_LIBS) + +tee: tee.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ tee.o $(SHOBJ_LIBS) + +mkdir: mkdir.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ mkdir.o $(SHOBJ_LIBS) + +rmdir: rmdir.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ rmdir.o $(SHOBJ_LIBS) + +head: head.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ head.o $(SHOBJ_LIBS) + +printenv: printenv.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ printenv.o $(SHOBJ_LIBS) + +id: id.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ id.o $(SHOBJ_LIBS) + +whoami: whoami.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ whoami.o $(SHOBJ_LIBS) + +uname: uname.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ uname.o $(SHOBJ_LIBS) + +sync: sync.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ sync.o $(SHOBJ_LIBS) + +push: push.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ push.o $(SHOBJ_LIBS) + +ln: ln.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ ln.o $(SHOBJ_LIBS) + +unlink: unlink.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ unlink.o $(SHOBJ_LIBS) + +cut: cut.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ cut.o $(SHOBJ_LIBS) + +realpath: realpath.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ realpath.o $(SHOBJ_LIBS) + +strftime: strftime.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ strftime.o $(SHOBJ_LIBS) + +# pushd is a special case. We use the same source that the builtin version +# uses, with special compilation options. +# +pushd.c: ${topdir}/builtins/pushd.def + $(RM) $@ + ${BUILD_DIR}/builtins/mkbuiltins -D ${topdir}/builtins ${topdir}/builtins/pushd.def + +pushd.o: pushd.c + $(RM) $@ + $(SHOBJ_CC) -DHAVE_CONFIG_H -DPUSHD_AND_POPD -DLOADABLE_BUILTIN $(SHOBJ_CFLAGS) $(CFLAGS) $(CPPFLAGS) $(INC) -c -o $@ $< + +pushd: pushd.o + $(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ pushd.o $(SHOBJ_LIBS) + +clean: + $(RM) $(ALLPROG) $(OTHERPROG) *.o + -( cd perl && ${MAKE} ${MFLAGS} $@ ) + +mostlyclean: clean + -( cd perl && ${MAKE} ${MFLAGS} $@ ) + +distclean maintainer-clean: clean + $(RM) Makefile pushd.c + -( cd perl && ${MAKE} ${MFLAGS} $@ ) + +print.o: print.c +truefalse.o: truefalse.c +sleep.o: sleep.c +finfo.o: finfo.c +logname.o: logname.c +basename.o: basename.c +dirname.o: dirname.c +tty.o: tty.c +pathchk.o: pathchk.c +tee.o: tee.c +head.o: head.c +rmdir.o: rmdir.c +necho.o: necho.c +getconf.o: getconf.c +hello.o: hello.c +cat.o: cat.c +printenv.o: printenv.c +id.o: id.c +whoami.o: whoami.c +uname.o: uname.c +sync.o: sync.c +push.o: push.c +mkdir.o: mkdir.c +realpath.o: realpath.c +strftime.o: strftime.c diff --git a/execute_cmd.c b/execute_cmd.c index 5864d1da8..ea7e5c690 100644 --- a/execute_cmd.c +++ b/execute_cmd.c @@ -3876,13 +3876,11 @@ fix_assignment_words (words) #endif if (global) w->word->flags |= W_ASSNGLOBAL; - if (integer) - w->word->flags |= W_ASSIGNINT; } #if defined (ARRAY_VARS) /* Note that we saw an associative array option to a builtin that takes assignment statements. This is a bit of a kludge. */ - else if (w->word->word[0] == '-' && (strchr (w->word->word+1, 'A') || strchr (w->word->word+1, 'a') || strchr (w->word->word+1, 'g'))) + else if (w->word->word[0] == '-' && (strpbrk (w->word->word+1, "Aag") != 0)) #else else if (w->word->word[0] == '-' && strchr (w->word->word+1, 'g')) #endif @@ -3903,8 +3901,6 @@ fix_assignment_words (words) array = 1; if ((wcmd->word->flags & W_ASSNBLTIN) && strchr (w->word->word+1, 'g')) global = 1; - if ((wcmd->word->flags & W_ASSNBLTIN) && strchr (w->word->word+1, 'i')) - integer = 1; } } diff --git a/lib/readline/complete.c.debug b/lib/readline/complete.c.debug new file mode 100644 index 000000000..00df4c76b --- /dev/null +++ b/lib/readline/complete.c.debug @@ -0,0 +1,2957 @@ +/* complete.c -- filename completion for readline. */ + +/* Copyright (C) 1987-2014 Free Software Foundation, Inc. + + This file is part of the GNU Readline Library (Readline), a library + for reading lines of text with interactive input and history editing. + + Readline is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + Readline is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with Readline. If not, see . +*/ + +#define READLINE_LIBRARY + +#if defined (HAVE_CONFIG_H) +# include +#endif + +#include +#include +#if defined (HAVE_SYS_FILE_H) +# include +#endif + +#include + +#if defined (HAVE_UNISTD_H) +# include +#endif /* HAVE_UNISTD_H */ + +#if defined (HAVE_STDLIB_H) +# include +#else +# include "ansi_stdlib.h" +#endif /* HAVE_STDLIB_H */ + +#include + +#include +#if !defined (errno) +extern int errno; +#endif /* !errno */ + +#if defined (HAVE_PWD_H) +#include +#endif + +#include "posixdir.h" +#include "posixstat.h" + +/* System-specific feature definitions and include files. */ +#include "rldefs.h" +#include "rlmbutil.h" + +/* Some standard library routines. */ +#include "readline.h" +#include "xmalloc.h" +#include "rlprivate.h" + +#if defined (COLOR_SUPPORT) +# include "colors.h" +#endif + +#ifdef __STDC__ +typedef int QSFUNC (const void *, const void *); +#else +typedef int QSFUNC (); +#endif + +#ifdef HAVE_LSTAT +# define LSTAT lstat +#else +# define LSTAT stat +#endif + +/* Unix version of a hidden file. Could be different on other systems. */ +#define HIDDEN_FILE(fname) ((fname)[0] == '.') + +/* Most systems don't declare getpwent in if _POSIX_SOURCE is + defined. */ +#if defined (HAVE_GETPWENT) && (!defined (HAVE_GETPW_DECLS) || defined (_POSIX_SOURCE)) +extern struct passwd *getpwent PARAMS((void)); +#endif /* HAVE_GETPWENT && (!HAVE_GETPW_DECLS || _POSIX_SOURCE) */ + +/* If non-zero, then this is the address of a function to call when + completing a word would normally display the list of possible matches. + This function is called instead of actually doing the display. + It takes three arguments: (char **matches, int num_matches, int max_length) + where MATCHES is the array of strings that matched, NUM_MATCHES is the + number of strings in that array, and MAX_LENGTH is the length of the + longest string in that array. */ +rl_compdisp_func_t *rl_completion_display_matches_hook = (rl_compdisp_func_t *)NULL; + +#if defined (VISIBLE_STATS) || defined (COLOR_SUPPORT) +# if !defined (X_OK) +# define X_OK 1 +# endif +#endif + +#if defined (VISIBLE_STATS) +static int stat_char PARAMS((char *)); +#endif + +#if defined (COLOR_SUPPORT) +static int colored_stat_start PARAMS((char *)); +static void colored_stat_end PARAMS((void)); +static int colored_prefix_start PARAMS((void)); +static void colored_prefix_end PARAMS((void)); +#endif + +static int path_isdir PARAMS((const char *)); + +static char *rl_quote_filename PARAMS((char *, int, char *)); + +static void _rl_complete_sigcleanup PARAMS((int, void *)); + +static void set_completion_defaults PARAMS((int)); +static int get_y_or_n PARAMS((int)); +static int _rl_internal_pager PARAMS((int)); +static char *printable_part PARAMS((char *)); +static int fnwidth PARAMS((const char *)); +static int fnprint PARAMS((const char *, int)); +static int print_filename PARAMS((char *, char *, int)); + +static char **gen_completion_matches PARAMS((char *, int, int, rl_compentry_func_t *, int, int)); + +static char **remove_duplicate_matches PARAMS((char **)); +static void insert_match PARAMS((char *, int, int, char *)); +static int append_to_match PARAMS((char *, int, int, int)); +static void insert_all_matches PARAMS((char **, int, char *)); +static int complete_fncmp PARAMS((const char *, int, const char *, int)); +static void display_matches PARAMS((char **)); +static int compute_lcd_of_matches PARAMS((char **, int, const char *)); +static int postprocess_matches PARAMS((char ***, int)); +static int complete_get_screenwidth PARAMS((void)); + +static char *make_quoted_replacement PARAMS((char *, int, char *)); + +/* **************************************************************** */ +/* */ +/* Completion matching, from readline's point of view. */ +/* */ +/* **************************************************************** */ + +/* Variables known only to the readline library. */ + +/* If non-zero, non-unique completions always show the list of matches. */ +int _rl_complete_show_all = 0; + +/* If non-zero, non-unique completions show the list of matches, unless it + is not possible to do partial completion and modify the line. */ +int _rl_complete_show_unmodified = 0; + +/* If non-zero, completed directory names have a slash appended. */ +int _rl_complete_mark_directories = 1; + +/* If non-zero, the symlinked directory completion behavior introduced in + readline-4.2a is disabled, and symlinks that point to directories have + a slash appended (subject to the value of _rl_complete_mark_directories). + This is user-settable via the mark-symlinked-directories variable. */ +int _rl_complete_mark_symlink_dirs = 0; + +/* If non-zero, completions are printed horizontally in alphabetical order, + like `ls -x'. */ +int _rl_print_completions_horizontally; + +/* Non-zero means that case is not significant in filename completion. */ +#if defined (__MSDOS__) && !defined (__DJGPP__) +int _rl_completion_case_fold = 1; +#else +int _rl_completion_case_fold = 0; +#endif + +/* Non-zero means that `-' and `_' are equivalent when comparing filenames + for completion. */ +int _rl_completion_case_map = 0; + +/* If zero, don't match hidden files (filenames beginning with a `.' on + Unix) when doing filename completion. */ +int _rl_match_hidden_files = 1; + +/* Length in characters of a common prefix replaced with an ellipsis (`...') + when displaying completion matches. Matches whose printable portion has + more than this number of displaying characters in common will have the common + display prefix replaced with an ellipsis. */ +int _rl_completion_prefix_display_length = 0; + +/* The readline-private number of screen columns to use when displaying + matches. If < 0 or > _rl_screenwidth, it is ignored. */ +int _rl_completion_columns = -1; + +/* Global variables available to applications using readline. */ + +#if defined (VISIBLE_STATS) +/* Non-zero means add an additional character to each filename displayed + during listing completion iff rl_filename_completion_desired which helps + to indicate the type of file being listed. */ +int rl_visible_stats = 0; +#endif /* VISIBLE_STATS */ + +#if defined (COLOR_SUPPORT) +/* Non-zero means to use colors to indicate file type when listing possible + completions. The colors used are taken from $LS_COLORS, if set. */ +int _rl_colored_stats = 0; + +int _rl_colored_completion_prefix = 1; +#endif + +/* If non-zero, when completing in the middle of a word, don't insert + characters from the match that match characters following point in + the word. This means, for instance, completing when the cursor is + after the `e' in `Makefile' won't result in `Makefilefile'. */ +int _rl_skip_completed_text = 0; + +/* If non-zero, menu completion displays the common prefix first in the + cycle of possible completions instead of the last. */ +int _rl_menu_complete_prefix_first = 0; + +/* If non-zero, then this is the address of a function to call when + completing on a directory name. The function is called with + the address of a string (the current directory name) as an arg. */ +rl_icppfunc_t *rl_directory_completion_hook = (rl_icppfunc_t *)NULL; + +rl_icppfunc_t *rl_directory_rewrite_hook = (rl_icppfunc_t *)NULL; + +rl_icppfunc_t *rl_filename_stat_hook = (rl_icppfunc_t *)NULL; + +/* If non-zero, this is the address of a function to call when reading + directory entries from the filesystem for completion and comparing + them to the partial word to be completed. The function should + either return its first argument (if no conversion takes place) or + newly-allocated memory. This can, for instance, convert filenames + between character sets for comparison against what's typed at the + keyboard. The returned value is what is added to the list of + matches. The second argument is the length of the filename to be + converted. */ +rl_dequote_func_t *rl_filename_rewrite_hook = (rl_dequote_func_t *)NULL; + +/* Non-zero means readline completion functions perform tilde expansion. */ +int rl_complete_with_tilde_expansion = 0; + +/* Pointer to the generator function for completion_matches (). + NULL means to use rl_filename_completion_function (), the default filename + completer. */ +rl_compentry_func_t *rl_completion_entry_function = (rl_compentry_func_t *)NULL; + +/* Pointer to generator function for rl_menu_complete (). NULL means to use + *rl_completion_entry_function (see above). */ +rl_compentry_func_t *rl_menu_completion_entry_function = (rl_compentry_func_t *)NULL; + +/* Pointer to alternative function to create matches. + Function is called with TEXT, START, and END. + START and END are indices in RL_LINE_BUFFER saying what the boundaries + of TEXT are. + If this function exists and returns NULL then call the value of + rl_completion_entry_function to try to match, otherwise use the + array of strings returned. */ +rl_completion_func_t *rl_attempted_completion_function = (rl_completion_func_t *)NULL; + +/* Non-zero means to suppress normal filename completion after the + user-specified completion function has been called. */ +int rl_attempted_completion_over = 0; + +/* Set to a character indicating the type of completion being performed + by rl_complete_internal, available for use by application completion + functions. */ +int rl_completion_type = 0; + +/* Up to this many items will be displayed in response to a + possible-completions call. After that, we ask the user if + she is sure she wants to see them all. A negative value means + don't ask. */ +int rl_completion_query_items = 100; + +int _rl_page_completions = 1; + +/* The basic list of characters that signal a break between words for the + completer routine. The contents of this variable is what breaks words + in the shell, i.e. " \t\n\"\\'`@$><=" */ +const char *rl_basic_word_break_characters = " \t\n\"\\'`@$><=;|&{("; /* }) */ + +/* List of basic quoting characters. */ +const char *rl_basic_quote_characters = "\"'"; + +/* The list of characters that signal a break between words for + rl_complete_internal. The default list is the contents of + rl_basic_word_break_characters. */ +/*const*/ char *rl_completer_word_break_characters = (/*const*/ char *)NULL; + +/* Hook function to allow an application to set the completion word + break characters before readline breaks up the line. Allows + position-dependent word break characters. */ +rl_cpvfunc_t *rl_completion_word_break_hook = (rl_cpvfunc_t *)NULL; + +/* List of characters which can be used to quote a substring of the line. + Completion occurs on the entire substring, and within the substring + rl_completer_word_break_characters are treated as any other character, + unless they also appear within this list. */ +const char *rl_completer_quote_characters = (const char *)NULL; + +/* List of characters that should be quoted in filenames by the completer. */ +const char *rl_filename_quote_characters = (const char *)NULL; + +/* List of characters that are word break characters, but should be left + in TEXT when it is passed to the completion function. The shell uses + this to help determine what kind of completing to do. */ +const char *rl_special_prefixes = (const char *)NULL; + +/* If non-zero, then disallow duplicates in the matches. */ +int rl_ignore_completion_duplicates = 1; + +/* Non-zero means that the results of the matches are to be treated + as filenames. This is ALWAYS zero on entry, and can only be changed + within a completion entry finder function. */ +int rl_filename_completion_desired = 0; + +/* Non-zero means that the results of the matches are to be quoted using + double quotes (or an application-specific quoting mechanism) if the + filename contains any characters in rl_filename_quote_chars. This is + ALWAYS non-zero on entry, and can only be changed within a completion + entry finder function. */ +int rl_filename_quoting_desired = 1; + +/* This function, if defined, is called by the completer when real + filename completion is done, after all the matching names have been + generated. It is passed a (char**) known as matches in the code below. + It consists of a NULL-terminated array of pointers to potential + matching strings. The 1st element (matches[0]) is the maximal + substring that is common to all matches. This function can re-arrange + the list of matches as required, but all elements of the array must be + free()'d if they are deleted. The main intent of this function is + to implement FIGNORE a la SunOS csh. */ +rl_compignore_func_t *rl_ignore_some_completions_function = (rl_compignore_func_t *)NULL; + +/* Set to a function to quote a filename in an application-specific fashion. + Called with the text to quote, the type of match found (single or multiple) + and a pointer to the quoting character to be used, which the function can + reset if desired. */ +rl_quote_func_t *rl_filename_quoting_function = rl_quote_filename; + +/* Function to call to remove quoting characters from a filename. Called + before completion is attempted, so the embedded quotes do not interfere + with matching names in the file system. Readline doesn't