- the < and > operators to the [[ command do not consider the current
locale when comparing strings
- interrupting a command list such as "a ; b ; c" causes the execution
- of the entire list to be aborted
+ of the entire list to be aborted (in versions before bash-4.0,
+ interrupting one command in a list caused the next to be executed)
-------------------------------------------------------------------------------
--- /dev/null
+Compatibility with previous versions
+====================================
+
+This document details the incompatibilities between this version of bash,
+bash-4.1, and the previous widely-available versions, bash-2.x (which is
+still the `standard' version for a few Linux distributions) and bash-3.x.
+These were discovered by users of bash-2.x and 3.x, so this list is not
+comprehensive. Some of these incompatibilities occur between the current
+version and versions 2.0 and above.
+
+1. Bash uses a new quoting syntax, $"...", to do locale-specific
+ string translation. Users who have relied on the (undocumented)
+ behavior of bash-1.14 will have to change their scripts. For
+ instance, if you are doing something like this to get the value of
+ a variable whose name is the value of a second variable:
+
+ eval var2=$"$var1"
+
+ you will have to change to a different syntax.
+
+ This capability is directly supported by bash-2.0:
+
+ var2=${!var1}
+
+ This alternate syntax will work portably between bash-1.14 and bash-2.0:
+
+ eval var2=\$${var1}
+
+2. One of the bugs fixed in the YACC grammar tightens up the rules
+ concerning group commands ( {...} ). The `list' that composes the
+ body of the group command must be terminated by a newline or
+ semicolon. That's because the braces are reserved words, and are
+ recognized as such only when a reserved word is legal. This means
+ that while bash-1.14 accepted shell function definitions like this:
+
+ foo() { : }
+
+ bash-2.0 requires this:
+
+ foo() { :; }
+
+ This is also an issue for commands like this:
+
+ mkdir dir || { echo 'could not mkdir' ; exit 1; }
+
+ The syntax required by bash-2.0 is also accepted by bash-1.14.
+
+3. The options to `bind' have changed to make them more consistent with
+ the rest of the bash builtins. If you are using `bind -d' to list
+ the readline key bindings in a form that can be re-read, use `bind -p'
+ instead. If you were using `bind -v' to list the key bindings, use
+ `bind -P' instead.
+
+4. The `long' invocation options must now be prefixed by `--' instead
+ of `-'. (The old form is still accepted, for the time being.)
+
+5. There was a bug in the version of readline distributed with bash-1.14
+ that caused it to write badly-formatted key bindings when using
+ `bind -d'. The only key sequences that were affected are C-\ (which
+ should appear as \C-\\ in a key binding) and C-" (which should appear
+ as \C-\"). If these key sequences appear in your inputrc, as, for
+ example,
+
+ "\C-\": self-insert
+
+ they will need to be changed to something like the following:
+
+ "\C-\\": self-insert
+
+6. A number of people complained about having to use ESC to terminate an
+ incremental search, and asked for an alternate mechanism. Bash-2.03
+ uses the value of the settable readline variable `isearch-terminators'
+ to decide which characters should terminate an incremental search. If
+ that variable has not been set, ESC and Control-J will terminate a
+ search.
+
+7. Some variables have been removed: MAIL_WARNING, notify, history_control,
+ command_oriented_history, glob_dot_filenames, allow_null_glob_expansion,
+ nolinks, hostname_completion_file, noclobber, no_exit_on_failed_exec, and
+ cdable_vars. Most of them are now implemented with the new `shopt'
+ builtin; others were already implemented by `set'. Here is a list of
+ correspondences:
+
+ MAIL_WARNING shopt mailwarn
+ notify set -o notify
+ history_control HISTCONTROL
+ command_oriented_history shopt cmdhist
+ glob_dot_filenames shopt dotglob
+ allow_null_glob_expansion shopt nullglob
+ nolinks set -o physical
+ hostname_completion_file HOSTFILE
+ noclobber set -o noclobber
+ no_exit_on_failed_exec shopt execfail
+ cdable_vars shopt cdable_vars
+
+8. `ulimit' now sets both hard and soft limits and reports the soft limit
+ by default (when neither -H nor -S is specified). This is compatible
+ with versions of sh and ksh that implement `ulimit'. The bash-1.14
+ behavior of, for example,
+
+ ulimit -c 0
+
+ can be obtained with
+
+ ulimit -S -c 0
+
+ It may be useful to define an alias:
+
+ alias ulimit="ulimit -S"
+
+9. Bash-2.01 uses a new quoting syntax, $'...' to do ANSI-C string
+ translation. Backslash-escaped characters in ... are expanded and
+ replaced as specified by the ANSI C standard.
+
+10. The sourcing of startup files has changed somewhat. This is explained
+ more completely in the INVOCATION section of the manual page.
+
+ A non-interactive shell not named `sh' and not in posix mode reads
+ and executes commands from the file named by $BASH_ENV. A
+ non-interactive shell started by `su' and not in posix mode will read
+ startup files. No other non-interactive shells read any startup files.
+
+ An interactive shell started in posix mode reads and executes commands
+ from the file named by $ENV.
+
+11. The <> redirection operator was changed to conform to the POSIX.2 spec.
+ In the absence of any file descriptor specification preceding the `<>',
+ file descriptor 0 is used. In bash-1.14, this was the behavior only
+ when in POSIX mode. The bash-1.14 behavior may be obtained with
+
+ <>filename 1>&0
+
+12. The `alias' builtin now checks for invalid options and takes a `-p'
+ option to display output in POSIX mode. If you have old aliases beginning
+ with `-' or `+', you will have to add the `--' to the alias command
+ that declares them:
+
+ alias -x='chmod a-x' --> alias -- -x='chmod a-x'
+
+13. The behavior of range specificiers within bracket matching expressions
+ in the pattern matcher (e.g., [A-Z]) depends on the current locale,
+ specifically the value of the LC_COLLATE environment variable. Setting
+ this variable to C or POSIX will result in the traditional ASCII behavior
+ for range comparisons. If the locale is set to something else, e.g.,
+ en_US (specified by the LANG or LC_ALL variables), collation order is
+ locale-dependent. For example, the en_US locale sorts the upper and
+ lower case letters like this:
+
+ AaBb...Zz
+
+ so a range specification like [A-Z] will match every letter except `z'.
+ Other locales collate like
+
+ aAbBcC...zZ
+
+ which means that [A-Z] matches every letter except `a'.
+
+ The portable way to specify upper case letters is [:upper:] instead of
+ A-Z; lower case may be specified as [:lower:] instead of a-z.
+
+ Look at the manual pages for setlocale(3), strcoll(3), and, if it is
+ present, locale(1).
+
+ You can find your current locale information by running locale(1):
+
+ caleb.ins.cwru.edu(2)$ locale
+ LANG=en_US
+ LC_CTYPE="en_US"
+ LC_NUMERIC="en_US"
+ LC_TIME="en_US"
+ LC_COLLATE="en_US"
+ LC_MONETARY="en_US"
+ LC_MESSAGES="en_US"
+ LC_ALL=en_US
+
+ 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.
+
+14. Bash versions up to 1.14.7 included an undocumented `-l' operator to
+ the `test/[' builtin. It was a unary operator that expanded to the
+ length of its string argument. This let you do things like
+
+ test -l $variable -lt 20
+
+ for example.
+
+ This was included for backwards compatibility with old versions of the
+ Bourne shell, which did not provide an easy way to obtain the length of
+ the value of a shell variable.
+
+ This operator is not part of the POSIX standard, because one can (and
+ should) use ${#variable} to get the length of a variable's value.
+ Bash-2.x does not support it.
+
+15. Bash no longer auto-exports the HOME, PATH, SHELL, TERM, HOSTNAME,
+ HOSTTYPE, MACHTYPE, or OSTYPE variables. If they appear in the initial
+ environment, the export attribute will be set, but if bash provides a
+ default value, they will remain local to the current shell.
+
+16. Bash no longer initializes the FUNCNAME, GROUPS, or DIRSTACK variables
+ to have special behavior if they appear in the initial environment.
+
+17. Bash no longer removes the export attribute from the SSH_CLIENT or
+ SSH2_CLIENT variables, and no longer attempts to discover whether or
+ not it has been invoked by sshd in order to run the startup files.
+
+18. Bash no longer requires that the body of a function be a group command;
+ any compound command is accepted.
+
+19. As of bash-3.0, the pattern substitution operators no longer perform
+ quote removal on the pattern before attempting the match. This is the
+ way the pattern removal functions behave, and is more consistent.
+
+20. After bash-3.0 was released, I reimplemented tilde expansion, incorporating
+ it into the mainline word expansion code. This fixes the bug that caused
+ the results of tilde expansion to be re-expanded. There is one
+ incompatibility: a ${paramOPword} expansion within double quotes will not
+ perform tilde expansion on WORD. This is consistent with the other
+ expansions, and what POSIX specifies.
+
+21. A number of variables have the integer attribute by default, so the +=
+ assignment operator returns expected results: RANDOM, LINENO, MAILCHECK,
+ HISTCMD, OPTIND.
+
+22. Bash-3.x is much stricter about $LINENO correctly reflecting the line
+ number in a script; assignments to LINENO have little effect.
+
+23. By default, readline binds the terminal special characters to their
+ readline equivalents. As of bash-3.1/readline-5.1, this is optional and
+ controlled by the bind-tty-special-chars readline variable.
+
+24. The \W prompt string expansion abbreviates $HOME as `~'. The previous
+ behavior is available with ${PWD##/*/}.
+
+25. The arithmetic exponentiation operator is right-associative as of bash-3.1.
+
+26. The rules concerning valid alias names are stricter, as per POSIX.2.
+
+27. The Readline key binding functions now obey the convert-meta setting active
+ when the binding takes place, as the dispatch code does when characters
+ are read and processed.
+
+28. The historical behavior of `trap' reverting signal disposition to the
+ original handling in the absence of a valid first argument is implemented
+ only if the first argument is a valid signal number.
+
+29. In versions of bash after 3.1, the ${parameter//pattern/replacement}
+ expansion does not interpret `%' or `#' specially. Those anchors don't
+ have any real meaning when replacing every match.
+
+30. Beginning with bash-3.1, the combination of posix mode and enabling the
+ `xpg_echo' option causes echo to ignore all options, not looking for `-n'
+
+31. Beginning with bash-3.2, bash follows the Bourne-shell-style (and POSIX-
+ style) rules for parsing the contents of old-style backquoted command
+ substitutions. Previous versions of bash attempted to recursively parse
+ embedded quoted strings and shell constructs; bash-3.2 uses strict POSIX
+ rules to find the closing backquote and simply passes the contents of the
+ command substitution to a subshell for parsing and execution.
+
+32. Beginning with bash-3.2, bash uses access(2) when executing primaries for
+ the test builtin and the [[ compound command, rather than looking at the
+ file permission bits obtained with stat(2). This obeys restrictions of
+ the file system (e.g., read-only or noexec mounts) not available via stat.
+
+33. Bash-3.2 adopts the convention used by other string and pattern matching
+ operators for the `[[' compound command, and matches any quoted portion
+ of the right-hand-side argument to the =~ operator as a string rather
+ than a regular expression.
+
+34. Bash-4.0 allows the behavior in the previous item to be modified using
+ the notion of a shell `compatibility level'. If the compat31 shopt
+ option is set, quoting the pattern has no special effect.
+
+35. Bash-3.2 (patched) and Bash-4.0 fix a bug that leaves the shell in an
+ inconsistent internal state following an assignment error. One of the
+ changes means that compound commands or { ... } grouping commands are
+ aborted under some circumstances in which they previously were not.
+ This is what Posix specifies.
+
+36. Bash-4.0 now allows process substitution constructs to pass unchanged
+ through brace expansion, so any expansion of the contents will have to be
+ separately specified, and each process subsitution will have to be
+ separately entered.
+
+37. Bash-4.0 now allows SIGCHLD to interrupt the wait builtin, as Posix
+ specifies, so the SIGCHLD trap is no longer always invoked once per
+ exiting child if you are using `wait' to wait for all children.
+
+38. Since bash-4.0 now follows Posix rules for finding the closing delimiter
+ of a $() command substitution, it will not behave as previous versions
+ did, but will catch more syntax and parsing errors before spawning a
+ subshell to evaluate the command substitution.
+
+39. The programmable completion code uses the same set of delimiting characters
+ as readline when breaking the command line into words, rather than the
+ set of shell metacharacters, so programmable completion and readline
+ should be more consistent.
+
+40. When the read builtin times out, it attempts to assign any input read to
+ specified variables, which also causes variables to be set to the empty
+ string if there is not enough input. Previous versions discarded the
+ characters read.
+
+41. Beginning with bash-4.0, when one of the commands in a pipeline is killed
+ by a SIGINT while executing a command list, the shell acts as if it
+ received the interrupt. This can be disabled by setting the compat31 or
+ compat32 shell options.
+
+42. Bash-4.0 changes the handling of the set -e option so that the shell exits
+ if a pipeline fails (and not just if the last command in the failing
+ pipeline is a simple command). This is not as Posix specifies. There is
+ work underway to update this portion of the standard; the bash-4.0
+ behavior attempts to capture the consensus at the time of release.
+
+43. Bash-4.0 fixes a Posix mode bug that caused the . (source) builtin to
+ search the current directory for its filename argument, even if "." is
+ not in $PATH. Posix says that the shell shouldn't look in $PWD in this
+ case.
+
+44. Bash-4.1 uses the current locale when comparing strings using the < and
+ > operators to the `[[' command. This can be reverted to the previous
+ behavior by setting one of the `compatNN' shopt options.
+
+Shell Compatibility Level
+=========================
+
+Bash-4.0 introduced the concept of a `shell compatibility level', specified
+as a set of options to the shopt builtin (compat31, compat32, compat40 at
+this writing). There is only one current compatibility level -- each
+option is mutually exclusive. This list does not mention behavior that is
+standard for a particular version (e.g., setting compat32 means that quoting
+the rhs of the regexp matching operator quotes special regexp characters in
+the word, which is default behavior in bash-3.2 and above).
+
+compat31 set
+ - the < and > operators to the [[ command do not consider the current
+ locale when comparing strings
+ - quoting the rhs of the regexp matching operator (=~) has no
+ special effect
+
+compat32 set
+ - the < and > operators to the [[ command do not consider the current
+ locale when comparing strings
+
+compat40 set
+ - the < and > operators to the [[ command do not consider the current
+ locale when comparing strings
+ - interrupting a command list such as "a ; b ; c" causes the execution
+ of the entire list to be aborted
+
+-------------------------------------------------------------------------------
+
+Copying and distribution of this file, with or without modification,
+are permitted in any medium without royalty provided the copyright
+notice and this notice are preserved. This file is offered as-is,
+without any warranty.
hint might contain an already-dequoted globbing character, but
glob_matches will be NULL. Fixes bug reported by
coyote@wariat.org.pl
+
+ 2/5
+ ---
+builtins/exec.def
+ - set extern variable "exec_argv0" to the argument to -a
+
+shell.c
+ - if exec_argv0 is set, set dollar_vars[0] to it and set it to NULL,
+ assuming it was set by `exec -a'. `exec -a foo' now sets $0 to
+ foo in an executable shell script without a leading `#!' (fixes
+ longstanding bug)
+
invisible. Pointed out by Mart Frauenlab <mart.frauenlob@chello.at>
- change array_value_internal to return NULL for variable which has
not been set
+
+ 1/30
+ ----
+bashline.c
+ - in command_word_completion_function, don't call glob_pattern_p
+ on hint -- use the already-computed `globpat'. At this point,
+ hint might contain an already-dequoted globbing character, but
+ glob_matches will be NULL. Fixes bug reported by
+ coyote@wariat.org.pl
+
+ 2/5
+ ---
+builtins/exec.def
+ - set extern variable "exec_argv0" to the argument to -a
+
+shell.c
+ - if exec_argv0 is set, set dollar_vars[0] to it and set it to NULL,
+ assuming it was set by `exec -a'. `exec -a foo' now sets $0 to
+ foo in an executable shell script without a leading `#!'
po/tr.po f
po/vi.gmo f
po/vi.po f
+po/zh_CN.gmo f
+po/zh_CN.po f
po/zh_TW.gmo f
po/zh_TW.po f
po/insert-header.sin f
return argv;
}
-/* Remember LIST in $0 ... $9, and REST_OF_ARGS. If DESTRUCTIVE is
+/* Remember LIST in $1 ... $9, and REST_OF_ARGS. If DESTRUCTIVE is
non-zero, then discard whatever the existing arguments are, else
only discard the ones that are to be replaced. */
void
--- /dev/null
+/* common.c - utility functions for all builtins */
+
+/* Copyright (C) 1987-2009 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 <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+
+#if defined (HAVE_UNISTD_H)
+# ifdef _MINIX
+# include <sys/types.h>
+# endif
+# include <unistd.h>
+#endif
+
+#include <stdio.h>
+#include <chartypes.h>
+#include "../bashtypes.h"
+#include "posixstat.h"
+#include <signal.h>
+
+#include <errno.h>
+
+#if defined (PREFER_STDARG)
+# include <stdarg.h>
+#else
+# include <varargs.h>
+#endif
+
+#include "../bashansi.h"
+#include "../bashintl.h"
+
+#define NEED_FPURGE_DECL
+
+#include "../shell.h"
+#include "maxpath.h"
+#include "../flags.h"
+#include "../jobs.h"
+#include "../builtins.h"
+#include "../input.h"
+#include "../execute_cmd.h"
+#include "../trap.h"
+#include "bashgetopt.h"
+#include "common.h"
+#include "builtext.h"
+#include <tilde/tilde.h>
+
+#if defined (HISTORY)
+# include "../bashhist.h"
+#endif
+
+#if !defined (errno)
+extern int errno;
+#endif /* !errno */
+
+extern int indirection_level, subshell_environment;
+extern int line_number;
+extern int last_command_exit_value;
+extern int running_trap;
+extern int posixly_correct;
+extern char *this_command_name, *shell_name;
+extern const char * const bash_getcwd_errstr;
+
+/* Used by some builtins and the mainline code. */
+sh_builtin_func_t *last_shell_builtin = (sh_builtin_func_t *)NULL;
+sh_builtin_func_t *this_shell_builtin = (sh_builtin_func_t *)NULL;
+
+/* **************************************************************** */
+/* */
+/* Error reporting, usage, and option processing */
+/* */
+/* **************************************************************** */
+
+/* This is a lot like report_error (), but it is for shell builtins
+ instead of shell control structures, and it won't ever exit the
+ shell. */
+
+static void
+builtin_error_prolog ()
+{
+ char *name;
+
+ name = get_name_for_error ();
+ fprintf (stderr, "%s: ", name);
+
+ if (interactive_shell == 0)
+ fprintf (stderr, _("line %d: "), executing_line_number ());
+
+ if (this_command_name && *this_command_name)
+ fprintf (stderr, "%s: ", this_command_name);
+}
+
+void
+#if defined (PREFER_STDARG)
+builtin_error (const char *format, ...)
+#else
+builtin_error (format, va_alist)
+ const char *format;
+ va_dcl
+#endif
+{
+ va_list args;
+
+ builtin_error_prolog ();
+
+ SH_VA_START (args, format);
+
+ vfprintf (stderr, format, args);
+ va_end (args);
+ fprintf (stderr, "\n");
+}
+
+void
+#if defined (PREFER_STDARG)
+builtin_warning (const char *format, ...)
+#else
+builtin_warning (format, va_alist)
+ const char *format;
+ va_dcl
+#endif
+{
+ va_list args;
+
+ builtin_error_prolog ();
+ fprintf (stderr, _("warning: "));
+
+ SH_VA_START (args, format);
+
+ vfprintf (stderr, format, args);
+ va_end (args);
+ fprintf (stderr, "\n");
+}
+
+/* Print a usage summary for the currently-executing builtin command. */
+void
+builtin_usage ()
+{
+ if (this_command_name && *this_command_name)
+ fprintf (stderr, _("%s: usage: "), this_command_name);
+ fprintf (stderr, "%s\n", current_builtin->short_doc);
+ fflush (stderr);
+}
+
+/* Return if LIST is NULL else barf and jump to top_level. Used by some
+ builtins that do not accept arguments. */
+void
+no_args (list)
+ WORD_LIST *list;
+{
+ if (list)
+ {
+ builtin_error (_("too many arguments"));
+ top_level_cleanup ();
+ jump_to_top_level (DISCARD);
+ }
+}
+
+/* Check that no options were given to the currently-executing builtin,
+ and return 0 if there were options. */
+int
+no_options (list)
+ WORD_LIST *list;
+{
+ reset_internal_getopt ();
+ if (internal_getopt (list, "") != -1)
+ {
+ builtin_usage ();
+ return (1);
+ }
+ return (0);
+}
+
+void
+sh_needarg (s)
+ char *s;
+{
+ builtin_error (_("%s: option requires an argument"), s);
+}
+
+void
+sh_neednumarg (s)
+ char *s;
+{
+ builtin_error (_("%s: numeric argument required"), s);
+}
+
+void
+sh_notfound (s)
+ char *s;
+{
+ builtin_error (_("%s: not found"), s);
+}
+
+/* Function called when one of the builtin commands detects an invalid
+ option. */
+void
+sh_invalidopt (s)
+ char *s;
+{
+ builtin_error (_("%s: invalid option"), s);
+}
+
+void
+sh_invalidoptname (s)
+ char *s;
+{
+ builtin_error (_("%s: invalid option name"), s);
+}
+
+void
+sh_invalidid (s)
+ char *s;
+{
+ builtin_error (_("`%s': not a valid identifier"), s);
+}
+
+void
+sh_invalidnum (s)
+ char *s;
+{
+ char *msg;
+
+ if (*s == '0' && isdigit (s[1]))
+ msg = _("invalid octal number");
+ else if (*s == '0' && s[1] == 'x')
+ msg = _("invalid hex number");
+ else
+ msg = _("invalid number");
+ builtin_error ("%s: %s", s, msg);
+}
+
+void
+sh_invalidsig (s)
+ char *s;
+{
+ builtin_error (_("%s: invalid signal specification"), s);
+}
+
+void
+sh_badpid (s)
+ char *s;
+{
+ builtin_error (_("`%s': not a pid or valid job spec"), s);
+}
+
+void
+sh_readonly (s)
+ const char *s;
+{
+ builtin_error (_("%s: readonly variable"), s);
+}
+
+void
+sh_erange (s, desc)
+ char *s, *desc;
+{
+ if (s)
+ builtin_error (_("%s: %s out of range"), s, desc ? desc : _("argument"));
+ else
+ builtin_error (_("%s out of range"), desc ? desc : _("argument"));
+}
+
+#if defined (JOB_CONTROL)
+void
+sh_badjob (s)
+ char *s;
+{
+ builtin_error (_("%s: no such job"), s);
+}
+
+void
+sh_nojobs (s)
+ char *s;
+{
+ if (s)
+ builtin_error (_("%s: no job control"), s);
+ else
+ builtin_error (_("no job control"));
+}
+#endif
+
+#if defined (RESTRICTED_SHELL)
+void
+sh_restricted (s)
+ char *s;
+{
+ if (s)
+ builtin_error (_("%s: restricted"), s);
+ else
+ builtin_error (_("restricted"));
+}
+#endif
+
+void
+sh_notbuiltin (s)
+ char *s;
+{
+ builtin_error (_("%s: not a shell builtin"), s);
+}
+
+void
+sh_wrerror ()
+{
+#if defined (DONT_REPORT_BROKEN_PIPE_WRITE_ERRORS) && defined (EPIPE)
+ if (errno != EPIPE)
+#endif /* DONT_REPORT_BROKEN_PIPE_WRITE_ERRORS && EPIPE */
+ builtin_error (_("write error: %s"), strerror (errno));
+}
+
+void
+sh_ttyerror (set)
+ int set;
+{
+ if (set)
+ builtin_error (_("error setting terminal attributes: %s"), strerror (errno));
+ else
+ builtin_error (_("error getting terminal attributes: %s"), strerror (errno));
+}
+
+int
+sh_chkwrite (s)
+ int s;
+{
+ fflush (stdout);
+ if (ferror (stdout))
+ {
+ sh_wrerror ();
+ fpurge (stdout);
+ clearerr (stdout);
+ return (EXECUTION_FAILURE);
+ }
+ return (s);
+}
+
+/* **************************************************************** */
+/* */
+/* Shell positional parameter manipulation */
+/* */
+/* **************************************************************** */
+
+/* Convert a WORD_LIST into a C-style argv. Return the number of elements
+ in the list in *IP, if IP is non-null. A convenience function for
+ loadable builtins; also used by `test'. */
+char **
+make_builtin_argv (list, ip)
+ WORD_LIST *list;
+ int *ip;
+{
+ char **argv;
+
+ argv = strvec_from_word_list (list, 0, 1, ip);
+ argv[0] = this_command_name;
+ return argv;
+}
+
+/* Remember LIST in $0 ... $9, and REST_OF_ARGS. If DESTRUCTIVE is
+ non-zero, then discard whatever the existing arguments are, else
+ only discard the ones that are to be replaced. */
+void
+remember_args (list, destructive)
+ WORD_LIST *list;
+ int destructive;
+{
+ register int i;
+
+ for (i = 1; i < 10; i++)
+ {
+ if ((destructive || list) && dollar_vars[i])
+ {
+ free (dollar_vars[i]);
+ dollar_vars[i] = (char *)NULL;
+ }
+
+ if (list)
+ {
+ dollar_vars[i] = savestring (list->word->word);
+ list = list->next;
+ }
+ }
+
+ /* If arguments remain, assign them to REST_OF_ARGS.
+ Note that copy_word_list (NULL) returns NULL, and
+ that dispose_words (NULL) does nothing. */
+ if (destructive || list)
+ {
+ dispose_words (rest_of_args);
+ rest_of_args = copy_word_list (list);
+ }
+
+ if (destructive)
+ set_dollar_vars_changed ();
+}
+
+static int changed_dollar_vars;
+
+/* Have the dollar variables been reset to new values since we last
+ checked? */
+int
+dollar_vars_changed ()
+{
+ return (changed_dollar_vars);
+}
+
+void
+set_dollar_vars_unchanged ()
+{
+ changed_dollar_vars = 0;
+}
+
+void
+set_dollar_vars_changed ()
+{
+ if (variable_context)
+ changed_dollar_vars |= ARGS_FUNC;
+ else if (this_shell_builtin == set_builtin)
+ changed_dollar_vars |= ARGS_SETBLTIN;
+ else
+ changed_dollar_vars |= ARGS_INVOC;
+}
+
+/* **************************************************************** */
+/* */
+/* Validating numeric input and arguments */
+/* */
+/* **************************************************************** */
+
+/* Read a numeric arg for this_command_name, the name of the shell builtin
+ that wants it. LIST is the word list that the arg is to come from.
+ Accept only the numeric argument; report an error if other arguments
+ follow. If FATAL is 1, call throw_to_top_level, which exits the
+ shell; if it's 2, call jump_to_top_level (DISCARD), which aborts the
+ current command; if FATAL is 0, return an indication of an invalid
+ number by setting *NUMOK == 0 and return -1. */
+int
+get_numeric_arg (list, fatal, count)
+ WORD_LIST *list;
+ int fatal;
+ intmax_t *count;
+{
+ char *arg;
+
+ if (count)
+ *count = 1;
+
+ if (list && list->word && ISOPTION (list->word->word, '-'))
+ list = list->next;
+
+ if (list)
+ {
+ arg = list->word->word;
+ if (arg == 0 || (legal_number (arg, count) == 0))
+ {
+ sh_neednumarg (list->word->word ? list->word->word : "`'");
+ if (fatal == 0)
+ return 0;
+ else if (fatal == 1) /* fatal == 1; abort */
+ throw_to_top_level ();
+ else /* fatal == 2; discard current command */
+ {
+ top_level_cleanup ();
+ jump_to_top_level (DISCARD);
+ }
+ }
+ no_args (list->next);
+ }
+
+ return (1);
+}
+
+/* Get an eight-bit status value from LIST */
+int
+get_exitstat (list)
+ WORD_LIST *list;
+{
+ int status;
+ intmax_t sval;
+ char *arg;
+
+ if (list && list->word && ISOPTION (list->word->word, '-'))
+ list = list->next;
+
+ if (list == 0)
+ return (last_command_exit_value);
+
+ arg = list->word->word;
+ if (arg == 0 || legal_number (arg, &sval) == 0)
+ {
+ sh_neednumarg (list->word->word ? list->word->word : "`'");
+ return 255;
+ }
+ no_args (list->next);
+
+ status = sval & 255;
+ return status;
+}
+
+/* Return the octal number parsed from STRING, or -1 to indicate
+ that the string contained a bad number. */
+int
+read_octal (string)
+ char *string;
+{
+ int result, digits;
+
+ result = digits = 0;
+ while (*string && ISOCTAL (*string))
+ {
+ digits++;
+ result = (result * 8) + (*string++ - '0');
+ if (result > 0777)
+ return -1;
+ }
+
+ if (digits == 0 || *string)
+ result = -1;
+
+ return (result);
+}
+
+/* **************************************************************** */
+/* */
+/* Manipulating the current working directory */
+/* */
+/* **************************************************************** */
+
+/* Return a consed string which is the current working directory.
+ FOR_WHOM is the name of the caller for error printing. */
+char *the_current_working_directory = (char *)NULL;
+
+char *
+get_working_directory (for_whom)
+ char *for_whom;
+{
+ if (no_symbolic_links)
+ {
+ FREE (the_current_working_directory);
+ the_current_working_directory = (char *)NULL;
+ }
+
+ if (the_current_working_directory == 0)
+ {
+#if defined (GETCWD_BROKEN)
+ the_current_working_directory = getcwd (0, PATH_MAX);
+#else
+ the_current_working_directory = getcwd (0, 0);
+#endif
+ if (the_current_working_directory == 0)
+ {
+ fprintf (stderr, _("%s: error retrieving current directory: %s: %s\n"),
+ (for_whom && *for_whom) ? for_whom : get_name_for_error (),
+ _(bash_getcwd_errstr), strerror (errno));
+ return (char *)NULL;
+ }
+ }
+
+ return (savestring (the_current_working_directory));
+}
+
+/* Make NAME our internal idea of the current working directory. */
+void
+set_working_directory (name)
+ char *name;
+{
+ FREE (the_current_working_directory);
+ the_current_working_directory = savestring (name);
+}
+
+/* **************************************************************** */
+/* */
+/* Job control support functions */
+/* */
+/* **************************************************************** */
+
+#if defined (JOB_CONTROL)
+int
+get_job_by_name (name, flags)
+ const char *name;
+ int flags;
+{
+ register int i, wl, cl, match, job;
+ register PROCESS *p;
+ register JOB *j;
+
+ job = NO_JOB;
+ wl = strlen (name);
+ for (i = js.j_jobslots - 1; i >= 0; i--)
+ {
+ j = get_job_by_jid (i);
+ if (j == 0 || ((flags & JM_STOPPED) && J_JOBSTATE(j) != JSTOPPED))
+ continue;
+
+ p = j->pipe;
+ do
+ {
+ if (flags & JM_EXACT)
+ {
+ cl = strlen (p->command);
+ match = STREQN (p->command, name, cl);
+ }
+ else if (flags & JM_SUBSTRING)
+ match = strcasestr (p->command, name) != (char *)0;
+ else
+ match = STREQN (p->command, name, wl);
+
+ if (match == 0)
+ {
+ p = p->next;
+ continue;
+ }
+ else if (flags & JM_FIRSTMATCH)
+ return i; /* return first match */
+ else if (job != NO_JOB)
+ {
+ if (this_shell_builtin)
+ builtin_error (_("%s: ambiguous job spec"), name);
+ else
+ report_error (_("%s: ambiguous job spec"), name);
+ return (DUP_JOB);
+ }
+ else
+ job = i;
+ }
+ while (p != j->pipe);
+ }
+
+ return (job);
+}
+
+/* Return the job spec found in LIST. */
+int
+get_job_spec (list)
+ WORD_LIST *list;
+{
+ register char *word;
+ int job, jflags;
+
+ if (list == 0)
+ return (js.j_current);
+
+ word = list->word->word;
+
+ if (*word == '\0')
+ return (NO_JOB);
+
+ if (*word == '%')
+ word++;
+
+ if (DIGIT (*word) && all_digits (word))
+ {
+ job = atoi (word);
+ return (job > js.j_jobslots ? NO_JOB : job - 1);
+ }
+
+ jflags = 0;
+ switch (*word)
+ {
+ case 0:
+ case '%':
+ case '+':
+ return (js.j_current);
+
+ case '-':
+ return (js.j_previous);
+
+ case '?': /* Substring search requested. */
+ jflags |= JM_SUBSTRING;
+ word++;
+ /* FALLTHROUGH */
+
+ default:
+ return get_job_by_name (word, jflags);
+ }
+}
+#endif /* JOB_CONTROL */
+
+/*
+ * NOTE: `kill' calls this function with forcecols == 0
+ */
+int
+display_signal_list (list, forcecols)
+ WORD_LIST *list;
+ int forcecols;
+{
+ register int i, column;
+ char *name;
+ int result, signum, dflags;
+ intmax_t lsignum;
+
+ result = EXECUTION_SUCCESS;
+ if (!list)
+ {
+ for (i = 1, column = 0; i < NSIG; i++)
+ {
+ name = signal_name (i);
+ if (STREQN (name, "SIGJUNK", 7) || STREQN (name, "Unknown", 7))
+ continue;
+
+ if (posixly_correct && !forcecols)
+ {
+ /* This is for the kill builtin. POSIX.2 says the signal names
+ are displayed without the `SIG' prefix. */
+ if (STREQN (name, "SIG", 3))
+ name += 3;
+ printf ("%s%s", name, (i == NSIG - 1) ? "" : " ");
+ }
+ else
+ {
+ printf ("%2d) %s", i, name);
+
+ if (++column < 5)
+ printf ("\t");
+ else
+ {
+ printf ("\n");
+ column = 0;
+ }
+ }
+ }
+
+ if ((posixly_correct && !forcecols) || column != 0)
+ printf ("\n");
+ return result;
+ }
+
+ /* List individual signal names or numbers. */
+ while (list)
+ {
+ if (legal_number (list->word->word, &lsignum))
+ {
+ /* This is specified by Posix.2 so that exit statuses can be
+ mapped into signal numbers. */
+ if (lsignum > 128)
+ lsignum -= 128;
+ if (lsignum < 0 || lsignum >= NSIG)
+ {
+ sh_invalidsig (list->word->word);
+ result = EXECUTION_FAILURE;
+ list = list->next;
+ continue;
+ }
+
+ signum = lsignum;
+ name = signal_name (signum);
+ if (STREQN (name, "SIGJUNK", 7) || STREQN (name, "Unknown", 7))
+ {
+ list = list->next;
+ continue;
+ }
+#if defined (JOB_CONTROL)
+ /* POSIX.2 says that `kill -l signum' prints the signal name without
+ the `SIG' prefix. */
+ printf ("%s\n", (this_shell_builtin == kill_builtin) ? name + 3 : name);
+#else
+ printf ("%s\n", name);
+#endif
+ }
+ else
+ {
+ dflags = DSIG_NOCASE;
+ if (posixly_correct == 0 || this_shell_builtin != kill_builtin)
+ dflags |= DSIG_SIGPREFIX;
+ signum = decode_signal (list->word->word, dflags);
+ if (signum == NO_SIG)
+ {
+ sh_invalidsig (list->word->word);
+ result = EXECUTION_FAILURE;
+ list = list->next;
+ continue;
+ }
+ printf ("%d\n", signum);
+ }
+ list = list->next;
+ }
+ return (result);
+}
+
+/* **************************************************************** */
+/* */
+/* Finding builtin commands and their functions */
+/* */
+/* **************************************************************** */
+
+/* Perform a binary search and return the address of the builtin function
+ whose name is NAME. If the function couldn't be found, or the builtin
+ is disabled or has no function associated with it, return NULL.
+ Return the address of the builtin.
+ DISABLED_OKAY means find it even if the builtin is disabled. */
+struct builtin *
+builtin_address_internal (name, disabled_okay)
+ char *name;
+ int disabled_okay;
+{
+ int hi, lo, mid, j;
+
+ hi = num_shell_builtins - 1;
+ lo = 0;
+
+ while (lo <= hi)
+ {
+ mid = (lo + hi) / 2;
+
+ j = shell_builtins[mid].name[0] - name[0];
+
+ if (j == 0)
+ j = strcmp (shell_builtins[mid].name, name);
+
+ if (j == 0)
+ {
+ /* It must have a function pointer. It must be enabled, or we
+ must have explicitly allowed disabled functions to be found,
+ and it must not have been deleted. */
+ if (shell_builtins[mid].function &&
+ ((shell_builtins[mid].flags & BUILTIN_DELETED) == 0) &&
+ ((shell_builtins[mid].flags & BUILTIN_ENABLED) || disabled_okay))
+ return (&shell_builtins[mid]);
+ else
+ return ((struct builtin *)NULL);
+ }
+ if (j > 0)
+ hi = mid - 1;
+ else
+ lo = mid + 1;
+ }
+ return ((struct builtin *)NULL);
+}
+
+/* Return the pointer to the function implementing builtin command NAME. */
+sh_builtin_func_t *
+find_shell_builtin (name)
+ char *name;
+{
+ current_builtin = builtin_address_internal (name, 0);
+ return (current_builtin ? current_builtin->function : (sh_builtin_func_t *)NULL);
+}
+
+/* Return the address of builtin with NAME, whether it is enabled or not. */
+sh_builtin_func_t *
+builtin_address (name)
+ char *name;
+{
+ current_builtin = builtin_address_internal (name, 1);
+ return (current_builtin ? current_builtin->function : (sh_builtin_func_t *)NULL);
+}
+
+/* Return the function implementing the builtin NAME, but only if it is a
+ POSIX.2 special builtin. */
+sh_builtin_func_t *
+find_special_builtin (name)
+ char *name;
+{
+ current_builtin = builtin_address_internal (name, 0);
+ return ((current_builtin && (current_builtin->flags & SPECIAL_BUILTIN)) ?
+ current_builtin->function :
+ (sh_builtin_func_t *)NULL);
+}
+
+static int
+shell_builtin_compare (sbp1, sbp2)
+ struct builtin *sbp1, *sbp2;
+{
+ int result;
+
+ if ((result = sbp1->name[0] - sbp2->name[0]) == 0)
+ result = strcmp (sbp1->name, sbp2->name);
+
+ return (result);
+}
+
+/* Sort the table of shell builtins so that the binary search will work
+ in find_shell_builtin. */
+void
+initialize_shell_builtins ()
+{
+ qsort (shell_builtins, num_shell_builtins, sizeof (struct builtin),
+ (QSFUNC *)shell_builtin_compare);
+}
extern int subshell_environment;
extern REDIRECT *redirection_undo_list;
+extern char *exec_argv0;
int no_exit_on_failed_exec;
char *argv0, *command, **args, **env, *newname, *com2;
cleanenv = login = 0;
- argv0 = (char *)NULL;
+ exec_argv0 = argv0 = (char *)NULL;
reset_internal_getopt ();
while ((opt = internal_getopt (list, "cla:")) != -1)
{
free (args[0]);
args[0] = login ? mkdashname (argv0) : savestring (argv0);
+ exec_argv0 = savestring (args[0]);
}
else if (login)
{
--- /dev/null
+This file is exec.def, from which is created exec.c.
+It implements the builtin "exec" in Bash.
+
+Copyright (C) 1987-2009 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 <http://www.gnu.org/licenses/>.
+
+$PRODUCES exec.c
+
+$BUILTIN exec
+$FUNCTION exec_builtin
+$SHORT_DOC exec [-cl] [-a name] [command [arguments ...]] [redirection ...]
+Replace the shell with the given command.
+
+Execute COMMAND, replacing this shell with the specified program.
+ARGUMENTS become the arguments to COMMAND. If COMMAND is not specified,
+any redirections take effect in the current shell.
+
+Options:
+ -a name pass NAME as the zeroth argument to COMMAND
+ -c execute COMMAND with an empty environment
+ -l place a dash in the zeroth argument to COMMAND
+
+If the command cannot be executed, a non-interactive shell exits, unless
+the shell option `execfail' is set.
+
+Exit Status:
+Returns success unless COMMAND is not found or a redirection error occurs.
+$END
+
+#include <config.h>
+
+#include "../bashtypes.h"
+#include "posixstat.h"
+#include <signal.h>
+#include <errno.h>
+
+#if defined (HAVE_UNISTD_H)
+# include <unistd.h>
+#endif
+
+#include "../bashansi.h"
+#include "../bashintl.h"
+
+#include "../shell.h"
+#include "../execute_cmd.h"
+#include "../findcmd.h"
+#if defined (JOB_CONTROL)
+# include "../jobs.h"
+#endif
+#include "../flags.h"
+#include "../trap.h"
+#if defined (HISTORY)
+# include "../bashhist.h"
+#endif
+#include "common.h"
+#include "bashgetopt.h"
+
+/* Not all systems declare ERRNO in errno.h... and some systems #define it! */
+#if !defined (errno)
+extern int errno;
+#endif /* !errno */
+
+extern int subshell_environment;
+extern REDIRECT *redirection_undo_list;
+extern char *exec_argv0;
+
+int no_exit_on_failed_exec;
+
+/* If the user wants this to look like a login shell, then
+ prepend a `-' onto NAME and return the new name. */
+static char *
+mkdashname (name)
+ char *name;
+{
+ char *ret;
+
+ ret = (char *)xmalloc (2 + strlen (name));
+ ret[0] = '-';
+ strcpy (ret + 1, name);
+ return ret;
+}
+
+int
+exec_builtin (list)
+ WORD_LIST *list;
+{
+ int exit_value = EXECUTION_FAILURE;
+ int cleanenv, login, opt;
+ char *argv0, *command, **args, **env, *newname, *com2;
+
+ cleanenv = login = 0;
+ exec_argv0 = argv0 = (char *)NULL;
+
+ reset_internal_getopt ();
+ while ((opt = internal_getopt (list, "cla:")) != -1)
+ {
+ switch (opt)
+ {
+ case 'c':
+ cleanenv = 1;
+ break;
+ case 'l':
+ login = 1;
+ break;
+ case 'a':
+ argv0 = list_optarg;
+ break;
+ default:
+ builtin_usage ();
+ return (EX_USAGE);
+ }
+ }
+ list = loptend;
+
+ /* First, let the redirections remain. */
+ dispose_redirects (redirection_undo_list);
+ redirection_undo_list = (REDIRECT *)NULL;
+
+ if (list == 0)
+ return (EXECUTION_SUCCESS);
+
+#if defined (RESTRICTED_SHELL)
+ if (restricted)
+ {
+ sh_restricted ((char *)NULL);
+ return (EXECUTION_FAILURE);
+ }
+#endif /* RESTRICTED_SHELL */
+
+ args = strvec_from_word_list (list, 1, 0, (int *)NULL);
+
+ /* A command with a slash anywhere in its name is not looked up in $PATH. */
+ command = absolute_program (args[0]) ? args[0] : search_for_command (args[0]);
+
+ if (command == 0)
+ {
+ sh_notfound (args[0]);
+ exit_value = EX_NOTFOUND; /* As per Posix.2, 3.14.6 */
+ goto failed_exec;
+ }
+
+ com2 = full_pathname (command);
+ if (com2)
+ {
+ if (command != args[0])
+ free (command);
+ command = com2;
+ }
+
+ if (argv0)
+ {
+ free (args[0]);
+ exec_argv0 = args[0] = login ? mkdashname (argv0) : savestring (argv0);
+ }
+ else if (login)
+ {
+ newname = mkdashname (args[0]);
+ free (args[0]);
+ args[0] = newname;
+ }
+
+ /* Decrement SHLVL by 1 so a new shell started here has the same value,
+ preserving the appearance. After we do that, we need to change the
+ exported environment to include the new value. */
+ if (cleanenv == 0)
+ adjust_shell_level (-1);
+
+ if (cleanenv)
+ env = (char **)NULL;
+ else
+ {
+ maybe_make_export_env ();
+ env = export_env;
+ }
+
+#if defined (HISTORY)
+ if (interactive_shell && subshell_environment == 0)
+ maybe_save_shell_history ();
+#endif /* HISTORY */
+
+ restore_original_signals ();
+
+#if defined (JOB_CONTROL)
+ if (subshell_environment == 0)
+ end_job_control ();
+#endif /* JOB_CONTROL */
+
+ shell_execve (command, args, env);
+
+ /* We have to set this to NULL because shell_execve has called realloc()
+ to stuff more items at the front of the array, which may have caused
+ the memory to be freed by realloc(). We don't want to free it twice. */
+ args = (char **)NULL;
+ if (cleanenv == 0)
+ adjust_shell_level (1);
+
+ if (executable_file (command) == 0)
+ {
+ builtin_error (_("%s: cannot execute: %s"), command, strerror (errno));
+ exit_value = EX_NOEXEC; /* As per Posix.2, 3.14.6 */
+ }
+ else
+ file_error (command);
+
+failed_exec:
+ FREE (command);
+
+ if (subshell_environment || (interactive == 0 && no_exit_on_failed_exec == 0))
+ exit_shell (exit_value);
+
+ if (args)
+ strvec_dispose (args);
+
+ initialize_traps ();
+ initialize_signals (1);
+
+#if defined (JOB_CONTROL)
+ if (interactive_shell || job_control)
+ restart_job_control ();
+#endif /* JOB_CONTROL */
+
+ return (exit_value);
+}
{
register int i, j;
register char *line;
- int string_array, texinfo, base_indent, last_cpp, filename_p;
+ int string_array, texinfo, base_indent, filename_p;
if (stream == 0)
return;
base_indent = (string_array && single_longdoc_strings && filename_p == 0) ? BASE_INDENT : 0;
- for (i = last_cpp = 0, texinfo = (flags & TEXINFO); line = documentation[i]; i++)
+ for (i = 0, texinfo = (flags & TEXINFO); line = documentation[i]; i++)
{
/* Allow #ifdef's to be written out verbatim, but don't put them into
separate help files. */
{
if (string_array && filename_p == 0 && single_longdoc_strings == 0)
fprintf (stream, "%s\n", line);
- last_cpp = 1;
continue;
}
- else
- last_cpp = 0;
/* prefix with N_( for gettext */
if (string_array && single_longdoc_strings == 0)
--- /dev/null
+/* mkbuiltins.c - Create builtins.c, builtext.h, and builtdoc.c from
+ a single source file called builtins.def. */
+
+/* Copyright (C) 1987-2009 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 <http://www.gnu.org/licenses/>.