do anything + with this; it's set only by applications. */ +rl_dequote_func_t *rl_filename_dequoting_function = (rl_dequote_func_t *)NULL; + +/* Function to call to decide whether or not a word break character is + quoted. If a character is quoted, it does not break words for the + completer. */ +rl_linebuf_func_t *rl_char_is_quoted_p = (rl_linebuf_func_t *)NULL; + +/* If non-zero, the completion functions don't append anything except a + possible closing quote. This is set to 0 by rl_complete_internal and + may be changed by an application-specific completion function. */ +int rl_completion_suppress_append = 0; + +/* Character appended to completed words when at the end of the line. The + default is a space. */ +int rl_completion_append_character = ' '; + +/* If non-zero, the completion functions don't append any closing quote. + This is set to 0 by rl_complete_internal and may be changed by an + application-specific completion function. */ +int rl_completion_suppress_quote = 0; + +/* Set to any quote character readline thinks it finds before any application + completion function is called. */ +int rl_completion_quote_character; + +/* Set to a non-zero value if readline found quoting anywhere in the word to + be completed; set before any application completion function is called. */ +int rl_completion_found_quote; + +/* If non-zero, a slash will be appended to completed filenames that are + symbolic links to directory names, subject to the value of the + mark-directories variable (which is user-settable). This exists so + that application completion functions can override the user's preference + (set via the mark-symlinked-directories variable) if appropriate. + It's set to the value of _rl_complete_mark_symlink_dirs in + rl_complete_internal before any application-specific completion + function is called, so without that function doing anything, the user's + preferences are honored. */ +int rl_completion_mark_symlink_dirs; + +/* If non-zero, inhibit completion (temporarily). */ +int rl_inhibit_completion; + +/* Set to the last key used to invoke one of the completion functions */ +int rl_completion_invoking_key; + +/* If non-zero, sort the completion matches. On by default. */ +int rl_sort_completion_matches = 1; + +/* Variables local to this file. */ + +/* Local variable states what happened during the last completion attempt. */ +static int completion_changed_buffer; + +/* The result of the query to the user about displaying completion matches */ +static int completion_y_or_n; + +static int _rl_complete_display_matches_interrupt = 0; + +/*************************************/ +/* */ +/* Bindable completion functions */ +/* */ +/*************************************/ + +/* Complete the word at or before point. You have supplied the function + that does the initial simple matching selection algorithm (see + rl_completion_matches ()). The default is to do filename completion. */ +int +rl_complete (ignore, invoking_key) + int ignore, invoking_key; +{ + rl_completion_invoking_key = invoking_key; + + if (rl_inhibit_completion) + return (_rl_insert_char (ignore, invoking_key)); + else if (rl_last_func == rl_complete && !completion_changed_buffer) + return (rl_complete_internal ('?')); + else if (_rl_complete_show_all) + return (rl_complete_internal ('!')); + else if (_rl_complete_show_unmodified) + return (rl_complete_internal ('@')); + else + return (rl_complete_internal (TAB)); +} + +/* List the possible completions. See description of rl_complete (). */ +int +rl_possible_completions (ignore, invoking_key) + int ignore, invoking_key; +{ + rl_completion_invoking_key = invoking_key; + return (rl_complete_internal ('?')); +} + +int +rl_insert_completions (ignore, invoking_key) + int ignore, invoking_key; +{ + rl_completion_invoking_key = invoking_key; + return (rl_complete_internal ('*')); +} + +/* Return the correct value to pass to rl_complete_internal performing + the same tests as rl_complete. This allows consecutive calls to an + application's completion function to list possible completions and for + an application-specific completion function to honor the + show-all-if-ambiguous readline variable. */ +int +rl_completion_mode (cfunc) + rl_command_func_t *cfunc; +{ + if (rl_last_func == cfunc && !completion_changed_buffer) + return '?'; + else if (_rl_complete_show_all) + return '!'; + else if (_rl_complete_show_unmodified) + return '@'; + else + return TAB; +} + +/************************************/ +/* */ +/* Completion utility functions */ +/* */ +/************************************/ + +/* Reset readline state on a signal or other event. */ +void +_rl_reset_completion_state () +{ + rl_completion_found_quote = 0; + rl_completion_quote_character = 0; +} + +static void +_rl_complete_sigcleanup (sig, ptr) + int sig; + void *ptr; +{ + if (sig == SIGINT) /* XXX - for now */ + { +_rl_errmsg("_rl_complete_sigcleanup: ptr = %p", ptr); + _rl_free_match_list ((char **)ptr); + _rl_complete_display_matches_interrupt = 1; + } +} + +/* Set default values for readline word completion. These are the variables + that application completion functions can change or inspect. */ +static void +set_completion_defaults (what_to_do) + int what_to_do; +{ + /* Only the completion entry function can change these. */ + rl_filename_completion_desired = 0; + rl_filename_quoting_desired = 1; + rl_completion_type = what_to_do; + rl_completion_suppress_append = rl_completion_suppress_quote = 0; + rl_completion_append_character = ' '; + + /* The completion entry function may optionally change this. */ + rl_completion_mark_symlink_dirs = _rl_complete_mark_symlink_dirs; + + /* Reset private state. */ + _rl_complete_display_matches_interrupt = 0; +} + +/* The user must press "y" or "n". Non-zero return means "y" pressed. */ +static int +get_y_or_n (for_pager) + int for_pager; +{ + int c; + + /* For now, disable pager in callback mode, until we later convert to state + driven functions. Have to wait until next major version to add new + state definition, since it will change value of RL_STATE_DONE. */ +#if defined (READLINE_CALLBACKS) + if (RL_ISSTATE (RL_STATE_CALLBACK)) + return 1; +#endif + + for (;;) + { + RL_SETSTATE(RL_STATE_MOREINPUT); + c = rl_read_key (); + RL_UNSETSTATE(RL_STATE_MOREINPUT); + + if (c == 'y' || c == 'Y' || c == ' ') + return (1); + if (c == 'n' || c == 'N' || c == RUBOUT) + return (0); + if (c == ABORT_CHAR || c < 0) +{ +_rl_errmsg("get_y_or_n: rl_read_key returns %d", c); + _rl_abort_internal (); +} + if (for_pager && (c == NEWLINE || c == RETURN)) + return (2); + if (for_pager && (c == 'q' || c == 'Q')) + return (0); + rl_ding (); + } +} + +static int +_rl_internal_pager (lines) + int lines; +{ + int i; + + fprintf (rl_outstream, "--More--"); + fflush (rl_outstream); + i = get_y_or_n (1); + _rl_erase_entire_line (); + if (i == 0) + return -1; + else if (i == 2) + return (lines - 1); + else + return 0; +} + +static int +path_isdir (filename) + const char *filename; +{ + struct stat finfo; + + return (stat (filename, &finfo) == 0 && S_ISDIR (finfo.st_mode)); +} + +#if defined (VISIBLE_STATS) +/* Return the character which best describes FILENAME. + `@' for symbolic links + `/' for directories + `*' for executables + `=' for sockets + `|' for FIFOs + `%' for character special devices + `#' for block special devices */ +static int +stat_char (filename) + char *filename; +{ + struct stat finfo; + int character, r; + char *f; + const char *fn; + + /* Short-circuit a //server on cygwin, since that will always behave as + a directory. */ +#if __CYGWIN__ + if (filename[0] == '/' && filename[1] == '/' && strchr (filename+2, '/') == 0) + return '/'; +#endif + + f = 0; + if (rl_filename_stat_hook) + { + f = savestring (filename); + (*rl_filename_stat_hook) (&f); + fn = f; + } + else + fn = filename; + +#if defined (HAVE_LSTAT) && defined (S_ISLNK) + r = lstat (fn, &finfo); +#else + r = stat (fn, &finfo); +#endif + + if (r == -1) + return (0); + + character = 0; + if (S_ISDIR (finfo.st_mode)) + character = '/'; +#if defined (S_ISCHR) + else if (S_ISCHR (finfo.st_mode)) + character = '%'; +#endif /* S_ISCHR */ +#if defined (S_ISBLK) + else if (S_ISBLK (finfo.st_mode)) + character = '#'; +#endif /* S_ISBLK */ +#if defined (S_ISLNK) + else if (S_ISLNK (finfo.st_mode)) + character = '@'; +#endif /* S_ISLNK */ +#if defined (S_ISSOCK) + else if (S_ISSOCK (finfo.st_mode)) + character = '='; +#endif /* S_ISSOCK */ +#if defined (S_ISFIFO) + else if (S_ISFIFO (finfo.st_mode)) + character = '|'; +#endif + else if (S_ISREG (finfo.st_mode)) + { + if (access (filename, X_OK) == 0) + character = '*'; + } + + xfree (f); + return (character); +} +#endif /* VISIBLE_STATS */ + +#if defined (COLOR_SUPPORT) +static int +colored_stat_start (filename) + char *filename; +{ + _rl_set_normal_color (); + return (_rl_print_color_indicator (filename)); +} + +static void +colored_stat_end () +{ + _rl_prep_non_filename_text (); + _rl_put_indicator (&_rl_color_indicator[C_CLR_TO_EOL]); +} + +static int +colored_prefix_start () +{ + _rl_set_normal_color (); + return (_rl_print_prefix_color ()); +} + +static void +colored_prefix_end () +{ + colored_stat_end (); /* for now */ +} +#endif + +/* Return the portion of PATHNAME that should be output when listing + possible completions. If we are hacking filename completion, we + are only interested in the basename, the portion following the + final slash. Otherwise, we return what we were passed. Since + printing empty strings is not very informative, if we're doing + filename completion, and the basename is the empty string, we look + for the previous slash and return the portion following that. If + there's no previous slash, we just return what we were passed. */ +static char * +printable_part (pathname) + char *pathname; +{ + char *temp, *x; + + if (rl_filename_completion_desired == 0) /* don't need to do anything */ + return (pathname); + + temp = strrchr (pathname, '/'); +#if defined (__MSDOS__) + if (temp == 0 && ISALPHA ((unsigned char)pathname[0]) && pathname[1] == ':') + temp = pathname + 1; +#endif + + if (temp == 0 || *temp == '\0') + return (pathname); + /* If the basename is NULL, we might have a pathname like '/usr/src/'. + Look for a previous slash and, if one is found, return the portion + following that slash. If there's no previous slash, just return the + pathname we were passed. */ + else if (temp[1] == '\0') + { + for (x = temp - 1; x > pathname; x--) + if (*x == '/') + break; + return ((*x == '/') ? x + 1 : pathname); + } + else + return ++temp; +} + +/* Compute width of STRING when displayed on screen by print_filename */ +static int +fnwidth (string) + const char *string; +{ + int width, pos; +#if defined (HANDLE_MULTIBYTE) + mbstate_t ps; + int left, w; + size_t clen; + wchar_t wc; + + left = strlen (string) + 1; + memset (&ps, 0, sizeof (mbstate_t)); +#endif + + width = pos = 0; + while (string[pos]) + { + if (CTRL_CHAR (string[pos]) || string[pos] == RUBOUT) + { + width += 2; + pos++; + } + else + { +#if defined (HANDLE_MULTIBYTE) + clen = mbrtowc (&wc, string + pos, left - pos, &ps); + if (MB_INVALIDCH (clen)) + { + width++; + pos++; + memset (&ps, 0, sizeof (mbstate_t)); + } + else if (MB_NULLWCH (clen)) + break; + else + { + pos += clen; + w = WCWIDTH (wc); + width += (w >= 0) ? w : 1; + } +#else + width++; + pos++; +#endif + } + } + + return width; +} + +#define ELLIPSIS_LEN 3 + +static int +fnprint (to_print, prefix_bytes) + const char *to_print; + int prefix_bytes; +{ + int printed_len, w; + const char *s; + int common_prefix_len; +#if defined (HANDLE_MULTIBYTE) + mbstate_t ps; + const char *end; + size_t tlen; + int width; + wchar_t wc; + + end = to_print + strlen (to_print) + 1; + memset (&ps, 0, sizeof (mbstate_t)); +#endif + + printed_len = common_prefix_len = 0; + + /* Don't print only the ellipsis if the common prefix is one of the + possible completions */ + if (to_print[prefix_bytes] == '\0') + prefix_bytes = 0; + + if (prefix_bytes && _rl_completion_prefix_display_length > 0) + { + char ellipsis; + + ellipsis = (to_print[prefix_bytes] == '.') ? '_' : '.'; + for (w = 0; w < ELLIPSIS_LEN; w++) + putc (ellipsis, rl_outstream); + printed_len = ELLIPSIS_LEN; + } +#if defined (COLOR_SUPPORT) + else if (prefix_bytes && _rl_colored_completion_prefix > 0) + { + common_prefix_len = prefix_bytes; + prefix_bytes = 0; + /* XXX - print color indicator start here */ + colored_prefix_start (); + } +#endif + + s = to_print + prefix_bytes; + while (*s) + { + if (CTRL_CHAR (*s)) + { + putc ('^', rl_outstream); + putc (UNCTRL (*s), rl_outstream); + printed_len += 2; + s++; +#if defined (HANDLE_MULTIBYTE) + memset (&ps, 0, sizeof (mbstate_t)); +#endif + } + else if (*s == RUBOUT) + { + putc ('^', rl_outstream); + putc ('?', rl_outstream); + printed_len += 2; + s++; +#if defined (HANDLE_MULTIBYTE) + memset (&ps, 0, sizeof (mbstate_t)); +#endif + } + else + { +#if defined (HANDLE_MULTIBYTE) + tlen = mbrtowc (&wc, s, end - s, &ps); + if (MB_INVALIDCH (tlen)) + { + tlen = 1; + width = 1; + memset (&ps, 0, sizeof (mbstate_t)); + } + else if (MB_NULLWCH (tlen)) + break; + else + { + w = WCWIDTH (wc); + width = (w >= 0) ? w : 1; + } + fwrite (s, 1, tlen, rl_outstream); + s += tlen; + printed_len += width; +#else + putc (*s, rl_outstream); + s++; + printed_len++; +#endif + } + if (common_prefix_len > 0 && (s - to_print) >= common_prefix_len) + { + /* printed bytes = s - to_print */ + /* printed bytes should never be > but check for paranoia's sake */ + colored_prefix_end (); + common_prefix_len = 0; + } + } + + return printed_len; +} + +/* Output TO_PRINT to rl_outstream. If VISIBLE_STATS is defined and we + are using it, check for and output a single character for `special' + filenames. Return the number of characters we output. */ + +static int +print_filename (to_print, full_pathname, prefix_bytes) + char *to_print, *full_pathname; + int prefix_bytes; +{ + int printed_len, extension_char, slen, tlen; + char *s, c, *new_full_pathname, *dn; + + extension_char = 0; +#if defined (COLOR_SUPPORT) + /* Defer printing if we want to prefix with a color indicator */ + if (_rl_colored_stats == 0 || rl_filename_completion_desired == 0) +#endif + printed_len = fnprint (to_print, prefix_bytes); + + if (rl_filename_completion_desired && ( +#if defined (VISIBLE_STATS) + rl_visible_stats || +#endif +#if defined (COLOR_SUPPORT) + _rl_colored_stats || +#endif + _rl_complete_mark_directories)) + { + /* If to_print != full_pathname, to_print is the basename of the + path passed. In this case, we try to expand the directory + name before checking for the stat character. */ + if (to_print != full_pathname) + { + /* Terminate the directory name. */ + c = to_print[-1]; + to_print[-1] = '\0'; + + /* If setting the last slash in full_pathname to a NUL results in + full_pathname being the empty string, we are trying to complete + files in the root directory. If we pass a null string to the + bash directory completion hook, for example, it will expand it + to the current directory. We just want the `/'. */ + if (full_pathname == 0 || *full_pathname == 0) + dn = "/"; + else if (full_pathname[0] != '/') + dn = full_pathname; + else if (full_pathname[1] == 0) + dn = "//"; /* restore trailing slash to `//' */ + else if (full_pathname[1] == '/' && full_pathname[2] == 0) + dn = "/"; /* don't turn /// into // */ + else + dn = full_pathname; + s = tilde_expand (dn); + if (rl_directory_completion_hook) + (*rl_directory_completion_hook) (&s); + + slen = strlen (s); + tlen = strlen (to_print); + new_full_pathname = (char *)xmalloc (slen + tlen + 2); + strcpy (new_full_pathname, s); + if (s[slen - 1] == '/') + slen--; + else + new_full_pathname[slen] = '/'; + new_full_pathname[slen] = '/'; + strcpy (new_full_pathname + slen + 1, to_print); + +#if defined (VISIBLE_STATS) + if (rl_visible_stats) + extension_char = stat_char (new_full_pathname); + else +#endif + if (_rl_complete_mark_directories) + { + dn = 0; + if (rl_directory_completion_hook == 0 && rl_filename_stat_hook) + { + dn = savestring (new_full_pathname); + (*rl_filename_stat_hook) (&dn); + xfree (new_full_pathname); + new_full_pathname = dn; + } + if (path_isdir (new_full_pathname)) + extension_char = '/'; + } + +#if defined (COLOR_SUPPORT) + if (_rl_colored_stats) + { + colored_stat_start (new_full_pathname); + printed_len = fnprint (to_print, prefix_bytes); + colored_stat_end (); + } +#endif + + xfree (new_full_pathname); + to_print[-1] = c; + } + else + { + s = tilde_expand (full_pathname); +#if defined (VISIBLE_STATS) + if (rl_visible_stats) + extension_char = stat_char (s); + else +#endif + if (_rl_complete_mark_directories && path_isdir (s)) + extension_char = '/'; + +#if defined (COLOR_SUPPORT) + if (_rl_colored_stats) + { + colored_stat_start (s); + printed_len = fnprint (to_print, prefix_bytes); + colored_stat_end (); + } +#endif + + } + + xfree (s); + if (extension_char) + { + putc (extension_char, rl_outstream); + printed_len++; + } + } + + return printed_len; +} + +static char * +rl_quote_filename (s, rtype, qcp) + char *s; + int rtype; + char *qcp; +{ + char *r; + + r = (char *)xmalloc (strlen (s) + 2); + *r = *rl_completer_quote_characters; + strcpy (r + 1, s); + if (qcp) + *qcp = *rl_completer_quote_characters; + return r; +} + +/* Find the bounds of the current word for completion purposes, and leave + rl_point set to the end of the word. This function skips quoted + substrings (characters between matched pairs of characters in + rl_completer_quote_characters). First we try to find an unclosed + quoted substring on which to do matching. If one is not found, we use + the word break characters to find the boundaries of the current word. + We call an application-specific function to decide whether or not a + particular word break character is quoted; if that function returns a + non-zero result, the character does not break a word. This function + returns the opening quote character if we found an unclosed quoted + substring, '\0' otherwise. FP, if non-null, is set to a value saying + which (shell-like) quote characters we found (single quote, double + quote, or backslash) anywhere in the string. DP, if non-null, is set to + the value of the delimiter character that caused a word break. */ + +char +_rl_find_completion_word (fp, dp) + int *fp, *dp; +{ + int scan, end, found_quote, delimiter, pass_next, isbrk; + char quote_char, *brkchars; + + end = rl_point; + found_quote = delimiter = 0; + quote_char = '\0'; + + brkchars = 0; + if (rl_completion_word_break_hook) + brkchars = (*rl_completion_word_break_hook) (); + if (brkchars == 0) + brkchars = rl_completer_word_break_characters; + + if (rl_completer_quote_characters) + { + /* We have a list of characters which can be used in pairs to + quote substrings for the completer. Try to find the start + of an unclosed quoted substring. */ + /* FOUND_QUOTE is set so we know what kind of quotes we found. */ + for (scan = pass_next = 0; scan < end; scan = MB_NEXTCHAR (rl_line_buffer, scan, 1, MB_FIND_ANY)) + { + if (pass_next) + { + pass_next = 0; + continue; + } + + /* Shell-like semantics for single quotes -- don't allow backslash + to quote anything in single quotes, especially not the closing + quote. If you don't like this, take out the check on the value + of quote_char. */ + if (quote_char != '\'' && rl_line_buffer[scan] == '\\') + { + pass_next = 1; + found_quote |= RL_QF_BACKSLASH; + continue; + } + + if (quote_char != '\0') + { + /* Ignore everything until the matching close quote char. */ + if (rl_line_buffer[scan] == quote_char) + { + /* Found matching close. Abandon this substring. */ + quote_char = '\0'; + rl_point = end; + } + } + else if (strchr (rl_completer_quote_characters, rl_line_buffer[scan])) + { + /* Found start of a quoted substring. */ + quote_char = rl_line_buffer[scan]; + rl_point = scan + 1; + /* Shell-like quoting conventions. */ + if (quote_char == '\'') + found_quote |= RL_QF_SINGLE_QUOTE; + else if (quote_char == '"') + found_quote |= RL_QF_DOUBLE_QUOTE; + else + found_quote |= RL_QF_OTHER_QUOTE; + } + } + } + + if (rl_point == end && quote_char == '\0') + { + /* We didn't find an unclosed quoted substring upon which to do + completion, so use the word break characters to find the + substring on which to complete. */ + while (rl_point = MB_PREVCHAR (rl_line_buffer, rl_point, MB_FIND_ANY)) + { + scan = rl_line_buffer[rl_point]; + + if (strchr (brkchars, scan) == 0) + continue; + + /* Call the application-specific function to tell us whether + this word break character is quoted and should be skipped. */ + if (rl_char_is_quoted_p && found_quote && + (*rl_char_is_quoted_p) (rl_line_buffer, rl_point)) + continue; + + /* Convoluted code, but it avoids an n^2 algorithm with calls + to char_is_quoted. */ + break; + } + } + + /* If we are at an unquoted word break, then advance past it. */ + scan = rl_line_buffer[rl_point]; + + /* If there is an application-specific function to say whether or not + a character is quoted and we found a quote character, let that + function decide whether or not a character is a word break, even + if it is found in rl_completer_word_break_characters. Don't bother + if we're at the end of the line, though. */ + if (scan) + { + if (rl_char_is_quoted_p) + isbrk = (found_quote == 0 || + (*rl_char_is_quoted_p) (rl_line_buffer, rl_point) == 0) && + strchr (brkchars, scan) != 0; + else + isbrk = strchr (brkchars, scan) != 0; + + if (isbrk) + { + /* If the character that caused the word break was a quoting + character, then remember it as the delimiter. */ + if (rl_basic_quote_characters && + strchr (rl_basic_quote_characters, scan) && + (end - rl_point) > 1) + delimiter = scan; + + /* If the character isn't needed to determine something special + about what kind of completion to perform, then advance past it. */ + if (rl_special_prefixes == 0 || strchr (rl_special_prefixes, scan) == 0) + rl_point++; + } + } + + if (fp) + *fp = found_quote; + if (dp) + *dp = delimiter; + + return (quote_char); +} + +static char ** +gen_completion_matches (text, start, end, our_func, found_quote, quote_char) + char *text; + int start, end; + rl_compentry_func_t *our_func; + int found_quote, quote_char; +{ + char **matches; + + rl_completion_found_quote = found_quote; + rl_completion_quote_character = quote_char; + + /* If the user wants to TRY to complete, but then wants to give + up and use the default completion function, they set the + variable rl_attempted_completion_function. */ + if (rl_attempted_completion_function) + { + matches = (*rl_attempted_completion_function) (text, start, end); + if (RL_SIG_RECEIVED()) + { + _rl_free_match_list (matches); + matches = 0; + RL_CHECK_SIGNALS (); + } + + if (matches || rl_attempted_completion_over) + { + rl_attempted_completion_over = 0; + return (matches); + } + } + + /* XXX -- filename dequoting moved into rl_filename_completion_function */ + + /* rl_completion_matches will check for signals as well to avoid a long + delay while reading a directory. */ + matches = rl_completion_matches (text, our_func); + if (RL_SIG_RECEIVED()) + { + _rl_free_match_list (matches); + matches = 0; + RL_CHECK_SIGNALS (); + } + return matches; +} + +/* Filter out duplicates in MATCHES. This frees up the strings in + MATCHES. */ +static char ** +remove_duplicate_matches (matches) + char **matches; +{ + char *lowest_common; + int i, j, newlen; + char dead_slot; + char **temp_array; + + /* Sort the items. */ + for (i = 0; matches[i]; i++) + ; + + /* Sort the array without matches[0], since we need it to + stay in place no matter what. */ + if (i && rl_sort_completion_matches) + qsort (matches+1, i-1, sizeof (char *), (QSFUNC *)_rl_qsort_string_compare); + + /* Remember the lowest common denominator for it may be unique. */ + lowest_common = savestring (matches[0]); + + for (i = newlen = 0; matches[i + 1]; i++) + { + if (strcmp (matches[i], matches[i + 1]) == 0) + { + xfree (matches[i]); + matches[i] = (char *)&dead_slot; + } + else + newlen++; + } + + /* We have marked all the dead slots with (char *)&dead_slot. + Copy all the non-dead entries into a new array. */ + temp_array = (char **)xmalloc ((3 + newlen) * sizeof (char *)); + for (i = j = 1; matches[i]; i++) + { + if (matches[i] != (char *)&dead_slot) + temp_array[j++] = matches[i]; + } + temp_array[j] = (char *)NULL; + + if (matches[0] != (char *)&dead_slot) + xfree (matches[0]); + + /* Place the lowest common denominator back in [0]. */ + temp_array[0] = lowest_common; + + /* If there is one string left, and it is identical to the + lowest common denominator, then the LCD is the string to + insert. */ + if (j == 2 && strcmp (temp_array[0], temp_array[1]) == 0) + { + xfree (temp_array[1]); + temp_array[1] = (char *)NULL; + } + return (temp_array); +} + +/* Find the common prefix of the list of matches, and put it into + matches[0]. */ +static int +compute_lcd_of_matches (match_list, matches, text) + char **match_list; + int matches; + const char *text; +{ + register int i, c1, c2, si; + int low; /* Count of max-matched characters. */ + int lx; + char *dtext; /* dequoted TEXT, if needed */ +#if defined (HANDLE_MULTIBYTE) + int v; + size_t v1, v2; + mbstate_t ps1, ps2; + wchar_t wc1, wc2; +#endif + + /* If only one match, just use that. Otherwise, compare each + member of the list with the next, finding out where they + stop matching. */ + if (matches == 1) + { + match_list[0] = match_list[1]; + match_list[1] = (char *)NULL; + return 1; + } + + for (i = 1, low = 100000; i < matches; i++) + { +#if defined (HANDLE_MULTIBYTE) + if (MB_CUR_MAX > 1 && rl_byte_oriented == 0) + { + memset (&ps1, 0, sizeof (mbstate_t)); + memset (&ps2, 0, sizeof (mbstate_t)); + } +#endif + if (_rl_completion_case_fold) + { + for (si = 0; + (c1 = _rl_to_lower(match_list[i][si])) && + (c2 = _rl_to_lower(match_list[i + 1][si])); + si++) +#if defined (HANDLE_MULTIBYTE) + if (MB_CUR_MAX > 1 && rl_byte_oriented == 0) + { + v1 = mbrtowc(&wc1, match_list[i]+si, strlen (match_list[i]+si), &ps1); + v2 = mbrtowc (&wc2, match_list[i+1]+si, strlen (match_list[i+1]+si), &ps2); + if (MB_INVALIDCH (v1) || MB_INVALIDCH (v2)) + { + if (c1 != c2) /* do byte comparison */ + break; + continue; + } + wc1 = towlower (wc1); + wc2 = towlower (wc2); + if (wc1 != wc2) + break; + else if (v1 > 1) + si += v1 - 1; + } + else +#endif + if (c1 != c2) + break; + } + else + { + for (si = 0; + (c1 = match_list[i][si]) && + (c2 = match_list[i + 1][si]); + si++) +#if defined (HANDLE_MULTIBYTE) + if (MB_CUR_MAX > 1 && rl_byte_oriented == 0) + { + mbstate_t ps_back; + ps_back = ps1; + if (!_rl_compare_chars (match_list[i], si, &ps1, match_list[i+1], si, &ps2)) + break; + else if ((v = _rl_get_char_len (&match_list[i][si], &ps_back)) > 1) + si += v - 1; + } + else +#endif + if (c1 != c2) + break; + } + + if (low > si) + low = si; + } + + /* If there were multiple matches, but none matched up to even the + first character, and the user typed something, use that as the + value of matches[0]. */ + if (low == 0 && text && *text) + { + match_list[0] = (char *)xmalloc (strlen (text) + 1); + strcpy (match_list[0], text); + } + else + { + match_list[0] = (char *)xmalloc (low + 1); + + /* XXX - this might need changes in the presence of multibyte chars */ + + /* If we are ignoring case, try to preserve the case of the string + the user typed in the face of multiple matches differing in case. */ + if (_rl_completion_case_fold) + { + /* We're making an assumption here: + IF we're completing filenames AND + the application has defined a filename dequoting function AND + we found a quote character AND + the application has requested filename quoting + THEN + we assume that TEXT was dequoted before checking against + the file system and needs to be dequoted here before we + check against the list of matches + FI */ + dtext = (char *)NULL; + if (rl_filename_completion_desired && + rl_filename_dequoting_function && + rl_completion_found_quote && + rl_filename_quoting_desired) + { + dtext = (*rl_filename_dequoting_function) ((char *)text, rl_completion_quote_character); + text = dtext; + } + + /* sort the list to get consistent answers. */ + qsort (match_list+1, matches, sizeof(char *), (QSFUNC *)_rl_qsort_string_compare); + + si = strlen (text); + lx = (si <= low) ? si : low; /* check shorter of text and matches */ + /* Try to preserve the case of what the user typed in the presence of + multiple matches: check each match for something that matches + what the user typed taking case into account; use it up to common + length of matches if one is found. If not, just use first match. */ + for (i = 1; i <= matches; i++) + if (strncmp (match_list[i], text, lx) == 0) + { + strncpy (match_list[0], match_list[i], low); + break; + } + /* no casematch, use first entry */ + if (i > matches) + strncpy (match_list[0], match_list[1], low); + + FREE (dtext); + } + else + strncpy (match_list[0], match_list[1], low); + + match_list[0][low] = '\0'; + } + + return matches; +} + +static int +postprocess_matches (matchesp, matching_filenames) + char ***matchesp; + int matching_filenames; +{ + char *t, **matches, **temp_matches; + int nmatch, i; + + matches = *matchesp; + + if (matches == 0) + return 0; + + /* It seems to me that in all the cases we handle we would like + to ignore duplicate possibilities. Scan for the text to + insert being identical to the other completions. */ + if (rl_ignore_completion_duplicates) + { + temp_matches = remove_duplicate_matches (matches); + xfree (matches); + matches = temp_matches; + } + + /* If we are matching filenames, then here is our chance to + do clever processing by re-examining the list. Call the + ignore function with the array as a parameter. It can + munge the array, deleting matches as it desires. */ + if (rl_ignore_some_completions_function && matching_filenames) + { + for (nmatch = 1; matches[nmatch]; nmatch++) + ; + (void)(*rl_ignore_some_completions_function) (matches); + if (matches == 0 || matches[0] == 0) + { + FREE (matches); + *matchesp = (char **)0; + return 0; + } + else + { + /* If we removed some matches, recompute the common prefix. */ + for (i = 1; matches[i]; i++) + ; + if (i > 1 && i < nmatch) + { + t = matches[0]; + compute_lcd_of_matches (matches, i - 1, t); + FREE (t); + } + } + } + + *matchesp = matches; + return (1); +} + +static int +complete_get_screenwidth () +{ + int cols; + char *envcols; + + cols = _rl_completion_columns; + if (cols >= 0 && cols <= _rl_screenwidth) + return cols; + envcols = getenv ("COLUMNS"); + if (envcols && *envcols) + cols = atoi (envcols); + if (cols >= 0 && cols <= _rl_screenwidth) + return cols; + return _rl_screenwidth; +} + +/* A convenience function for displaying a list of strings in + columnar format on readline's output stream. MATCHES is the list + of strings, in argv format, LEN is the number of strings in MATCHES, + and MAX is the length of the longest string in MATCHES. */ +void +rl_display_match_list (matches, len, max) + char **matches; + int len, max; +{ + int count, limit, printed_len, lines, cols; + int i, j, k, l, common_length, sind; + char *temp, *t; + + /* Find the length of the prefix common to all items: length as displayed + characters (common_length) and as a byte index into the matches (sind) */ + common_length = sind = 0; + if (_rl_completion_prefix_display_length > 0) + { + t = printable_part (matches[0]); + temp = strrchr (t, '/'); /* check again in case of /usr/src/ */ + common_length = temp ? fnwidth (temp) : fnwidth (t); + sind = temp ? strlen (temp) : strlen (t); + + if (common_length > _rl_completion_prefix_display_length && common_length > ELLIPSIS_LEN) + max -= common_length - ELLIPSIS_LEN; + else + common_length = sind = 0; + } +#if defined (COLOR_SUPPORT) + else if (_rl_colored_completion_prefix > 0) + { + t = printable_part (matches[0]); + temp = strrchr (t, '/'); + common_length = temp ? fnwidth (temp) : fnwidth (t); + sind = temp ? RL_STRLEN (temp+1) : RL_STRLEN (t); /* want portion after final slash */ + } +#endif + + /* How many items of MAX length can we fit in the screen window? */ + cols = complete_get_screenwidth (); + max += 2; + limit = cols / max; + if (limit != 1 && (limit * max == cols)) + limit--; + + /* If cols == 0, limit will end up -1 */ + if (cols < _rl_screenwidth && limit < 0) + limit = 1; + + /* Avoid a possible floating exception. If max > cols, + limit will be 0 and a divide-by-zero fault will result. */ + if (limit == 0) + limit = 1; + + /* How many iterations of the printing loop? */ + count = (len + (limit - 1)) / limit; + + /* Watch out for special case. If LEN is less than LIMIT, then + just do the inner printing loop. + 0 < len <= limit implies count = 1. */ + + /* Sort the items if they are not already sorted. */ + if (rl_ignore_completion_duplicates == 0 && rl_sort_completion_matches) + qsort (matches + 1, len, sizeof (char *), (QSFUNC *)_rl_qsort_string_compare); + + rl_crlf (); + + lines = 0; + if (_rl_print_completions_horizontally == 0) + { + /* Print the sorted items, up-and-down alphabetically, like ls. */ + for (i = 1; i <= count; i++) + { + for (j = 0, l = i; j < limit; j++) + { + if (l > len || matches[l] == 0) + break; + else + { + temp = printable_part (matches[l]); + printed_len = print_filename (temp, matches[l], sind); + +fflush(rl_outstream); +usleep(500000); + if (j + 1 < limit) + for (k = 0; k < max - printed_len; k++) + putc (' ', rl_outstream); + } + l += count; + } + rl_crlf (); + if (RL_SIG_RECEIVED ()) + return; + lines++; + if (_rl_page_completions && lines >= (_rl_screenheight - 1) && i < count) + { + lines = _rl_internal_pager (lines); + if (lines < 0) + return; + } + } + } + else + { + /* Print the sorted items, across alphabetically, like ls -x. */ + for (i = 1; matches[i]; i++) + { + temp = printable_part (matches[i]); + printed_len = print_filename (temp, matches[i], sind); + /* Have we reached the end of this line? */ + if (RL_SIG_RECEIVED ()) + return; + if (matches[i+1]) + { + if (limit == 1 || (i && (limit > 1) && (i % limit) == 0)) + { + rl_crlf (); + lines++; + if (_rl_page_completions && lines >= _rl_screenheight - 1) + { + lines = _rl_internal_pager (lines); + if (lines < 0) + return; + } + } + else + for (k = 0; k < max - printed_len; k++) + putc (' ', rl_outstream); + } + } + rl_crlf (); + } +} + +/* Display MATCHES, a list of matching filenames in argv format. This + handles the simple case -- a single match -- first. If there is more + than one match, we compute the number of strings in the list and the + length of the longest string, which will be needed by the display + function. If the application wants to handle displaying the list of + matches itself, it sets RL_COMPLETION_DISPLAY_MATCHES_HOOK to the + address of a function, and we just call it. If we're handling the + display ourselves, we just call rl_display_match_list. We also check + that the list of matches doesn't exceed the user-settable threshold, + and ask the user if he wants to see the list if there are more matches + than RL_COMPLETION_QUERY_ITEMS. */ +static void +display_matches (matches) + char **matches; +{ + int len, max, i; + char *temp; + + /* Move to the last visible line of a possibly-multiple-line command. */ + _rl_move_vert (_rl_vis_botlin); + + /* Handle simple case first. What if there is only one answer? */ + if (matches[1] == 0) + { + temp = printable_part (matches[0]); + rl_crlf (); + print_filename (temp, matches[0], 0); + rl_crlf (); + + rl_forced_update_display (); + rl_display_fixed = 1; + + return; + } + + /* There is more than one answer. Find out how many there are, + and find the maximum printed length of a single entry. */ + for (max = 0, i = 1; matches[i]; i++) + { + temp = printable_part (matches[i]); + len = fnwidth (temp); + + if (len > max) + max = len; + } + + len = i - 1; + + /* If the caller has defined a display hook, then call that now. */ + if (rl_completion_display_matches_hook) + { + (*rl_completion_display_matches_hook) (matches, len, max); + return; + } + + /* If there are many items, then ask the user if she really wants to + see them all. */ + if (rl_completion_query_items > 0 && len >= rl_completion_query_items) + { + rl_crlf (); + fprintf (rl_outstream, "Display all %d possibilities? (y or n)", len); + fflush (rl_outstream); + if ((completion_y_or_n = get_y_or_n (0)) == 0) + { + rl_crlf (); + + rl_forced_update_display (); + rl_display_fixed = 1; + + return; + } + } + + rl_display_match_list (matches, len, max); + + rl_forced_update_display (); + rl_display_fixed = 1; +} + +static char * +make_quoted_replacement (match, mtype, qc) + char *match; + int mtype; + char *qc; /* Pointer to quoting character, if any */ +{ + int should_quote, do_replace; + char *replacement; + + /* If we are doing completion on quoted substrings, and any matches + contain any of the completer_word_break_characters, then auto- + matically prepend the substring with a quote character (just pick + the first one from the list of such) if it does not already begin + with a quote string. FIXME: Need to remove any such automatically + inserted quote character when it no longer is necessary, such as + if we change the string we are completing on and the new set of + matches don't require a quoted substring. */ + replacement = match; + + should_quote = match && rl_completer_quote_characters && + rl_filename_completion_desired && + rl_filename_quoting_desired; + + if (should_quote) + should_quote = should_quote && (!qc || !*qc || + (rl_completer_quote_characters && strchr (rl_completer_quote_characters, *qc))); + + if (should_quote) + { + /* If there is a single match, see if we need to quote it. + This also checks whether the common prefix of several + matches needs to be quoted. */ + should_quote = rl_filename_quote_characters + ? (_rl_strpbrk (match, rl_filename_quote_characters) != 0) + : 0; + + do_replace = should_quote ? mtype : NO_MATCH; + /* Quote the replacement, since we found an embedded + word break character in a potential match. */ + if (do_replace != NO_MATCH && rl_filename_quoting_function) + replacement = (*rl_filename_quoting_function) (match, do_replace, qc); + } + return (replacement); +} + +static void +insert_match (match, start, mtype, qc) + char *match; + int start, mtype; + char *qc; +{ + char *replacement, *r; + char oqc; + int end, rlen; + + oqc = qc ? *qc : '\0'; + replacement = make_quoted_replacement (match, mtype, qc); + + /* Now insert the match. */ + if (replacement) + { + rlen = strlen (replacement); + /* Don't double an opening quote character. */ + if (qc && *qc && start && rl_line_buffer[start - 1] == *qc && + replacement[0] == *qc) + start--; + /* If make_quoted_replacement changed the quoting character, remove + the opening quote and insert the (fully-quoted) replacement. */ + else if (qc && (*qc != oqc) && start && rl_line_buffer[start - 1] == oqc && + replacement[0] != oqc) + start--; + end = rl_point - 1; + /* Don't double a closing quote character */ + if (qc && *qc && end && rl_line_buffer[rl_point] == *qc && replacement[rlen - 1] == *qc) + end++; + if (_rl_skip_completed_text) + { + r = replacement; + while (start < rl_end && *r && rl_line_buffer[start] == *r) + { + start++; + r++; + } + if (start <= end || *r) + _rl_replace_text (r, start, end); + rl_point = start + strlen (r); + } + else + _rl_replace_text (replacement, start, end); + if (replacement != match) + xfree (replacement); + } +} + +/* Append any necessary closing quote and a separator character to the + just-inserted match. If the user has specified that directories + should be marked by a trailing `/', append one of those instead. The + default trailing character is a space. Returns the number of characters + appended. If NONTRIVIAL_MATCH is set, we test for a symlink (if the OS + has them) and don't add a suffix for a symlink to a directory. A + nontrivial match is one that actually adds to the word being completed. + The variable rl_completion_mark_symlink_dirs controls this behavior + (it's initially set to the what the user has chosen, indicated by the + value of _rl_complete_mark_symlink_dirs, but may be modified by an + application's completion function). */ +static int +append_to_match (text, delimiter, quote_char, nontrivial_match) + char *text; + int delimiter, quote_char, nontrivial_match; +{ + char temp_string[4], *filename, *fn; + int temp_string_index, s; + struct stat finfo; + + temp_string_index = 0; + if (quote_char && rl_point && rl_completion_suppress_quote == 0 && + rl_line_buffer[rl_point - 1] != quote_char) + temp_string[temp_string_index++] = quote_char; + + if (delimiter) + temp_string[temp_string_index++] = delimiter; + else if (rl_completion_suppress_append == 0 && rl_completion_append_character) + temp_string[temp_string_index++] = rl_completion_append_character; + + temp_string[temp_string_index++] = '\0'; + + if (rl_filename_completion_desired) + { + filename = tilde_expand (text); + if (rl_filename_stat_hook) + { + fn = savestring (filename); + (*rl_filename_stat_hook) (&fn); + xfree (filename); + filename = fn; + } + s = (nontrivial_match && rl_completion_mark_symlink_dirs == 0) + ? LSTAT (filename, &finfo) + : stat (filename, &finfo); + if (s == 0 && S_ISDIR (finfo.st_mode)) + { + if (_rl_complete_mark_directories /* && rl_completion_suppress_append == 0 */) + { + /* This is clumsy. Avoid putting in a double slash if point + is at the end of the line and the previous character is a + slash. */ + if (rl_point && rl_line_buffer[rl_point] == '\0' && rl_line_buffer[rl_point - 1] == '/') + ; + else if (rl_line_buffer[rl_point] != '/') + rl_insert_text ("/"); + } + } +#ifdef S_ISLNK + /* Don't add anything if the filename is a symlink and resolves to a + directory. */ + else if (s == 0 && S_ISLNK (finfo.st_mode) && path_isdir (filename)) + ; +#endif + else + { + if (rl_point == rl_end && temp_string_index) + rl_insert_text (temp_string); + } + xfree (filename); + } + else + { + if (rl_point == rl_end && temp_string_index) + rl_insert_text (temp_string); + } + + return (temp_string_index); +} + +static void +insert_all_matches (matches, point, qc) + char **matches; + int point; + char *qc; +{ + int i; + char *rp; + + rl_begin_undo_group (); + /* remove any opening quote character; make_quoted_replacement will add + it back. */ + if (qc && *qc && point && rl_line_buffer[point - 1] == *qc) + point--; + rl_delete_text (point, rl_point); + rl_point = point; + + if (matches[1]) + { + for (i = 1; matches[i]; i++) + { + rp = make_quoted_replacement (matches[i], SINGLE_MATCH, qc); + rl_insert_text (rp); + rl_insert_text (" "); + if (rp != matches[i]) + xfree (rp); + } + } + else + { + rp = make_quoted_replacement (matches[0], SINGLE_MATCH, qc); + rl_insert_text (rp); + rl_insert_text (" "); + if (rp != matches[0]) + xfree (rp); + } + rl_end_undo_group (); +} + +void +_rl_free_match_list (matches) + char **matches; +{ + register int i; + + if (matches == 0) + return; + + for (i = 0; matches[i]; i++) + xfree (matches[i]); + xfree (matches); +} + +/* Complete the word at or before point. + WHAT_TO_DO says what to do with the completion. + `?' means list the possible completions. + TAB means do standard completion. + `*' means insert all of the possible completions. + `!' means to do standard completion, and list all possible completions if + there is more than one. + `@' means to do standard completion, and list all possible completions if + there is more than one and partial completion is not possible. */ +int +rl_complete_internal (what_to_do) + int what_to_do; +{ + char **matches; + rl_compentry_func_t *our_func; + int start, end, delimiter, found_quote, i, nontrivial_lcd; + char *text, *saved_line_buffer; + char quote_char; +#if 1 + int tlen, mlen; +#endif + + RL_SETSTATE(RL_STATE_COMPLETING); + + set_completion_defaults (what_to_do); + + saved_line_buffer = rl_line_buffer ? savestring (rl_line_buffer) : (char *)NULL; + our_func = rl_completion_entry_function + ? rl_completion_entry_function + : rl_filename_completion_function; + /* We now look backwards for the start of a filename/variable word. */ + end = rl_point; + found_quote = delimiter = 0; + quote_char = '\0'; + + if (rl_point) + /* This (possibly) changes rl_point. If it returns a non-zero char, + we know we have an open quote. */ + quote_char = _rl_find_completion_word (&found_quote, &delimiter); + + start = rl_point; + rl_point = end; + + text = rl_copy_text (start, end); + matches = gen_completion_matches (text, start, end, our_func, found_quote, quote_char); + /* nontrivial_lcd is set if the common prefix adds something to the word + being completed. */ + nontrivial_lcd = matches && strcmp (text, matches[0]) != 0; + if (what_to_do == '!' || what_to_do == '@') + tlen = strlen (text); + xfree (text); + + if (matches == 0) + { + rl_ding (); + FREE (saved_line_buffer); + completion_changed_buffer = 0; + RL_UNSETSTATE(RL_STATE_COMPLETING); + _rl_reset_completion_state (); + return (0); + } + + /* If we are matching filenames, the attempted completion function will + have set rl_filename_completion_desired to a non-zero value. The basic + rl_filename_completion_function does this. */ + i = rl_filename_completion_desired; + + if (postprocess_matches (&matches, i) == 0) + { + rl_ding (); + FREE (saved_line_buffer); + completion_changed_buffer = 0; + RL_UNSETSTATE(RL_STATE_COMPLETING); + _rl_reset_completion_state (); + return (0); + } + + switch (what_to_do) + { + case TAB: + case '!': + case '@': + /* Insert the first match with proper quoting. */ + if (what_to_do == TAB) + { + if (*matches[0]) + insert_match (matches[0], start, matches[1] ? MULT_MATCH : SINGLE_MATCH, "e_char); + } + else if (*matches[0] && matches[1] == 0) + /* should we perform the check only if there are multiple matches? */ + insert_match (matches[0], start, matches[1] ? MULT_MATCH : SINGLE_MATCH, "e_char); + else if (*matches[0]) /* what_to_do != TAB && multiple matches */ + { + mlen = *matches[0] ? strlen (matches[0]) : 0; + if (mlen >= tlen) + insert_match (matches[0], start, matches[1] ? MULT_MATCH : SINGLE_MATCH, "e_char); + } + + /* If there are more matches, ring the bell to indicate. + If we are in vi mode, Posix.2 says to not ring the bell. + If the `show-all-if-ambiguous' variable is set, display + all the matches immediately. Otherwise, if this was the + only match, and we are hacking files, check the file to + see if it was a directory. If so, and the `mark-directories' + variable is set, add a '/' to the name. If not, and we + are at the end of the line, then add a space. */ + if (matches[1]) + { + if (what_to_do == '!') + { + display_matches (matches); + break; + } + else if (what_to_do == '@') + { + if (nontrivial_lcd == 0) + display_matches (matches); + break; + } + else if (rl_editing_mode != vi_mode) + rl_ding (); /* There are other matches remaining. */ + } + else + append_to_match (matches[0], delimiter, quote_char, nontrivial_lcd); + + break; + + case '*': + insert_all_matches (matches, start, "e_char); + break; + + case '?': + if (rl_completion_display_matches_hook == 0) + { + _rl_sigcleanup = _rl_complete_sigcleanup; + _rl_sigcleanarg = matches; + } + display_matches (matches); + if (_rl_complete_display_matches_interrupt) + { + matches = 0; + _rl_complete_display_matches_interrupt = 0; + } + _rl_sigcleanup = 0; + _rl_sigcleanarg = 0; + break; + + default: + _rl_ttymsg ("bad value %d for what_to_do in rl_complete", what_to_do); + rl_ding (); + FREE (saved_line_buffer); + RL_UNSETSTATE(RL_STATE_COMPLETING); + _rl_free_match_list (matches); + _rl_reset_completion_state (); + return 1; + } + + _rl_free_match_list (matches); + + /* Check to see if the line has changed through all of this manipulation. */ + if (saved_line_buffer) + { + completion_changed_buffer = strcmp (rl_line_buffer, saved_line_buffer) != 0; + xfree (saved_line_buffer); + } + + RL_UNSETSTATE(RL_STATE_COMPLETING); + _rl_reset_completion_state (); + return 0; +} + +/***************************************************************/ +/* */ +/* Application-callable completion match generator functions */ +/* */ +/***************************************************************/ + +/* Return an array of (char *) which is a list of completions for TEXT. + If there are no completions, return a NULL pointer. + The first entry in the returned array is the substitution for TEXT. + The remaining entries are the possible completions. + The array is terminated with a NULL pointer. + + ENTRY_FUNCTION is a function of two args, and returns a (char *). + The first argument is TEXT. + The second is a state argument; it should be zero on the first call, and + non-zero on subsequent calls. It returns a NULL pointer to the caller + when there are no more matches. + */ +char ** +rl_completion_matches (text, entry_function) + const char *text; + rl_compentry_func_t *entry_function; +{ + register int i; + + /* Number of slots in match_list. */ + int match_list_size; + + /* The list of matches. */ + char **match_list; + + /* Number of matches actually found. */ + int matches; + + /* Temporary string binder. */ + char *string; + + matches = 0; + match_list_size = 10; + match_list = (char **)xmalloc ((match_list_size + 1) * sizeof (char *)); + match_list[1] = (char *)NULL; + + while (string = (*entry_function) (text, matches)) + { + if (RL_SIG_RECEIVED ()) + { + /* Start at 1 because we don't set matches[0] in this function. + Only free the list members if we're building match list from + rl_filename_completion_function, since we know that doesn't + free the strings it returns. */ + if (entry_function == rl_filename_completion_function) + { + for (i = 1; match_list[i]; i++) + xfree (match_list[i]); + } + xfree (match_list); + match_list = 0; + match_list_size = 0; + matches = 0; + RL_CHECK_SIGNALS (); + } + + if (matches + 1 >= match_list_size) + match_list = (char **)xrealloc + (match_list, ((match_list_size += 10) + 1) * sizeof (char *)); + + if (match_list == 0) + return (match_list); + + match_list[++matches] = string; + match_list[matches + 1] = (char *)NULL; + } + + /* If there were any matches, then look through them finding out the + lowest common denominator. That then becomes match_list[0]. */ + if (matches) + compute_lcd_of_matches (match_list, matches, text); + else /* There were no matches. */ + { + xfree (match_list); + match_list = (char **)NULL; + } + return (match_list); +} + +/* A completion function for usernames. + TEXT contains a partial username preceded by a random + character (usually `~'). */ +char * +rl_username_completion_function (text, state) + const char *text; + int state; +{ +#if defined (__WIN32__) || defined (__OPENNT) + return (char *)NULL; +#else /* !__WIN32__ && !__OPENNT) */ + static char *username = (char *)NULL; + static struct passwd *entry; + static int namelen, first_char, first_char_loc; + char *value; + + if (state == 0) + { + FREE (username); + + first_char = *text; + first_char_loc = first_char == '~'; + + username = savestring (&text[first_char_loc]); + namelen = strlen (username); +#if defined (HAVE_GETPWENT) + setpwent (); +#endif + } + +#if defined (HAVE_GETPWENT) + while (entry = getpwent ()) + { + /* Null usernames should result in all users as possible completions. */ + if (namelen == 0 || (STREQN (username, entry->pw_name, namelen))) + break; + } +#endif + + if (entry == 0) + { +#if defined (HAVE_GETPWENT) + endpwent (); +#endif + return ((char *)NULL); + } + else + { + value = (char *)xmalloc (2 + strlen (entry->pw_name)); + + *value = *text; + + strcpy (value + first_char_loc, entry->pw_name); + + if (first_char == '~') + rl_filename_completion_desired = 1; + + return (value); + } +#endif /* !