+*/
+
+#if !defined (CROSS_COMPILING)
+# include <config.h>
+#else /* CROSS_COMPILING */
+/* A conservative set of defines based on POSIX/SUS3/XPG6 */
+# define HAVE_UNISTD_H
+# define HAVE_STRING_H
+# define HAVE_STDLIB_H
+
+# define HAVE_RENAME
+#endif /* CROSS_COMPILING */
+
+#if defined (HAVE_UNISTD_H)
+# ifdef _MINIX
+# include <sys/types.h>
+# endif
+# include <unistd.h>
+#endif
+
+#ifndef _MINIX
+# include "../bashtypes.h"
+# if defined (HAVE_SYS_FILE_H)
+# include <sys/file.h>
+# endif
+#endif
+
+#include "posixstat.h"
+#include "filecntl.h"
+
+#include "../bashansi.h"
+#include <stdio.h>
+#include <errno.h>
+
+#include "stdc.h"
+
+#define DOCFILE "builtins.texi"
+
+#ifndef errno
+extern int errno;
+#endif
+
+static char *xmalloc (), *xrealloc ();
+
+#if !defined (__STDC__) && !defined (strcpy)
+extern char *strcpy ();
+#endif /* !__STDC__ && !strcpy */
+
+#define savestring(x) strcpy (xmalloc (1 + strlen (x)), (x))
+#define whitespace(c) (((c) == ' ') || ((c) == '\t'))
+
+/* Flag values that builtins can have. */
+#define BUILTIN_FLAG_SPECIAL 0x01
+#define BUILTIN_FLAG_ASSIGNMENT 0x02
+#define BUILTIN_FLAG_POSIX_BUILTIN 0x04
+
+#define BASE_INDENT 4
+
+/* If this stream descriptor is non-zero, then write
+ texinfo documentation to it. */
+FILE *documentation_file = (FILE *)NULL;
+
+/* Non-zero means to only produce documentation. */
+int only_documentation = 0;
+
+/* Non-zero means to not do any productions. */
+int inhibit_production = 0;
+
+/* Non-zero means to produce separate help files for each builtin, named by
+ the builtin name, in `./helpfiles'. */
+int separate_helpfiles = 0;
+
+/* Non-zero means to create single C strings for each `longdoc', with
+ embedded newlines, for ease of translation. */
+int single_longdoc_strings = 1;
+
+/* The name of a directory into which the separate external help files will
+ eventually be installed. */
+char *helpfile_directory;
+
+/* The name of a directory to precede the filename when reporting
+ errors. */
+char *error_directory = (char *)NULL;
+
+/* The name of the structure file. */
+char *struct_filename = (char *)NULL;
+
+/* The name of the external declaration file. */
+char *extern_filename = (char *)NULL;
+
+/* Here is a structure for manipulating arrays of data. */
+typedef struct {
+ int size; /* Number of slots allocated to array. */
+ int sindex; /* Current location in array. */
+ int width; /* Size of each element. */
+ int growth_rate; /* How fast to grow. */
+ char **array; /* The array itself. */
+} ARRAY;
+
+/* Here is a structure defining a single BUILTIN. */
+typedef struct {
+ char *name; /* The name of this builtin. */
+ char *function; /* The name of the function to call. */
+ char *shortdoc; /* The short documentation for this builtin. */
+ char *docname; /* Possible name for documentation string. */
+ ARRAY *longdoc; /* The long documentation for this builtin. */
+ ARRAY *dependencies; /* Null terminated array of #define names. */
+ int flags; /* Flags for this builtin. */
+} BUILTIN_DESC;
+
+/* Here is a structure which defines a DEF file. */
+typedef struct {
+ char *filename; /* The name of the input def file. */
+ ARRAY *lines; /* The contents of the file. */
+ int line_number; /* The current line number. */
+ char *production; /* The name of the production file. */
+ FILE *output; /* Open file stream for PRODUCTION. */
+ ARRAY *builtins; /* Null terminated array of BUILTIN_DESC *. */
+} DEF_FILE;
+
+/* The array of all builtins encountered during execution of this code. */
+ARRAY *saved_builtins = (ARRAY *)NULL;
+
+/* The Posix.2 so-called `special' builtins. */
+char *special_builtins[] =
+{
+ ":", ".", "source", "break", "continue", "eval", "exec", "exit",
+ "export", "readonly", "return", "set", "shift", "times", "trap", "unset",
+ (char *)NULL
+};
+
+/* The builtin commands that take assignment statements as arguments. */
+char *assignment_builtins[] =
+{
+ "alias", "declare", "export", "local", "readonly", "typeset",
+ (char *)NULL
+};
+
+/* The builtin commands that are special to the POSIX search order. */
+char *posix_builtins[] =
+{
+ "alias", "bg", "cd", "command", "false", "fc", "fg", "getopts", "jobs",
+ "kill", "newgrp", "pwd", "read", "true", "umask", "unalias", "wait",
+ (char *)NULL
+};
+
+/* Forward declarations. */
+static int is_special_builtin ();
+static int is_assignment_builtin ();
+static int is_posix_builtin ();
+
+#if !defined (HAVE_RENAME)
+static int rename ();
+#endif
+
+void extract_info ();
+
+void file_error ();
+void line_error ();
+
+void write_file_headers ();
+void write_file_footers ();
+void write_ifdefs ();
+void write_endifs ();
+void write_documentation ();
+void write_longdocs ();
+void write_builtins ();
+
+int write_helpfiles ();
+
+void free_defs ();
+void add_documentation ();
+
+void must_be_building ();
+void remove_trailing_whitespace ();
+
+#define document_name(b) ((b)->docname ? (b)->docname : (b)->name)
+
+\f
+/* For each file mentioned on the command line, process it and
+ write the information to STRUCTFILE and EXTERNFILE, while
+ creating the production file if neccessary. */
+int
+main (argc, argv)
+ int argc;
+ char **argv;
+{
+ int arg_index = 1;
+ FILE *structfile, *externfile;
+ char *documentation_filename, *temp_struct_filename;
+
+ structfile = externfile = (FILE *)NULL;
+ documentation_filename = DOCFILE;
+ temp_struct_filename = (char *)NULL;
+
+ while (arg_index < argc && argv[arg_index][0] == '-')
+ {
+ char *arg = argv[arg_index++];
+
+ if (strcmp (arg, "-externfile") == 0)
+ extern_filename = argv[arg_index++];
+ else if (strcmp (arg, "-structfile") == 0)
+ struct_filename = argv[arg_index++];
+ else if (strcmp (arg, "-noproduction") == 0)
+ inhibit_production = 1;
+ else if (strcmp (arg, "-document") == 0)
+ documentation_file = fopen (documentation_filename, "w");
+ else if (strcmp (arg, "-D") == 0)
+ {
+ int len;
+
+ if (error_directory)
+ free (error_directory);
+
+ error_directory = xmalloc (2 + strlen (argv[arg_index]));
+ strcpy (error_directory, argv[arg_index]);
+ len = strlen (error_directory);
+
+ if (len && error_directory[len - 1] != '/')
+ strcat (error_directory, "/");
+
+ arg_index++;
+ }
+ else if (strcmp (arg, "-documentonly") == 0)
+ {
+ only_documentation = 1;
+ documentation_file = fopen (documentation_filename, "w");
+ }
+ else if (strcmp (arg, "-H") == 0)
+ {
+ separate_helpfiles = 1;
+ helpfile_directory = argv[arg_index++];
+ }
+ else if (strcmp (arg, "-S") == 0)
+ single_longdoc_strings = 0;
+ else
+ {
+ fprintf (stderr, "%s: Unknown flag %s.\n", argv[0], arg);
+ exit (2);
+ }
+ }
+
+ /* If there are no files to process, just quit now. */
+ if (arg_index == argc)
+ exit (0);
+
+ if (!only_documentation)
+ {
+ /* Open the files. */
+ if (struct_filename)
+ {
+ temp_struct_filename = xmalloc (15);
+ sprintf (temp_struct_filename, "mk-%ld", (long) getpid ());
+ structfile = fopen (temp_struct_filename, "w");
+
+ if (!structfile)
+ file_error (temp_struct_filename);
+ }
+
+ if (extern_filename)
+ {
+ externfile = fopen (extern_filename, "w");
+
+ if (!externfile)
+ file_error (extern_filename);
+ }
+
+ /* Write out the headers. */
+ write_file_headers (structfile, externfile);
+ }
+
+ if (documentation_file)
+ {
+ fprintf (documentation_file, "@c Table of builtins created with %s.\n",
+ argv[0]);
+ fprintf (documentation_file, "@ftable @asis\n");
+ }
+
+ /* Process the .def files. */
+ while (arg_index < argc)
+ {
+ register char *arg;
+
+ arg = argv[arg_index++];
+
+ extract_info (arg, structfile, externfile);
+ }
+
+ /* Close the files. */
+ if (!only_documentation)
+ {
+ /* Write the footers. */
+ write_file_footers (structfile, externfile);
+
+ if (structfile)
+ {
+ write_longdocs (structfile, saved_builtins);
+ fclose (structfile);
+ rename (temp_struct_filename, struct_filename);
+ }
+
+ if (externfile)
+ fclose (externfile);
+ }
+
+ if (separate_helpfiles)
+ {
+ write_helpfiles (saved_builtins);
+ }
+
+ if (documentation_file)
+ {
+ fprintf (documentation_file, "@end ftable\n");
+ fclose (documentation_file);
+ }
+
+ exit (0);
+}
+
+/* **************************************************************** */
+/* */
+/* Array Functions and Manipulators */
+/* */
+/* **************************************************************** */
+
+/* Make a new array, and return a pointer to it. The array will
+ contain elements of size WIDTH, and is initialized to no elements. */
+ARRAY *
+array_create (width)
+ int width;
+{
+ ARRAY *array;
+
+ array = (ARRAY *)xmalloc (sizeof (ARRAY));
+ array->size = 0;
+ array->sindex = 0;
+ array->width = width;
+
+ /* Default to increasing size in units of 20. */
+ array->growth_rate = 20;
+
+ array->array = (char **)NULL;
+
+ return (array);
+}
+
+/* Copy the array of strings in ARRAY. */
+ARRAY *
+copy_string_array (array)
+ ARRAY *array;
+{
+ register int i;
+ ARRAY *copy;
+
+ if (!array)
+ return (ARRAY *)NULL;
+
+ copy = array_create (sizeof (char *));
+
+ copy->size = array->size;
+ copy->sindex = array->sindex;
+ copy->width = array->width;
+
+ copy->array = (char **)xmalloc ((1 + array->sindex) * sizeof (char *));
+
+ for (i = 0; i < array->sindex; i++)
+ copy->array[i] = savestring (array->array[i]);
+
+ copy->array[i] = (char *)NULL;
+
+ return (copy);
+}
+
+/* Add ELEMENT to ARRAY, growing the array if neccessary. */
+void
+array_add (element, array)
+ char *element;
+ ARRAY *array;
+{
+ if (array->sindex + 2 > array->size)
+ array->array = (char **)xrealloc
+ (array->array, (array->size += array->growth_rate) * array->width);
+
+ array->array[array->sindex++] = element;
+ array->array[array->sindex] = (char *)NULL;
+}
+
+/* Free an allocated array and data pointer. */
+void
+array_free (array)
+ ARRAY *array;
+{
+ if (array->array)
+ free (array->array);
+
+ free (array);
+}
+
+/* **************************************************************** */
+/* */
+/* Processing a DEF File */
+/* */
+/* **************************************************************** */
+
+/* The definition of a function. */
+typedef int Function ();
+typedef int mk_handler_func_t __P((char *, DEF_FILE *, char *));
+
+/* Structure handles processor directives. */
+typedef struct {
+ char *directive;
+ mk_handler_func_t *function;
+} HANDLER_ENTRY;
+
+extern int builtin_handler __P((char *, DEF_FILE *, char *));
+extern int function_handler __P((char *, DEF_FILE *, char *));
+extern int short_doc_handler __P((char *, DEF_FILE *, char *));
+extern int comment_handler __P((char *, DEF_FILE *, char *));
+extern int depends_on_handler __P((char *, DEF_FILE *, char *));
+extern int produces_handler __P((char *, DEF_FILE *, char *));
+extern int end_handler __P((char *, DEF_FILE *, char *));
+extern int docname_handler __P((char *, DEF_FILE *, char *));
+
+HANDLER_ENTRY handlers[] = {
+ { "BUILTIN", builtin_handler },
+ { "DOCNAME", docname_handler },
+ { "FUNCTION", function_handler },
+ { "SHORT_DOC", short_doc_handler },
+ { "$", comment_handler },
+ { "COMMENT", comment_handler },
+ { "DEPENDS_ON", depends_on_handler },
+ { "PRODUCES", produces_handler },
+ { "END", end_handler },
+ { (char *)NULL, (mk_handler_func_t *)NULL }
+};
+
+/* Return the entry in the table of handlers for NAME. */
+HANDLER_ENTRY *
+find_directive (directive)
+ char *directive;
+{
+ register int i;
+
+ for (i = 0; handlers[i].directive; i++)
+ if (strcmp (handlers[i].directive, directive) == 0)
+ return (&handlers[i]);
+
+ return ((HANDLER_ENTRY *)NULL);
+}
+
+/* Non-zero indicates that a $BUILTIN has been seen, but not
+ the corresponding $END. */
+static int building_builtin = 0;
+
+/* Non-zero means to output cpp line and file information before
+ printing the current line to the production file. */
+int output_cpp_line_info = 0;
+
+/* The main function of this program. Read FILENAME and act on what is
+ found. Lines not starting with a dollar sign are copied to the
+ $PRODUCES target, if one is present. Lines starting with a dollar sign
+ are directives to this program, specifying the name of the builtin, the
+ function to call, the short documentation and the long documentation
+ strings. FILENAME can contain multiple $BUILTINs, but only one $PRODUCES
+ target. After the file has been processed, write out the names of
+ builtins found in each $BUILTIN. Plain text found before the $PRODUCES
+ is ignored, as is "$$ comment text". */
+void
+extract_info (filename, structfile, externfile)
+ char *filename;
+ FILE *structfile, *externfile;
+{
+ register int i;
+ DEF_FILE *defs;
+ struct stat finfo;
+ size_t file_size;
+ char *buffer, *line;
+ int fd, nr;
+
+ if (stat (filename, &finfo) == -1)
+ file_error (filename);
+
+ fd = open (filename, O_RDONLY, 0666);
+
+ if (fd == -1)
+ file_error (filename);
+
+ file_size = (size_t)finfo.st_size;
+ buffer = xmalloc (1 + file_size);
+
+ if ((nr = read (fd, buffer, file_size)) < 0)
+ file_error (filename);
+
+ /* This is needed on WIN32, and does not hurt on Unix. */
+ if (nr < file_size)
+ file_size = nr;
+
+ close (fd);
+
+ if (nr == 0)
+ {
+ fprintf (stderr, "mkbuiltins: %s: skipping zero-length file\n", filename);
+ return;
+ }
+
+ /* Create and fill in the initial structure describing this file. */
+ defs = (DEF_FILE *)xmalloc (sizeof (DEF_FILE));
+ defs->filename = filename;
+ defs->lines = array_create (sizeof (char *));
+ defs->line_number = 0;
+ defs->production = (char *)NULL;
+ defs->output = (FILE *)NULL;
+ defs->builtins = (ARRAY *)NULL;
+
+ /* Build the array of lines. */
+ i = 0;
+ while (i < file_size)
+ {
+ array_add (&buffer[i], defs->lines);
+
+ while (buffer[i] != '\n' && i < file_size)
+ i++;
+ buffer[i++] = '\0';
+ }
+
+ /* Begin processing the input file. We don't write any output
+ until we have a file to write output to. */
+ output_cpp_line_info = 1;
+
+ /* Process each line in the array. */
+ for (i = 0; line = defs->lines->array[i]; i++)
+ {
+ defs->line_number = i;
+
+ if (*line == '$')
+ {
+ register int j;
+ char *directive;
+ HANDLER_ENTRY *handler;
+
+ /* Isolate the directive. */
+ for (j = 0; line[j] && !whitespace (line[j]); j++);
+
+ directive = xmalloc (j);
+ strncpy (directive, line + 1, j - 1);
+ directive[j -1] = '\0';
+
+ /* Get the function handler and call it. */
+ handler = find_directive (directive);
+
+ if (!handler)
+ {
+ line_error (defs, "Unknown directive `%s'", directive);
+ free (directive);
+ continue;
+ }
+ else
+ {
+ /* Advance to the first non-whitespace character. */
+ while (whitespace (line[j]))
+ j++;
+
+ /* Call the directive handler with the FILE, and ARGS. */
+ (*(handler->function)) (directive, defs, line + j);
+ }
+ free (directive);
+ }
+ else
+ {
+ if (building_builtin)
+ add_documentation (defs, line);
+ else if (defs->output)
+ {
+ if (output_cpp_line_info)
+ {
+ /* If we're handed an absolute pathname, don't prepend
+ the directory name. */
+ if (defs->filename[0] == '/')
+ fprintf (defs->output, "#line %d \"%s\"\n",
+ defs->line_number + 1, defs->filename);
+ else
+ fprintf (defs->output, "#line %d \"%s%s\"\n",
+ defs->line_number + 1,
+ error_directory ? error_directory : "./",
+ defs->filename);
+ output_cpp_line_info = 0;
+ }
+
+ fprintf (defs->output, "%s\n", line);
+ }
+ }
+ }
+
+ /* Close the production file. */
+ if (defs->output)
+ fclose (defs->output);
+
+ /* The file has been processed. Write the accumulated builtins to
+ the builtins.c file, and write the extern definitions to the
+ builtext.h file. */
+ write_builtins (defs, structfile, externfile);
+
+ free (buffer);
+ free_defs (defs);
+}
+
+#define free_safely(x) if (x) free (x)
+
+static void
+free_builtin (builtin)
+ BUILTIN_DESC *builtin;
+{
+ register int i;
+
+ free_safely (builtin->name);
+ free_safely (builtin->function);
+ free_safely (builtin->shortdoc);
+ free_safely (builtin->docname);
+
+ if (builtin->longdoc)
+ array_free (builtin->longdoc);
+
+ if (builtin->dependencies)
+ {
+ for (i = 0; builtin->dependencies->array[i]; i++)
+ free (builtin->dependencies->array[i]);
+ array_free (builtin->dependencies);
+ }
+}
+
+/* Free all of the memory allocated to a DEF_FILE. */
+void
+free_defs (defs)
+ DEF_FILE *defs;
+{
+ register int i;
+ register BUILTIN_DESC *builtin;
+
+ if (defs->production)
+ free (defs->production);
+
+ if (defs->lines)
+ array_free (defs->lines);
+
+ if (defs->builtins)
+ {
+ for (i = 0; builtin = (BUILTIN_DESC *)defs->builtins->array[i]; i++)
+ {
+ free_builtin (builtin);
+ free (builtin);
+ }
+ array_free (defs->builtins);
+ }
+ free (defs);
+}
+
+/* **************************************************************** */
+/* */
+/* The Handler Functions Themselves */
+/* */
+/* **************************************************************** */
+
+/* Strip surrounding whitespace from STRING, and
+ return a pointer to the start of it. */
+char *
+strip_whitespace (string)
+ char *string;
+{
+ while (whitespace (*string))
+ string++;
+
+ remove_trailing_whitespace (string);
+ return (string);
+}
+
+/* Remove only the trailing whitespace from STRING. */
+void
+remove_trailing_whitespace (string)
+ char *string;
+{
+ register int i;
+
+ i = strlen (string) - 1;
+
+ while (i > 0 && whitespace (string[i]))
+ i--;
+
+ string[++i] = '\0';
+}
+
+/* Ensure that there is a argument in STRING and return it.
+ FOR_WHOM is the name of the directive which needs the argument.
+ DEFS is the DEF_FILE in which the directive is found.
+ If there is no argument, produce an error. */
+char *
+get_arg (for_whom, defs, string)
+ char *for_whom, *string;
+ DEF_FILE *defs;
+{
+ char *new;
+
+ new = strip_whitespace (string);
+
+ if (!*new)
+ line_error (defs, "%s requires an argument", for_whom);
+
+ return (savestring (new));
+}
+
+/* Error if not building a builtin. */
+void
+must_be_building (directive, defs)
+ char *directive;
+ DEF_FILE *defs;
+{
+ if (!building_builtin)
+ line_error (defs, "%s must be inside of a $BUILTIN block", directive);
+}
+
+/* Return the current builtin. */
+BUILTIN_DESC *
+current_builtin (directive, defs)
+ char *directive;
+ DEF_FILE *defs;
+{
+ must_be_building (directive, defs);
+ if (defs->builtins)
+ return ((BUILTIN_DESC *)defs->builtins->array[defs->builtins->sindex - 1]);
+ else
+ return ((BUILTIN_DESC *)NULL);
+}
+
+/* Add LINE to the long documentation for the current builtin.
+ Ignore blank lines until the first non-blank line has been seen. */
+void
+add_documentation (defs, line)
+ DEF_FILE *defs;
+ char *line;
+{
+ register BUILTIN_DESC *builtin;
+
+ builtin = current_builtin ("(implied LONGDOC)", defs);
+
+ remove_trailing_whitespace (line);
+
+ if (!*line && !builtin->longdoc)
+ return;
+
+ if (!builtin->longdoc)
+ builtin->longdoc = array_create (sizeof (char *));
+
+ array_add (line, builtin->longdoc);
+}
+
+/* How to handle the $BUILTIN directive. */
+int
+builtin_handler (self, defs, arg)
+ char *self;
+ DEF_FILE *defs;
+ char *arg;
+{
+ BUILTIN_DESC *new;
+ char *name;
+
+ /* If we are already building a builtin, we cannot start a new one. */
+ if (building_builtin)
+ {
+ line_error (defs, "%s found before $END", self);
+ return (-1);
+ }
+
+ output_cpp_line_info++;
+
+ /* Get the name of this builtin, and stick it in the array. */
+ name = get_arg (self, defs, arg);
+
+ /* If this is the first builtin, create the array to hold them. */
+ if (!defs->builtins)
+ defs->builtins = array_create (sizeof (BUILTIN_DESC *));
+
+ new = (BUILTIN_DESC *)xmalloc (sizeof (BUILTIN_DESC));
+ new->name = name;
+ new->function = (char *)NULL;
+ new->shortdoc = (char *)NULL;
+ new->docname = (char *)NULL;
+ new->longdoc = (ARRAY *)NULL;
+ new->dependencies = (ARRAY *)NULL;
+ new->flags = 0;
+
+ if (is_special_builtin (name))
+ new->flags |= BUILTIN_FLAG_SPECIAL;
+ if (is_assignment_builtin (name))
+ new->flags |= BUILTIN_FLAG_ASSIGNMENT;
+ if (is_posix_builtin (name))
+ new->flags |= BUILTIN_FLAG_POSIX_BUILTIN;
+
+ array_add ((char *)new, defs->builtins);
+ building_builtin = 1;
+
+ return (0);
+}
+
+/* How to handle the $FUNCTION directive. */
+int
+function_handler (self, defs, arg)
+ char *self;
+ DEF_FILE *defs;
+ char *arg;
+{
+ register BUILTIN_DESC *builtin;
+
+ builtin = current_builtin (self, defs);
+
+ if (builtin == 0)
+ {
+ line_error (defs, "syntax error: no current builtin for $FUNCTION directive");
+ exit (1);
+ }
+ if (builtin->function)
+ line_error (defs, "%s already has a function (%s)",
+ builtin->name, builtin->function);
+ else
+ builtin->function = get_arg (self, defs, arg);
+
+ return (0);
+}
+
+/* How to handle the $DOCNAME directive. */
+int
+docname_handler (self, defs, arg)
+ char *self;
+ DEF_FILE *defs;
+ char *arg;
+{
+ register BUILTIN_DESC *builtin;
+
+ builtin = current_builtin (self, defs);
+
+ if (builtin->docname)
+ line_error (defs, "%s already had a docname (%s)",
+ builtin->name, builtin->docname);
+ else
+ builtin->docname = get_arg (self, defs, arg);
+
+ return (0);
+}
+
+/* How to handle the $SHORT_DOC directive. */
+int
+short_doc_handler (self, defs, arg)
+ char *self;
+ DEF_FILE *defs;
+ char *arg;
+{
+ register BUILTIN_DESC *builtin;
+
+ builtin = current_builtin (self, defs);
+
+ if (builtin->shortdoc)
+ line_error (defs, "%s already has short documentation (%s)",
+ builtin->name, builtin->shortdoc);
+ else
+ builtin->shortdoc = get_arg (self, defs, arg);
+
+ return (0);
+}
+
+/* How to handle the $COMMENT directive. */
+int
+comment_handler (self, defs, arg)
+ char *self;
+ DEF_FILE *defs;
+ char *arg;
+{
+ return (0);
+}
+
+/* How to handle the $DEPENDS_ON directive. */
+int
+depends_on_handler (self, defs, arg)
+ char *self;
+ DEF_FILE *defs;
+ char *arg;
+{
+ register BUILTIN_DESC *builtin;
+ char *dependent;
+
+ builtin = current_builtin (self, defs);
+ dependent = get_arg (self, defs, arg);
+
+ if (!builtin->dependencies)
+ builtin->dependencies = array_create (sizeof (char *));
+
+ array_add (dependent, builtin->dependencies);
+
+ return (0);
+}
+
+/* How to handle the $PRODUCES directive. */
+int
+produces_handler (self, defs, arg)
+ char *self;
+ DEF_FILE *defs;
+ char *arg;
+{
+ /* If just hacking documentation, don't change any of the production
+ files. */
+ if (only_documentation)
+ return (0);
+
+ output_cpp_line_info++;
+
+ if (defs->production)
+ line_error (defs, "%s already has a %s definition", defs->filename, self);
+ else
+ {
+ defs->production = get_arg (self, defs, arg);
+
+ if (inhibit_production)
+ return (0);
+
+ defs->output = fopen (defs->production, "w");
+
+ if (!defs->output)
+ file_error (defs->production);
+
+ fprintf (defs->output, "/* %s, created from %s. */\n",
+ defs->production, defs->filename);
+ }
+ return (0);
+}
+
+/* How to handle the $END directive. */
+int
+end_handler (self, defs, arg)
+ char *self;
+ DEF_FILE *defs;
+ char *arg;
+{
+ must_be_building (self, defs);
+ building_builtin = 0;
+ return (0);
+}
+
+/* **************************************************************** */
+/* */
+/* Error Handling Functions */
+/* */
+/* **************************************************************** */
+
+/* Produce an error for DEFS with FORMAT and ARGS. */
+void
+line_error (defs, format, arg1, arg2)
+ DEF_FILE *defs;
+ char *format, *arg1, *arg2;
+{
+ if (defs->filename[0] != '/')
+ fprintf (stderr, "%s", error_directory ? error_directory : "./");
+ fprintf (stderr, "%s:%d:", defs->filename, defs->line_number + 1);
+ fprintf (stderr, format, arg1, arg2);
+ fprintf (stderr, "\n");
+ fflush (stderr);
+}
+
+/* Print error message for FILENAME. */
+void
+file_error (filename)
+ char *filename;
+{
+ perror (filename);
+ exit (2);
+}
+
+/* **************************************************************** */
+/* */
+/* xmalloc and xrealloc () */
+/* */
+/* **************************************************************** */
+
+static void memory_error_and_abort ();
+
+static char *
+xmalloc (bytes)
+ int bytes;
+{
+ char *temp = (char *)malloc (bytes);
+
+ if (!temp)
+ memory_error_and_abort ();
+ return (temp);
+}
+
+static char *
+xrealloc (pointer, bytes)
+ char *pointer;
+ int bytes;
+{
+ char *temp;
+
+ if (!pointer)
+ temp = (char *)malloc (bytes);
+ else
+ temp = (char *)realloc (pointer, bytes);
+
+ if (!temp)
+ memory_error_and_abort ();
+
+ return (temp);
+}
+
+static void
+memory_error_and_abort ()
+{
+ fprintf (stderr, "mkbuiltins: out of virtual memory\n");
+ abort ();
+}
+
+/* **************************************************************** */
+/* */
+/* Creating the Struct and Extern Files */
+/* */
+/* **************************************************************** */
+
+/* Return a pointer to a newly allocated builtin which is
+ an exact copy of BUILTIN. */
+BUILTIN_DESC *
+copy_builtin (builtin)
+ BUILTIN_DESC *builtin;
+{
+ BUILTIN_DESC *new;
+
+ new = (BUILTIN_DESC *)xmalloc (sizeof (BUILTIN_DESC));
+
+ new->name = savestring (builtin->name);
+ new->shortdoc = savestring (builtin->shortdoc);
+ new->longdoc = copy_string_array (builtin->longdoc);
+ new->dependencies = copy_string_array (builtin->dependencies);
+
+ new->function =
+ builtin->function ? savestring (builtin->function) : (char *)NULL;
+ new->docname =
+ builtin->docname ? savestring (builtin->docname) : (char *)NULL;
+
+ return (new);
+}
+
+/* How to save away a builtin. */
+void
+save_builtin (builtin)
+ BUILTIN_DESC *builtin;
+{
+ BUILTIN_DESC *newbuiltin;
+
+ newbuiltin = copy_builtin (builtin);
+
+ /* If this is the first builtin to be saved, create the array
+ to hold it. */
+ if (!saved_builtins)
+ saved_builtins = array_create (sizeof (BUILTIN_DESC *));
+
+ array_add ((char *)newbuiltin, saved_builtins);
+}
+
+/* Flags that mean something to write_documentation (). */
+#define STRING_ARRAY 0x01
+#define TEXINFO 0x02
+#define PLAINTEXT 0x04
+#define HELPFILE 0x08
+
+char *structfile_header[] = {
+ "/* builtins.c -- the built in shell commands. */",
+ "",
+ "/* This file is manufactured by ./mkbuiltins, and should not be",
+ " edited by hand. See the source to mkbuiltins for details. */",
+ "",
+ "/* Copyright (C) 1987-2009 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 <http://www.gnu.org/licenses/>.",
+ "*/",
+ "",
+ "/* The list of shell builtins. Each element is name, function, flags,",
+ " long-doc, short-doc. The long-doc field contains a pointer to an array",
+ " of help lines. The function takes a WORD_LIST *; the first word in the",
+ " list is the first arg to the command. The list has already had word",
+ " expansion performed.",
+ "",
+ " Functions which need to look at only the simple commands (e.g.",
+ " the enable_builtin ()), should ignore entries where",
+ " (array[i].function == (sh_builtin_func_t *)NULL). Such entries are for",
+ " the list of shell reserved control structures, like `if' and `while'.",
+ " The end of the list is denoted with a NULL name field. */",
+ "",
+ "#include \"../builtins.h\"",
+ (char *)NULL
+ };
+
+char *structfile_footer[] = {
+ " { (char *)0x0, (sh_builtin_func_t *)0x0, 0, (char **)0x0, (char *)0x0 }",
+ "};",
+ "",
+ "struct builtin *shell_builtins = static_shell_builtins;",
+ "struct builtin *current_builtin;",
+ "",
+ "int num_shell_builtins =",
+ "\tsizeof (static_shell_builtins) / sizeof (struct builtin) - 1;",
+ (char *)NULL
+};
+
+/* Write out any neccessary opening information for
+ STRUCTFILE and EXTERNFILE. */
+void
+write_file_headers (structfile, externfile)
+ FILE *structfile, *externfile;
+{
+ register int i;
+
+ if (structfile)
+ {
+ for (i = 0; structfile_header[i]; i++)
+ fprintf (structfile, "%s\n", structfile_header[i]);
+
+ fprintf (structfile, "#include \"%s\"\n",
+ extern_filename ? extern_filename : "builtext.h");
+
+ fprintf (structfile, "#include \"bashintl.h\"\n");
+
+ fprintf (structfile, "\nstruct builtin static_shell_builtins[] = {\n");
+ }
+
+ if (externfile)
+ fprintf (externfile,
+ "/* %s - The list of builtins found in libbuiltins.a. */\n",
+ extern_filename ? extern_filename : "builtext.h");
+}
+
+/* Write out any necessary closing information for
+ STRUCTFILE and EXTERNFILE. */
+void
+write_file_footers (structfile, externfile)
+ FILE *structfile, *externfile;
+{
+ register int i;
+
+ /* Write out the footers. */
+ if (structfile)
+ {
+ for (i = 0; structfile_footer[i]; i++)
+ fprintf (structfile, "%s\n", structfile_footer[i]);
+ }
+}
+
+/* Write out the information accumulated in DEFS to
+ STRUCTFILE and EXTERNFILE. */
+void
+write_builtins (defs, structfile, externfile)
+ DEF_FILE *defs;
+ FILE *structfile, *externfile;
+{
+ register int i;
+
+ /* Write out the information. */
+ if (defs->builtins)
+ {
+ register BUILTIN_DESC *builtin;
+
+ for (i = 0; i < defs->builtins->sindex; i++)
+ {
+ builtin = (BUILTIN_DESC *)defs->builtins->array[i];
+
+ /* Write out any #ifdefs that may be there. */
+ if (!only_documentation)
+ {
+ if (builtin->dependencies)
+ {
+ write_ifdefs (externfile, builtin->dependencies->array);
+ write_ifdefs (structfile, builtin->dependencies->array);
+ }
+
+ /* Write the extern definition. */
+ if (externfile)
+ {
+ if (builtin->function)
+ fprintf (externfile, "extern int %s __P((WORD_LIST *));\n",
+ builtin->function);
+
+ fprintf (externfile, "extern char * const %s_doc[];\n",
+ document_name (builtin));
+ }
+
+ /* Write the structure definition. */
+ if (structfile)
+ {
+ fprintf (structfile, " { \"%s\", ", builtin->name);
+
+ if (builtin->function)
+ fprintf (structfile, "%s, ", builtin->function);
+ else
+ fprintf (structfile, "(sh_builtin_func_t *)0x0, ");
+
+ fprintf (structfile, "%s%s%s%s, %s_doc,\n",
+ "BUILTIN_ENABLED | STATIC_BUILTIN",
+ (builtin->flags & BUILTIN_FLAG_SPECIAL) ? " | SPECIAL_BUILTIN" : "",
+ (builtin->flags & BUILTIN_FLAG_ASSIGNMENT) ? " | ASSIGNMENT_BUILTIN" : "",
+ (builtin->flags & BUILTIN_FLAG_POSIX_BUILTIN) ? " | POSIX_BUILTIN" : "",
+ document_name (builtin));
+
+ fprintf
+ (structfile, " N_(\"%s\"), (char *)NULL },\n",
+ builtin->shortdoc ? builtin->shortdoc : builtin->name);
+
+ }
+
+ if (structfile || separate_helpfiles)
+ /* Save away this builtin for later writing of the
+ long documentation strings. */
+ save_builtin (builtin);
+
+ /* Write out the matching #endif, if neccessary. */
+ if (builtin->dependencies)
+ {
+ if (externfile)
+ write_endifs (externfile, builtin->dependencies->array);
+
+ if (structfile)
+ write_endifs (structfile, builtin->dependencies->array);
+ }
+ }
+
+ if (documentation_file)
+ {
+ fprintf (documentation_file, "@item %s\n", builtin->name);
+ write_documentation
+ (documentation_file, builtin->longdoc->array, 0, TEXINFO);
+ }
+ }
+ }
+}
+
+/* Write out the long documentation strings in BUILTINS to STREAM. */
+void
+write_longdocs (stream, builtins)
+ FILE *stream;
+ ARRAY *builtins;
+{
+ register int i;
+ register BUILTIN_DESC *builtin;
+ char *dname;
+ char *sarray[2];
+
+ for (i = 0; i < builtins->sindex; i++)
+ {
+ builtin = (BUILTIN_DESC *)builtins->array[i];
+
+ if (builtin->dependencies)
+ write_ifdefs (stream, builtin->dependencies->array);
+
+ /* Write the long documentation strings. */
+ dname = document_name (builtin);
+ fprintf (stream, "char * const %s_doc[] =", dname);
+
+ if (separate_helpfiles)
+ {
+ int l = strlen (helpfile_directory) + strlen (dname) + 1;
+ sarray[0] = (char *)xmalloc (l + 1);
+ sprintf (sarray[0], "%s/%s", helpfile_directory, dname);
+ sarray[1] = (char *)NULL;
+ write_documentation (stream, sarray, 0, STRING_ARRAY|HELPFILE);
+ free (sarray[0]);
+ }
+ else
+ write_documentation (stream, builtin->longdoc->array, 0, STRING_ARRAY);
+
+ if (builtin->dependencies)
+ write_endifs (stream, builtin->dependencies->array);
+
+ }
+}
+
+/* Write an #ifdef string saying what needs to be defined (or not defined)
+ in order to allow compilation of the code that will follow.
+ STREAM is the stream to write the information to,
+ DEFINES is a null terminated array of define names.
+ If a define is preceded by an `!', then the sense of the test is
+ reversed. */
+void
+write_ifdefs (stream, defines)
+ FILE *stream;
+ char **defines;
+{
+ register int i;
+
+ if (!stream)
+ return;
+
+ fprintf (stream, "#if ");
+
+ for (i = 0; defines[i]; i++)
+ {
+ char *def = defines[i];
+
+ if (*def == '!')
+ fprintf (stream, "!defined (%s)", def + 1);
+ else
+ fprintf (stream, "defined (%s)", def);
+
+ if (defines[i + 1])
+ fprintf (stream, " && ");
+ }
+ fprintf (stream, "\n");
+}
+
+/* Write an #endif string saying what defines controlled the compilation
+ of the immediately preceding code.
+ STREAM is the stream to write the information to.
+ DEFINES is a null terminated array of define names. */
+void
+write_endifs (stream, defines)
+ FILE *stream;
+ char **defines;
+{
+ register int i;
+
+ if (!stream)
+ return;
+
+ fprintf (stream, "#endif /* ");
+
+ for (i = 0; defines[i]; i++)
+ {
+ fprintf (stream, "%s", defines[i]);
+
+ if (defines[i + 1])
+ fprintf (stream, " && ");
+ }
+
+ fprintf (stream, " */\n");
+}
+
+/* Write DOCUMENTATION to STREAM, perhaps surrounding it with double-quotes
+ and quoting special characters in the string. Handle special things for
+ internationalization (gettext) and the single-string vs. multiple-strings
+ issues. */
+void
+write_documentation (stream, documentation, indentation, flags)
+ FILE *stream;
+ char **documentation;
+ int indentation, flags;
+{
+ register int i, j;
+ register char *line;
+ int string_array, texinfo, base_indent, last_cpp, filename_p;
+
+ if (stream == 0)
+ return;
+
+ string_array = flags & STRING_ARRAY;
+ filename_p = flags & HELPFILE;
+
+ if (string_array)
+ {
+ fprintf (stream, " {\n#if defined (HELP_BUILTIN)\n"); /* } */
+ if (single_longdoc_strings)
+ {
+ if (filename_p == 0)
+ {
+ if (documentation && documentation[0] && documentation[0][0])
+ fprintf (stream, "N_(\"");
+ else
+ fprintf (stream, "N_(\" "); /* the empty string translates specially. */
+ }
+ else
+ fprintf (stream, "\"");
+ }
+ }
+
+ base_indent = (string_array && single_longdoc_strings && filename_p == 0) ? BASE_INDENT : 0;
+
+ for (i = last_cpp = 0, texinfo = (flags & TEXINFO); line = documentation[i]; i++)
+ {
+ /* Allow #ifdef's to be written out verbatim, but don't put them into
+ separate help files. */
+ if (*line == '#')
+ {
+ if (string_array && filename_p == 0 && single_longdoc_strings == 0)
+ fprintf (stream, "%s\n", line);
+ last_cpp = 1;
+ continue;
+ }
+ else
+ last_cpp = 0;
+
+ /* prefix with N_( for gettext */
+ if (string_array && single_longdoc_strings == 0)
+ {
+ if (filename_p == 0)
+ {
+ if (line[0])
+ fprintf (stream, " N_(\"");
+ else
+ fprintf (stream, " N_(\" "); /* the empty string translates specially. */
+ }
+ else
+ fprintf (stream, " \"");
+ }
+
+ if (indentation)
+ for (j = 0; j < indentation; j++)
+ fprintf (stream, " ");
+
+ /* Don't indent the first line, because of how the help builtin works. */
+ if (i == 0)
+ indentation += base_indent;
+
+ if (string_array)
+ {
+ for (j = 0; line[j]; j++)
+ {
+ switch (line[j])
+ {
+ case '\\':
+ case '"':
+ fprintf (stream, "\\%c", line[j]);
+ break;
+
+ default:
+ fprintf (stream, "%c", line[j]);
+ }
+ }
+
+ /* closing right paren for gettext */
+ if (single_longdoc_strings == 0)
+ {
+ if (filename_p == 0)
+ fprintf (stream, "\"),\n");
+ else
+ fprintf (stream, "\",\n");
+ }
+ else if (documentation[i+1])
+ /* don't add extra newline after last line */
+ fprintf (stream, "\\n\\\n");
+ }
+ else if (texinfo)
+ {
+ for (j = 0; line[j]; j++)
+ {
+ switch (line[j])
+ {
+ case '@':
+ case '{':
+ case '}':
+ fprintf (stream, "@%c", line[j]);
+ break;
+
+ default:
+ fprintf (stream, "%c", line[j]);
+ }
+ }
+ fprintf (stream, "\n");
+ }
+ else
+ fprintf (stream, "%s\n", line);
+ }
+
+ /* closing right paren for gettext */
+ if (string_array && single_longdoc_strings)
+ {
+ if (filename_p == 0)
+ fprintf (stream, "\"),\n");
+ else
+ fprintf (stream, "\",\n");
+ }
+
+ if (string_array)
+ fprintf (stream, "#endif /* HELP_BUILTIN */\n (char *)NULL\n};\n");
+}
+
+int
+write_helpfiles (builtins)
+ ARRAY *builtins;
+{
+ char *helpfile, *bname;
+ FILE *helpfp;
+ int i, hdlen;
+ BUILTIN_DESC *builtin;
+
+ i = mkdir ("helpfiles", 0777);
+ if (i < 0 && errno != EEXIST)
+ {
+ fprintf (stderr, "write_helpfiles: helpfiles: cannot create directory\n");
+ return -1;
+ }
+
+ hdlen = strlen ("helpfiles/");
+ for (i = 0; i < builtins->sindex; i++)
+ {
+ builtin = (BUILTIN_DESC *)builtins->array[i];
+
+ bname = document_name (builtin);
+ helpfile = (char *)xmalloc (hdlen + strlen (bname) + 1);
+ sprintf (helpfile, "helpfiles/%s", bname);
+
+ helpfp = fopen (helpfile, "w");
+ if (helpfp == 0)
+ {
+ fprintf (stderr, "write_helpfiles: cannot open %s\n", helpfile);
+ free (helpfile);
+ continue;
+ }
+
+ write_documentation (helpfp, builtin->longdoc->array, 4, PLAINTEXT);
+
+ fflush (helpfp);
+ fclose (helpfp);
+ free (helpfile);
+ }
+ return 0;
+}
+
+static int
+_find_in_table (name, name_table)
+ char *name, *name_table[];
+{
+ register int i;
+
+ for (i = 0; name_table[i]; i++)
+ if (strcmp (name, name_table[i]) == 0)
+ return 1;
+ return 0;
+}
+
+static int
+is_special_builtin (name)
+ char *name;
+{
+ return (_find_in_table (name, special_builtins));
+}
+
+static int
+is_assignment_builtin (name)
+ char *name;
+{
+ return (_find_in_table (name, assignment_builtins));
+}
+
+static int
+is_posix_builtin (name)
+ char *name;
+{
+ return (_find_in_table (name, posix_builtins));
+}
+
+#if !defined (HAVE_RENAME)
+static int
+rename (from, to)
+ char *from, *to;
+{
+ unlink (to);
+ if (link (from, to) < 0)
+ return (-1);
+ unlink (from);
+ return (0);
+}
+#endif /* !HAVE_RENAME */
-This is the Bash FAQ, version 4.11, for Bash version 4.1.
+This is the Bash FAQ, version 4.12, for Bash version 4.1.
This document contains a set of frequently-asked questions concerning
Bash, the GNU Bourne-Again Shell. Bash is a freely-available command
- the < and > operators to the [[ command do not consider the current
locale when comparing strings
- interrupting a command list such as "a ; b ; c" causes the execution
- of the entire list to be aborted
+ of the entire list to be aborted (in versions before bash-4.0,
+ interrupting one command in a list caused the next to be executed)
Section F: Things to watch out for on certain Unix versions
--- /dev/null
+This is the Bash FAQ, version 4.11, for Bash version 4.1.
+
+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.ramey@case.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 Shell and Utilities standard'?
+A10) What is the bash `posix mode'?
+
+Section B: The latest version
+
+B1) What's new in version 4.1?
+B2) Are there any user-visible incompatibilities between bash-4.1 and
+ previous bash versions?
+
+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?
+E12) Why don't negative offsets in substring expansion work like I expect?
+E13) Why does filename completion misbehave if a colon appears in the filename?
+E14) Why does quoting the pattern argument to the regular expression matching
+ conditional operator (=~) cause matching to stop working?
+E15) Tell me more about the shell compatibility level.
+
+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 4.1, first made available on 31 December, 2009.
+
+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 4.1:
+
+ftp://ftp.gnu.org/pub/gnu/bash/bash-4.1.tar.gz
+ftp://ftp.cwru.edu/pub/bash/bash-4.1.tar.gz
+
+Formatted versions of the documentation are available with the URLs:
+
+ftp://ftp.gnu.org/pub/gnu/bash/bash-doc-4.1.tar.gz
+ftp://ftp.cwru.edu/pub/bash/bash-doc-4.1.tar.gz
+
+Any patches for the current version are available with the URL:
+
+ftp://ftp.cwru.edu/pub/bash/bash-4.1-patches/
+
+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 (now part of Red Hat) as part
+of their CYGWIN project. For more information about the project, see
+http://www.cygwin.com/.
+
+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
+ports of bash-3.2 and bash-4.0 to the CYGWIN environment, and both
+are available as part of their current release.
+
+Bash-2.05b and later versions should require no local Cygnus changes to
+build and run under CYGWIN.
+
+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 <snowball3@bigfoot.com> 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 began to work with bash-2.05, but I don't know the current status.
+
+Bash-3.0 compiles and runs with no modifications under Microsoft's Services
+for Unix (SFU), once known as Interix. I do not anticipate any problems
+with building bash-4.1, but will gladly accept any patches that are needed.
+
+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 Shell and Utilities 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 was originally developed by
+IEEE Working Group 1003.2 (POSIX.2). Today it has been merged with
+the original 1003.1 Working Group and is maintained by the Austin
+Group (a joint working group of the IEEE, The Open Group and
+ISO/IEC SC22/WG15). Today the Shell and Utilities are a volume
+within the set of documents that make up IEEE Std 1003.1-2001, and
+thus now the former POSIX.2 (from 1992) is now part of the current
+POSIX.1 standard (POSIX 1003.1-2001).
+
+The Shell and Utilities volume concentrates on the command
+interpreter interface and utility programs commonly executed from
+the command line or by other programs. The standard is freely
+available on the web at http://www.UNIX-systems.org/version3/ .
+Work continues at the Austin Group on maintenance issues; see
+http://www.opengroup.org/austin/ to join the discussions.
+
+Bash is concerned with the aspects of the shell's behavior defined
+by the POSIX Shell and Utilities volume. 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 not
+devoted to the shell which are commonly (and in some cases must
+be) implemented as builtin commands, such as `read' and `test'.
+POSIX 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 latest version of the POSIX Shell and Utilities standard is
+available (now updated to the 2004 Edition) as part of the Single
+UNIX Specification Version 3 at
+
+http://www.UNIX-systems.org/version3/
+
+A10) What is the bash `posix mode'?
+
+Although bash is an implementation of the POSIX 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 4.1?
+
+Bash-4.1 is the first revision to the fourth major release of bash.
+
+Bash-4.1 contains the following new features (see the manual page for
+complete descriptions and the CHANGES and NEWS files in the bash-4.1
+distribution):
+
+o Here-documents within $(...) command substitutions may once more be
+ delimited by the closing right paren, instead of requiring a newline.
+
+o Bash's file status checks (executable, readable, etc.) now take file
+ system ACLs into account on file systems that support them.
+
+o Bash now passes environment variables with names that are not valid
+ shell variable names through into the environment passed to child
+ processes.
+
+o The `execute-unix-command' readline function now attempts to clear and
+ reuse the current line rather than move to a new one after the command
+ executes.
+
+o `printf -v' can now assign values to array indices.
+
+o New `complete -E' and `compopt -E' options that work on the "empty"
+ completion: completion attempted on an empty command line.
+
+o New complete/compgen/compopt -D option to define a `default' completion:
+ a completion to be invoked on command for which no completion has been
+ defined. If this function returns 124, programmable completion is
+ attempted again, allowing a user to dynamically build a set of completions
+ as completion is attempted by having the default completion function
+ install individual completion functions each time it is invoked.
+
+o When displaying associative arrays, subscripts are now quoted.
+
+o Changes to dabbrev-expand to make it more `emacs-like': no space appended
+ after matches, completions are not sorted, and most recent history entries
+ are presented first.
+
+o The [[ and (( commands are now subject to the setting of `set -e' and the
+ ERR trap.
+
+o The source/. builtin now removes NUL bytes from the file before attempting
+ to parse commands.
+
+o There is a new configuration option (in config-top.h) that forces bash to
+ forward all history entries to syslog.
+
+o A new variable $BASHOPTS to export shell options settable using `shopt' to
+ child processes.
+
+o There is a new confgure option that forces the extglob option to be
+ enabled by default.
+
+o New variable $BASH_XTRACEFD; when set to an integer bash will write xtrace
+ output to that file descriptor.
+
+o If the optional left-hand-side of a redirection is of the form {var}, the
+ shell assigns the file descriptor used to $var or uses $var as the file
+ descriptor to move or close, depending on the redirection operator.
+
+o The < and > operators to the [[ conditional command now do string
+ comparison according to the current locale.
+
+o Programmable completion now uses the completion for `b' instead of `a'
+ when completion is attempted on a line like: a $(b c.
+
+o Force extglob on temporarily when parsing the pattern argument to
+ the == and != operators to the [[ command, for compatibility.
+
+o Changed the behavior of interrupting the wait builtin when a SIGCHLD is
+ received and a trap on SIGCHLD is set to be Posix-mode only.
+
+o The read builtin has a new `-N nchars' option, which reads exactly NCHARS
+ characters, ignoring delimiters like newline.
+
+o The mapfile/readarray builtin no longer stores the commands it invokes via
+ callbacks in the history list.
+
+o There is a new `compat40' shopt option.
+
+o The < and > operators to [[ do string comparisons using the current locale
+ only if the compatibility level is greater than 40 (set to 41 by default).
+
+o New bindable readline function: menu-complete-backward.
+
+o In the readline vi-mode insertion keymap, C-n is now bound to menu-complete
+ by default, and C-p to menu-complete-backward.
+
+o When in readline vi command mode, repeatedly hitting ESC now does nothing,
+ even when ESC introduces a bound key sequence. This is closer to how
+ historical vi behaves.
+
+o New bindable readline function: skip-csi-sequence. Can be used as a
+ default to consume key sequences generated by keys like Home and End
+ without having to bind all keys.
+
+o New bindable readline variable: skip-completed-text, active when
+ completing in the middle of a word. If enabled, it means that characters
+ in the completion that match characters in the remainder of the word are
+ "skipped" rather than inserted into the line.
+
+o The pre-readline-6.0 version of menu completion is available as
+ "old-menu-complete" for users who do not like the readline-6.0 version.
+
+o New bindable readline variable: echo-control-characters. If enabled, and
+ the tty ECHOCTL bit is set, controls the echoing of characters
+ corresponding to keyboard-generated signals.
+
+o New bindable readline variable: enable-meta-key. Controls whether or not
+ readline sends the smm/rmm sequences if the terminal indicates it has a
+ meta key that enables eight-bit characters.
+
+A short feature history dating from Bash-2.0:
+
+Bash-4.0 contained the following new features:
+
+o When using substring expansion on the positional parameters, a starting
+ index of 0 now causes $0 to be prefixed to the list.
+
+o There is a new variable, $BASHPID, which always returns the process id of
+ the current shell.
+
+o There is a new `autocd' option that, when enabled, causes bash to attempt
+ to `cd' to a directory name that is supplied as the first word of a
+ simple command.
+
+o There is a new `checkjobs' option that causes the shell to check for and
+ report any running or stopped jobs at exit.
+
+o The programmable completion code exports a new COMP_TYPE variable, set to
+ a character describing the type of completion being attempted.
+
+o The programmable completion code exports a new COMP_KEY variable, set to
+ the character that caused the completion to be invoked (e.g., TAB).
+
+o The programmable completion code now uses the same set of characters as
+ readline when breaking the command line into a list of words.
+
+o The block multiplier for the ulimit -c and -f options is now 512 when in
+ Posix mode, as Posix specifies.
+
+o Changed the behavior of the read builtin to save any partial input received
+ in the specified variable when the read builtin times out. This also
+ results in variables specified as arguments to read to be set to the empty
+ string when there is no input available. When the read builtin times out,
+ it returns an exit status greater than 128.
+
+o The shell now has the notion of a `compatibility level', controlled by
+ new variables settable by `shopt'. Setting this variable currently
+ restores the bash-3.1 behavior when processing quoted strings on the rhs
+ of the `=~' operator to the `[[' command.
+
+o The `ulimit' builtin now has new -b (socket buffer size) and -T (number
+ of threads) options.
+
+o There is a new `compopt' builtin that allows completion functions to modify
+ completion options for existing completions or the completion currently
+ being executed.
+
+o The `read' builtin has a new -i option which inserts text into the reply
+ buffer when using readline.
+
+o A new `-E' option to the complete builtin allows control of the default
+ behavior for completion on an empty line.
+
+o There is now limited support for completing command name words containing
+ globbing characters.
+
+o The `help' builtin now has a new -d option, to display a short description,
+ and a -m option, to print help information in a man page-like format.
+
+o There is a new `mapfile' builtin to populate an array with lines from a
+ given file.
+
+o If a command is not found, the shell attempts to execute a shell function
+ named `command_not_found_handle', supplying the command words as the
+ function arguments.
+
+o There is a new shell option: `globstar'. When enabled, the globbing code
+ treats `**' specially -- it matches all directories (and files within
+ them, when appropriate) recursively.
+
+o There is a new shell option: `dirspell'. When enabled, the filename
+ completion code performs spelling correction on directory names during
+ completion.
+
+o The `-t' option to the `read' builtin now supports fractional timeout
+ values.
+
+o Brace expansion now allows zero-padding of expanded numeric values and
+ will add the proper number of zeroes to make sure all values contain the
+ same number of digits.
+
+o There is a new bash-specific bindable readline function: `dabbrev-expand'.
+ It uses menu completion on a set of words taken from the history list.
+
+o The command assigned to a key sequence with `bind -x' now sets two new
+ variables in the environment of the executed command: READLINE_LINE_BUFFER
+ and READLINE_POINT. The command can change the current readline line
+ and cursor position by modifying READLINE_LINE_BUFFER and READLINE_POINT,
+ respectively.
+
+o There is a new >>& redirection operator, which appends the standard output
+ and standard error to the named file.
+
+o The parser now understands `|&' as a synonym for `2>&1 |', which redirects
+ the standard error for a command through a pipe.
+
+o The new `;&' case statement action list terminator causes execution to
+ continue with the action associated with the next pattern in the
+ statement rather than terminating the command.
+
+o The new `;;&' case statement action list terminator causes the shell to
+ test the next set of patterns after completing execution of the current
+ action, rather than terminating the command.
+
+o The shell understands a new variable: PROMPT_DIRTRIM. When set to an
+ integer value greater than zero, prompt expansion of \w and \W will
+ retain only that number of trailing pathname components and replace
+ the intervening characters with `...'.
+
+o There are new case-modifying word expansions: uppercase (^[^]) and
+ lowercase (,[,]). They can work on either the first character or
+ array element, or globally. They accept an optional shell pattern
+ that determines which characters to modify. There is an optionally-
+ configured feature to include capitalization operators.
+
+o The shell provides associative array variables, with the appropriate
+ support to create, delete, assign values to, and expand them.
+
+o The `declare' builtin now has new -l (convert value to lowercase upon
+ assignment) and -u (convert value to uppercase upon assignment) options.
+ There is an optionally-configurable -c option to capitalize a value at
+ assignment.
+
+o There is a new `coproc' reserved word that specifies a coprocess: an
+ asynchronous command run with two pipes connected to the creating shell.
+ Coprocs can be named. The input and output file descriptors and the
+ PID of the coprocess are available to the calling shell in variables
+ with coproc-specific names.
+
+o A value of 0 for the -t option to `read' now returns success if there is
+ input available to be read from the specified file descriptor.
+
+o CDPATH and GLOBIGNORE are ignored when the shell is running in privileged
+ mode.
+
+o New bindable readline functions shell-forward-word and shell-backward-word,
+ which move forward and backward words delimited by shell metacharacters
+ and honor shell quoting.
+
+o New bindable readline functions shell-backward-kill-word and shell-kill-word
+ which kill words backward and forward, but use the same word boundaries
+ as shell-forward-word and shell-backward-word.
+
+Bash-3.2 contained the following new features:
+
+o Bash-3.2 now checks shell scripts for NUL characters rather than non-printing
+ characters when deciding whether or not a script is a binary file.
+
+o Quoting the string argument to the [[ command's =~ (regexp) operator now
+ forces string matching, as with the other pattern-matching operators.
+
+Bash-3.1 contained the following new features:
+
+o Bash-3.1 may now be configured and built in a mode that enforces strict
+ POSIX compliance.
+
+o The `+=' assignment operator, which appends to the value of a string or
+ array variable, has been implemented.
+
+o It is now possible to ignore case when matching in contexts other than
+ filename generation using the new `nocasematch' shell option.
+
+Bash-3.0 contained the following new features:
+
+o Features to support the bash debugger have been implemented, and there
+ is a new `extdebug' option to turn the non-default options on
+
+o HISTCONTROL is now a colon-separated list of options and has been
+ extended with a new `erasedups' option that will result in only one
+ copy of a command being kept in the history list
+
+o Brace expansion has been extended with a new {x..y} form, producing
+ sequences of digits or characters
+
+o Timestamps are now kept with history entries, with an option to save
+ and restore them from the history file; there is a new HISTTIMEFORMAT
+ variable describing how to display the timestamps when listing history
+ entries
+
+o The `[[' command can now perform extended regular expression (egrep-like)
+ matching, with matched subexpressions placed in the BASH_REMATCH array
+ variable
+
+o A new `pipefail' option causes a pipeline to return a failure status if
+ any command in it fails
+
+o The `jobs', `kill', and `wait' builtins now accept job control notation
+ in their arguments even if job control is not enabled
+
+o The `gettext' package and libintl have been integrated, and the shell
+ messages may be translated into other languages
+
+Bash-2.05b introduced the following new features:
+
+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
+
+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 $(<filename) command substitution, which is equivalent to
+ $(cat filename)
+new tilde prefixes that expand to directories from the directory stack
+new `**' arithmetic operator to do exponentiation
+case-insensitive globbing (filename expansion)
+menu completion a la tcsh
+`magic-space' history expansion function like tcsh
+the readline inputrc `language' has a new file inclusion directive ($include)
+
+Bash-2.01 contained only a few new features:
+
+new `GROUPS' builtin array variable containing the user's group list
+new bindable readline commands: history-and-alias-expand-line and
+ alias-expand-line
+
+Bash-2.0 contained extensive changes and new features from bash-1.14.7.
+Here's a short list:
+
+new `time' reserved word to time pipelines, shell builtins, and
+ shell functions
+one-dimensional arrays with a new compound assignment statement,
+ appropriate expansion constructs and modifications to some
+ of the builtins (read, declare, etc.) to use them
+new quoting syntaxes for ANSI-C string expansion and locale-specific
+ string translation
+new expansions to do substring extraction, pattern replacement, and
+ indirect variable expansion
+new builtins: `disown' and `shopt'
+new variables: HISTIGNORE, SHELLOPTS, PIPESTATUS, DIRSTACK, GLOBIGNORE,
+ MACHTYPE, BASH_VERSINFO
+special handling of many unused or redundant variables removed
+ (e.g., $notify, $glob_dot_filenames, $no_exit_on_failed_exec)
+dynamic loading of new builtin commands; many loadable examples provided
+new prompt expansions: \a, \e, \n, \H, \T, \@, \v, \V
+history and aliases available in shell scripts
+new readline variables: enable-keypad, mark-directories, input-meta,
+ visible-stats, disable-completion, comment-begin
+new readline commands to manipulate the mark and operate on the region
+new readline emacs mode commands and bindings for ksh-88 compatibility
+updated and extended builtins
+new DEBUG trap
+expanded (and now documented) restricted shell mode
+
+implementation stuff:
+autoconf-based configuration
+nearly all of the bugs reported since version 1.14 have been fixed
+most builtins converted to use builtin `getopt' for consistency
+most builtins use -p option to display output in a reusable form
+ (for consistency)
+grammar tighter and smaller (66 reduce-reduce conflicts gone)
+lots of code now smaller and faster
+test suite greatly expanded
+
+B2) Are there any user-visible incompatibilities between bash-4.1 and
+ previous bash versions?
+
+There are a few incompatibilities between version 4.1 and previous
+versions. They are detailed in the file COMPAT in the bash distribution.
+That file is not meant to be all-encompassing; send mail to
+bash-maintainers@gnu.org (or bug-bash@gnu.org if you would like
+community discussion) if if you find something that's not mentioned there.
+
+Section C: Differences from other Unix shells
+
+C1) How does bash differ from sh, the Bourne shell?
+
+This is a non-comprehensive list of features that differentiate bash
+from the SVR4.2 shell. The bash manual page explains these more
+completely.