__WIN32__ && !__OPENNT */ +} + +/* Return non-zero if CONVFN matches FILENAME up to the length of FILENAME + (FILENAME_LEN). If _rl_completion_case_fold is set, compare without + regard to the alphabetic case of characters. If + _rl_completion_case_map is set, make `-' and `_' equivalent. CONVFN is + the possibly-converted directory entry; FILENAME is what the user typed. */ +static int +complete_fncmp (convfn, convlen, filename, filename_len) + const char *convfn; + int convlen; + const char *filename; + int filename_len; +{ + register char *s1, *s2; + int d, len; +#if defined (HANDLE_MULTIBYTE) + size_t v1, v2; + mbstate_t ps1, ps2; + wchar_t wc1, wc2; +#endif + +#if defined (HANDLE_MULTIBYTE) + memset (&ps1, 0, sizeof (mbstate_t)); + memset (&ps2, 0, sizeof (mbstate_t)); +#endif + + if (filename_len == 0) + return 1; + if (convlen < filename_len) + return 0; + + len = filename_len; + s1 = (char *)convfn; + s2 = (char *)filename; + + /* Otherwise, if these match up to the length of filename, then + it is a match. */ + if (_rl_completion_case_fold && _rl_completion_case_map) + { + /* Case-insensitive comparison treating _ and - as equivalent */ +#if defined (HANDLE_MULTIBYTE) + if (MB_CUR_MAX > 1 && rl_byte_oriented == 0) + { + do + { + v1 = mbrtowc (&wc1, s1, convlen, &ps1); + v2 = mbrtowc (&wc2, s2, filename_len, &ps2); + if (v1 == 0 && v2 == 0) + return 1; + else if (MB_INVALIDCH (v1) || MB_INVALIDCH (v2)) + { + if (*s1 != *s2) /* do byte comparison */ + return 0; + else if ((*s1 == '-' || *s1 == '_') && (*s2 == '-' || *s2 == '_')) + return 0; + s1++; s2++; len--; + continue; + } + wc1 = towlower (wc1); + wc2 = towlower (wc2); + s1 += v1; + s2 += v1; + len -= v1; + if ((wc1 == L'-' || wc1 == L'_') && (wc2 == L'-' || wc2 == L'_')) + continue; + if (wc1 != wc2) + return 0; + } + while (len != 0); + } + else +#endif + { + do + { + d = _rl_to_lower (*s1) - _rl_to_lower (*s2); + /* *s1 == [-_] && *s2 == [-_] */ + if ((*s1 == '-' || *s1 == '_') && (*s2 == '-' || *s2 == '_')) + d = 0; + if (d != 0) + return 0; + s1++; s2++; /* already checked convlen >= filename_len */ + } + while (--len != 0); + } + + return 1; + } + else if (_rl_completion_case_fold) + { +#if defined (HANDLE_MULTIBYTE) + if (MB_CUR_MAX > 1 && rl_byte_oriented == 0) + { + do + { + v1 = mbrtowc (&wc1, s1, convlen, &ps1); + v2 = mbrtowc (&wc2, s2, filename_len, &ps2); + if (v1 == 0 && v2 == 0) + return 1; + else if (MB_INVALIDCH (v1) || MB_INVALIDCH (v2)) + { + if (*s1 != *s2) /* do byte comparison */ + return 0; + s1++; s2++; len--; + continue; + } + wc1 = towlower (wc1); + wc2 = towlower (wc2); + if (wc1 != wc2) + return 0; + s1 += v1; + s2 += v1; + len -= v1; + } + while (len != 0); + return 1; + } + else +#endif + if ((_rl_to_lower (convfn[0]) == _rl_to_lower (filename[0])) && + (convlen >= filename_len) && + (_rl_strnicmp (filename, convfn, filename_len) == 0)) + return 1; + } + else + { + if ((convfn[0] == filename[0]) && + (convlen >= filename_len) && + (strncmp (filename, convfn, filename_len) == 0)) + return 1; + } + return 0; +} + +/* Okay, now we write the entry_function for filename completion. In the + general case. Note that completion in the shell is a little different + because of all the pathnames that must be followed when looking up the + completion for a command. */ +char * +rl_filename_completion_function (text, state) + const char *text; + int state; +{ + static DIR *directory = (DIR *)NULL; + static char *filename = (char *)NULL; + static char *dirname = (char *)NULL; + static char *users_dirname = (char *)NULL; + static int filename_len; + char *temp, *dentry, *convfn; + int dirlen, dentlen, convlen; + struct dirent *entry; + + /* If we don't have any state, then do some initialization. */ + if (state == 0) + { + /* If we were interrupted before closing the directory or reading + all of its contents, close it. */ + if (directory) + { + closedir (directory); + directory = (DIR *)NULL; + } + FREE (dirname); + FREE (filename); + FREE (users_dirname); + + filename = savestring (text); + if (*text == 0) + text = "."; + dirname = savestring (text); + + temp = strrchr (dirname, '/'); + +#if defined (__MSDOS__) + /* special hack for //X/... */ + if (dirname[0] == '/' && dirname[1] == '/' && ISALPHA ((unsigned char)dirname[2]) && dirname[3] == '/') + temp = strrchr (dirname + 3, '/'); +#endif + + if (temp) + { + strcpy (filename, ++temp); + *temp = '\0'; + } +#if defined (__MSDOS__) + /* searches from current directory on the drive */ + else if (ISALPHA ((unsigned char)dirname[0]) && dirname[1] == ':') + { + strcpy (filename, dirname + 2); + dirname[2] = '\0'; + } +#endif + else + { + dirname[0] = '.'; + dirname[1] = '\0'; + } + + /* We aren't done yet. We also support the "~user" syntax. */ + + /* Save the version of the directory that the user typed, dequoting + it if necessary. */ + if (rl_completion_found_quote && rl_filename_dequoting_function) + users_dirname = (*rl_filename_dequoting_function) (dirname, rl_completion_quote_character); + else + users_dirname = savestring (dirname); + + if (*dirname == '~') + { + temp = tilde_expand (dirname); + xfree (dirname); + dirname = temp; + } + + /* We have saved the possibly-dequoted version of the directory name + the user typed. Now transform the directory name we're going to + pass to opendir(2). The directory rewrite hook modifies only the + directory name; the directory completion hook modifies both the + directory name passed to opendir(2) and the version the user + typed. Both the directory completion and rewrite hooks should perform + any necessary dequoting. The hook functions return 1 if they modify + the directory name argument. If either hook returns 0, it should + not modify the directory name pointer passed as an argument. */ + if (rl_directory_rewrite_hook) + (*rl_directory_rewrite_hook) (&dirname); + else if (rl_directory_completion_hook && (*rl_directory_completion_hook) (&dirname)) + { + xfree (users_dirname); + users_dirname = savestring (dirname); + } + else if (rl_completion_found_quote && rl_filename_dequoting_function) + { + /* delete single and double quotes */ + xfree (dirname); + dirname = savestring (users_dirname); + } + directory = opendir (dirname); + + /* Now dequote a non-null filename. FILENAME will not be NULL, but may + be empty. */ + if (*filename && rl_completion_found_quote && rl_filename_dequoting_function) + { + /* delete single and double quotes */ + temp = (*rl_filename_dequoting_function) (filename, rl_completion_quote_character); + xfree (filename); + filename = temp; + } + filename_len = strlen (filename); + + rl_filename_completion_desired = 1; + } + + /* At this point we should entertain the possibility of hacking wildcarded + filenames, like /usr/man/man/te. If the directory name + contains globbing characters, then build an array of directories, and + then map over that list while completing. */ + /* *** UNIMPLEMENTED *** */ + + /* Now that we have some state, we can read the directory. */ + + entry = (struct dirent *)NULL; + while (directory && (entry = readdir (directory))) + { + convfn = dentry = entry->d_name; + convlen = dentlen = D_NAMLEN (entry); + + if (rl_filename_rewrite_hook) + { + convfn = (*rl_filename_rewrite_hook) (dentry, dentlen); + convlen = (convfn == dentry) ? dentlen : strlen (convfn); + } + + /* Special case for no filename. If the user has disabled the + `match-hidden-files' variable, skip filenames beginning with `.'. + All other entries except "." and ".." match. */ + if (filename_len == 0) + { + if (_rl_match_hidden_files == 0 && HIDDEN_FILE (convfn)) + continue; + + if (convfn[0] != '.' || + (convfn[1] && (convfn[1] != '.' || convfn[2]))) + break; + } + else + { + if (complete_fncmp (convfn, convlen, filename, filename_len)) + break; + } + } + + if (entry == 0) + { + if (directory) + { + closedir (directory); + directory = (DIR *)NULL; + } + if (dirname) + { + xfree (dirname); + dirname = (char *)NULL; + } + if (filename) + { + xfree (filename); + filename = (char *)NULL; + } + if (users_dirname) + { + xfree (users_dirname); + users_dirname = (char *)NULL; + } + + return (char *)NULL; + } + else + { + /* dirname && (strcmp (dirname, ".") != 0) */ + if (dirname && (dirname[0] != '.' || dirname[1])) + { + if (rl_complete_with_tilde_expansion && *users_dirname == '~') + { + dirlen = strlen (dirname); + temp = (char *)xmalloc (2 + dirlen + D_NAMLEN (entry)); + strcpy (temp, dirname); + /* Canonicalization cuts off any final slash present. We + may need to add it back. */ + if (dirname[dirlen - 1] != '/') + { + temp[dirlen++] = '/'; + temp[dirlen] = '\0'; + } + } + else + { + dirlen = strlen (users_dirname); + temp = (char *)xmalloc (2 + dirlen + D_NAMLEN (entry)); + strcpy (temp, users_dirname); + /* Make sure that temp has a trailing slash here. */ + if (users_dirname[dirlen - 1] != '/') + temp[dirlen++] = '/'; + } + + strcpy (temp + dirlen, convfn); + } + else + temp = savestring (convfn); + + if (convfn != dentry) + xfree (convfn); + + return (temp); + } +} + +/* An initial implementation of a menu completion function a la tcsh. The + first time (if the last readline command was not rl_old_menu_complete), we + generate the list of matches. This code is very similar to the code in + rl_complete_internal -- there should be a way to combine the two. Then, + for each item in the list of matches, we insert the match in an undoable + fashion, with the appropriate character appended (this happens on the + second and subsequent consecutive calls to rl_old_menu_complete). When we + hit the end of the match list, we restore the original unmatched text, + ring the bell, and reset the counter to zero. */ +int +rl_old_menu_complete (count, invoking_key) + int count, invoking_key; +{ + rl_compentry_func_t *our_func; + int matching_filenames, found_quote; + + static char *orig_text; + static char **matches = (char **)0; + static int match_list_index = 0; + static int match_list_size = 0; + static int orig_start, orig_end; + static char quote_char; + static int delimiter; + + /* The first time through, we generate the list of matches and set things + up to insert them. */ + if (rl_last_func != rl_old_menu_complete) + { + /* Clean up from previous call, if any. */ + FREE (orig_text); + if (matches) + _rl_free_match_list (matches); + + match_list_index = match_list_size = 0; + matches = (char **)NULL; + + rl_completion_invoking_key = invoking_key; + + RL_SETSTATE(RL_STATE_COMPLETING); + + /* Only the completion entry function can change these. */ + set_completion_defaults ('%'); + + our_func = rl_menu_completion_entry_function; + if (our_func == 0) + our_func = rl_completion_entry_function + ? rl_completion_entry_function + : rl_filename_completion_function; + + /* We now look backwards for the start of a filename/variable word. */ + orig_end = rl_point; + found_quote = delimiter = 0; + quote_char = '\0'; + + if (rl_point) + /* This (possibly) changes rl_point. If it returns a non-zero char, + we know we have an open quote. */ + quote_char = _rl_find_completion_word (&found_quote, &delimiter); + + orig_start = rl_point; + rl_point = orig_end; + + orig_text = rl_copy_text (orig_start, orig_end); + matches = gen_completion_matches (orig_text, orig_start, orig_end, + our_func, found_quote, quote_char); + + /* If we are matching filenames, the attempted completion function will + have set rl_filename_completion_desired to a non-zero value. The basic + rl_filename_completion_function does this. */ + matching_filenames = rl_filename_completion_desired; + + if (matches == 0 || postprocess_matches (&matches, matching_filenames) == 0) + { + rl_ding (); + FREE (matches); + matches = (char **)0; + FREE (orig_text); + orig_text = (char *)0; + completion_changed_buffer = 0; + RL_UNSETSTATE(RL_STATE_COMPLETING); + return (0); + } + + RL_UNSETSTATE(RL_STATE_COMPLETING); + + for (match_list_size = 0; matches[match_list_size]; match_list_size++) + ; + /* matches[0] is lcd if match_list_size > 1, but the circular buffer + code below should take care of it. */ + + if (match_list_size > 1 && _rl_complete_show_all) + display_matches (matches); + } + + /* Now we have the list of matches. Replace the text between + rl_line_buffer[orig_start] and rl_line_buffer[rl_point] with + matches[match_list_index], and add any necessary closing char. */ + + if (matches == 0 || match_list_size == 0) + { + rl_ding (); + FREE (matches); + matches = (char **)0; + completion_changed_buffer = 0; + return (0); + } + + match_list_index += count; + if (match_list_index < 0) + { + while (match_list_index < 0) + match_list_index += match_list_size; + } + else + match_list_index %= match_list_size; + + if (match_list_index == 0 && match_list_size > 1) + { + rl_ding (); + insert_match (orig_text, orig_start, MULT_MATCH, "e_char); + } + else + { + insert_match (matches[match_list_index], orig_start, SINGLE_MATCH, "e_char); + append_to_match (matches[match_list_index], delimiter, quote_char, + strcmp (orig_text, matches[match_list_index])); + } + + completion_changed_buffer = 1; + return (0); +} + +int +rl_menu_complete (count, ignore) + int count, ignore; +{ + rl_compentry_func_t *our_func; + int matching_filenames, found_quote; + + static char *orig_text; + static char **matches = (char **)0; + static int match_list_index = 0; + static int match_list_size = 0; + static int nontrivial_lcd = 0; + static int full_completion = 0; /* set to 1 if menu completion should reinitialize on next call */ + static int orig_start, orig_end; + static char quote_char; + static int delimiter, cstate; + + /* The first time through, we generate the list of matches and set things + up to insert them. */ + if ((rl_last_func != rl_menu_complete && rl_last_func != rl_backward_menu_complete) || full_completion) + { + /* Clean up from previous call, if any. */ + FREE (orig_text); + if (matches) + _rl_free_match_list (matches); + + match_list_index = match_list_size = 0; + matches = (char **)NULL; + + full_completion = 0; + + RL_SETSTATE(RL_STATE_COMPLETING); + + /* Only the completion entry function can change these. */ + set_completion_defaults ('%'); + + our_func = rl_menu_completion_entry_function; + if (our_func == 0) + our_func = rl_completion_entry_function + ? rl_completion_entry_function + : rl_filename_completion_function; + + /* We now look backwards for the start of a filename/variable word. */ + orig_end = rl_point; + found_quote = delimiter = 0; + quote_char = '\0'; + + if (rl_point) + /* This (possibly) changes rl_point. If it returns a non-zero char, + we know we have an open quote. */ + quote_char = _rl_find_completion_word (&found_quote, &delimiter); + + orig_start = rl_point; + rl_point = orig_end; + + orig_text = rl_copy_text (orig_start, orig_end); + matches = gen_completion_matches (orig_text, orig_start, orig_end, + our_func, found_quote, quote_char); + + nontrivial_lcd = matches && strcmp (orig_text, matches[0]) != 0; + + /* If we are matching filenames, the attempted completion function will + have set rl_filename_completion_desired to a non-zero value. The basic + rl_filename_completion_function does this. */ + matching_filenames = rl_filename_completion_desired; + + if (matches == 0 || postprocess_matches (&matches, matching_filenames) == 0) + { + rl_ding (); + FREE (matches); + matches = (char **)0; + FREE (orig_text); + orig_text = (char *)0; + completion_changed_buffer = 0; + RL_UNSETSTATE(RL_STATE_COMPLETING); + return (0); + } + + RL_UNSETSTATE(RL_STATE_COMPLETING); + + for (match_list_size = 0; matches[match_list_size]; match_list_size++) + ; + + if (match_list_size == 0) + { + rl_ding (); + FREE (matches); + matches = (char **)0; + match_list_index = 0; + completion_changed_buffer = 0; + return (0); + } + + /* matches[0] is lcd if match_list_size > 1, but the circular buffer + code below should take care of it. */ + if (*matches[0]) + { + insert_match (matches[0], orig_start, matches[1] ? MULT_MATCH : SINGLE_MATCH, "e_char); + orig_end = orig_start + strlen (matches[0]); + completion_changed_buffer = STREQ (orig_text, matches[0]) == 0; + } + + if (match_list_size > 1 && _rl_complete_show_all) + { + display_matches (matches); + /* If there are so many matches that the user has to be asked + whether or not he wants to see the matches, menu completion + is unwieldy. */ + if (rl_completion_query_items > 0 && match_list_size >= rl_completion_query_items) + { + rl_ding (); + FREE (matches); + matches = (char **)0; + full_completion = 1; + return (0); + } + else if (_rl_menu_complete_prefix_first) + { + rl_ding (); + return (0); + } + } + else if (match_list_size <= 1) + { + append_to_match (matches[0], delimiter, quote_char, nontrivial_lcd); + full_completion = 1; + return (0); + } + else if (_rl_menu_complete_prefix_first && match_list_size > 1) + { + rl_ding (); + return (0); + } + } + + /* Now we have the list of matches. Replace the text between + rl_line_buffer[orig_start] and rl_line_buffer[rl_point] with + matches[match_list_index], and add any necessary closing char. */ + + if (matches == 0 || match_list_size == 0) + { + rl_ding (); + FREE (matches); + matches = (char **)0; + completion_changed_buffer = 0; + return (0); + } + + match_list_index += count; + if (match_list_index < 0) + { + while (match_list_index < 0) + match_list_index += match_list_size; + } + else + match_list_index %= match_list_size; + + if (match_list_index == 0 && match_list_size > 1) + { + rl_ding (); + insert_match (matches[0], orig_start, MULT_MATCH, "e_char); + } + else + { + insert_match (matches[match_list_index], orig_start, SINGLE_MATCH, "e_char); + append_to_match (matches[match_list_index], delimiter, quote_char, + strcmp (orig_text, matches[match_list_index])); + } + + completion_changed_buffer = 1; + return (0); +} + +int +rl_backward_menu_complete (count, key) + int count, key; +{ + /* Positive arguments to backward-menu-complete translate into negative + arguments for menu-complete, and vice versa. */ + return (rl_menu_complete (-count, key)); +} diff --git a/lib/readline/doc/Makefile.old b/lib/readline/doc/Makefile.old new file mode 100644 index 000000000..58d4dd762 --- /dev/null +++ b/lib/readline/doc/Makefile.old @@ -0,0 +1,76 @@ +# This makefile for Readline library documentation is in -*- text -*- mode. +# Emacs likes it that way. +RM = rm -f + +MAKEINFO = makeinfo +TEXI2DVI = texi2dvi +TEXI2HTML = texi2html +QUIETPS = #set this to -q to shut up dvips +DVIPS = dvips -D 300 $(QUIETPS) -o $@ # tricky + +INSTALL_DATA = cp +infodir = /usr/local/info + +RLSRC = rlman.texinfo rluser.texinfo rltech.texinfo +HISTSRC = hist.texinfo hsuser.texinfo hstech.texinfo + +DVIOBJ = readline.dvi history.dvi +INFOOBJ = readline.info history.info +PSOBJ = readline.ps history.ps +HTMLOBJ = readline.html history.html + +all: info dvi html ps +nodvi: info html + +readline.dvi: $(RLSRC) + $(TEXI2DVI) rlman.texinfo + mv rlman.dvi readline.dvi + +readline.info: $(RLSRC) + $(MAKEINFO) --no-split -o $@ rlman.texinfo + +history.dvi: ${HISTSRC} + $(TEXI2DVI) hist.texinfo + mv hist.dvi history.dvi + +history.info: ${HISTSRC} + $(MAKEINFO) --no-split -o $@ hist.texinfo + +readline.ps: readline.dvi + $(RM) $@ + $(DVIPS) readline.dvi + +history.ps: history.dvi + $(RM) $@ + $(DVIPS) history.dvi + +readline.html: ${RLSRC} + $(TEXI2HTML) rlman.texinfo + sed -e 's:rlman.html:readline.html:' -e 's:rlman_toc.html:readline_toc.html:' rlman.html > readline.html + sed -e 's:rlman.html:readline.html:' -e 's:rlman_toc.html:readline_toc.html:' rlman_toc.html > readline_toc.html + $(RM) rlman.html rlman_toc.html + +history.html: ${HISTSRC} + $(TEXI2HTML) hist.texinfo + sed -e 's:hist.html:history.html:' -e 's:hist_toc.html:history_toc.html:' hist.html > history.html + sed -e 's:hist.html:history.html:' -e 's:hist_toc.html:history_toc.html:' hist_toc.html > history_toc.html + $(RM) hist.html hist_toc.html + +info: $(INFOOBJ) +dvi: $(DVIOBJ) +ps: $(PSOBJ) +html: $(HTMLOBJ) + +clean: + $(RM) *.aux *.cp *.fn *.ky *.log *.pg *.toc *.tp *.vr *.cps *.pgs \ + *.fns *.kys *.tps *.vrs *.o core + +distclean: clean +mostlyclean: clean + +maintainer-clean: clean + $(RM) *.dvi *.info *.info-* *.ps *.html + +install: info + ${INSTALL_DATA} readline.info $(infodir)/readline.info + ${INSTALL_DATA} history.info $(infodir)/history.info diff --git a/lib/readline/readline.c b/lib/readline/readline.c index 6089eee6b..6d2e36b97 100644 --- a/lib/readline/readline.c +++ b/lib/readline/readline.c @@ -532,7 +532,7 @@ readline_internal_charloop () static int lastc, eof_found; int c, code, lk; - lastc = -1; + lastc = EOF; eof_found = 0; #if !defined (READLINE_CALLBACKS) @@ -586,15 +586,36 @@ readline_internal_charloop () #endif } - /* EOF typed to a non-blank line is a . If we want to change this, - to force any existing line to be ignored when read(2) reads EOF, - for example, this is the place to change. */ + /* EOF typed to a non-blank line is ^D the first time, EOF the second + time in a row. This won't return any partial line read from the tty. + If we want to change this, to force any existing line to be returned + when read(2) reads EOF, for example, this is the place to change. */ if (c == EOF && rl_end) - c = NEWLINE; + { + if (RL_SIG_RECEIVED ()) + { + RL_CHECK_SIGNALS (); + if (rl_signal_event_hook) + (*rl_signal_event_hook) (); /* XXX */ + } + + /* XXX - reading two consecutive EOFs returns EOF */ + if (RL_ISSTATE (RL_STATE_TERMPREPPED)) + { + if (lastc == _rl_eof_char || lastc == EOF) + rl_end = 0; + else + c = _rl_eof_char; + } + else + c = NEWLINE; + } /* The character _rl_eof_char typed to blank line, and not as the - previous character is interpreted as EOF. */ - if (((c == _rl_eof_char && lastc != c) || c == EOF) && !rl_end) + previous character is interpreted as EOF. This doesn't work when + READLINE_CALLBACKS is defined, so hitting a series of ^Ds will + erase all the chars on the line and then return EOF. */ + if (((c == _rl_eof_char && lastc != c) || c == EOF) && rl_end == 0) { #if defined (READLINE_CALLBACKS) RL_SETSTATE(RL_STATE_DONE); diff --git a/lib/readline/readline.c~ b/lib/readline/readline.c~ new file mode 100644 index 000000000..533e85428 --- /dev/null +++ b/lib/readline/readline.c~ @@ -0,0 +1,1423 @@ +/* readline.c -- a general facility for reading lines of input + with emacs style editing and completion. */ + +/* Copyright (C) 1987-2013 Free Software Foundation, Inc. + + This file is part of the GNU Readline Library (Readline), a library + for reading lines of text with interactive input and history editing. + + Readline is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + Readline is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with Readline. If not, see . +*/ + +#define READLINE_LIBRARY + +#if defined (HAVE_CONFIG_H) +# include +#endif + +#include +#include "posixstat.h" +#include +#if defined (HAVE_SYS_FILE_H) +# include +#endif /* HAVE_SYS_FILE_H */ + +#if defined (HAVE_UNISTD_H) +# include +#endif /* HAVE_UNISTD_H */ + +#if defined (HAVE_STDLIB_H) +# include +#else +# include "ansi_stdlib.h" +#endif /* HAVE_STDLIB_H */ + +#if defined (HAVE_LOCALE_H) +# include +#endif + +#include +#include "posixjmp.h" +#include + +#if !defined (errno) +extern int errno; +#endif /* !errno */ + +/* System-specific feature definitions and include files. */ +#include "rldefs.h" +#include "rlmbutil.h" + +#if defined (__EMX__) +# define INCL_DOSPROCESS +# include +#endif /* __EMX__ */ + +/* Some standard library routines. */ +#include "readline.h" +#include "history.h" + +#include "rlprivate.h" +#include "rlshell.h" +#include "xmalloc.h" + +#ifndef RL_LIBRARY_VERSION +# define RL_LIBRARY_VERSION "5.1" +#endif + +#ifndef RL_READLINE_VERSION +# define RL_READLINE_VERSION 0x0501 +#endif + +extern void _rl_free_history_entry PARAMS((HIST_ENTRY *)); + +#if defined (COLOR_SUPPORT) +extern void _rl_parse_colors PARAMS((void)); /* XXX */ +#endif + + +/* Forward declarations used in this file. */ +static char *readline_internal PARAMS((void)); +static void readline_initialize_everything PARAMS((void)); + +static void bind_arrow_keys_internal PARAMS((Keymap)); +static void bind_arrow_keys PARAMS((void)); + +static void bind_bracketed_paste_prefix PARAMS((void)); + +static void readline_default_bindings PARAMS((void)); +static void reset_default_bindings PARAMS((void)); + +static int _rl_subseq_result PARAMS((int, Keymap, int, int)); +static int _rl_subseq_getchar PARAMS((int)); + +/* **************************************************************** */ +/* */ +/* Line editing input utility */ +/* */ +/* **************************************************************** */ + +const char *rl_library_version = RL_LIBRARY_VERSION; + +int rl_readline_version = RL_READLINE_VERSION; + +/* True if this is `real' readline as opposed to some stub substitute. */ +int rl_gnu_readline_p = 1; + +/* A pointer to the keymap that is currently in use. + By default, it is the standard emacs keymap. */ +Keymap _rl_keymap = emacs_standard_keymap; + +/* The current style of editing. */ +int rl_editing_mode = emacs_mode; + +/* The current insert mode: input (the default) or overwrite */ +int rl_insert_mode = RL_IM_DEFAULT; + +/* Non-zero if we called this function from _rl_dispatch(). It's present + so functions can find out whether they were called from a key binding + or directly from an application. */ +int rl_dispatching; + +/* Non-zero if the previous command was a kill command. */ +int _rl_last_command_was_kill = 0; + +/* The current value of the numeric argument specified by the user. */ +int rl_numeric_arg = 1; + +/* Non-zero if an argument was typed. */ +int rl_explicit_arg = 0; + +/* Temporary value used while generating the argument. */ +int rl_arg_sign = 1; + +/* Non-zero means we have been called at least once before. */ +static int rl_initialized; + +#if 0 +/* If non-zero, this program is running in an EMACS buffer. */ +static int running_in_emacs; +#endif + +/* Flags word encapsulating the current readline state. */ +int rl_readline_state = RL_STATE_NONE; + +/* The current offset in the current input line. */ +int rl_point; + +/* Mark in the current input line. */ +int rl_mark; + +/* Length of the current input line. */ +int rl_end; + +/* Make this non-zero to return the current input_line. */ +int rl_done; + +/* The last function executed by readline. */ +rl_command_func_t *rl_last_func = (rl_command_func_t *)NULL; + +/* Top level environment for readline_internal (). */ +procenv_t _rl_top_level; + +/* The streams we interact with. */ +FILE *_rl_in_stream, *_rl_out_stream; + +/* The names of the streams that we do input and output to. */ +FILE *rl_instream = (FILE *)NULL; +FILE *rl_outstream = (FILE *)NULL; + +/* Non-zero means echo characters as they are read. Defaults to no echo; + set to 1 if there is a controlling terminal, we can get its attributes, + and the attributes include `echo'. Look at rltty.c:prepare_terminal_settings + for the code that sets it. */ +int _rl_echoing_p = 0; + +/* Current prompt. */ +char *rl_prompt = (char *)NULL; +int rl_visible_prompt_length = 0; + +/* Set to non-zero by calling application if it has already printed rl_prompt + and does not want readline to do it the first time. */ +int rl_already_prompted = 0; + +/* The number of characters read in order to type this complete command. */ +int rl_key_sequence_length = 0; + +/* If non-zero, then this is the address of a function to call just + before readline_internal_setup () prints the first prompt. */ +rl_hook_func_t *rl_startup_hook = (rl_hook_func_t *)NULL; + +/* If non-zero, this is the address of a function to call just before + readline_internal_setup () returns and readline_internal starts + reading input characters. */ +rl_hook_func_t *rl_pre_input_hook = (rl_hook_func_t *)NULL; + +/* What we use internally. You should always refer to RL_LINE_BUFFER. */ +static char *the_line; + +/* The character that can generate an EOF. Really read from + the terminal driver... just defaulted here. */ +int _rl_eof_char = CTRL ('D'); + +/* Non-zero makes this the next keystroke to read. */ +int rl_pending_input = 0; + +/* Pointer to a useful terminal name. */ +const char *rl_terminal_name = (const char *)NULL; + +/* Non-zero means to always use horizontal scrolling in line display. */ +int _rl_horizontal_scroll_mode = 0; + +/* Non-zero means to display an asterisk at the starts of history lines + which have been modified. */ +int _rl_mark_modified_lines = 0; + +/* The style of `bell' notification preferred. This can be set to NO_BELL, + AUDIBLE_BELL, or VISIBLE_BELL. */ +int _rl_bell_preference = AUDIBLE_BELL; + +/* String inserted into the line by rl_insert_comment (). */ +char *_rl_comment_begin; + +/* Keymap holding the function currently being executed. */ +Keymap rl_executing_keymap; + +/* Keymap we're currently using to dispatch. */ +Keymap _rl_dispatching_keymap; + +/* Non-zero means to erase entire line, including prompt, on empty input lines. */ +int rl_erase_empty_line = 0; + +/* Non-zero means to read only this many characters rather than up to a + character bound to accept-line. */ +int rl_num_chars_to_read; + +/* Line buffer and maintenance. */ +char *rl_line_buffer = (char *)NULL; +int rl_line_buffer_len = 0; + +/* Key sequence `contexts' */ +_rl_keyseq_cxt *_rl_kscxt = 0; + +int rl_executing_key; +char *rl_executing_keyseq = 0; +int _rl_executing_keyseq_size = 0; + +/* Timeout (specified in milliseconds) when reading characters making up an + ambiguous multiple-key sequence */ +int _rl_keyseq_timeout = 500; + +#define RESIZE_KEYSEQ_BUFFER() \ + do \ + { \ + if (rl_key_sequence_length + 2 >= _rl_executing_keyseq_size) \ + { \ + _rl_executing_keyseq_size += 16; \ + rl_executing_keyseq = xrealloc (rl_executing_keyseq, _rl_executing_keyseq_size); \ + } \ + } \ + while (0); + +/* Forward declarations used by the display, termcap, and history code. */ + +/* **************************************************************** */ +/* */ +/* `Forward' declarations */ +/* */ +/* **************************************************************** */ + +/* Non-zero means do not parse any lines other than comments and + parser directives. */ +unsigned char _rl_parsing_conditionalized_out = 0; + +/* Non-zero means to convert characters with the meta bit set to + escape-prefixed characters so we can indirect through + emacs_meta_keymap or vi_escape_keymap. */ +int _rl_convert_meta_chars_to_ascii = 1; + +/* Non-zero means to output characters with the meta bit set directly + rather than as a meta-prefixed escape sequence. */ +int _rl_output_meta_chars = 0; + +/* Non-zero means to look at the termios special characters and bind + them to equivalent readline functions at startup. */ +int _rl_bind_stty_chars = 1; + +/* Non-zero means to go through the history list at every newline (or + whenever rl_done is set and readline returns) and revert each line to + its initial state. */ +int _rl_revert_all_at_newline = 0; + +/* Non-zero means to honor the termios ECHOCTL bit and echo control + characters corresponding to keyboard-generated signals. */ +int _rl_echo_control_chars = 1; + +/* Non-zero means to prefix the displayed prompt with a character indicating + the editing mode: @ for emacs, : for vi-command, + for vi-insert. */ +int _rl_show_mode_in_prompt = 0; + +/* Non-zero means to attempt to put the terminal in `bracketed paste mode', + where it will prefix pasted text with an escape sequence and send + another to mark the end of the paste. */ +int _rl_enable_bracketed_paste = 0; + +/* **************************************************************** */ +/* */ +/* Top Level Functions */ +/* */ +/* **************************************************************** */ + +/* Non-zero means treat 0200 bit in terminal input as Meta bit. */ +int _rl_meta_flag = 0; /* Forward declaration */ + +/* Set up the prompt and expand it. Called from readline() and + rl_callback_handler_install (). */ +int +rl_set_prompt (prompt) + const char *prompt; +{ + FREE (rl_prompt); + rl_prompt = prompt ? savestring (prompt) : (char *)NULL; + rl_display_prompt = rl_prompt ? rl_prompt : ""; + + rl_visible_prompt_length = rl_expand_prompt (rl_prompt); + return 0; +} + +/* Read a line of input. Prompt with PROMPT. An empty PROMPT means + none. A return value of NULL means that EOF was encountered. */ +char * +readline (prompt) + const char *prompt; +{ + char *value; +#if 0 + int in_callback; +#endif + + /* If we are at EOF return a NULL string. */ + if (rl_pending_input == EOF) + { + rl_clear_pending_input (); + return ((char *)NULL); + } + +#if 0 + /* If readline() is called after installing a callback handler, temporarily + turn off the callback state to avoid ensuing messiness. Patch supplied + by the gdb folks. XXX -- disabled. This can be fooled and readline + left in a strange state by a poorly-timed longjmp. */ + if (in_callback = RL_ISSTATE (RL_STATE_CALLBACK)) + RL_UNSETSTATE (RL_STATE_CALLBACK); +#endif + + rl_set_prompt (prompt); + + rl_initialize (); + if (rl_prep_term_function) + (*rl_prep_term_function) (_rl_meta_flag); + +#if defined (HANDLE_SIGNALS) + rl_set_signals (); +#endif + + value = readline_internal (); + if (rl_deprep_term_function) + (*rl_deprep_term_function) (); + +#if defined (HANDLE_SIGNALS) + rl_clear_signals (); +#endif + +#if 0 + if (in_callback) + RL_SETSTATE (RL_STATE_CALLBACK); +#endif + +#if HAVE_DECL_AUDIT_TTY && defined (ENABLE_TTY_AUDIT_SUPPORT) + if (value) + _rl_audit_tty (value); +#endif + + return (value); +} + +#if defined (READLINE_CALLBACKS) +# define STATIC_CALLBACK +#else +# define STATIC_CALLBACK static +#endif + +STATIC_CALLBACK void +readline_internal_setup () +{ + char *nprompt; + + _rl_in_stream = rl_instream; + _rl_out_stream = rl_outstream; + + /* Enable the meta key only for the duration of readline(), if this + terminal has one and the terminal has been initialized */ + if (_rl_enable_meta & RL_ISSTATE (RL_STATE_TERMPREPPED)) + _rl_enable_meta_key (); + + if (rl_startup_hook) + (*rl_startup_hook) (); + +#if defined (VI_MODE) + if (rl_editing_mode == vi_mode) + rl_vi_insertion_mode (1, 'i'); /* don't want to reset last */ +#endif /* VI_MODE */ + + /* If we're not echoing, we still want to at least print a prompt, because + rl_redisplay will not do it for us. If the calling application has a + custom redisplay function, though, let that function handle it. */ + if (_rl_echoing_p == 0 && rl_redisplay_function == rl_redisplay) + { + if (rl_prompt && rl_already_prompted == 0) + { + nprompt = _rl_strip_prompt (rl_prompt); + fprintf (_rl_out_stream, "%s", nprompt); + fflush (_rl_out_stream); + xfree (nprompt); + } + } + else + { + if (rl_prompt && rl_already_prompted) + rl_on_new_line_with_prompt (); + else + rl_on_new_line (); + (*rl_redisplay_function) (); + } + + if (rl_pre_input_hook) + (*rl_pre_input_hook) (); + + RL_CHECK_SIGNALS (); +} + +STATIC_CALLBACK char * +readline_internal_teardown (eof) + int eof; +{ + char *temp; + HIST_ENTRY *entry; + + RL_CHECK_SIGNALS (); + + /* Restore the original of this history line, iff the line that we + are editing was originally in the history, AND the line has changed. */ + entry = current_history (); + + if (entry && rl_undo_list) + { + temp = savestring (the_line); + rl_revert_line (1, 0); + entry = replace_history_entry (where_history (), the_line, (histdata_t)NULL); + _rl_free_history_entry (entry); + + strcpy (the_line, temp); + xfree (temp); + } + + if (_rl_revert_all_at_newline) + _rl_revert_all_lines (); + + /* At any rate, it is highly likely that this line has an undo list. Get + rid of it now. */ + if (rl_undo_list) + rl_free_undo_list (); + + /* Disable the meta key, if this terminal has one and we were told to use it. + The check whether or not we sent the enable string is in + _rl_disable_meta_key(); the flag is set in _rl_enable_meta_key */ + _rl_disable_meta_key (); + + /* Restore normal cursor, if available. */ + _rl_set_insert_mode (RL_IM_INSERT, 0); + + return (eof ? (char *)NULL : savestring (the_line)); +} + +void +_rl_internal_char_cleanup () +{ +#if defined (VI_MODE) + /* In vi mode, when you exit insert mode, the cursor moves back + over the previous character. We explicitly check for that here. */ + if (rl_editing_mode == vi_mode && _rl_keymap == vi_movement_keymap) + rl_vi_check (); +#endif /* VI_MODE */ + + if (rl_num_chars_to_read && rl_end >= rl_num_chars_to_read) + { + (*rl_redisplay_function) (); + _rl_want_redisplay = 0; + rl_newline (1, '\n'); + } + + if (rl_done == 0) + { + (*rl_redisplay_function) (); + _rl_want_redisplay = 0; + } + + /* If the application writer has told us to erase the entire line if + the only character typed was something bound to rl_newline, do so. */ + if (rl_erase_empty_line && rl_done && rl_last_func == rl_newline && + rl_point == 0 && rl_end == 0) + _rl_erase_entire_line (); +} + +STATIC_CALLBACK int +#if defined (READLINE_CALLBACKS) +readline_internal_char () +#else +readline_internal_charloop () +#endif +{ + static int lastc, eof_found; + int c, code, lk; + + lastc = EOF; + eof_found = 0; + +#if !defined (READLINE_CALLBACKS) + while (rl_done == 0) + { +#endif + lk = _rl_last_command_was_kill; + +#if defined (HAVE_POSIX_SIGSETJMP) + code = sigsetjmp (_rl_top_level, 0); +#else + code = setjmp (_rl_top_level); +#endif + + if (code) + { + (*rl_redisplay_function) (); + _rl_want_redisplay = 0; + /* If we get here, we're not being called from something dispatched + from _rl_callback_read_char(), which sets up its own value of + _rl_top_level (saving and restoring the old, of course), so + we can just return here. */ + if (RL_ISSTATE (RL_STATE_CALLBACK)) + return (0); + } + + if (rl_pending_input == 0) + { + /* Then initialize the argument and number of keys read. */ + _rl_reset_argument (); + rl_key_sequence_length = 0; + rl_executing_keyseq[0] = 0; + } + + RL_SETSTATE(RL_STATE_READCMD); + c = rl_read_key (); + RL_UNSETSTATE(RL_STATE_READCMD); + + /* look at input.c:rl_getc() for the circumstances under which this will + be returned; punt immediately on read error without converting it to + a newline; assume that rl_read_key has already called the signal + handler. */ + if (c == READERR) + { +#if defined (READLINE_CALLBACKS) + RL_SETSTATE(RL_STATE_DONE); + return (rl_done = 1); +#else + eof_found = 1; + break; +#endif + } + + /* EOF typed to a non-blank line is a . If we want to change this, + to force any existing line to be ignored when read(2) reads EOF, + for example, this is the place to change. */ + if (c == EOF && rl_end) + { + if (RL_SIG_RECEIVED ()) + { + RL_CHECK_SIGNALS (); + if (rl_signal_event_hook) + (*rl_signal_event_hook) (); /* XXX */ + } + + /* XXX - reading two consecutive EOFs returns EOF */ + if (RL_ISSTATE (RL_STATE_TERMPREPPED)) + { + if (lastc == _rl_eof_char || lastc == EOF) + rl_end = 0; + else + c = _rl_eof_char; + } + else + c = NEWLINE; + } + + /* The character _rl_eof_char typed to blank line, and not as the + previous character is interpreted as EOF. */ + if (((c == _rl_eof_char && lastc != c) || c == EOF) && rl_end == 0) + { +#if defined (READLINE_CALLBACKS) + RL_SETSTATE(RL_STATE_DONE); + return (rl_done = 1); +#else + eof_found = 1; + break; +#endif + } + + lastc = c; + _rl_dispatch ((unsigned char)c, _rl_keymap); + RL_CHECK_SIGNALS (); + + /* If there was no change in _rl_last_command_was_kill, then no kill + has taken place. Note that if input is pending we are reading + a prefix command, so nothing has changed yet. */ + if (rl_pending_input == 0 && lk == _rl_last_command_was_kill) + _rl_last_command_was_kill = 0; + + _rl_internal_char_cleanup (); + +#if defined (READLINE_CALLBACKS) + return 0; +#else + } + + return (eof_found); +#endif +} + +#if defined (READLINE_CALLBACKS) +static int +readline_internal_charloop () +{ + int eof = 1; + + while (rl_done == 0) + eof = readline_internal_char (); + return (eof); +} +#endif /* READLINE_CALLBACKS */ + +/* Read a line of input from the global rl_instream, doing output on + the global rl_outstream. + If rl_prompt is non-null, then that is our prompt. */ +static char * +readline_internal () +{ + int eof; + + readline_internal_setup (); + eof = readline_internal_charloop (); + return (readline_internal_teardown (eof)); +} + +void +_rl_init_line_state () +{ + rl_point = rl_end = rl_mark = 0; + the_line = rl_line_buffer; + the_line[0] = 0; +} + +void +_rl_set_the_line () +{ + the_line = rl_line_buffer; +} + +#if defined (READLINE_CALLBACKS) +_rl_keyseq_cxt * +_rl_keyseq_cxt_alloc () +{ + _rl_keyseq_cxt *cxt; + + cxt = (_rl_keyseq_cxt *)xmalloc (sizeof (_rl_keyseq_cxt)); + + cxt->flags = cxt->subseq_arg = cxt->subseq_retval = 0; + + cxt->okey = 0; + cxt->ocxt = _rl_kscxt; + cxt->childval = 42; /* sentinel value */ + + return cxt; +} + +void +_rl_keyseq_cxt_dispose (cxt) + _rl_keyseq_cxt *cxt; +{ + xfree (cxt); +} + +void +_rl_keyseq_chain_dispose () +{ + _rl_keyseq_cxt *cxt; + + while (_rl_kscxt) + { + cxt = _rl_kscxt; + _rl_kscxt = _rl_kscxt->ocxt; + _rl_keyseq_cxt_dispose (cxt); + } +} +#endif + +static int +_rl_subseq_getchar (key) + int key; +{ + int k; + + if (key == ESC) + RL_SETSTATE(RL_STATE_METANEXT); + RL_SETSTATE(RL_STATE_MOREINPUT); + k = rl_read_key (); + RL_UNSETSTATE(RL_STATE_MOREINPUT); + if (key == ESC) + RL_UNSETSTATE(RL_STATE_METANEXT); + + return k; +} + +#if defined (READLINE_CALLBACKS) +int +_rl_dispatch_callback (cxt) + _rl_keyseq_cxt *cxt; +{ + int nkey, r; + + /* For now */ + /* The first time this context is used, we want to read input and dispatch + on it. When traversing the chain of contexts back `up', we want to use + the value from the next context down. We're simulating recursion using + a chain of contexts. */ + if ((cxt->flags & KSEQ_DISPATCHED) == 0) + { + nkey = _rl_subseq_getchar (cxt->okey); + if (nkey < 0) + { + _rl_abort_internal (); + return -1; + } + r = _rl_dispatch_subseq (nkey, cxt->dmap, cxt->subseq_arg); + cxt->flags |= KSEQ_DISPATCHED; + } + else + r = cxt->childval; + + /* For now */ + if (r != -3) /* don't do this if we indicate there will be other matches */ + r = _rl_subseq_result (r, cxt->oldmap, cxt->okey, (cxt->flags & KSEQ_SUBSEQ)); + + RL_CHECK_SIGNALS (); + /* We only treat values < 0 specially to simulate recursion. */ + if (r >= 0 || (r == -1 && (cxt->flags & KSEQ_SUBSEQ) == 0)) /* success! or failure! */ + { + _rl_keyseq_chain_dispose (); + RL_UNSETSTATE (RL_STATE_MULTIKEY); + return r; + } + + if (r != -3) /* magic value that says we added to the chain */ + _rl_kscxt = cxt->ocxt; + if (_rl_kscxt) + _rl_kscxt->childval = r; + if (r != -3) + _rl_keyseq_cxt_dispose (cxt); + + return r; +} +#endif /* READLINE_CALLBACKS */ + +/* Do the command associated with KEY in MAP. + If the associated command is really a keymap, then read + another key, and dispatch into that map. */ +int +_rl_dispatch (key, map) + register int key; + Keymap map; +{ + _rl_dispatching_keymap = map; + return _rl_dispatch_subseq (key, map, 0); +} + +int +_rl_dispatch_subseq (key, map, got_subseq) + register int key; + Keymap map; + int got_subseq; +{ + int r, newkey; + char *macro; + rl_command_func_t *func; +#if defined (READLINE_CALLBACKS) + _rl_keyseq_cxt *cxt; +#endif + + if (META_CHAR (key) && _rl_convert_meta_chars_to_ascii) + { + if (map[ESC].type == ISKMAP) + { + if (RL_ISSTATE (RL_STATE_MACRODEF)) + _rl_add_macro_char (ESC); + RESIZE_KEYSEQ_BUFFER (); + rl_executing_keyseq[rl_key_sequence_length++] = ESC; + map = FUNCTION_TO_KEYMAP (map, ESC); + key = UNMETA (key); + return (_rl_dispatch (key, map)); + } + else + rl_ding (); + return 0; + } + + if (RL_ISSTATE (RL_STATE_MACRODEF)) + _rl_add_macro_char (key); + + r = 0; + switch (map[key].type) + { + case ISFUNC: + func = map[key].function; + if (func) + { + /* Special case rl_do_lowercase_version (). */ + if (func == rl_do_lowercase_version) + /* Should we do anything special if key == ANYOTHERKEY? */ + return (_rl_dispatch (_rl_to_lower (key), map)); + + rl_executing_keymap = map; + rl_executing_key = key; + + RESIZE_KEYSEQ_BUFFER(); + rl_executing_keyseq[rl_key_sequence_length++] = key; + rl_executing_keyseq[rl_key_sequence_length] = '\0'; + + rl_dispatching = 1; + RL_SETSTATE(RL_STATE_DISPATCHING); + r = (*func) (rl_numeric_arg * rl_arg_sign, key); + RL_UNSETSTATE(RL_STATE_DISPATCHING); + rl_dispatching = 0; + + /* If we have input pending, then the last command was a prefix + command. Don't change the state of rl_last_func. Otherwise, + remember the last command executed in this variable. */ + if (rl_pending_input == 0 && map[key].function != rl_digit_argument) + rl_last_func = map[key].function; + + RL_CHECK_SIGNALS (); + } + else if (map[ANYOTHERKEY].function) + { + /* OK, there's no function bound in this map, but there is a + shadow function that was overridden when the current keymap + was created. Return -2 to note that. */ + if (RL_ISSTATE (RL_STATE_MACROINPUT)) + _rl_prev_macro_key (); + else + _rl_unget_char (key); + return -2; + } + else if (got_subseq) + { + /* Return -1 to note that we're in a subsequence, but we don't + have a matching key, nor was one overridden. This means + we need to back up the recursion chain and find the last + subsequence that is bound to a function. */ + if (RL_ISSTATE (RL_STATE_MACROINPUT)) + _rl_prev_macro_key (); + else + _rl_unget_char (key); + return -1; + } + else + { +#if defined (READLINE_CALLBACKS) + RL_UNSETSTATE (RL_STATE_MULTIKEY); + _rl_keyseq_chain_dispose (); +#endif + _rl_abort_internal (); + return -1; + } + break; + + case ISKMAP: + if (map[key].function != 0) + { +#if defined (VI_MODE) + /* The only way this test will be true is if a subsequence has been + bound starting with ESC, generally the arrow keys. What we do is + check whether there's input in the queue, which there generally + will be if an arrow key has been pressed, and, if there's not, + just dispatch to (what we assume is) rl_vi_movement_mode right + away. This is essentially an input test with a zero timeout (by + default) or a timeout determined by the value of `keyseq-timeout' */ + /* _rl_keyseq_timeout specified in milliseconds; _rl_input_queued + takes microseconds, so multiply by 1000 */ + if (rl_editing_mode == vi_mode && key == ESC && map == vi_insertion_keymap + && _rl_input_queued ((_rl_keyseq_timeout > 0) ? _rl_keyseq_timeout*1000 : 0) == 0) + return (_rl_dispatch (ANYOTHERKEY, FUNCTION_TO_KEYMAP (map, key))); +#endif + + RESIZE_KEYSEQ_BUFFER (); + rl_executing_keyseq[rl_key_sequence_length++] = key; + _rl_dispatching_keymap = FUNCTION_TO_KEYMAP (map, key); + + /* Allocate new context here. Use linked contexts (linked through + cxt->ocxt) to simulate recursion */ +#if defined (READLINE_CALLBACKS) + if (RL_ISSTATE (RL_STATE_CALLBACK)) + { + /* Return 0 only the first time, to indicate success to + _rl_callback_read_char. The rest of the time, we're called + from _rl_dispatch_callback, so we return -3 to indicate + special handling is necessary. */ + r = RL_ISSTATE (RL_STATE_MULTIKEY) ? -3 : 0; + cxt = _rl_keyseq_cxt_alloc (); + + if (got_subseq) + cxt->flags |= KSEQ_SUBSEQ; + cxt->okey = key; + cxt->oldmap = map; + cxt->dmap = _rl_dispatching_keymap; + cxt->subseq_arg = got_subseq || cxt->dmap[ANYOTHERKEY].function; + + RL_SETSTATE (RL_STATE_MULTIKEY); + _rl_kscxt = cxt; + + return r; /* don't indicate immediate success */ + } +#endif + + /* Tentative inter-character timeout for potential multi-key + sequences? If no input within timeout, abort sequence and + act as if we got non-matching input. */ + /* _rl_keyseq_timeout specified in milliseconds; _rl_input_queued + takes microseconds, so multiply by 1000 */ + if (_rl_keyseq_timeout > 0 && + (RL_ISSTATE (RL_STATE_INPUTPENDING|RL_STATE_MACROINPUT) == 0) && + _rl_pushed_input_available () == 0 && + _rl_dispatching_keymap[ANYOTHERKEY].function && + _rl_input_queued (_rl_keyseq_timeout*1000) == 0) + return (_rl_subseq_result (-2, map, key, got_subseq)); + + newkey = _rl_subseq_getchar (key); + if (newkey < 0) + { + _rl_abort_internal (); + return -1; + } + + r = _rl_dispatch_subseq (newkey, _rl_dispatching_keymap, got_subseq || map[ANYOTHERKEY].function); + return _rl_subseq_result (r, map, key, got_subseq); + } + else + { + _rl_abort_internal (); /* XXX */ + return -1; + } + break; + + case ISMACR: + if (map[key].function != 0) + { + rl_executing_keyseq[rl_key_sequence_length] = '\0'; + macro = savestring ((char *)map[key].function); + _rl_with_macro_input (macro); + return 0; + } + break; + } +#if defined (VI_MODE) + if (rl_editing_mode == vi_mode && _rl_keymap == vi_movement_keymap && + key != ANYOTHERKEY && + _rl_dispatching_keymap == vi_movement_keymap && + _rl_vi_textmod_command (key)) + _rl_vi_set_last (key, rl_numeric_arg, rl_arg_sign); +#endif + + return (r); +} + +static int +_rl_subseq_result (r, map, key, got_subseq) + int r; + Keymap map; + int key, got_subseq; +{ + Keymap m; + int type, nt; + rl_command_func_t *func, *nf; + + if (r == -2) + /* We didn't match anything, and the keymap we're indexed into + shadowed a function previously bound to that prefix. Call + the function. The recursive call to _rl_dispatch_subseq has + already taken care of pushing any necessary input back onto + the input queue with _rl_unget_char. */ + { + m = _rl_dispatching_keymap; + type = m[ANYOTHERKEY].type; + func = m[ANYOTHERKEY].function; + if (type == ISFUNC && func == rl_do_lowercase_version) + r = _rl_dispatch (_rl_to_lower (key), map); + else if (type == ISFUNC && func == rl_insert) + { + /* If the function that was shadowed was self-insert, we + somehow need a keymap with map[key].func == self-insert. + Let's use this one. */ + nt = m[key].type; + nf = m[key].function; + + m[key].type = type; + m[key].function = func; + r = _rl_dispatch (key, m); + m[key].type = nt; + m[key].function = nf; + } + else + r = _rl_dispatch (ANYOTHERKEY, m); + } + else if (r && map[ANYOTHERKEY].function) + { + /* We didn't match (r is probably -1), so return something to + tell the caller that it should try ANYOTHERKEY for an + overridden function. */ + if (RL_ISSTATE (RL_STATE_MACROINPUT)) + _rl_prev_macro_key (); + else + _rl_unget_char (key); + _rl_dispatching_keymap = map; + return -2; + } + else if (r && got_subseq) + { + /* OK, back up the chain. */ + if (RL_ISSTATE (RL_STATE_MACROINPUT)) + _rl_prev_macro_key (); + else + _rl_unget_char (key); + _rl_dispatching_keymap = map; + return -1; + } + + return r; +} + +/* **************************************************************** */ +/* */ +/* Initializations */ +/* */ +/* **************************************************************** */ + +/* Initialize readline (and terminal if not already). */ +int +rl_initialize () +{ + /* If we have never been called before, initialize the + terminal and data structures. */ + if (!rl_initialized) + { + RL_SETSTATE(RL_STATE_INITIALIZING); + readline_initialize_everything (); + RL_UNSETSTATE(RL_STATE_INITIALIZING); + rl_initialized++; + RL_SETSTATE(RL_STATE_INITIALIZED); + } + + /* Initialize the current line information. */ + _rl_init_line_state (); + + /* We aren't done yet. We haven't even gotten started yet! */ + rl_done = 0; + RL_UNSETSTATE(RL_STATE_DONE); + + /* Tell the history routines what is going on. */ + _rl_start_using_history (); + + /* Make the display buffer match the state of the line. */ + rl_reset_line_state (); + + /* No such function typed yet. */ + rl_last_func = (rl_command_func_t *)NULL; + + /* Parsing of key-bindings begins in an enabled state. */ + _rl_parsing_conditionalized_out = 0; + +#if defined (VI_MODE) + if (rl_editing_mode == vi_mode) + _rl_vi_initialize_line (); +#endif + + /* Each line starts in insert mode (the default). */ + _rl_set_insert_mode (RL_IM_DEFAULT, 1); + + return 0; +} + +#if 0 +#if defined (__EMX__) +static void +_emx_build_environ () +{ + TIB *tibp; + PIB *pibp; + char *t, **tp; + int c; + + DosGetInfoBlocks (&tibp, &pibp); + t = pibp->pib_pchenv; + for (c = 1; *t; c++) + t += strlen (t) + 1; + tp = environ = (char **)xmalloc ((c + 1) * sizeof (char *)); + t = pibp->pib_pchenv; + while (*t) + { + *tp++ = t; + t += strlen (t) + 1; + } + *tp = 0; +} +#endif /* __EMX__ */ +#endif + +/* Initialize the entire state of the world. */ +static void +readline_initialize_everything () +{ +#if 0 +#if defined (__EMX__) + if (environ == 0) + _emx_build_environ (); +#endif +#endif + +#if 0 + /* Find out if we are running in Emacs -- UNUSED. */ + running_in_emacs = sh_get_env_value ("EMACS") != (char *)0; +#endif + + /* Set up input and output if they are not already set up. */ + if (!rl_instream) + rl_instream = stdin; + + if (!rl_outstream) + rl_outstream = stdout; + + /* Bind _rl_in_stream and _rl_out_stream immediately. These values + may change, but they may also be used before readline_internal () + is called. */ + _rl_in_stream = rl_instream; + _rl_out_stream = rl_outstream; + + /* Allocate data structures. */ + if (rl_line_buffer == 0) + rl_line_buffer = (char *)xmalloc (rl_line_buffer_len = DEFAULT_BUFFER_SIZE); + + /* Initialize the terminal interface. */ + if (rl_terminal_name == 0) + rl_terminal_name = sh_get_env_value ("TERM"); + _rl_init_terminal_io (rl_terminal_name); + + /* Bind tty characters to readline functions. */ + readline_default_bindings (); + + /* Initialize the function names. */ + rl_initialize_funmap (); + + /* Decide whether we should automatically go into eight-bit mode. */ + _rl_init_eightbit (); + + /* Read in the init file. */ + rl_read_init_file ((char *)NULL); + + /* XXX */ + if (_rl_horizontal_scroll_mode && _rl_term_autowrap) + { + _rl_screenwidth--; + _rl_screenchars -= _rl_screenheight; + } + + /* Override the effect of any `set keymap' assignments in the + inputrc file. */ + rl_set_keymap_from_edit_mode (); + + /* Try to bind a common arrow key prefix, if not already bound. */ + bind_arrow_keys (); + + /* Bind the bracketed paste prefix assuming that the user will enable + it on terminals that support it. */ + bind_bracketed_paste_prefix (); + + /* If the completion parser's default word break characters haven't + been set yet, then do so now. */ + if (rl_completer_word_break_characters == (char *)NULL) + rl_completer_word_break_characters = (char *)rl_basic_word_break_characters; + +#if defined (COLOR_SUPPORT) + if (_rl_colored_stats || _rl_colored_completion_prefix) + _rl_parse_colors (); +#endif + + rl_executing_keyseq = malloc (_rl_executing_keyseq_size = 16); + if (rl_executing_keyseq) + rl_executing_keyseq[0] = '\0'; +} + +/* If this system allows us to look at the values of the regular + input editing characters, then bind them to their readline + equivalents, iff the characters are not bound to keymaps. */ +static void +readline_default_bindings () +{ + if (_rl_bind_stty_chars) + rl_tty_set_default_bindings (_rl_keymap); +} + +/* Reset the default bindings for the terminal special characters we're + interested in back to rl_insert and read the new ones. */ +static void +reset_default_bindings () +{ + if (_rl_bind_stty_chars) + { + rl_tty_unset_default_bindings (_rl_keymap); + rl_tty_set_default_bindings (_rl_keymap); + } +} + +/* Bind some common arrow key sequences in MAP. */ +static void +bind_arrow_keys_internal (map) + Keymap map; +{ + Keymap xkeymap; + + xkeymap = _rl_keymap; + _rl_keymap = map; + +#if defined (__MSDOS__) + rl_bind_keyseq_if_unbound ("\033[0A", rl_get_previous_history); + rl_bind_keyseq_if_unbound ("\033[0B", rl_backward_char); + rl_bind_keyseq_if_unbound ("\033[0C", rl_forward_char); + rl_bind_keyseq_if_unbound ("\033[0D", rl_get_next_history); +#endif + + rl_bind_keyseq_if_unbound ("\033[A", rl_get_previous_history); + rl_bind_keyseq_if_unbound ("\033[B", rl_get_next_history); + rl_bind_keyseq_if_unbound ("\033[C", rl_forward_char); + rl_bind_keyseq_if_unbound ("\033[D", rl_backward_char); + rl_bind_keyseq_if_unbound ("\033[H", rl_beg_of_line); + rl_bind_keyseq_if_unbound ("\033[F", rl_end_of_line); + + rl_bind_keyseq_if_unbound ("\033OA", rl_get_previous_history); + rl_bind_keyseq_if_unbound ("\033OB", rl_get_next_history); + rl_bind_keyseq_if_unbound ("\033OC", rl_forward_char); + rl_bind_keyseq_if_unbound ("\033OD", rl_backward_char); + rl_bind_keyseq_if_unbound ("\033OH", rl_beg_of_line); + rl_bind_keyseq_if_unbound ("\033OF", rl_end_of_line); + +#if defined (__MINGW32__) + rl_bind_keyseq_if_unbound ("\340H", rl_get_previous_history); + rl_bind_keyseq_if_unbound ("\340P", rl_get_next_history); + rl_bind_keyseq_if_unbound ("\340M", rl_forward_char); + rl_bind_keyseq_if_unbound ("\340K", rl_backward_char); + rl_bind_keyseq_if_unbound ("\340G", rl_beg_of_line); + rl_bind_keyseq_if_unbound ("\340O", rl_end_of_line); + rl_bind_keyseq_if_unbound ("\340S", rl_delete); + rl_bind_keyseq_if_unbound ("\340R", rl_overwrite_mode); + + /* These may or may not work because of the embedded NUL. */ + rl_bind_keyseq_if_unbound ("\\000H", rl_get_previous_history); + rl_bind_keyseq_if_unbound ("\\000P", rl_get_next_history); + rl_bind_keyseq_if_unbound ("\\000M", rl_forward_char); + rl_bind_keyseq_if_unbound ("\\000K", rl_backward_char); + rl_bind_keyseq_if_unbound ("\\000G", rl_beg_of_line); + rl_bind_keyseq_if_unbound ("\\000O", rl_end_of_line); + rl_bind_keyseq_if_unbound ("\\000S", rl_delete); + rl_bind_keyseq_if_unbound ("\\000R", rl_overwrite_mode); +#endif + + _rl_keymap = xkeymap; +} + +/* Try and bind the common arrow key prefixes after giving termcap and + the inputrc file a chance to bind them and create `real' keymaps + for the arrow key prefix. */ +static void +bind_arrow_keys () +{ + bind_arrow_keys_internal (emacs_standard_keymap); + +#if defined (VI_MODE) + bind_arrow_keys_internal (vi_movement_keymap); + /* Unbind vi_movement_keymap[ESC] to allow users to repeatedly hit ESC + in vi command mode while still allowing the arrow keys to work. */ + if (vi_movement_keymap[ESC].type == ISKMAP) + rl_bind_keyseq_in_map ("\033", (rl_command_func_t *)NULL, vi_movement_keymap); + bind_arrow_keys_internal (vi_insertion_keymap); +#endif +} + +static void +bind_bracketed_paste_prefix () +{ + Keymap xkeymap; + + xkeymap = _rl_keymap; + + _rl_keymap = emacs_standard_keymap; + rl_bind_keyseq_if_unbound (BRACK_PASTE_PREF, rl_bracketed_paste_begin); + + _rl_keymap = vi_insertion_keymap; + rl_bind_keyseq_if_unbound (BRACK_PASTE_PREF, rl_bracketed_paste_begin); + + _rl_keymap = xkeymap; +} + +/* **************************************************************** */ +/* */ +/* Saving and Restoring Readline's state */ +/* */ +/* **************************************************************** */ + +int +rl_save_state (sp) + struct readline_state *sp; +{ + if (sp == 0) + return -1; + + sp->point = rl_point; + sp->end = rl_end; + sp->mark = rl_mark; + sp->buffer = rl_line_buffer; + sp->buflen = rl_line_buffer_len; + sp->ul = rl_undo_list; + sp->prompt = rl_prompt; + + sp->rlstate = rl_readline_state; + sp->done = rl_done; + sp->kmap = _rl_keymap; + + sp->lastfunc = rl_last_func; + sp->insmode = rl_insert_mode; + sp->edmode = rl_editing_mode; + sp->kseq = rl_executing_keyseq; + sp->kseqlen = rl_key_sequence_length; + sp->inf = rl_instream; + sp->outf = rl_outstream; + sp->pendingin = rl_pending_input; + sp->macro = rl_executing_macro; + + sp->catchsigs = rl_catch_signals; + sp->catchsigwinch = rl_catch_sigwinch; + + sp->entryfunc = rl_completion_entry_function; + sp->menuentryfunc = rl_menu_completion_entry_function; + sp->ignorefunc = rl_ignore_some_completions_function; + sp->attemptfunc = rl_attempted_completion_function; + sp->wordbreakchars = rl_completer_word_break_characters; + + return (0); +} + +int +rl_restore_state (sp) + struct readline_state *sp; +{ + if (sp == 0) + return -1; + + rl_point = sp->point; + rl_end = sp->end; + rl_mark = sp->mark; + the_line = rl_line_buffer = sp->buffer; + rl_line_buffer_len = sp->buflen; + rl_undo_list = sp->ul; + rl_prompt = sp->prompt; + + rl_readline_state = sp->rlstate; + rl_done = sp->done; + _rl_keymap = sp->kmap; + + rl_last_func = sp->lastfunc; + rl_insert_mode = sp->insmode; + rl_editing_mode = sp->edmode; + rl_executing_keyseq = sp->kseq; + rl_key_sequence_length = sp->kseqlen; + rl_instream = sp->inf; + rl_outstream = sp->outf; + rl_pending_input = sp->pendingin; + rl_executing_macro = sp->macro; + + rl_catch_signals = sp->catchsigs; + rl_catch_sigwinch = sp->catchsigwinch; + + rl_completion_entry_function = sp->entryfunc; + rl_menu_completion_entry_function = sp->menuentryfunc; + rl_ignore_some_completions_function = sp->ignorefunc; + rl_attempted_completion_function = sp->attemptfunc; + rl_completer_word_break_characters = sp->wordbreakchars; + + return (0); +} diff --git a/lib/readline/rlconf.h~ b/lib/readline/rlconf.h~ new file mode 100644 index 000000000..043bba6b2 --- /dev/null +++ b/lib/readline/rlconf.h~ @@ -0,0 +1,81 @@ +/* rlconf.h -- readline configuration definitions */ + +/* Copyright (C) 1992-2012 Free Software Foundation, Inc. + + This file is part of the GNU Readline Library (Readline), a library + for reading lines of text with interactive input and history editing. + + Readline is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + Readline is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with Readline. If not, see . +*/ + +#if !defined (_RLCONF_H_) +#define _RLCONF_H_ + +/* Define this if you want the vi-mode editing available. */ +#define VI_MODE + +/* Define this to get an indication of file type when listing completions. */ +#define VISIBLE_STATS + +/* Define this to get support for colors when listing completions and in + other places. */ +#define COLOR_SUPPORT + +/* This definition is needed by readline.c, rltty.c, and signals.c. */ +/* If on, then readline handles signals in a way that doesn't suck. */ +#define HANDLE_SIGNALS + +/* Ugly but working hack for binding prefix meta. */ +#define PREFIX_META_HACK + +/* The next-to-last-ditch effort file name for a user-specific init file. */ +#define DEFAULT_INPUTRC "~/.inputrc" + +/* The ultimate last-ditch filenname for an init file -- system-wide. */ +#define SYS_INPUTRC "/etc/inputrc" + +/* If defined, expand tabs to spaces. */ +#define DISPLAY_TABS + +/* If defined, use the terminal escape sequence to move the cursor forward + over a character when updating the line rather than rewriting it. */ +/* #define HACK_TERMCAP_MOTION */ + +/* The string inserted by the `insert comment' command. */ +#define RL_COMMENT_BEGIN_DEFAULT "#" + +/* Define this if you want code that allows readline to be used in an + X `callback' style. */ +#ifndef SHELL +#define READLINE_CALLBACKS +#endif + +/* Define this if you want the cursor to indicate insert or overwrite mode. */ +/* #define CURSOR_MODE */ + +/* Define this if you want to enable code that talks to the Linux kernel + tty auditing system. */ +#define ENABLE_TTY_AUDIT_SUPPORT + +/* Defaults for the various editing mode indicators, inserted at the beginning + of the last (maybe only) line of the prompt if show-mode-in-prompt is on */ +#define RL_EMACS_MODESTR_DEFAULT "@" +#define RL_EMACS_MODESTR_DEFLEN 1 + +#define RL_VI_INS_MODESTR_DEFAULT "(ins)" +#define RL_VI_INS_MODESTR_DEFLEN 5 +#define RL_VI_CMD_MODESTR_DEFAULT "(cmd)" +#define RL_VI_CMD_MODESTR_DEFLEN 5 + +#endif /* _RLCONF_H_ */ diff --git a/lib/sh/Makefile.in b/lib/sh/Makefile.in index 36a830522..13862e267 100644 --- a/lib/sh/Makefile.in +++ b/lib/sh/Makefile.in @@ -170,6 +170,7 @@ pathcanon.o: pathcanon.c pathphys.o: pathphys.c rename.o: rename.c setlinebuf.o: setlinebuf.c +shmatch.o: shmatch.c shmbchar.o: shmbchar.c shquote.o: shquote.c shtty.o: shtty.c @@ -243,7 +244,8 @@ pathcanon.o: ${BUILD_DIR}/config.h pathphys.o: ${BUILD_DIR}/config.h rename.o: ${BUILD_DIR}/config.h setlinebuf.o: ${BUILD_DIR}/config.h -shmbchare.o: ${BUILD_DIR}/config.h +shmatch.o: ${BUILD_DIR}/config.h +shmbchar.o: ${BUILD_DIR}/config.h shquote.o: ${BUILD_DIR}/config.h shtty.o: ${BUILD_DIR}/config.h snprintf.o: ${BUILD_DIR}/config.h @@ -389,6 +391,16 @@ eaccess.o: ${topdir}/make_cmd.h ${topdir}/subst.h ${topdir}/sig.h eaccess.o: ${BUILD_DIR}/pathnames.h ${topdir}/externs.h #eaccess.o: ${BUILD_DIR}/version.h +shmatch.o: ${BASHINCDIR}/stdc.h ${topdir}/bashansi.h +shmatch.o: ${BASHINCDIR}/ansi_stdlib.h ${topdir}/xmalloc.h +shmatch.o: ${topdir}/shell.h ${topdir}/syntax.h ${topdir}/bashjmp.h ${BASHINCDIR}/posixjmp.h +shmatch.o: ${topdir}/command.h ${BASHINCDIR}/stdc.h ${topdir}/error.h +shmatch.o: ${topdir}/general.h ${topdir}/bashtypes.h ${topdir}/variables.h ${topdir}/conftypes.h +shmatch.o: ${topdir}/array.h ${topdir}/hashlib.h ${topdir}/quit.h +shmatch.o: ${topdir}/unwind_prot.h ${topdir}/dispose_cmd.h +shmatch.o: ${topdir}/make_cmd.h ${topdir}/subst.h ${topdir}/sig.h +shmatch.o: ${BUILD_DIR}/pathnames.h ${topdir}/externs.h + shquote.o: ${BASHINCDIR}/stdc.h ${topdir}/bashansi.h shquote.o: ${BASHINCDIR}/ansi_stdlib.h ${topdir}/xmalloc.h diff --git a/parse.y b/parse.y index f170bc76a..b0903b9f5 100644 --- a/parse.y +++ b/parse.y @@ -1432,9 +1432,9 @@ yy_readline_get () int line_len; unsigned char c; - if (!current_readline_line) + if (current_readline_line == 0) { - if (!bash_readline_initialized) + if (bash_readline_initialized == 0) initialize_readline (); #if defined (JOB_CONTROL) diff --git a/po/._fr.po b/po/._fr.po index 7b99b5d83..bac4217f6 100644 Binary files a/po/._fr.po and b/po/._fr.po differ diff --git a/subst.c b/subst.c index 40537c480..ec5766be5 100644 --- a/subst.c +++ b/subst.c @@ -404,11 +404,6 @@ dump_word_flags (flags) f &= ~W_ASSNGLOBAL; fprintf (stderr, "W_ASSNGLOBAL%s", f ? "|" : ""); } - if (f & W_ASSIGNINT) - { - f &= ~W_ASSIGNINT; - fprintf (stderr, "W_ASSIGNINT%s", f ? "|" : ""); - } if (f & W_COMPASSIGN) { f &= ~W_COMPASSIGN; @@ -9978,7 +9973,7 @@ shell_expand_word_list (tlist, eflags) if ((tlist->word->flags & (W_COMPASSIGN|W_ASSIGNARG)) == (W_COMPASSIGN|W_ASSIGNARG)) { int t; - char opts[8], opti; + char opts[16], opti; opti = 0; if (tlist->word->flags & (W_ASSIGNASSOC|W_ASSNGLOBAL|W_ASSIGNARRAY)) @@ -10001,11 +9996,43 @@ shell_expand_word_list (tlist, eflags) else if (tlist->word->flags & W_ASSNGLOBAL) opts[opti++] = 'g'; -#if 0 - /* If we have special handling note the integer attribute */ - if (opti > 0 && (tlist->word->flags & W_ASSIGNINT)) - opts[opti++] = 'i'; -#endif + /* If we have special handling note the integer attribute and others + that transform the value upon assignment. What we do is take all + of the option arguments and scan through them looking for options + that cause such transformations, and add them to the `opts' array. */ +/* if (opti > 0) */ + { + char omap[128]; + int oind; + WORD_LIST *l; + + memset (omap, '\0', sizeof (omap)); + for (l = orig_list->next; l != tlist; l = l->next) + { + if (l->word->word[0] != '-') + break; /* non-option argument */ + if (l->word->word[0] == '-' && l->word->word[1] == '-' && l->word->word[2] == 0) + break; /* -- signals end of options */ + for (oind = 1; l->word->word[oind]; oind++) + switch (l->word->word[oind]) + { + case 'i': + case 'l': + case 'u': + case 'c': + omap[l->word->word[oind]] = 1; + if (opti == 0) + opts[opti++] = '-'; + break; + default: + break; + } + } + + for (oind = 0; oind < sizeof (omap); oind++) + if (omap[oind]) + opts[opti++] = oind; + } opts[opti] = '\0'; if (opti > 0) diff --git a/tests/RUN-ONE-TEST b/tests/RUN-ONE-TEST index 72ec06a2c..3efcf32d6 100755 --- a/tests/RUN-ONE-TEST +++ b/tests/RUN-ONE-TEST @@ -1,4 +1,4 @@ -BUILD_DIR=/usr/local/build/bash/bash-current +BUILD_DIR=/usr/local/build/chet/bash/bash-current THIS_SH=$BUILD_DIR/bash PATH=$PATH:$BUILD_DIR diff --git a/tests/misc/regress/log.orig b/tests/misc/regress/log.orig new file mode 100644 index 000000000..c1f1e1991 --- /dev/null +++ b/tests/misc/regress/log.orig @@ -0,0 +1,50 @@ +:; ./shx + +sh: +<&$fd ok +nlbq Mon Aug 3 02:45:00 EDT 1992 +bang geoff +quote 712824302 +setbq defmsgid=<1992Aug3.024502.6176@host> +bgwait sleep done... wait 6187 + + +bash: +<&$fd ok +nlbq Mon Aug 3 02:45:09 EDT 1992 +bang geoff +quote 712824311 +setbq defmsgid=<1992Aug3.024512.6212@host> +bgwait sleep done... wait 6223 + + +ash: +<&$fd shx1: 4: Syntax error: Bad fd number +nlbq Mon Aug 3 02:45:19 EDT 1992 +bang geoff +quote getdate: `"now"' not a valid date + +setbq defmsgid=<1992Aug3.` echo 024521 +bgwait sleep done... wait 6241 + + +ksh: +<&$fd ok +nlbq ./shx: 6248 Memory fault - core dumped +bang geoff +quote getdate: `"now"' not a valid date + +setbq defmsgid=<1992Aug3.024530.6257@host> +bgwait no such job: 6265 +wait 6265 +sleep done... + +zsh: +<&$fd ok +nlbq Mon Aug 3 02:45:36 EDT 1992 +bang shx3: event not found: /s/ [4] +quote 712824337 +setbq defmsgid=<..6290@host> +bgwait shx7: unmatched " [9] +sleep done... +:; diff --git a/tests/misc/regress/shx.orig b/tests/misc/regress/shx.orig new file mode 100644 index 000000000..4b3bf2b82 --- /dev/null +++ b/tests/misc/regress/shx.orig @@ -0,0 +1,10 @@ +#! /bin/sh +for cmd in sh bash ash ksh zsh +do + echo + echo $cmd: + for demo in shx? + do + $cmd $demo + done +done