+
+Things bash has that sh does not:
+ long invocation options
+ [+-]O invocation option
+ -l invocation option
+ `!' reserved word to invert pipeline return value
+ `time' reserved word to time pipelines and shell builtins
+ the `function' reserved word
+ the `select' compound command and reserved word
+ arithmetic for command: for ((expr1 ; expr2; expr3 )); do list; done
+ new $'...' and $"..." quoting
+ the $(...) form of command substitution
+ the $(<filename) form of command substitution, equivalent to
+ $(cat filename)
+ the ${#param} parameter value length operator
+ the ${!param} indirect parameter expansion operator
+ the ${!param*} prefix expansion operator
+ the ${param:offset[:length]} parameter substring operator
+ the ${param/pat[/string]} parameter pattern substitution operator
+ expansions to perform substring removal (${p%[%]w}, ${p#[#]w})
+ expansion of positional parameters beyond $9 with ${num}
+ variables: BASH, BASHPID, BASH_VERSION, BASH_VERSINFO, UID, EUID, REPLY,
+ TIMEFORMAT, PPID, PWD, OLDPWD, SHLVL, RANDOM, SECONDS,
+ LINENO, HISTCMD, HOSTTYPE, OSTYPE, MACHTYPE, HOSTNAME,
+ ENV, PS3, PS4, DIRSTACK, PIPESTATUS, HISTSIZE, HISTFILE,
+ HISTFILESIZE, HISTCONTROL, HISTIGNORE, GLOBIGNORE, GROUPS,
+ PROMPT_COMMAND, FCEDIT, FIGNORE, IGNOREEOF, INPUTRC,
+ SHELLOPTS, OPTERR, HOSTFILE, TMOUT, FUNCNAME, histchars,
+ auto_resume, PROMPT_DIRTRIM, BASHOPTS, BASH_XTRACEFD
+ DEBUG trap
+ ERR trap
+ variable arrays with new compound assignment syntax
+ redirections: <>, &>, >|, <<<, [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/-i/-N,
+ readonly -a/-f/name=value, trap -l, set +o,
+ set -b/-m/-o option/-h/-p/-B/-C/-H/-P,
+ unset -f/-v, ulimit -i/-m/-p/-q/-u/-x,
+ 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, compopt, mapfile
+ 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 and strict posix conformance
+ redirection to /dev/fd/N, /dev/stdin, /dev/stdout, /dev/stderr,
+ /dev/tcp/host/port, /dev/udp/host/port
+ debugger support, including `caller' builtin and new variables
+ RETURN trap
+ the `+=' assignment operator
+ autocd shell option and behavior
+ command-not-found hook with command_not_found_handle shell function
+ globstar shell option and `**' globbing behavior
+ |& synonym for `2>&1 |'
+ ;& and ;;& case action list terminators
+ case-modifying word expansions and variable attributes
+ associative arrays
+ coprocesses using the `coproc' reserved word and variables
+ shell assignment of a file descriptor used in a redirection to a variable
+
+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, BASHPID, 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_DIRTRIM
+ 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/-N, 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 -i/-q/-u/-x, umask -S, alias -p,
+ shopt, disown, printf, complete, compgen, compopt, mapfile
+ `!' 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'
+ debugger support, including the `caller' builtin
+ RETURN trap
+ Timestamps in history entries
+ {x..y} brace expansion
+ The `+=' assignment operator
+ autocd shell option and behavior
+ command-not-found hook with command_not_found_handle shell function
+ globstar shell option and `**' globbing behavior
+ |& synonym for `2>&1 |'
+ ;& and ;;& case action list terminators
+ case-modifying word expansions and variable attributes
+ associative arrays
+ coprocesses using the `coproc' reserved word and variables
+ shell assignment of a file descriptor used in a redirection to a variable
+
+Things ksh88 has or uses that bash does not:
+ tracked aliases (alias -t)
+ variables: ERRNO, FPATH, EDITOR, VISUAL
+ co-processes (bash uses different syntax)
+ 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, newgrp, print,
+ read -p/-s/var?prompt, set -A/-o gmacs/
+ -o bgnice/-o markdirs/-o trackall/-o viraw/-s,
+ typeset -H/-L/-R/-Z/-A/-ft/-fu/-fx/-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?
+
+This list is current through ksh93t+ (05/05/2009)
+
+New things in ksh-93 not in bash-4.1:
+ 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
+ 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 (match all instead of any)
+ exit statuses between 0 and 255
+ FPATH and PATH mixing
+ lexical scoping for local variables in `ksh' functions
+ no scoping for local variables in `POSIX' functions
+ $'' \C[.collating-element.] escape sequence
+ -C/-I invocation options
+ print -f (bash uses printf)
+ `fc' has been renamed to `hist'
+ `.' can execute shell functions
+ getopts -a
+ printf %B, %H, %P, %R, %T, %Z modifiers, output base for %d, `=' flag
+ read -n/-N differ/-v
+ set -o showme/-o multiline (bash default)
+ `sleep' and `getconf' builtins (bash has loadable versions)
+ typeset -n and `nameref' variables
+ [[ -R name ]] (checks whether or not name is a nameref)
+ typeset -C/-S/-T/-X/-h/-s
+ experimental `type' definitions (a la typedef) using typeset
+ negative subscripts for indexed array variables
+ array expansions ${array[sub1..sub2]} and ${!array[sub1..sub2]}
+ associative array assignments using `;' as element separator
+ command substitution $(n<#) expands to current byte offset for fd N
+ new '${ ' form of command substitution, executed in current shell
+ new >;/<>;/<#pat/<##pat/<#/># redirections
+ brace expansion printf-like formats
+ [[ -v var ]] operators (checks whether or not var is set)
+
+New things in ksh-93 present in bash-4.1:
+ associative arrays
+ [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'
+ new $'...' and $"..." quoting
+ FIGNORE (but bash uses GLOBIGNORE), HISTCMD
+ brace expansion and set -B
+ changes to kill builtin
+ `command', `builtin', `disown' builtins
+ echo -e
+ exec -c/-a
+ read -A (bash uses read -a)
+ read -t/-d
+ trap -p
+ `.' restores the positional parameters when it completes
+ set -o notify/-C
+ set -o pipefail
+ set -G (-o globstar) and **
+ POSIX.2 `test'
+ umask -S
+ unalias -a
+ command and arithmetic substitution performed on PS1, PS4, and ENV
+ command name completion, TAB displaying possible completions
+ ENV processed only for interactive shells
+ The `+=' assignment operator
+ the `;&' case statement "fallthrough" pattern list terminator
+ csh-style history expansion and set -H
+ negative offsets in ${param:offset:length}
+ redirection operators preceded with {varname} to store fd number in varname
+ DEBUG can force skipping following command
+
+Section D: Why does bash do some things differently than other Unix shells?
+
+D1) Why does bash run a different version of `command' than
+ `which command' says it will?
+
+On many systems, `which' is actually a csh script that assumes
+you're running csh. In tcsh, `which' and its cousin `where'
+are builtins. On other Unix systems, `which' is a perl script
+that uses the PATH environment variable. Many Linux distributions
+use GNU `which', which is a C program that can understand shell
+aliases.
+
+The csh script version reads the csh startup files from your
+home directory and uses those to determine which `command' will
+be invoked. Since bash doesn't use any of those startup files,
+there's a good chance that your bash environment differs from
+your csh environment. The bash `type' builtin does everything
+`which' does, and will report correct results for the running
+shell. If you're really wedded to the name `which', try adding
+the following function definition to your .bashrc:
+
+ which()
+ {
+ builtin type "$@"
+ }
+
+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.
+
+As of bash-3.1, bash does not report SIGPIPE errors by default. You
+can build a version of bash that will report such errors.
+
+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 $variable when the read command finishes?
+
+This has to do with the parent-child relationship between Unix
+processes. It affects all commands run in pipelines, not just
+simple calls to `read'. For example, piping a command's output
+into a `while' loop that repeatedly calls `read' will result in
+the same behavior.
+
+Each element of a pipeline, even a builtin or shell function,
+runs in a separate process, a child of the shell running the
+pipeline. A subprocess cannot affect its parent's environment.
+When the `read' command sets the variable to the input, that
+variable is set only in the subshell, not the parent shell. When
+the subshell exits, the value of the variable is lost.
+
+Many pipelines that end with `read variable' can be converted
+into command substitutions, which will capture the output of
+a specified command. The output can then be assigned to a
+variable:
+
+ grep ^gnu /usr/lib/news/active | wc -l | read ngroup
+
+can be converted into
+
+ ngroup=$(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 updated POSIX standard has 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'.
+
+E12) Why don't negative offsets in substring expansion work like I expect?
+
+When substring expansion of the form ${param:offset[:length} is used,
+an `offset' that evaluates to a number less than zero counts back from
+the end of the expanded value of $param.
+
+When a negative `offset' begins with a minus sign, however, unexpected things
+can happen. Consider
+
+ a=12345678
+ echo ${a:-4}
+
+intending to print the last four characters of $a. The problem is that
+${param:-word} already has a well-defined meaning: expand to word if the
+expanded value of param is unset or null, and $param otherwise.
+
+To use negative offsets that begin with a minus sign, separate the
+minus sign and the colon with a space.
+
+E13) Why does filename completion misbehave if a colon appears in the filename?
+
+Filename completion (and word completion in general) may appear to behave
+improperly if there is a colon in the word to be completed.
+
+The colon is special to readline's word completion code: it is one of the
+characters that breaks words for the completer. Readline uses these characters
+in sort of the same way that bash uses $IFS: they break or separate the words
+the completion code hands to the application-specific or default word
+completion functions. The original intent was to make it easy to edit
+colon-separated lists (such as $PATH in bash) in various applications using
+readline for input.
+
+This is complicated by the fact that some versions of the popular
+`bash-completion' programmable completion package have problems with the
+default completion behavior in the presence of colons.
+
+The current set of completion word break characters is available in bash as
+the value of the COMP_WORDBREAKS variable. Removing `:' from that value is
+enough to make the colon not special to completion:
+
+COMP_WORDBREAKS=${COMP_WORDBREAKS//:}
+
+You can also quote the colon with a backslash to achieve the same result
+temporarily.
+
+E14) Why does quoting the pattern argument to the regular expression matching
+ conditional operator (=~) cause regexp matching to stop working?
+
+In versions of bash prior to bash-3.2, the effect of quoting the regular
+expression argument to the [[ command's =~ operator was not specified.
+The practical effect was that double-quoting the pattern argument required
+backslashes to quote special pattern characters, which interfered with the
+backslash processing performed by double-quoted word expansion and was
+inconsistent with how the == shell pattern matching operator treated
+quoted characters.
+
+In bash-3.2, the shell was changed to internally quote characters in single-
+and double-quoted string arguments to the =~ operator, which suppresses the
+special meaning of the characters special to regular expression processing
+(`.', `[', `\', `(', `), `*', `+', `?', `{', `|', `^', and `$') and forces
+them to be matched literally. This is consistent with how the `==' pattern
+matching operator treats quoted portions of its pattern argument.
+
+Since the treatment of quoted string arguments was changed, several issues
+have arisen, chief among them the problem of white space in pattern arguments
+and the differing treatment of quoted strings between bash-3.1 and bash-3.2.
+Both problems may be solved by using a shell variable to hold the pattern.
+Since word splitting is not performed when expanding shell variables in all
+operands of the [[ command, this allows users to quote patterns as they wish
+when assigning the variable, then expand the values to a single string that
+may contain whitespace. The first problem may be solved by using backslashes
+or any other quoting mechanism to escape the white space in the patterns.
+
+Bash-4.0 introduces the concept of a `compatibility level', controlled by
+several options to the `shopt' builtin. If the `compat31' option is enabled,
+bash reverts to the bash-3.1 behavior with respect to quoting the rhs of
+the =~ operator.
+
+E15) Tell me more about the shell compatibility level.
+
+Bash-4.0 introduced the concept of a `shell compatibility level', specified
+as a set of options to the shopt builtin (compat31, compat32, compat40 at
+this writing). There is only one current compatibility level -- each
+option is mutually exclusive. This list does not mention behavior that is
+standard for a particular version (e.g., setting compat32 means that quoting
+the rhs of the regexp matching operator quotes special regexp characters in
+the word, which is default behavior in bash-3.2 and above).
+
+compat31 set
+ - the < and > operators to the [[ command do not consider the current
+ locale when comparing strings
+ - quoting the rhs of the regexp matching operator (=~) has no
+ special effect
+
+compat32 set
+ - the < and > operators to the [[ command do not consider the current
+ locale when comparing strings
+
+compat40 set
+ - the < and > operators to the [[ command do not consider the current
+ locale when comparing strings
+ - interrupting a command list such as "a ; b ; c" causes the execution
+ of the entire list to be aborted
+
+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 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.
+
+The script examples/scripts.noah/meta.bash encapsulates the bind
+commands in a shell function.
+
+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. It's a variant of
+
+ echo .[!.]* ..?* *
+
+(The ..?* catches files with names of three or more characters beginning
+with `..')
+
+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
+of the third edition, published in March, 2005, is 0-596-00965-8. Look for
+it in fine bookstores near you. This edition of the book has been updated
+to cover bash-3.0.
+
+The GNU Bash Reference Manual has been published as a printed book by
+Network Theory Ltd (Paperback, ISBN: 0-9541617-7-7, Nov. 2006). It covers
+bash-3.2 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.
+
+Arnold Robbins and Nelson Beebe have written ``Classic Shell Scripting'',
+published by O'Reilly. The first edition, with ISBN number 0-596-00595-4,
+was published in May, 2005.
+
+Chris F. A. Johnson, a frequent contributor to comp.unix.shell and
+gnu.bash.bug, has written ``Shell Scripting Recipes: A Problem-Solution
+Approach,'' a new book on shell scripting, concentrating on features of
+the POSIX standard helpful to shell script writers. The first edition from
+Apress, with ISBN number 1-59059-471-1, was published in May, 2005.
+
+H3) What's coming in future versions?
+
+These are features I hope to include in a future version of bash.
+
+Rocky Bernstein's bash debugger (support is included with bash-4.0)
+
+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
+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 `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 2010. Never make predictions.
+
+This document is Copyright 1995-2010 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.
.B Bash
can be configured to be POSIX-conformant by default.
.SH OPTIONS
-In addition to the single-character shell options documented in the
-description of the \fBset\fR builtin command, \fBbash\fR
+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
.B extdebug
option to the
.B shopt
-builtin below)
-and shell function tracing (see the description of the
-\fB\-o functrace\fP option to the
-.B set
builtin below).
.TP
.B \-\-dump\-po\-strings
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 compspec for that command. This allows a set of
+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
.\" Case Western Reserve University
.\" chet@po.cwru.edu
.\"
-.\" Last Change: Tue Dec 29 15:36:16 EST 2009
+.\" Last Change: Fri Jan 15 10:50:42 EST 2010
.\"
.\" bash_builtins, strip all but Built-Ins section
.if \n(zZ=1 .ig zZ
.if \n(zY=1 .ig zY
-.TH BASH 1 "2009 December 29" "GNU Bash-4.1"
+.TH BASH 1 "2010 January 15" "GNU Bash-4.1"
.\"
.\" There's some problem with having a `@'
.\" in a tagged paragraph with the BSD man macros.
.B Bash
can be configured to be POSIX-conformant by default.
.SH OPTIONS
-In addition to the single-character shell options documented in the
-description of the \fBset\fR builtin command, \fBbash\fR
+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
.B extdebug
option to the
.B shopt
-builtin below)
-and shell function tracing (see the description of the
-\fB\-o functrace\fP option to the
-.B set
builtin below).
.TP
.B \-\-dump\-po\-strings
.TP
.B BASH_ALIASES
An associative array variable whose members correspond to the internal
-list of aliases as maintained by the \fBalias\fP builtin
+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
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
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
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
.B PATH
is not used to search for the resultant file name.
.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 BASH_XTRACEFD
If set to an integer corresponding to a valid file descriptor, \fBbash\fP
will write the trace output generated when
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 COLUMNS
Used by the \fBselect\fP builtin command to determine the terminal width
-when printing selection lists. Automatically set upon receipt of a SIGWINCH.
+when printing selection lists. Automatically set upon receipt of a
+.SM
+.BR SIGWINCH .
.TP
.B COMPREPLY
An array variable from which \fBbash\fP reads the possible completions
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
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..
+the first character in the expanded value.
If \fIpattern\fP is omitted, it is treated like a \fB?\fP, which matches
every character.
If
.B \-x \fIfile\fP
True if \fIfile\fP exists and is executable.
.TP
-.B \-O \fIfile\fP
-True if \fIfile\fP exists and is owned by the effective user id.
-.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
-.B \-N \fIfile\fP
-True if \fIfile\fP exists and has been modified since it was last read.
+\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,
True if \fIfile1\fP is older than \fIfile2\fP, or if \fIfile2\fP exists
and \fIfile1\fP does not.
.TP
-\fIfile1\fP \fB\-ef\fP \fIfile2\fP
-True if \fIfile1\fP and \fIfile2\fP refer to the same device and
-inode numbers.
-.TP
.B \-o \fIoptname\fP
True if shell option
.I optname
.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.
+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
Names of all shell variables. May also be specified as \fB\-v\fP.
.RE
.TP 8
-\fB\-G\fP \fIglobpat\fP
-The pathname expansion pattern \fIglobpat\fP is expanded to generate
-the possible completions.
-.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\-C\fP \fIcommand\fP
\fIcommand\fP is executed in a subshell environment, and its output is
used as the possible completions.
.B COMPREPLY
array variable.
.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.
+\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
\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
\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-executing100 completion if no \fIname\fPs are supplied.
+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
or an attempt is made to display a non-existent function with \fB\-f\fP.
.RE
.TP
-.B dirs [+\fIn\fP] [\-\fIn\fP] [\fB\-cplv\fP]
+.B dirs [+\fIn\fP] [\-\fIn\fP] [\fB\-clpv\fP]
Without options, displays the list of currently remembered directories.
The default display is on a single line with directory names separated
by spaces.
List process IDs
in addition to the normal information.
.TP
-.B \-p
-List only the process ID of the job's process group
-leader.
-.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
Restrict output to running jobs.
.TP
.B 6.
Error tracing is enabled: command substitution, shell functions, and
subshells invoked with \fB(\fP \fIcommand\fP \fB)\fP inherit the
-\fBERROR\fP trap.
+\fBERR\fP trap.
.RE
.TP 8
.B extglob
.I sigspec
is either
a signal name defined in <\fIsignal.h\fP>, or a signal number.
-Signal names are case insensitive and the SIG prefix is optional.
+Signal names are case insensitive and the
+.SM
+.B SIG
+prefix is optional.
.if t .sp 0.5
.if n .sp 1
If a
The maximum number of processes available to a single user
.TP
.B \-v
-The maximum amount of virtual memory available to the shell
+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
bash [long-opt] -s [-abefhkmnptuvxdBCDHP] [-o @var{option}] [-O @var{shopt_option}] [@var{argument} @dots{}]
@end example
-In addition to the single-character shell command-line options
-(@pxref{The Set Builtin}), there are several multi-character
+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.
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) and shell function tracing
-(see @ref{The Set Builtin} for a description of the @code{-o functrace}
-option).
+builtin).
@item --dump-po-strings
A list of all double-quoted strings preceded by @samp{$}
--- /dev/null
+\input texinfo.tex @c -*- texinfo -*-
+@c %**start of header
+@setfilename bashref.info
+@settitle Bash Reference Manual
+@c %**end of header
+
+@setchapternewpage odd
+
+@include version.texi
+
+@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--2009 Free Software Foundation, Inc.
+
+Permission is granted to make and distribute verbatim copies of
+this manual provided the copyright notice and this permission notice
+are preserved on all copies.
+
+@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, with the Front-Cover texts being ``A GNU Manual'',
+and with the Back-Cover Texts as in (a) below. A copy of the license is
+included in the section entitled ``GNU Free Documentation License''.
+
+(a) The FSF's Back-Cover Text is: You are free to copy and modify
+this GNU manual. Buying copies from GNU Press supports the FSF in
+developing GNU and promoting software freedom.''
+
+@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
+
+@sp 1
+Published by the Free Software Foundation @*
+59 Temple Place, Suite 330, @*
+Boston, MA 02111-1307 @*
+USA @*
+
+@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}).
+
+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 based upon which one of these other shells inspired the
+feature.
+
+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 \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.
+@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 simple commands separated by one of
+the control operators @samp{|} or @samp{|&}.
+
+@rwindex time
+@rwindex !
+@cindex command timing
+The format for a pipeline is
+@example
+[@code{time} [@code{-p}]] [@code{!}] @var{command1} [ [@code{|} or @code{|&}] @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, the standard error of @var{command1} 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 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}.
+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.
+
+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.
+
+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{list}
+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
+@code{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 shell option @code{nocasematch}
+(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.
+
+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 @samp{[[} and @samp{]]}; 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 @samp{[[}, 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}.
+If the shell option @code{nocasematch}
+(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 it 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 shell option @code{nocasematch}
+(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 it 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.
+
+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
+@code{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 coproc is executed, the shell creates an array variable
+(@pxref{Arrays})
+named @var{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 @var{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 @var{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 process id of the shell spawned to execute the coprocess is
+available as the value of the variable @var{NAME}_PID.
+The @code{wait}
+builtin command may be used to wait for the coprocess to terminate.
+
+The return status of a coprocess is the exit status of @var{command}.
+
+@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
+[ @code{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.
+@var{compound-command} is executed whenever @var{name} is specified as the
+name of a command.
+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.
+
+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} or @code{typeset}
+builtin commands (@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. 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.
+
+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.
+When @samp{+=} is applied to a variable for which the 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.
+
+@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 *
+Expands to the positional parameters, starting from one. 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}$2@var{c}@dots{}"}, where @var{c}
+is the first character of the value of the @code{IFS}
+variable.
+If @env{IFS} is unset, the parameters are separated by spaces.
+If @env{IFS} is null, the parameters are joined without intervening
+separators.
+
+
+@item @@
+Expands to the positional parameters, starting from one. When the
+expansion occurs within double quotes, each parameter expands to a
+separate word. That is, @code{"$@@"} 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 #
+Expands to the number of positional parameters in decimal.
+
+@item ?
+Expands to the exit status of the most recently executed foreground
+pipeline.
+
+@item -
+(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 $
+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 !
+Expands to the process @sc{id} of the most recently executed background
+(asynchronous) command.
+
+@item 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 _
+(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, variable, and 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 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{"$@{@var{name}[@@]@}"}
+(@pxref{Arrays}).
+
+After all expansions, @code{quote removal} (@pxref{Quote Removal})
+is performed.
+
+@node Brace Expansion
+@subsection Brace Expansion
+@cindex brace expansion
+@cindex expansion, brace
+
+Brace expansion is a mechanism by which arbitrary strings may be generated.
+This mechanism is similar to
+@var{filename expansion} (@pxref{Filename Expansion}),
+but the file names generated need not exist.
+Patterns to be brace expanded take the form of an optional @var{preamble},
+followed by either a series of comma-separated strings or a seqeunce expression
+between a pair of braces,
+followed by an optional @var{postscript}.
+The preamble is prefixed to each string contained within the braces, and
+the postscript is then appended to each resulting string, expanding left
+to right.
+
+Brace expansions may be nested.
+The results of each expanded string are not sorted; left to right order
+is preserved.
+For example,
+@example
+bash$ 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. 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 file names 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 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 (!),
+a level of variable indirection is introduced.
+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, 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 $@{@var{parameter}:@var{offset}:@var{length}@}
+Expands to up to @var{length} characters of @var{parameter}
+starting at the character specified by @var{offset}.
+If @var{length} is omitted, expands to the substring of
+@var{parameter} starting at the character specified by @var{offset}.
+@var{length} and @var{offset} are arithmetic expressions
+(@pxref{Shell Arithmetic}).
+This is referred to as Substring Expansion.
+
+@var{length} must evaluate to a number greater than or equal to zero.
+If @var{offset} evaluates to a number less than zero, the value
+is used as an offset from the end of the value of @var{parameter}.
+If @var{parameter} is @samp{@@}, the result is @var{length} positional
+parameters beginning at @var{offset}.
+If @var{parameter} is an indexed array name subscripted
+by @samp{@@} or @samp{*}, the result is the @var{length}
+members of the array beginning with @code{$@{@var{parameter}[@var{offset}]@}}.
+A negative @var{offset} is taken relative to one greater than the maximum
+index of the specified array.
+Substring expansion applied to an associative array produces undefined
+results.
+
+Note that a negative offset must be separated from the colon by at least
+one space to avoid being confused with the @samp{:-} expansion.
+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.
+
+@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 @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 $@{@var{parameter},,@var{pattern}@}
+This expansion modifies the case of alphabetic characters in @var{parameter}.
+The @var{pattern} is expanded to produce a pattern just as in
+filename expansion.
+The @samp{^} operator converts lowercase letters matching @var{pattern}
+to uppercase; the @samp{,} operator converts matching uppercase letters
+to lowercase.
+The @samp{^^} and @samp{,,} expansions convert each matched character in the
+expanded value; the @samp{^} and @samp{,} expansions match and convert only
+the first character in the expanded value.
+If @var{pattern} is omitted, it is treated like a @samp{?}, which matches
+every character.
+If @var{parameter} is @samp{@@} or @samp{*},
+the case modification operation is applied to each positional
+parameter in turn, and the expansion is the resultant list.
+If @var{parameter}
+is an array variable subscripted with @samp{@@} or @samp{*},
+the case modification operation is applied to each member of the
+array in turn, and the expansion is the resultant list.
+
+@end table
+
+@node Command Substitution
+@subsection Command Substitution
+@cindex command substitution
+
+Command substitution allows the output of a command to replace
+the command itself.
+Command substitution occurs when a command is enclosed as follows:
+@example
+$(@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
+$(( @var{expression} ))
+@end example
+
+The expression is treated as if it were within double quotes, but
+a double quote inside the parentheses is not treated specially.
+All tokens in the expression undergo parameter expansion, command
+substitution, and quote removal.
+Arithmetic expansions may be nested.
+
+The evaluation is performed according to the rules listed below
+(@pxref{Shell Arithmetic}).
+If the expression is invalid, Bash prints a message indicating
+failure to the standard error and no substitution occurs.
+
+@node Process Substitution
+@subsection Process Substitution
+@cindex process substitution
+
+Process substitution is supported on systems that support named
+pipes (@sc{fifo}s) or the @file{/dev/fd} method of naming open files.
+It takes the form of
+@example
+<(@var{list})
+@end example
+@noindent
+or
+@example
+>(@var{list})
+@end example
+@noindent
+The process @var{list} is run with its input or output connected to a
+@sc{fifo} or some file in @file{/dev/fd}. The name of this file is
+passed as an argument to the current command as the result of the
+expansion. If the @code{>(@var{list})} form is used, writing to
+the file will provide input for @var{list}. If the
+@code{<(@var{list})} form is used, the file passed as an
+argument should be read to obtain the output of @var{list}.
+Note that no space may appear between the @code{<} or @code{>}
+and the left parenthesis, otherwise the construct would be interpreted
+as a redirection.
+
+When available, process substitution is performed simultaneously with
+parameter and variable expansion, command substitution, and arithmetic
+expansion.
+
+@node Word Splitting
+@subsection Word Splitting
+@cindex word splitting
+
+The shell scans the results of parameter expansion, command substitution,
+and arithmetic expansion that did not occur within double quotes for
+word splitting.
+
+The shell treats each character of @env{$IFS} as a delimiter, and splits
+the results of the other expansions into words on these characters.
+If @env{IFS} is unset, or its value is exactly @code{<space><tab><newline>},
+the default, then sequences of
+@code{ <space>}, @code{<tab>}, and @code{<newline>}
+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
+file names matching the pattern. If no matching file names 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 file name, 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. 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 sorts 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 value of the @env{LC_COLLATE} shell variable,
+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}.
+
+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 may also be used to open and close files for 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 a TCP
+connection to the corresponding 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 a UDP
+connection to the corresponding 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
+
+@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
+
+@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 for a command.
+
+The format of here-documents is:
+@example
+<<[@minus{}]@var{word}
+ @var{here-document}
+@var{delimiter}
+@end example
+
+No parameter 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. In the latter
+case, 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{word}
+@end example
+
+The @var{word} is expanded and supplied to the command on its standard
+input.
+
+@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.
+As a special case, if @var{n} is omitted, and @var{word} does not
+expand to one or more digits, 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 path name 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.
+
+@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] [@var{directory}]
+@end example
+Change the current working directory to @var{directory}.
+If @var{directory} is not given, the value of the @env{HOME} shell
+variable is used.
+If the shell variable @env{CDPATH} exists, it is used as a search path.
+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 followed by default or with the @option{-L} option.
+If @var{directory} is @samp{-}, it is equivalent to @env{$OLDPWD}.
+
+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 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 exported names 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 white space.
+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 @code{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
+Remember the full pathnames of 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}.
+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 [-aApf] [@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 no @var{name} arguments are given, or if the @option{-p}
+option is supplied, a list of all readonly names is printed.
+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 exit with the return value @var{n}.
+If @var{n} is not supplied, the return value is the exit status of the
+last command executed in the function.
+This may also be used to terminate execution of a script being executed
+with the @code{.} (or @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.
+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 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 [
+Evaluate a conditional expression @var{expr}.
+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.
+
+@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
+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
+
+@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 simple command has 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,
+or if the command's return
+status is being inverted using @code{!}.
+These are the same conditions obeyed by the @code{errexit} 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 [-fv] [@var{name}]
+@end example
+Each variable or function @var{name} is removed.
+If no options are supplied, or the @option{-v} option is given, each
+@var{name} refers to a shell variable.
+If the @option{-f} option is given, the @var{name}s refer to shell
+functions, and the function definition is removed.
+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 [@code{-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}] [-lpsvPSV]
+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 @var{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.
+@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 [-aAfFilrtux] [-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
+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 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 -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. 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 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 always 0.
+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
+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)
+@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}]
+@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 [-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 -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 as an additional argument.
+@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 @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, @samp{%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),
+and @samp{%q} causes @code{printf} to output the
+corresponding @var{argument} in a format that can be reused as shell input.
+
+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 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.
+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), 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 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 @var{timeout} is 0, @code{read} returns success if input is available on
+the specified file descriptor, failure 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 [-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,
+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 [-afFrxi] [-p] [@var{name}[=@var{value}] @dots{}]
+@end example
+The @code{typeset} command is supplied for compatibility with the Korn
+shell; however, it has been deprecated in favor of the @code{declare}
+builtin command.
+
+@item ulimit
+@btindex ulimit
+@example
+ulimit [-abcdefilmnpqrstuvxHST] [@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 -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 -T
+The maximum number of threads.
+
+@end table
+
+If @var{limit} is given, it 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{-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}] [@var{argument} @dots{}]
+set [+abefhkmnptuvxBCEHPT] [+o @var{option}] [@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 subshell command enclosed in parentheses (@pxref{Command Grouping}),
+or one of the commands executed as part of a command list enclosed
+by braces (@pxref{Command Grouping})
+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{!}.
+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.
+
+@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}).
+
+@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 @code{-p} option is not supplied, these actions
+are taken and the effective user id is set to the real user id.
+If the @code{-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 follow 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 variables controlling optional shell behavior.
+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, the display is limited to
+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 =~ operator.
+
+@item compat32
+If set, Bash
+changes its behavior to that of version 3.2 with respect to locale-specific
+string comparison when using the conditional command's < and > operators.
+
+@item compat40
+If set, Bash
+changes its behavior to that of version 4.0 with respect to locale-specific
+string comparison when using the conditional command's < and > operators
+and the effect of interrupting a command list.
+
+@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), a call to
+@code{return} is simulated.
+
+@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 globstar
+If set, the pattern @samp{**} used in a filename expansion context will
+match a 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 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.
+
+@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{Printing a 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 and the @env{MAILPATH} variable
+is not set, Bash informs the user of the arrival of mail in
+the specified file.
+
+@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 file name 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{Printing a 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_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
+corresponding to each member of @var{FUNCNAME}.
+@code{$@{BASH_LINENO[$i]@}} is the line number in the source file where
+@code{$@{FUNCNAME[$i]@}} was called (or @code{$@{BASH_LINENO[$i-1]@}} if
+referenced within another shell function).
+The corresponding source file name is @code{$@{BASH_SOURCE[$i]@}}.
+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 corresponding
+to the elements in the @code{FUNCNAME} array variable.
+
+@item BASH_SUBSHELL
+Incremented by one each time a subshell or subshell environment is spawned.
+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 COLUMNS
+Used by the @code{select} builtin command to determine the terminal width
+when printing selection lists. Automatically set 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}).
+
+@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 file name whose suffix matches one of the entries in
+@env{FIGNORE}
+is excluded from the list of matched file names. 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 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.
+
+@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, by removing the oldest entries,
+to contain no more than that number of lines.
+The history file is also truncated to this size after
+writing it when an interactive shell exits.
+The default value is 500.
+
+@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.
+The default value is 500.
+
+@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} builtin command to determine the column length
+for printing selection lists. Automatically set 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 @code{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, @code{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{Printing a 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 input after issuing the primary
+prompt when the shell is interactive.
+Bash terminates after that number of seconds if 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 section 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.
+* Printing a Prompt:: Controlling the PS1 string.
+* 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
+
+In addition to the single-character shell command-line options
+(@pxref{The Set Builtin}), 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) and shell function tracing
+(see @ref{The Set Builtin} for a description of the @code{-o functrace}
+option).
+
+@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 @var{string}
+Read and execute commands from @var{string} after processing the
+options, then exit. Any remaining arguments are assigned to the
+positional parameters, starting with @code{$0}.
+
+@item -i
+Force the shell to run interactively. Interactive shells are
+described in @ref{Interactive Shells}.
+
+@item -l
+Make this shell act as if it had been directly invoked by login.
+When the shell is interactive, this is equivalent to starting a
+login shell with @samp{exec -l bash}.
+When the shell is not interactive, the login shell startup files will
+be executed.
+@samp{exec bash -l} or @samp{exec bash --login}
+will replace the current shell with a Bash login shell.
+@xref{Bash Startup Files}, for a description of the special behavior
+of a login shell.
+
+@item -r
+Make the shell a restricted shell (@pxref{The Restricted Shell}).
+
+@item -s
+If this option is present, or if no arguments remain after option
+processing, then commands are read from the standard input.
+This option allows the positional parameters to be set
+when invoking an interactive shell.
+
+@item -D
+A list of all double-quoted strings preceded by @samp{$}
+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 file names 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
+file name.
+
+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 a network connection, as if 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
+@code{rshd} does not 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 @code{-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 @code{-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{$HISTFILE}
+when an interactive shell exits.
+
+@item
+Alias expansion (@pxref{Aliases}) is performed by default.
+
+@item
+In the absence of any traps, Bash ignores @code{SIGTERM}
+(@pxref{Signals}).
+
+@item
+In the absence of any traps, @code{SIGINT} is caught and handled
+((@pxref{Signals}).
+@code{SIGINT} will interrupt some shell builtins.
+
+@item
+An interactive login shell sends a @code{SIGHUP} to all jobs on exit
+if the @code{huponexit} shell option has been enabled (@pxref{Signals}).
+
+@item
+The @option{-n} invocation option is ignored, and @samp{set -n} has
+no effect (@pxref{The Set Builtin}).
+
+@item
+Bash will check for mail periodically, depending on the values of the
+@env{MAIL}, @env{MAILPATH}, and @env{MAILCHECK} shell variables
+(@pxref{Bash Variables}).
+
+@item
+Expansion errors due to references to unbound shell variables after
+@samp{set -u} has been enabled will not cause the shell to exit
+(@pxref{The Set Builtin}).
+
+@item
+The shell will not exit on expansion errors caused by @var{var} being unset
+or null in @code{$@{@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 @samp{[[}, The @samp{<} and @samp{>} operators sort
+lexicographically using the current locale.
+
+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 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 -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.
+@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 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 @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.
+The 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
+space or tab character, 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 compound 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.
+
+An indexed array is created automatically if any variable is assigned to
+using the syntax
+@example
+name[@var{subscript}]=@var{value}
+@end example
+
+@noindent
+The @var{subscript}
+is treated as an arithmetic expression that must evaluate to a number
+greater than or equal to zero. 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.
+
+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
+name=(value@var{1} @dots{} value@var{n})
+@end example
+@noindent
+where each
+@var{value} is of the form @code{[@var{subscript}]=}@var{string}.
+Indexed array assignments do not require the bracket and subscript.
+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{name[}@var{subscript}@code{]=}@var{value} syntax introduced above.
+
+Any element of an array may be referenced using
+@code{$@{name[}@var{subscript}@code{]@}}.
+The braces are required to avoid
+conflicts with the shell's filename expansion operators. If the
+@var{subscript} is @samp{@@} or @samp{*}, the word expands to all members
+of the array @var{name}. These subscripts differ only when the word
+appears within double quotes.
+If the word is double-quoted,
+@code{$@{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{$@{name[@@]@}} expands each element of
+@var{name} to a separate word. When there are no array members,
+@code{$@{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{$@{#name[}@var{subscript}@code{]@}} expands to the length of
+@code{$@{name[}@var{subscript}@code{]@}}.
+If @var{subscript} is @samp{@@} or
+@samp{*}, the expansion is the number of elements in the array.
+Referencing an array variable without a subscript is equivalent to
+referencing with a subscript of 0.
+
+An array variable is considered set if a subscript has been assigned a
+value. The null string is a valid value.
+
+The @code{unset} builtin is used to destroy arrays.
+@code{unset} @var{name}[@var{subscript}]
+destroys the array element at index @var{subscript}.
+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.
+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 [+@var{N} | -@var{N}] [-clpv]
+@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 +@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.
+@item -c
+Clears the directory stack by deleting all of the elements.
+@item -l
+Produces a longer listing; 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.
+@end table
+
+@item popd
+@btindex popd
+@example
+popd [+@var{N} | -@var{N}] [-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}; i.e., @code{popd} is equivalent to @code{popd +0}.
+@table @code
+@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.
+@item -n
+Suppresses the normal change of directory when removing directories
+from the stack, so that only the stack is manipulated.
+@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, and then
+executes the equivalent of `@code{cd} @var{dir}'.
+@code{cd}s to @var{dir}.
+@end table
+
+@end table
+
+@node Printing a 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:
+
+@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 default history file is @file{~/.sh_history} (this is the
+default value of @env{$HISTFILE}).
+
+@item
+The output of @samp{kill -l} prints all the signal names on a single line,
+separated by spaces, without the @samp{SIG} prefix.
+
+@item
+The @code{kill} builtin does not accept signal names with a @samp{SIG}
+prefix.
+
+@item
+Non-interactive shells exit if @var{filename} in @code{.} @var{filename}
+is not found.
+
+@item
+Non-interactive shells exit if a syntax error in an arithmetic expansion
+results in an invalid expression.
+
+@item
+Redirection operators do not perform filename expansion on the word
+in the redirection unless the shell is interactive.
+
+@item
+Redirection operators do not perform word splitting on the word in the
+redirection.
+
+@item
+Function names must be valid shell @code{name}s. That is, they may not
+contain characters other than letters, digits, and underscores, and
+may not start with a digit. Declaring a function with an invalid name
+causes a fatal syntax error in non-interactive shells.
+
+@item
+@sc{posix} special builtins are found before shell functions
+during command lookup.
+
+@item
+If a @sc{posix} special builtin returns an error status, a
+non-interactive shell exits. The fatal errors are those listed in
+the @sc{posix} standard, and include things like passing incorrect options,
+redirection errors, variable assignment errors for assignments preceding
+the command name, and so on.
+
+@item
+If @env{CDPATH} is set, the @code{cd} builtin will not implicitly
+append the current directory to it. This means that @code{cd} will
+fail if no valid directory name can be constructed from
+any of the entries in @env{$CDPATH}, even if the a directory with
+the same name as the name given as an argument to @code{cd} exists
+in the current directory.
+
+@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 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
+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{$PWD} and the directory name supplied as an argument
+does not refer to an existing directory, @code{cd} will fail instead of
+falling back to @var{physical} mode.
+
+@item
+When the @code{pwd} builtin is supplied the @option{-P} option, it resets
+@code{$PWD} to a pathname containing no symlinks.
+
+@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{$EDITOR}.
+
+@item
+When the @code{xpg_echo} option is enabled, Bash does not attempt to interpret
+any arguments to @code{echo} as options. Each argument is displayed, after
+escape characters are converted.
+
+@item
+The @code{ulimit} builtin uses a block size of 512 bytes for the @option{-c}
+and @option{-f} options.
+
+@item
+The arrival of @code{SIGCHLD} when a trap is set on @code{SIGCHLD} does
+not interrupt the @code{wait} builtin and cause it to return immediately.
+The trap command is run once for each child that exits.
+
+@end enumerate
+
+There is other @sc{posix} behavior that Bash does not implement by
+default even when in @sc{posix} mode.
+Specifically:
+
+@enumerate
+
+@item
+The @code{fc} builtin checks @code{$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
+Restrict output to running jobs.
+
+@item -s
+Restrict output to 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 [@var{jobspec} or @var{pid} ...]
+@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 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, each @var{jobspec} is removed 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 @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.in} is used to create @code{configure}
+by a program called Autoconf. You only need
+@file{configure.in} 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} 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-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-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{Printing a 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} builtin, 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{chet.ramey@@case.edu}.
+
+@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
+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} (@code{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{Printing a 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
int asynchronous, pipe_in, pipe_out;
struct fd_bitmap *fds_to_close;
{
- REDIRECT *rp;
COMMAND *tc, *second;
int ignore_return, exec_result, was_error_trap, invert;
volatile int save_line_number;
if (tc == 0)
return (EXECUTION_SUCCESS);
- rp = tc->redirects;
-
if (ignore_return)
tc->flags |= CMD_IGNORE_RETURN;
tc->flags |= CMD_AMPERSAND;
WORD_LIST *l;
char *repl_string, *t;
+#if 0
t = get_string_value ("LINES");
LINES = (t && *t) ? atoi (t) : 24;
+#endif
t = get_string_value ("COLUMNS");
COLS = (t && *t) ? atoi (t) : 80;
{
int result;
REDIRECT *saved_undo_list;
- sh_builtin_func_t *saved_this_shell_builtin;
if (do_redirections (redirects, RX_ACTIVE|RX_UNDOABLE) != 0)
{
return (EX_REDIRFAIL); /* was EXECUTION_FAILURE */
}
- saved_this_shell_builtin = this_shell_builtin;
saved_undo_list = redirection_undo_list;
/* Calling the "exec" builtin changes redirections forever. */
--- /dev/null
+/* execute_cmd.c -- Execute a COMMAND structure. */
+
+/* Copyright (C) 1987-2009 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 <http://www.gnu.org/licenses/>.
+*/
+
+#include "config.h"
+
+#if !defined (__GNUC__) && !defined (HAVE_ALLOCA_H) && defined (_AIX)
+ #pragma alloca
+#endif /* _AIX && RISC6000 && !__GNUC__ */
+
+#include <stdio.h>
+#include "chartypes.h"
+#include "bashtypes.h"
+#if !defined (_MINIX) && defined (HAVE_SYS_FILE_H)
+# include <sys/file.h>
+#endif
+#include "filecntl.h"
+#include "posixstat.h"
+#include <signal.h>
+#ifndef _MINIX
+# include <sys/param.h>
+#endif
+
+#if defined (HAVE_UNISTD_H)
+# include <unistd.h>
+#endif
+
+#include "posixtime.h"
+
+#if defined (HAVE_SYS_RESOURCE_H) && !defined (RLIMTYPE)
+# include <sys/resource.h>
+#endif
+
+#if defined (HAVE_SYS_TIMES_H) && defined (HAVE_TIMES)
+# include <sys/times.h>
+#endif
+
+#include <errno.h>
+
+#if !defined (errno)
+extern int errno;
+#endif
+
+#define NEED_FPURGE_DECL
+
+#include "bashansi.h"
+#include "bashintl.h"
+
+#include "memalloc.h"
+#include "shell.h"
+#include <y.tab.h> /* use <...> so we pick it up from the build directory */
+#include "flags.h"
+#include "builtins.h"
+#include "hashlib.h"
+#include "jobs.h"
+#include "execute_cmd.h"
+#include "findcmd.h"
+#include "redir.h"
+#include "trap.h"
+#include "pathexp.h"
+#include "hashcmd.h"
+
+#if defined (COND_COMMAND)
+# include "test.h"
+#endif
+
+#include "builtins/common.h"
+#include "builtins/builtext.h" /* list of builtins */
+
+#include <glob/strmatch.h>
+#include <tilde/tilde.h>
+
+#if defined (BUFFERED_INPUT)
+# include "input.h"
+#endif
+
+#if defined (ALIAS)
+# include "alias.h"
+#endif
+
+#if defined (HISTORY)
+# include "bashhist.h"
+#endif
+
+extern int posixly_correct;
+extern int expand_aliases;
+extern int autocd;
+extern int breaking, continuing, loop_level;
+extern int parse_and_execute_level, running_trap, sourcelevel;
+extern int command_string_index, line_number;
+extern int dot_found_in_search;
+extern int already_making_children;
+extern int tempenv_assign_error;
+extern char *the_printed_command, *shell_name;
+extern pid_t last_command_subst_pid;
+extern sh_builtin_func_t *last_shell_builtin, *this_shell_builtin;
+extern char **subshell_argv, **subshell_envp;
+extern int subshell_argc;
+extern char *exec_argv0;
+#if 0
+extern char *glob_argv_flags;
+#endif
+
+extern int close __P((int));
+
+/* Static functions defined and used in this file. */
+static void close_pipes __P((int, int));
+static void do_piping __P((int, int));
+static void bind_lastarg __P((char *));
+static int shell_control_structure __P((enum command_type));
+static void cleanup_redirects __P((REDIRECT *));
+
+#if defined (JOB_CONTROL)
+static int restore_signal_mask __P((sigset_t *));
+#endif
+
+static void async_redirect_stdin __P((void));
+
+static int builtin_status __P((int));
+
+static int execute_for_command __P((FOR_COM *));
+#if defined (SELECT_COMMAND)
+static int print_index_and_element __P((int, int, WORD_LIST *));
+static void indent __P((int, int));
+static void print_select_list __P((WORD_LIST *, int, int, int));
+static char *select_query __P((WORD_LIST *, int, char *, int));
+static int execute_select_command __P((SELECT_COM *));
+#endif
+#if defined (DPAREN_ARITHMETIC)
+static int execute_arith_command __P((ARITH_COM *));
+#endif
+#if defined (COND_COMMAND)
+static int execute_cond_node __P((COND_COM *));
+static int execute_cond_command __P((COND_COM *));
+#endif
+#if defined (COMMAND_TIMING)
+static int mkfmt __P((char *, int, int, time_t, int));
+static void print_formatted_time __P((FILE *, char *,
+ time_t, int, time_t, int,
+ time_t, int, int));
+static int time_command __P((COMMAND *, int, int, int, struct fd_bitmap *));
+#endif
+#if defined (ARITH_FOR_COMMAND)
+static intmax_t eval_arith_for_expr __P((WORD_LIST *, int *));
+static int execute_arith_for_command __P((ARITH_FOR_COM *));
+#endif
+static int execute_case_command __P((CASE_COM *));
+static int execute_while_command __P((WHILE_COM *));
+static int execute_until_command __P((WHILE_COM *));
+static int execute_while_or_until __P((WHILE_COM *, int));
+static int execute_if_command __P((IF_COM *));
+static int execute_null_command __P((REDIRECT *, int, int, int));
+static void fix_assignment_words __P((WORD_LIST *));
+static int execute_simple_command __P((SIMPLE_COM *, int, int, int, struct fd_bitmap *));
+static int execute_builtin __P((sh_builtin_func_t *, WORD_LIST *, int, int));
+static int execute_function __P((SHELL_VAR *, WORD_LIST *, int, struct fd_bitmap *, int, int));
+static int execute_builtin_or_function __P((WORD_LIST *, sh_builtin_func_t *,
+ SHELL_VAR *,
+ REDIRECT *, struct fd_bitmap *, int));
+static void execute_subshell_builtin_or_function __P((WORD_LIST *, REDIRECT *,
+ sh_builtin_func_t *,
+ SHELL_VAR *,
+ int, int, int,
+ struct fd_bitmap *,
+ int));
+static void execute_disk_command __P((WORD_LIST *, REDIRECT *, char *,
+ int, int, int, struct fd_bitmap *, int));
+
+static char *getinterp __P((char *, int, int *));
+static void initialize_subshell __P((void));
+static int execute_in_subshell __P((COMMAND *, int, int, int, struct fd_bitmap *));
+#if defined (COPROCESS_SUPPORT)
+static int execute_coproc __P((COMMAND *, int, int, struct fd_bitmap *));
+#endif
+
+static int execute_pipeline __P((COMMAND *, int, int, int, struct fd_bitmap *));
+
+static int execute_connection __P((COMMAND *, int, int, int, struct fd_bitmap *));
+
+static int execute_intern_function __P((WORD_DESC *, COMMAND *));
+
+/* Set to 1 if fd 0 was the subject of redirection to a subshell. Global
+ so that reader_loop can set it to zero before executing a command. */
+int stdin_redir;
+
+/* The name of the command that is currently being executed.
+ `test' needs this, for example. */
+char *this_command_name;
+
+/* The printed representation of the currently-executing command (same as
+ the_printed_command), except when a trap is being executed. Useful for
+ a debugger to know where exactly the program is currently executing. */
+char *the_printed_command_except_trap;
+
+/* For catching RETURN in a function. */
+int return_catch_flag;
+int return_catch_value;
+procenv_t return_catch;
+
+/* The value returned by the last synchronous command. */
+int last_command_exit_value;
+
+/* Whether or not the last command (corresponding to last_command_exit_value)
+ was terminated by a signal, and, if so, which one. */
+int last_command_exit_signal;
+
+/* The list of redirections to perform which will undo the redirections
+ that I made in the shell. */
+REDIRECT *redirection_undo_list = (REDIRECT *)NULL;
+
+/* The list of redirections to perform which will undo the internal
+ redirections performed by the `exec' builtin. These are redirections
+ that must be undone even when exec discards redirection_undo_list. */
+REDIRECT *exec_redirection_undo_list = (REDIRECT *)NULL;
+
+/* When greater than zero, value is the `level' of builtins we are
+ currently executing (e.g. `eval echo a' would have it set to 2). */
+int executing_builtin = 0;
+
+/* Non-zero if we are executing a command list (a;b;c, etc.) */
+int executing_list = 0;
+
+/* Non-zero if failing commands in a command substitution should not exit the
+ shell even if -e is set. Used to pass the CMD_IGNORE_RETURN flag down to
+ commands run in command substitutions by parse_and_execute. */
+int comsub_ignore_return = 0;
+
+/* Non-zero if we have just forked and are currently running in a subshell
+ environment. */
+int subshell_environment;
+
+/* Count of nested subshells, like SHLVL. Available via $BASH_SUBSHELL */
+int subshell_level = 0;
+
+/* Currently-executing shell function. */
+SHELL_VAR *this_shell_function;
+
+/* If non-zero, matches in case and [[ ... ]] are case-insensitive */
+int match_ignore_case = 0;
+
+struct stat SB; /* used for debugging */
+
+static int special_builtin_failed;
+
+static COMMAND *currently_executing_command;
+
+/* The line number that the currently executing function starts on. */
+static int function_line_number;
+
+/* XXX - set to 1 if we're running the DEBUG trap and we want to show the line
+ number containing the function name. Used by executing_line_number to
+ report the correct line number. Kind of a hack. */
+static int showing_function_line;
+
+static int line_number_for_err_trap;
+
+/* A sort of function nesting level counter */
+static int funcnest = 0;
+int funcnest_max = 0; /* XXX - for bash-4.2 */
+
+struct fd_bitmap *current_fds_to_close = (struct fd_bitmap *)NULL;
+
+#define FD_BITMAP_DEFAULT_SIZE 32
+
+/* Functions to allocate and deallocate the structures used to pass
+ information from the shell to its children about file descriptors
+ to close. */
+struct fd_bitmap *
+new_fd_bitmap (size)
+ int size;
+{
+ struct fd_bitmap *ret;
+
+ ret = (struct fd_bitmap *)xmalloc (sizeof (struct fd_bitmap));
+
+ ret->size = size;
+
+ if (size)
+ {
+ ret->bitmap = (char *)xmalloc (size);
+ memset (ret->bitmap, '\0', size);
+ }
+ else
+ ret->bitmap = (char *)NULL;
+ return (ret);
+}
+
+void
+dispose_fd_bitmap (fdbp)
+ struct fd_bitmap *fdbp;
+{
+ FREE (fdbp->bitmap);
+ free (fdbp);
+}
+
+void
+close_fd_bitmap (fdbp)
+ struct fd_bitmap *fdbp;
+{
+ register int i;
+
+ if (fdbp)
+ {
+ for (i = 0; i < fdbp->size; i++)
+ if (fdbp->bitmap[i])
+ {
+ close (i);
+ fdbp->bitmap[i] = 0;
+ }
+ }
+}
+
+/* Return the line number of the currently executing command. */
+int
+executing_line_number ()
+{
+ if (executing && showing_function_line == 0 &&
+ (variable_context == 0 || interactive_shell == 0) &&
+ currently_executing_command)
+ {
+#if defined (COND_COMMAND)
+ if (currently_executing_command->type == cm_cond)
+ return currently_executing_command->value.Cond->line;
+#endif
+#if defined (DPAREN_ARITHMETIC)
+ else if (currently_executing_command->type == cm_arith)
+ return currently_executing_command->value.Arith->line;
+#endif
+#if defined (ARITH_FOR_COMMAND)
+ else if (currently_executing_command->type == cm_arith_for)
+ return currently_executing_command->value.ArithFor->line;
+#endif
+
+ return line_number;
+ }
+ else
+ return line_number;
+}
+
+/* Execute the command passed in COMMAND. COMMAND is exactly what
+ read_command () places into GLOBAL_COMMAND. See "command.h" for the
+ details of the command structure.
+
+ EXECUTION_SUCCESS or EXECUTION_FAILURE are the only possible
+ return values. Executing a command with nothing in it returns
+ EXECUTION_SUCCESS. */
+int
+execute_command (command)
+ COMMAND *command;
+{
+ struct fd_bitmap *bitmap;
+ int result;
+
+ current_fds_to_close = (struct fd_bitmap *)NULL;
+ bitmap = new_fd_bitmap (FD_BITMAP_DEFAULT_SIZE);
+ begin_unwind_frame ("execute-command");
+ add_unwind_protect (dispose_fd_bitmap, (char *)bitmap);
+
+ /* Just do the command, but not asynchronously. */
+ result = execute_command_internal (command, 0, NO_PIPE, NO_PIPE, bitmap);
+
+ dispose_fd_bitmap (bitmap);
+ discard_unwind_frame ("execute-command");
+
+#if defined (PROCESS_SUBSTITUTION)
+ /* don't unlink fifos if we're in a shell function; wait until the function
+ returns. */
+ if (variable_context == 0)
+ unlink_fifo_list ();
+#endif /* PROCESS_SUBSTITUTION */
+
+ QUIT;
+ return (result);
+}
+
+/* Return 1 if TYPE is a shell control structure type. */
+static int
+shell_control_structure (type)
+ enum command_type type;
+{
+ switch (type)
+ {
+#if defined (ARITH_FOR_COMMAND)
+ case cm_arith_for:
+#endif
+#if defined (SELECT_COMMAND)
+ case cm_select:
+#endif
+#if defined (DPAREN_ARITHMETIC)
+ case cm_arith:
+#endif
+#if defined (COND_COMMAND)
+ case cm_cond:
+#endif
+ case cm_case:
+ case cm_while:
+ case cm_until:
+ case cm_if:
+ case cm_for:
+ case cm_group:
+ case cm_function_def:
+ return (1);
+
+ default:
+ return (0);
+ }
+}
+
+/* A function to use to unwind_protect the redirection undo list
+ for loops. */
+static void
+cleanup_redirects (list)
+ REDIRECT *list;
+{
+ do_redirections (list, RX_ACTIVE);
+ dispose_redirects (list);
+}
+
+#if 0
+/* Function to unwind_protect the redirections for functions and builtins. */
+static void
+cleanup_func_redirects (list)
+ REDIRECT *list;
+{
+ do_redirections (list, RX_ACTIVE);
+}
+#endif
+
+void
+dispose_exec_redirects ()
+{
+ if (exec_redirection_undo_list)
+ {
+ dispose_redirects (exec_redirection_undo_list);
+ exec_redirection_undo_list = (REDIRECT *)NULL;
+ }
+}
+
+#if defined (JOB_CONTROL)
+/* A function to restore the signal mask to its proper value when the shell
+ is interrupted or errors occur while creating a pipeline. */
+static int
+restore_signal_mask (set)
+ sigset_t *set;
+{
+ return (sigprocmask (SIG_SETMASK, set, (sigset_t *)NULL));
+}
+#endif /* JOB_CONTROL */
+
+#ifdef DEBUG
+/* A debugging function that can be called from gdb, for instance. */
+void
+open_files ()
+{
+ register int i;
+ int f, fd_table_size;
+
+ fd_table_size = getdtablesize ();
+
+ fprintf (stderr, "pid %ld open files:", (long)getpid ());
+ for (i = 3; i < fd_table_size; i++)
+ {
+ if ((f = fcntl (i, F_GETFD, 0)) != -1)
+ fprintf (stderr, " %d (%s)", i, f ? "close" : "open");
+ }
+ fprintf (stderr, "\n");
+}
+#endif
+
+static void
+async_redirect_stdin ()
+{
+ int fd;
+
+ fd = open ("/dev/null", O_RDONLY);
+ if (fd > 0)
+ {
+ dup2 (fd, 0);
+ close (fd);
+ }
+ else if (fd < 0)
+ internal_error (_("cannot redirect standard input from /dev/null: %s"), strerror (errno));
+}
+
+#define DESCRIBE_PID(pid) do { if (interactive) describe_pid (pid); } while (0)
+
+/* Execute the command passed in COMMAND, perhaps doing it asynchrounously.
+ COMMAND is exactly what read_command () places into GLOBAL_COMMAND.
+ ASYNCHROUNOUS, if non-zero, says to do this command in the background.
+ PIPE_IN and PIPE_OUT are file descriptors saying where input comes
+ from and where it goes. They can have the value of NO_PIPE, which means
+ I/O is stdin/stdout.
+ FDS_TO_CLOSE is a list of file descriptors to close once the child has
+ been forked. This list often contains the unusable sides of pipes, etc.
+
+ EXECUTION_SUCCESS or EXECUTION_FAILURE are the only possible
+ return values. Executing a command with nothing in it returns
+ EXECUTION_SUCCESS. */
+int
+execute_command_internal (command, asynchronous, pipe_in, pipe_out,
+ fds_to_close)
+ COMMAND *command;
+ int asynchronous;
+ int pipe_in, pipe_out;
+ struct fd_bitmap *fds_to_close;
+{
+ int exec_result, user_subshell, invert, ignore_return, was_error_trap;
+ REDIRECT *my_undo_list, *exec_undo_list;
+ volatile int last_pid;
+ volatile int save_line_number;
+
+#if 0
+ if (command == 0 || breaking || continuing || read_but_dont_execute)
+ return (EXECUTION_SUCCESS);
+#else
+ if (breaking || continuing)
+ return (last_command_exit_value);
+ if (command == 0 || read_but_dont_execute)
+ return (EXECUTION_SUCCESS);
+#endif
+
+ QUIT;
+ run_pending_traps ();
+
+#if 0
+ if (running_trap == 0)
+#endif
+ currently_executing_command = command;
+
+ invert = (command->flags & CMD_INVERT_RETURN) != 0;
+
+ /* If we're inverting the return value and `set -e' has been executed,
+ we don't want a failing command to inadvertently cause the shell
+ to exit. */
+ if (exit_immediately_on_error && invert) /* XXX */
+ command->flags |= CMD_IGNORE_RETURN; /* XXX */
+
+ exec_result = EXECUTION_SUCCESS;
+
+ /* If a command was being explicitly run in a subshell, or if it is
+ a shell control-structure, and it has a pipe, then we do the command
+ in a subshell. */
+ if (command->type == cm_subshell && (command->flags & CMD_NO_FORK))
+ return (execute_in_subshell (command, asynchronous, pipe_in, pipe_out, fds_to_close));
+
+#if defined (COPROCESS_SUPPORT)
+ if (command->type == cm_coproc)
+ return (execute_coproc (command, pipe_in, pipe_out, fds_to_close));
+#endif
+
+ user_subshell = command->type == cm_subshell || ((command->flags & CMD_WANT_SUBSHELL) != 0);
+
+ if (command->type == cm_subshell ||
+ (command->flags & (CMD_WANT_SUBSHELL|CMD_FORCE_SUBSHELL)) ||
+ (shell_control_structure (command->type) &&
+ (pipe_out != NO_PIPE || pipe_in != NO_PIPE || asynchronous)))
+ {
+ pid_t paren_pid;
+
+ /* Fork a subshell, turn off the subshell bit, turn off job
+ control and call execute_command () on the command again. */
+ line_number_for_err_trap = line_number;
+ paren_pid = make_child (savestring (make_command_string (command)),
+ asynchronous);
+ if (paren_pid == 0)
+ exit (execute_in_subshell (command, asynchronous, pipe_in, pipe_out, fds_to_close));
+ /* NOTREACHED */
+ else
+ {
+ close_pipes (pipe_in, pipe_out);
+
+#if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD)
+ unlink_fifo_list ();
+#endif
+ /* If we are part of a pipeline, and not the end of the pipeline,
+ then we should simply return and let the last command in the
+ pipe be waited for. If we are not in a pipeline, or are the
+ last command in the pipeline, then we wait for the subshell
+ and return its exit status as usual. */
+ if (pipe_out != NO_PIPE)
+ return (EXECUTION_SUCCESS);
+
+ stop_pipeline (asynchronous, (COMMAND *)NULL);
+
+ if (asynchronous == 0)
+ {
+ was_error_trap = signal_is_trapped (ERROR_TRAP) && signal_is_ignored (ERROR_TRAP) == 0;
+ invert = (command->flags & CMD_INVERT_RETURN) != 0;
+ ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0;
+
+ last_command_exit_value = wait_for (paren_pid);
+
+ /* If we have to, invert the return value. */
+ if (invert)
+ exec_result = ((last_command_exit_value == EXECUTION_SUCCESS)
+ ? EXECUTION_FAILURE
+ : EXECUTION_SUCCESS);
+ else
+ exec_result = last_command_exit_value;
+
+ if (user_subshell && was_error_trap && ignore_return == 0 && invert == 0 && exec_result != EXECUTION_SUCCESS)
+ {
+ last_command_exit_value = exec_result;
+ save_line_number = line_number;
+ line_number = line_number_for_err_trap;
+ run_error_trap ();
+ line_number = save_line_number;
+ }
+
+ if (user_subshell && ignore_return == 0 && invert == 0 && exit_immediately_on_error && exec_result != EXECUTION_SUCCESS)
+ {
+ last_command_exit_value = exec_result;
+ run_pending_traps ();
+ jump_to_top_level (ERREXIT);
+ }
+
+ return (last_command_exit_value = exec_result);
+ }
+ else
+ {
+ DESCRIBE_PID (paren_pid);
+
+ run_pending_traps ();
+
+ return (EXECUTION_SUCCESS);
+ }
+ }
+ }
+
+#if defined (COMMAND_TIMING)
+ if (command->flags & CMD_TIME_PIPELINE)
+ {
+ if (asynchronous)
+ {
+ command->flags |= CMD_FORCE_SUBSHELL;
+ exec_result = execute_command_internal (command, 1, pipe_in, pipe_out, fds_to_close);
+ }
+ else
+ {
+ exec_result = time_command (command, asynchronous, pipe_in, pipe_out, fds_to_close);
+#if 0
+ if (running_trap == 0)
+#endif
+ currently_executing_command = (COMMAND *)NULL;
+ }
+ return (exec_result);
+ }
+#endif /* COMMAND_TIMING */
+
+ if (shell_control_structure (command->type) && command->redirects)
+ stdin_redir = stdin_redirects (command->redirects);
+
+ /* Handle WHILE FOR CASE etc. with redirections. (Also '&' input
+ redirection.) */
+ if (do_redirections (command->redirects, RX_ACTIVE|RX_UNDOABLE) != 0)
+ {
+ cleanup_redirects (redirection_undo_list);
+ redirection_undo_list = (REDIRECT *)NULL;
+ dispose_exec_redirects ();
+ return (last_command_exit_value = EXECUTION_FAILURE);
+ }
+
+ if (redirection_undo_list)
+ {
+ my_undo_list = (REDIRECT *)copy_redirects (redirection_undo_list);
+ dispose_redirects (redirection_undo_list);
+ redirection_undo_list = (REDIRECT *)NULL;
+ }
+ else
+ my_undo_list = (REDIRECT *)NULL;
+
+ if (exec_redirection_undo_list)
+ {
+ exec_undo_list = (REDIRECT *)copy_redirects (exec_redirection_undo_list);
+ dispose_redirects (exec_redirection_undo_list);
+ exec_redirection_undo_list = (REDIRECT *)NULL;
+ }
+ else
+ exec_undo_list = (REDIRECT *)NULL;
+
+ if (my_undo_list || exec_undo_list)
+ begin_unwind_frame ("loop_redirections");
+
+ if (my_undo_list)
+ add_unwind_protect ((Function *)cleanup_redirects, my_undo_list);
+
+ if (exec_undo_list)
+ add_unwind_protect ((Function *)dispose_redirects, exec_undo_list);
+
+ ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0;
+
+ QUIT;
+
+ switch (command->type)
+ {
+ case cm_simple:
+ {
+ save_line_number = line_number;
+ /* We can't rely on variables retaining their values across a
+ call to execute_simple_command if a longjmp occurs as the
+ result of a `return' builtin. This is true for sure with gcc. */
+#if defined (RECYCLES_PIDS)
+ last_made_pid = NO_PID;
+#endif
+ last_pid = last_made_pid;
+ was_error_trap = signal_is_trapped (ERROR_TRAP) && signal_is_ignored (ERROR_TRAP) == 0;
+
+ if (ignore_return && command->value.Simple)
+ command->value.Simple->flags |= CMD_IGNORE_RETURN;
+ if (command->flags & CMD_STDIN_REDIR)
+ command->value.Simple->flags |= CMD_STDIN_REDIR;
+
+ line_number_for_err_trap = line_number = command->value.Simple->line;
+ exec_result =
+ execute_simple_command (command->value.Simple, pipe_in, pipe_out,
+ asynchronous, fds_to_close);
+ line_number = save_line_number;
+
+ /* The temporary environment should be used for only the simple
+ command immediately following its definition. */
+ dispose_used_env_vars ();
+
+#if (defined (ultrix) && defined (mips)) || defined (C_ALLOCA)
+ /* Reclaim memory allocated with alloca () on machines which
+ may be using the alloca emulation code. */
+ (void) alloca (0);
+#endif /* (ultrix && mips) || C_ALLOCA */
+
+ /* If we forked to do the command, then we must wait_for ()
+ the child. */
+
+ /* XXX - this is something to watch out for if there are problems
+ when the shell is compiled without job control. */
+ if (already_making_children && pipe_out == NO_PIPE &&
+ last_made_pid != last_pid)
+ {
+ stop_pipeline (asynchronous, (COMMAND *)NULL);
+
+ if (asynchronous)
+ {
+ DESCRIBE_PID (last_made_pid);
+ }
+ else
+#if !defined (JOB_CONTROL)
+ /* Do not wait for asynchronous processes started from
+ startup files. */
+ if (last_made_pid != last_asynchronous_pid)
+#endif
+ /* When executing a shell function that executes other
+ commands, this causes the last simple command in
+ the function to be waited for twice. This also causes
+ subshells forked to execute builtin commands (e.g., in
+ pipelines) to be waited for twice. */
+ exec_result = wait_for (last_made_pid);
+ }
+ }
+
+ /* 2009/02/13 -- pipeline failure is processed elsewhere. This handles
+ only the failure of a simple command. */
+ if (was_error_trap && ignore_return == 0 && invert == 0 && pipe_in == NO_PIPE && pipe_out == NO_PIPE && exec_result != EXECUTION_SUCCESS)
+ {
+ last_command_exit_value = exec_result;
+ line_number = line_number_for_err_trap;
+ run_error_trap ();
+ line_number = save_line_number;
+ }
+
+ if (ignore_return == 0 && invert == 0 &&
+ ((posixly_correct && interactive == 0 && special_builtin_failed) ||
+ (exit_immediately_on_error && pipe_in == NO_PIPE && pipe_out == NO_PIPE && exec_result != EXECUTION_SUCCESS)))
+ {
+ last_command_exit_value = exec_result;
+ run_pending_traps ();
+ jump_to_top_level (ERREXIT);
+ }
+
+ break;
+
+ case cm_for:
+ if (ignore_return)
+ command->value.For->flags |= CMD_IGNORE_RETURN;
+ exec_result = execute_for_command (command->value.For);
+ break;
+
+#if defined (ARITH_FOR_COMMAND)
+ case cm_arith_for:
+ if (ignore_return)
+ command->value.ArithFor->flags |= CMD_IGNORE_RETURN;
+ exec_result = execute_arith_for_command (command->value.ArithFor);
+ break;
+#endif
+
+#if defined (SELECT_COMMAND)
+ case cm_select:
+ if (ignore_return)
+ command->value.Select->flags |= CMD_IGNORE_RETURN;
+ exec_result = execute_select_command (command->value.Select);
+ break;
+#endif
+
+ case cm_case:
+ if (ignore_return)
+ command->value.Case->flags |= CMD_IGNORE_RETURN;
+ exec_result = execute_case_command (command->value.Case);
+ break;
+
+ case cm_while:
+ if (ignore_return)
+ command->value.While->flags |= CMD_IGNORE_RETURN;
+ exec_result = execute_while_command (command->value.While);
+ break;
+
+ case cm_until:
+ if (ignore_return)
+ command->value.While->flags |= CMD_IGNORE_RETURN;
+ exec_result = execute_until_command (command->value.While);
+ break;
+
+ case cm_if:
+ if (ignore_return)
+ command->value.If->flags |= CMD_IGNORE_RETURN;
+ exec_result = execute_if_command (command->value.If);
+ break;
+
+ case cm_group:
+
+ /* This code can be executed from either of two paths: an explicit
+ '{}' command, or via a function call. If we are executed via a
+ function call, we have already taken care of the function being
+ executed in the background (down there in execute_simple_command ()),
+ and this command should *not* be marked as asynchronous. If we
+ are executing a regular '{}' group command, and asynchronous == 1,
+ we must want to execute the whole command in the background, so we
+ need a subshell, and we want the stuff executed in that subshell
+ (this group command) to be executed in the foreground of that
+ subshell (i.e. there will not be *another* subshell forked).
+
+ What we do is to force a subshell if asynchronous, and then call
+ execute_command_internal again with asynchronous still set to 1,
+ but with the original group command, so the printed command will
+ look right.
+
+ The code above that handles forking off subshells will note that
+ both subshell and async are on, and turn off async in the child
+ after forking the subshell (but leave async set in the parent, so
+ the normal call to describe_pid is made). This turning off
+ async is *crucial*; if it is not done, this will fall into an
+ infinite loop of executions through this spot in subshell after
+ subshell until the process limit is exhausted. */
+
+ if (asynchronous)
+ {
+ command->flags |= CMD_FORCE_SUBSHELL;
+ exec_result =
+ execute_command_internal (command, 1, pipe_in, pipe_out,
+ fds_to_close);
+ }
+ else
+ {
+ if (ignore_return && command->value.Group->command)
+ command->value.Group->command->flags |= CMD_IGNORE_RETURN;
+ exec_result =
+ execute_command_internal (command->value.Group->command,
+ asynchronous, pipe_in, pipe_out,
+ fds_to_close);
+ }
+ break;
+
+ case cm_connection:
+ exec_result = execute_connection (command, asynchronous,
+ pipe_in, pipe_out, fds_to_close);
+ break;
+
+#if defined (DPAREN_ARITHMETIC)
+ case cm_arith:
+ was_error_trap = signal_is_trapped (ERROR_TRAP) && signal_is_ignored (ERROR_TRAP) == 0;
+ if (ignore_return)
+ command->value.Arith->flags |= CMD_IGNORE_RETURN;
+ line_number_for_err_trap = save_line_number = line_number;
+ exec_result = execute_arith_command (command->value.Arith);
+ line_number = save_line_number;
+
+ if (was_error_trap && ignore_return == 0 && invert == 0 && exec_result != EXECUTION_SUCCESS)
+ {
+ last_command_exit_value = exec_result;
+ save_line_number = line_number;
+ line_number = line_number_for_err_trap;
+ run_error_trap ();
+ line_number = save_line_number;
+ }
+
+ if (ignore_return == 0 && invert == 0 && exit_immediately_on_error && exec_result != EXECUTION_SUCCESS)
+ {
+ last_command_exit_value = exec_result;
+ run_pending_traps ();
+ jump_to_top_level (ERREXIT);
+ }
+
+ break;
+#endif
+
+#if defined (COND_COMMAND)
+ case cm_cond:
+ was_error_trap = signal_is_trapped (ERROR_TRAP) && signal_is_ignored (ERROR_TRAP) == 0;
+ if (ignore_return)
+ command->value.Cond->flags |= CMD_IGNORE_RETURN;
+
+ line_number_for_err_trap = save_line_number = line_number;
+ exec_result = execute_cond_command (command->value.Cond);
+ line_number = save_line_number;
+
+ if (was_error_trap && ignore_return == 0 && invert == 0 && exec_result != EXECUTION_SUCCESS)
+ {
+ last_command_exit_value = exec_result;
+ save_line_number = line_number;
+ line_number = line_number_for_err_trap;
+ run_error_trap ();
+ line_number = save_line_number;
+ }
+
+ if (ignore_return == 0 && invert == 0 && exit_immediately_on_error && exec_result != EXECUTION_SUCCESS)
+ {
+ last_command_exit_value = exec_result;
+ run_pending_traps ();
+ jump_to_top_level (ERREXIT);
+ }
+
+ break;
+#endif
+
+ case cm_function_def:
+ exec_result = execute_intern_function (command->value.Function_def->name,
+ command->value.Function_def->command);
+ break;
+
+ default:
+ command_error ("execute_command", CMDERR_BADTYPE, command->type, 0);
+ }
+
+ if (my_undo_list)
+ {
+ do_redirections (my_undo_list, RX_ACTIVE);
+ dispose_redirects (my_undo_list);
+ }
+
+ if (exec_undo_list)
+ dispose_redirects (exec_undo_list);
+
+ if (my_undo_list || exec_undo_list)
+ discard_unwind_frame ("loop_redirections");
+
+ /* Invert the return value if we have to */
+ if (invert)
+ exec_result = (exec_result == EXECUTION_SUCCESS)
+ ? EXECUTION_FAILURE
+ : EXECUTION_SUCCESS;
+
+#if defined (DPAREN_ARITHMETIC) || defined (COND_COMMAND)
+ /* This is where we set PIPESTATUS from the exit status of the appropriate
+ compound commands (the ones that look enough like simple commands to
+ cause confusion). We might be able to optimize by not doing this if
+ subshell_environment != 0. */
+ switch (command->type)
+ {
+# if defined (DPAREN_ARITHMETIC)
+ case cm_arith:
+# endif
+# if defined (COND_COMMAND)
+ case cm_cond:
+# endif
+ set_pipestatus_from_exit (exec_result);
+ break;
+ }
+#endif
+
+ last_command_exit_value = exec_result;
+ run_pending_traps ();
+#if 0
+ if (running_trap == 0)
+#endif
+ currently_executing_command = (COMMAND *)NULL;
+ return (last_command_exit_value);
+}
+
+#if defined (COMMAND_TIMING)
+
+#if defined (HAVE_GETRUSAGE) && defined (HAVE_GETTIMEOFDAY)
+extern struct timeval *difftimeval __P((struct timeval *, struct timeval *, struct timeval *));
+extern struct timeval *addtimeval __P((struct timeval *, struct timeval *, struct timeval *));
+extern int timeval_to_cpu __P((struct timeval *, struct timeval *, struct timeval *));
+#endif
+
+#define POSIX_TIMEFORMAT "real %2R\nuser %2U\nsys %2S"
+#define BASH_TIMEFORMAT "\nreal\t%3lR\nuser\t%3lU\nsys\t%3lS"
+
+static const int precs[] = { 0, 100, 10, 1 };
+
+/* Expand one `%'-prefixed escape sequence from a time format string. */
+static int
+mkfmt (buf, prec, lng, sec, sec_fraction)
+ char *buf;
+ int prec, lng;
+ time_t sec;
+ int sec_fraction;
+{
+ time_t min;
+ char abuf[INT_STRLEN_BOUND(time_t) + 1];
+ int ind, aind;
+
+ ind = 0;
+ abuf[sizeof(abuf) - 1] = '\0';
+
+ /* If LNG is non-zero, we want to decompose SEC into minutes and seconds. */
+ if (lng)
+ {
+ min = sec / 60;
+ sec %= 60;
+ aind = sizeof(abuf) - 2;
+ do
+ abuf[aind--] = (min % 10) + '0';
+ while (min /= 10);
+ aind++;
+ while (abuf[aind])
+ buf[ind++] = abuf[aind++];
+ buf[ind++] = 'm';
+ }
+
+ /* Now add the seconds. */
+ aind = sizeof (abuf) - 2;
+ do
+ abuf[aind--] = (sec % 10) + '0';
+ while (sec /= 10);
+ aind++;
+ while (abuf[aind])
+ buf[ind++] = abuf[aind++];
+
+ /* We want to add a decimal point and PREC places after it if PREC is
+ nonzero. PREC is not greater than 3. SEC_FRACTION is between 0
+ and 999. */
+ if (prec != 0)
+ {
+ buf[ind++] = '.';
+ for (aind = 1; aind <= prec; aind++)
+ {
+ buf[ind++] = (sec_fraction / precs[aind]) + '0';
+ sec_fraction %= precs[aind];
+ }
+ }
+
+ if (lng)
+ buf[ind++] = 's';
+ buf[ind] = '\0';
+
+ return (ind);
+}
+
+/* Interpret the format string FORMAT, interpolating the following escape
+ sequences:
+ %[prec][l][RUS]
+
+ where the optional `prec' is a precision, meaning the number of
+ characters after the decimal point, the optional `l' means to format
+ using minutes and seconds (MMmNN[.FF]s), like the `times' builtin',
+ and the last character is one of
+
+ R number of seconds of `real' time
+ U number of seconds of `user' time
+ S number of seconds of `system' time
+
+ An occurrence of `%%' in the format string is translated to a `%'. The
+ result is printed to FP, a pointer to a FILE. The other variables are
+ the seconds and thousandths of a second of real, user, and system time,
+ resectively. */
+static void
+print_formatted_time (fp, format, rs, rsf, us, usf, ss, ssf, cpu)
+ FILE *fp;
+ char *format;
+ time_t rs;
+ int rsf;
+ time_t us;
+ int usf;
+ time_t ss;
+ int ssf, cpu;
+{
+ int prec, lng, len;
+ char *str, *s, ts[INT_STRLEN_BOUND (time_t) + sizeof ("mSS.FFFF")];
+ time_t sum;
+ int sum_frac;
+ int sindex, ssize;
+
+ len = strlen (format);
+ ssize = (len + 64) - (len % 64);
+ str = (char *)xmalloc (ssize);
+ sindex = 0;
+
+ for (s = format; *s; s++)
+ {
+ if (*s != '%' || s[1] == '\0')
+ {
+ RESIZE_MALLOCED_BUFFER (str, sindex, 1, ssize, 64);
+ str[sindex++] = *s;
+ }
+ else if (s[1] == '%')
+ {
+ s++;
+ RESIZE_MALLOCED_BUFFER (str, sindex, 1, ssize, 64);
+ str[sindex++] = *s;
+ }
+ else if (s[1] == 'P')
+ {
+ s++;
+#if 0
+ /* clamp CPU usage at 100% */
+ if (cpu > 10000)
+ cpu = 10000;
+#endif
+ sum = cpu / 100;
+ sum_frac = (cpu % 100) * 10;
+ len = mkfmt (ts, 2, 0, sum, sum_frac);
+ RESIZE_MALLOCED_BUFFER (str, sindex, len, ssize, 64);
+ strcpy (str + sindex, ts);
+ sindex += len;
+ }
+ else
+ {
+ prec = 3; /* default is three places past the decimal point. */
+ lng = 0; /* default is to not use minutes or append `s' */
+ s++;
+ if (DIGIT (*s)) /* `precision' */
+ {
+ prec = *s++ - '0';
+ if (prec > 3) prec = 3;
+ }
+ if (*s == 'l') /* `length extender' */
+ {
+ lng = 1;
+ s++;
+ }
+ if (*s == 'R' || *s == 'E')
+ len = mkfmt (ts, prec, lng, rs, rsf);
+ else if (*s == 'U')
+ len = mkfmt (ts, prec, lng, us, usf);
+ else if (*s == 'S')
+ len = mkfmt (ts, prec, lng, ss, ssf);
+ else
+ {
+ internal_error (_("TIMEFORMAT: `%c': invalid format character"), *s);
+ free (str);
+ return;
+ }
+ RESIZE_MALLOCED_BUFFER (str, sindex, len, ssize, 64);
+ strcpy (str + sindex, ts);
+ sindex += len;
+ }
+ }
+
+ str[sindex] = '\0';
+ fprintf (fp, "%s\n", str);
+ fflush (fp);
+
+ free (str);
+}
+
+static int
+time_command (command, asynchronous, pipe_in, pipe_out, fds_to_close)
+ COMMAND *command;
+ int asynchronous, pipe_in, pipe_out;
+ struct fd_bitmap *fds_to_close;
+{
+ int rv, posix_time, old_flags;
+ time_t rs, us, ss;
+ int rsf, usf, ssf;
+ int cpu;
+ char *time_format;
+
+#if defined (HAVE_GETRUSAGE) && defined (HAVE_GETTIMEOFDAY)
+ struct timeval real, user, sys;
+ struct timeval before, after;
+# if defined (HAVE_STRUCT_TIMEZONE)
+ struct timezone dtz; /* posix doesn't define this */
+# endif
+ struct rusage selfb, selfa, kidsb, kidsa; /* a = after, b = before */
+#else
+# if defined (HAVE_TIMES)
+ clock_t tbefore, tafter, real, user, sys;
+ struct tms before, after;
+# endif
+#endif
+
+#if defined (HAVE_GETRUSAGE) && defined (HAVE_GETTIMEOFDAY)
+# if defined (HAVE_STRUCT_TIMEZONE)
+ gettimeofday (&before, &dtz);
+# else
+ gettimeofday (&before, (void *)NULL);
+# endif /* !HAVE_STRUCT_TIMEZONE */
+ getrusage (RUSAGE_SELF, &selfb);
+ getrusage (RUSAGE_CHILDREN, &kidsb);
+#else
+# if defined (HAVE_TIMES)
+ tbefore = times (&before);
+# endif
+#endif
+
+ posix_time = (command->flags & CMD_TIME_POSIX);
+
+ old_flags = command->flags;
+ command->flags &= ~(CMD_TIME_PIPELINE|CMD_TIME_POSIX);
+ rv = execute_command_internal (command, asynchronous, pipe_in, pipe_out, fds_to_close);
+ command->flags = old_flags;
+
+ rs = us = ss = 0;
+ rsf = usf = ssf = cpu = 0;
+
+#if defined (HAVE_GETRUSAGE) && defined (HAVE_GETTIMEOFDAY)
+# if defined (HAVE_STRUCT_TIMEZONE)
+ gettimeofday (&after, &dtz);
+# else
+ gettimeofday (&after, (void *)NULL);
+# endif /* !HAVE_STRUCT_TIMEZONE */
+ getrusage (RUSAGE_SELF, &selfa);
+ getrusage (RUSAGE_CHILDREN, &kidsa);
+
+ difftimeval (&real, &before, &after);
+ timeval_to_secs (&real, &rs, &rsf);
+
+ addtimeval (&user, difftimeval(&after, &selfb.ru_utime, &selfa.ru_utime),
+ difftimeval(&before, &kidsb.ru_utime, &kidsa.ru_utime));
+ timeval_to_secs (&user, &us, &usf);
+
+ addtimeval (&sys, difftimeval(&after, &selfb.ru_stime, &selfa.ru_stime),
+ difftimeval(&before, &kidsb.ru_stime, &kidsa.ru_stime));
+ timeval_to_secs (&sys, &ss, &ssf);
+
+ cpu = timeval_to_cpu (&real, &user, &sys);
+#else
+# if defined (HAVE_TIMES)
+ tafter = times (&after);
+
+ real = tafter - tbefore;
+ clock_t_to_secs (real, &rs, &rsf);
+
+ user = (after.tms_utime - before.tms_utime) + (after.tms_cutime - before.tms_cutime);
+ clock_t_to_secs (user, &us, &usf);
+
+ sys = (after.tms_stime - before.tms_stime) + (after.tms_cstime - before.tms_cstime);
+ clock_t_to_secs (sys, &ss, &ssf);
+
+ cpu = (real == 0) ? 0 : ((user + sys) * 10000) / real;
+
+# else
+ rs = us = ss = 0;
+ rsf = usf = ssf = cpu = 0;
+# endif
+#endif
+
+ if (posix_time)
+ time_format = POSIX_TIMEFORMAT;
+ else if ((time_format = get_string_value ("TIMEFORMAT")) == 0)
+ time_format = BASH_TIMEFORMAT;
+
+ if (time_format && *time_format)
+ print_formatted_time (stderr, time_format, rs, rsf, us, usf, ss, ssf, cpu);
+
+ return rv;
+}
+#endif /* COMMAND_TIMING */
+
+/* Execute a command that's supposed to be in a subshell. This must be
+ called after make_child and we must be running in the child process.
+ The caller will return or exit() immediately with the value this returns. */
+static int
+execute_in_subshell (command, asynchronous, pipe_in, pipe_out, fds_to_close)
+ COMMAND *command;
+ int asynchronous;
+ int pipe_in, pipe_out;
+ struct fd_bitmap *fds_to_close;
+{
+ int user_subshell, return_code, function_value, should_redir_stdin, invert;
+ int ois, user_coproc;
+ int result;
+ COMMAND *tcom;
+
+ USE_VAR(user_subshell);
+ USE_VAR(user_coproc);
+ USE_VAR(invert);
+ USE_VAR(tcom);
+ USE_VAR(asynchronous);
+
+ subshell_level++;
+ should_redir_stdin = (asynchronous && (command->flags & CMD_STDIN_REDIR) &&
+ pipe_in == NO_PIPE &&
+ stdin_redirects (command->redirects) == 0);
+
+ invert = (command->flags & CMD_INVERT_RETURN) != 0;
+ user_subshell = command->type == cm_subshell || ((command->flags & CMD_WANT_SUBSHELL) != 0);
+ user_coproc = command->type == cm_coproc;
+
+ command->flags &= ~(CMD_FORCE_SUBSHELL | CMD_WANT_SUBSHELL | CMD_INVERT_RETURN);
+
+ /* If a command is asynchronous in a subshell (like ( foo ) & or
+ the special case of an asynchronous GROUP command where the
+ the subshell bit is turned on down in case cm_group: below),
+ turn off `asynchronous', so that two subshells aren't spawned.
+ XXX - asynchronous used to be set to 0 in this block, but that
+ means that setup_async_signals was never run. Now it's set to
+ 0 after subshell_environment is set appropriately and setup_async_signals
+ is run.
+
+ This seems semantically correct to me. For example,
+ ( foo ) & seems to say ``do the command `foo' in a subshell
+ environment, but don't wait for that subshell to finish'',
+ and "{ foo ; bar ; } &" seems to me to be like functions or
+ builtins in the background, which executed in a subshell
+ environment. I just don't see the need to fork two subshells. */
+
+ /* Don't fork again, we are already in a subshell. A `doubly
+ async' shell is not interactive, however. */
+ if (asynchronous)
+ {
+#if defined (JOB_CONTROL)
+ /* If a construct like ( exec xxx yyy ) & is given while job
+ control is active, we want to prevent exec from putting the
+ subshell back into the original process group, carefully
+ undoing all the work we just did in make_child. */
+ original_pgrp = -1;
+#endif /* JOB_CONTROL */
+ ois = interactive_shell;
+ interactive_shell = 0;
+ /* This test is to prevent alias expansion by interactive shells that
+ run `(command) &' but to allow scripts that have enabled alias
+ expansion with `shopt -s expand_alias' to continue to expand
+ aliases. */
+ if (ois != interactive_shell)
+ expand_aliases = 0;
+ }
+
+ /* Subshells are neither login nor interactive. */
+ login_shell = interactive = 0;
+
+ if (user_subshell)
+ subshell_environment = SUBSHELL_PAREN;
+ else
+ {
+ subshell_environment = 0; /* XXX */
+ if (asynchronous)
+ subshell_environment |= SUBSHELL_ASYNC;
+ if (pipe_in != NO_PIPE || pipe_out != NO_PIPE)
+ subshell_environment |= SUBSHELL_PIPE;
+ if (user_coproc)
+ subshell_environment |= SUBSHELL_COPROC;
+ }
+
+ reset_terminating_signals (); /* in sig.c */
+ /* Cancel traps, in trap.c. */
+ restore_original_signals ();
+
+ /* Make sure restore_original_signals doesn't undo the work done by
+ make_child to ensure that asynchronous children are immune to SIGINT
+ and SIGQUIT. Turn off asynchronous to make sure more subshells are
+ not spawned. */
+ if (asynchronous)
+ {
+ setup_async_signals ();
+ asynchronous = 0;
+ }
+
+#if defined (JOB_CONTROL)
+ set_sigchld_handler ();
+#endif /* JOB_CONTROL */
+
+ set_sigint_handler ();
+
+#if defined (JOB_CONTROL)
+ /* Delete all traces that there were any jobs running. This is
+ only for subshells. */
+ without_job_control ();
+#endif /* JOB_CONTROL */
+
+ if (fds_to_close)
+ close_fd_bitmap (fds_to_close);
+
+ do_piping (pipe_in, pipe_out);
+
+#if defined (COPROCESS_SUPPORT)
+ coproc_closeall ();
+#endif
+
+ /* If this is a user subshell, set a flag if stdin was redirected.
+ This is used later to decide whether to redirect fd 0 to
+ /dev/null for async commands in the subshell. This adds more
+ sh compatibility, but I'm not sure it's the right thing to do. */
+ if (user_subshell)
+ {
+ stdin_redir = stdin_redirects (command->redirects);
+ restore_default_signal (0);
+ }
+
+ /* If this is an asynchronous command (command &), we want to
+ redirect the standard input from /dev/null in the absence of
+ any specific redirection involving stdin. */
+ if (should_redir_stdin && stdin_redir == 0)
+ async_redirect_stdin ();
+
+ /* Do redirections, then dispose of them before recursive call. */
+ if (command->redirects)
+ {
+ if (do_redirections (command->redirects, RX_ACTIVE) != 0)
+ exit (invert ? EXECUTION_SUCCESS : EXECUTION_FAILURE);
+
+ dispose_redirects (command->redirects);
+ command->redirects = (REDIRECT *)NULL;
+ }
+
+ if (command->type == cm_subshell)
+ tcom = command->value.Subshell->command;
+ else if (user_coproc)
+ tcom = command->value.Coproc->command;
+ else
+ tcom = command;
+
+ if (command->flags & CMD_TIME_PIPELINE)
+ tcom->flags |= CMD_TIME_PIPELINE;
+ if (command->flags & CMD_TIME_POSIX)
+ tcom->flags |= CMD_TIME_POSIX;
+
+ /* Make sure the subshell inherits any CMD_IGNORE_RETURN flag. */
+ if ((command->flags & CMD_IGNORE_RETURN) && tcom != command)
+ tcom->flags |= CMD_IGNORE_RETURN;
+
+ /* If this is a simple command, tell execute_disk_command that it
+ might be able to get away without forking and simply exec.
+ This means things like ( sleep 10 ) will only cause one fork.
+ If we're timing the command or inverting its return value, however,
+ we cannot do this optimization. */
+ if ((user_subshell || user_coproc) && (tcom->type == cm_simple || tcom->type == cm_subshell) &&
+ ((tcom->flags & CMD_TIME_PIPELINE) == 0) &&
+ ((tcom->flags & CMD_INVERT_RETURN) == 0))
+ {
+ tcom->flags |= CMD_NO_FORK;
+ if (tcom->type == cm_simple)
+ tcom->value.Simple->flags |= CMD_NO_FORK;
+ }
+
+ invert = (tcom->flags & CMD_INVERT_RETURN) != 0;
+ tcom->flags &= ~CMD_INVERT_RETURN;
+
+ result = setjmp (top_level);
+
+ /* If we're inside a function while executing this subshell, we
+ need to handle a possible `return'. */
+ function_value = 0;
+ if (return_catch_flag)
+ function_value = setjmp (return_catch);
+
+ /* If we're going to exit the shell, we don't want to invert the return
+ status. */
+ if (result == EXITPROG)
+ invert = 0, return_code = last_command_exit_value;
+ else if (result)
+ return_code = EXECUTION_FAILURE;
+ else if (function_value)
+ return_code = return_catch_value;
+ else
+ return_code = execute_command_internal (tcom, asynchronous, NO_PIPE, NO_PIPE, fds_to_close);
+
+ /* If we are asked to, invert the return value. */
+ if (invert)
+ return_code = (return_code == EXECUTION_SUCCESS) ? EXECUTION_FAILURE
+ : EXECUTION_SUCCESS;
+
+ /* If we were explicitly placed in a subshell with (), we need
+ to do the `shell cleanup' things, such as running traps[0]. */
+ if (user_subshell && signal_is_trapped (0))
+ {
+ last_command_exit_value = return_code;
+ return_code = run_exit_trap ();
+ }
+
+ subshell_level--;
+ return (return_code);
+ /* NOTREACHED */
+}
+
+#if defined (COPROCESS_SUPPORT)
+#define COPROC_MAX 16
+
+typedef struct cpelement
+ {
+ struct cpelement *next;
+ struct coproc *coproc;
+ }
+cpelement_t;
+
+typedef struct cplist
+ {
+ struct cpelement *head;
+ struct cpelement *tail;
+ int ncoproc;
+ }
+cplist_t;
+
+static struct cpelement *cpe_alloc __P((struct coproc *));
+static void cpe_dispose __P((struct cpelement *));
+static struct cpelement *cpl_add __P((struct coproc *));
+static struct cpelement *cpl_delete __P((pid_t));
+static void cpl_reap __P((void));
+static void cpl_flush __P((void));
+static struct cpelement *cpl_search __P((pid_t));
+static struct cpelement *cpl_searchbyname __P((char *));
+static void cpl_prune __P((void));
+
+Coproc sh_coproc = { 0, NO_PID, -1, -1, 0, 0 };
+
+cplist_t coproc_list = {0, 0, 0};
+
+/* Functions to manage the list of coprocs */
+
+static struct cpelement *
+cpe_alloc (cp)
+ Coproc *cp;
+{
+ struct cpelement *cpe;
+
+ cpe = (struct cpelement *)xmalloc (sizeof (struct cpelement));
+ cpe->coproc = cp;
+ cpe->next = (struct cpelement *)0;
+ return cpe;
+}
+
+static void
+cpe_dispose (cpe)
+ struct cpelement *cpe;
+{
+ free (cpe);
+}
+
+static struct cpelement *
+cpl_add (cp)
+ Coproc *cp;
+{
+ struct cpelement *cpe;
+
+ cpe = cpe_alloc (cp);
+
+ if (coproc_list.head == 0)
+ {
+ coproc_list.head = coproc_list.tail = cpe;
+ coproc_list.ncoproc = 0; /* just to make sure */
+ }
+ else
+ {
+ coproc_list.tail->next = cpe;
+ coproc_list.tail = cpe;
+ }
+ coproc_list.ncoproc++;
+
+ return cpe;
+}
+
+static struct cpelement *
+cpl_delete (pid)
+ pid_t pid;
+{
+ struct cpelement *prev, *p;
+
+ for (prev = p = coproc_list.head; p; prev = p, p = p->next)
+ if (p->coproc->c_pid == pid)
+ {
+ prev->next = p->next; /* remove from list */
+ break;
+ }
+
+ if (p == 0)
+ return 0; /* not found */
+
+#if defined (DEBUG)
+ itrace("cpl_delete: deleting %d", pid);
+#endif
+
+ /* Housekeeping in the border cases. */
+ if (p == coproc_list.head)
+ coproc_list.head = coproc_list.head->next;
+ else if (p == coproc_list.tail)
+ coproc_list.tail = prev;
+
+ coproc_list.ncoproc--;
+ if (coproc_list.ncoproc == 0)
+ coproc_list.head = coproc_list.tail = 0;
+ else if (coproc_list.ncoproc == 1)
+ coproc_list.tail = coproc_list.head; /* just to make sure */
+
+ return (p);
+}
+
+static void
+cpl_reap ()
+{
+ struct cpelement *prev, *p;
+
+ for (prev = p = coproc_list.head; p; prev = p, p = p->next)
+ if (p->coproc->c_flags & COPROC_DEAD)
+ {
+ prev->next = p->next; /* remove from list */
+
+ /* Housekeeping in the border cases. */
+ if (p == coproc_list.head)
+ coproc_list.head = coproc_list.head->next;
+ else if (p == coproc_list.tail)
+ coproc_list.tail = prev;
+
+ coproc_list.ncoproc--;
+ if (coproc_list.ncoproc == 0)
+ coproc_list.head = coproc_list.tail = 0;
+ else if (coproc_list.ncoproc == 1)
+ coproc_list.tail = coproc_list.head; /* just to make sure */
+
+#if defined (DEBUG)
+ itrace("cpl_reap: deleting %d", p->coproc->c_pid);
+#endif
+
+ coproc_dispose (p->coproc);
+ cpe_dispose (p);
+ }
+}
+
+/* Clear out the list of saved statuses */
+static void
+cpl_flush ()
+{
+ struct cpelement *cpe, *p;
+
+ for (cpe = coproc_list.head; cpe; )
+ {
+ p = cpe;
+ cpe = cpe->next;
+
+ coproc_dispose (p->coproc);
+ cpe_dispose (p);
+ }
+
+ coproc_list.head = coproc_list.tail = 0;
+ coproc_list.ncoproc = 0;
+}
+
+/* Search for PID in the list of coprocs; return the cpelement struct if
+ found. If not found, return NULL. */
+static struct cpelement *
+cpl_search (pid)
+ pid_t pid;
+{
+ struct cpelement *cp;
+
+ for (cp = coproc_list.head ; cp; cp = cp->next)
+ if (cp->coproc->c_pid == pid)
+ return cp;
+ return (struct cpelement *)NULL;
+}
+
+/* Search for the coproc named NAME in the list of coprocs; return the
+ cpelement struct if found. If not found, return NULL. */
+static struct cpelement *
+cpl_searchbyname (name)
+ char *name;
+{
+ struct cpelement *cp;
+
+ for (cp = coproc_list.head ; cp; cp = cp->next)
+ if (STREQ (cp->coproc->c_name, name))
+ return cp;
+ return (struct cpelement *)NULL;
+}
+
+#if 0
+static void
+cpl_prune ()
+{
+ struct cpelement *cp;
+
+ while (coproc_list.head && coproc_list.ncoproc > COPROC_MAX)
+ {
+ cp = coproc_list.head;
+ coproc_list.head = coproc_list.head->next;
+ coproc_dispose (cp->coproc);
+ cpe_dispose (cp);
+ coproc_list.ncoproc--;
+ }
+}
+#endif
+
+/* These currently use a single global "shell coproc" but are written in a
+ way to not preclude additional coprocs later (using the list management
+ package above). */
+
+struct coproc *
+getcoprocbypid (pid)
+ pid_t pid;
+{
+ return (pid == sh_coproc.c_pid ? &sh_coproc : 0);
+}
+
+struct coproc *
+getcoprocbyname (name)
+ const char *name;
+{
+ return ((sh_coproc.c_name && STREQ (sh_coproc.c_name, name)) ? &sh_coproc : 0);
+}
+
+void
+coproc_init (cp)
+ struct coproc *cp;
+{
+ cp->c_name = 0;
+ cp->c_pid = NO_PID;
+ cp->c_rfd = cp->c_wfd = -1;
+ cp->c_rsave = cp->c_wsave = -1;
+ cp->c_flags = cp->c_status = 0;
+}
+
+struct coproc *
+coproc_alloc (name, pid)
+ char *name;
+ pid_t pid;
+{
+ struct coproc *cp;
+
+ cp = &sh_coproc; /* XXX */
+ coproc_init (cp);
+
+ cp->c_name = savestring (name);
+ cp->c_pid = pid;
+
+ return (cp);
+}
+
+void
+coproc_dispose (cp)
+ struct coproc *cp;
+{
+ if (cp == 0)
+ return;
+
+ coproc_unsetvars (cp);
+ FREE (cp->c_name);
+ coproc_close (cp);
+ coproc_init (cp);
+}
+
+/* Placeholder for now. */
+void
+coproc_flush ()
+{
+ coproc_dispose (&sh_coproc);
+}
+
+void
+coproc_close (cp)
+ struct coproc *cp;
+{
+ if (cp->c_rfd >= 0)
+ {
+ close (cp->c_rfd);
+ cp->c_rfd = -1;
+ }
+ if (cp->c_wfd >= 0)
+ {
+ close (cp->c_wfd);
+ cp->c_wfd = -1;
+ }
+ cp->c_rsave = cp->c_wsave = -1;
+}
+
+void
+coproc_closeall ()
+{
+ coproc_close (&sh_coproc);
+}
+
+void
+coproc_reap ()
+{
+ struct coproc *cp;
+
+ cp = &sh_coproc;
+ if (cp && (cp->c_flags & COPROC_DEAD))
+ coproc_dispose (cp);
+}
+
+void
+coproc_rclose (cp, fd)
+ struct coproc *cp;
+ int fd;
+{
+ if (cp->c_rfd >= 0 && cp->c_rfd == fd)
+ {
+ close (cp->c_rfd);
+ cp->c_rfd = -1;
+ }
+}
+
+void
+coproc_wclose (cp, fd)
+ struct coproc *cp;
+ int fd;
+{
+ if (cp->c_wfd >= 0 && cp->c_wfd == fd)
+ {
+ close (cp->c_wfd);
+ cp->c_wfd = -1;
+ }
+}
+
+void
+coproc_checkfd (cp, fd)
+ struct coproc *cp;
+ int fd;
+{
+ int update;
+
+ update = 0;
+ if (cp->c_rfd >= 0 && cp->c_rfd == fd)
+ update = cp->c_rfd = -1;
+ if (cp->c_wfd >= 0 && cp->c_wfd == fd)
+ update = cp->c_wfd = -1;
+ if (update)
+ coproc_setvars (cp);
+}
+
+void
+coproc_fdchk (fd)
+ int fd;
+{
+ coproc_checkfd (&sh_coproc, fd);
+}
+
+void
+coproc_fdclose (cp, fd)
+ struct coproc *cp;
+ int fd;
+{
+ coproc_rclose (cp, fd);
+ coproc_wclose (cp, fd);
+ coproc_setvars (cp);
+}
+
+void
+coproc_fdsave (cp)
+ struct coproc *cp;
+{
+ cp->c_rsave = cp->c_rfd;
+ cp->c_wsave = cp->c_wfd;
+}
+
+void
+coproc_fdrestore (cp)
+ struct coproc *cp;
+{
+ cp->c_rfd = cp->c_rsave;
+ cp->c_wfd = cp->c_wsave;
+}
+
+void
+coproc_pidchk (pid, status)
+ pid_t pid;
+{
+ struct coproc *cp;
+
+ cp = getcoprocbypid (pid);
+#if 0
+ if (cp)
+ itrace("coproc_pidchk: pid %d has died", pid);
+#endif
+ if (cp)
+ {
+ cp->c_status = status;
+ cp->c_flags |= COPROC_DEAD;
+ cp->c_flags &= ~COPROC_RUNNING;
+#if 0
+ coproc_dispose (cp);
+#endif
+ }
+}
+
+void
+coproc_setvars (cp)
+ struct coproc *cp;
+{
+ SHELL_VAR *v;
+ char *namevar, *t;
+ int l;
+#if defined (ARRAY_VARS)
+ arrayind_t ind;
+#endif
+
+ if (cp->c_name == 0)
+ return;
+
+ l = strlen (cp->c_name);
+ namevar = xmalloc (l + 16);
+
+#if defined (ARRAY_VARS)
+ v = find_variable (cp->c_name);
+ if (v == 0)
+ v = make_new_array_variable (cp->c_name);
+ if (array_p (v) == 0)
+ v = convert_var_to_array (v);
+
+ t = itos (cp->c_rfd);
+ ind = 0;
+ v = bind_array_variable (cp->c_name, ind, t, 0);
+ free (t);
+
+ t = itos (cp->c_wfd);
+ ind = 1;
+ bind_array_variable (cp->c_name, ind, t, 0);
+ free (t);
+#else
+ sprintf (namevar, "%s_READ", cp->c_name);
+ t = itos (cp->c_rfd);
+ bind_variable (namevar, t, 0);
+ free (t);
+ sprintf (namevar, "%s_WRITE", cp->c_name);
+ t = itos (cp->c_wfd);
+ bind_variable (namevar, t, 0);
+ free (t);
+#endif
+
+ sprintf (namevar, "%s_PID", cp->c_name);
+ t = itos (cp->c_pid);
+ bind_variable (namevar, t, 0);
+ free (t);
+
+ free (namevar);
+}
+
+void
+coproc_unsetvars (cp)
+ struct coproc *cp;
+{
+ int l;
+ char *namevar;
+
+ if (cp->c_name == 0)
+ return;
+
+ l = strlen (cp->c_name);
+ namevar = xmalloc (l + 16);
+
+ sprintf (namevar, "%s_PID", cp->c_name);
+ unbind_variable (namevar);
+
+#if defined (ARRAY_VARS)
+ unbind_variable (cp->c_name);
+#else
+ sprintf (namevar, "%s_READ", cp->c_name);
+ unbind_variable (namevar);
+ sprintf (namevar, "%s_WRITE", cp->c_name);
+ unbind_variable (namevar);
+#endif
+
+ free (namevar);
+}
+
+static int
+execute_coproc (command, pipe_in, pipe_out, fds_to_close)
+ COMMAND *command;
+ int pipe_in, pipe_out;
+ struct fd_bitmap *fds_to_close;
+{
+ int rpipe[2], wpipe[2], estat;
+ pid_t coproc_pid;
+ Coproc *cp;
+ char *tcmd;
+
+ /* XXX -- will require changes to handle multiple coprocs */
+ if (sh_coproc.c_pid != NO_PID)
+ {
+#if 0
+ internal_error ("execute_coproc: coproc [%d:%s] already exists", sh_coproc.c_pid, sh_coproc.c_name);
+ return (last_command_exit_value = EXECUTION_FAILURE);
+#else
+ internal_warning ("execute_coproc: coproc [%d:%s] still exists", sh_coproc.c_pid, sh_coproc.c_name);
+#endif
+ }
+ coproc_init (&sh_coproc);
+
+ command_string_index = 0;
+ tcmd = make_command_string (command);
+
+ sh_openpipe ((int *)&rpipe); /* 0 = parent read, 1 = child write */
+ sh_openpipe ((int *)&wpipe); /* 0 = child read, 1 = parent write */
+
+ coproc_pid = make_child (savestring (tcmd), 1);
+ if (coproc_pid == 0)
+ {
+ close (rpipe[0]);
+ close (wpipe[1]);
+
+ estat = execute_in_subshell (command, 1, wpipe[0], rpipe[1], fds_to_close);
+
+ fflush (stdout);
+ fflush (stderr);
+
+ exit (estat);
+ }
+
+ close (rpipe[1]);
+ close (wpipe[0]);
+
+ cp = coproc_alloc (command->value.Coproc->name, coproc_pid);
+ cp->c_rfd = rpipe[0];
+ cp->c_wfd = wpipe[1];
+
+ SET_CLOSE_ON_EXEC (cp->c_rfd);
+ SET_CLOSE_ON_EXEC (cp->c_wfd);
+
+ coproc_setvars (cp);
+
+#if 0
+ itrace ("execute_coproc: [%d] %s", coproc_pid, the_printed_command);
+#endif
+
+ close_pipes (pipe_in, pipe_out);
+#if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD)
+ unlink_fifo_list ();
+#endif
+ stop_pipeline (1, (COMMAND *)NULL);
+ DESCRIBE_PID (coproc_pid);
+ run_pending_traps ();
+
+ return (EXECUTION_SUCCESS);
+}
+#endif
+
+static int
+execute_pipeline (command, asynchronous, pipe_in, pipe_out, fds_to_close)
+ COMMAND *command;
+ int asynchronous, pipe_in, pipe_out;
+ struct fd_bitmap *fds_to_close;
+{
+ int prev, fildes[2], new_bitmap_size, dummyfd, ignore_return, exec_result;
+ COMMAND *cmd;
+ struct fd_bitmap *fd_bitmap;
+
+#if defined (JOB_CONTROL)
+ sigset_t set, oset;
+ BLOCK_CHILD (set, oset);
+#endif /* JOB_CONTROL */
+
+ ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0;
+
+ prev = pipe_in;
+ cmd = command;
+
+ while (cmd && cmd->type == cm_connection &&
+ cmd->value.Connection && cmd->value.Connection->connector == '|')
+ {
+ /* Make a pipeline between the two commands. */
+ if (pipe (fildes) < 0)
+ {
+ sys_error (_("pipe error"));
+#if defined (JOB_CONTROL)
+ terminate_current_pipeline ();
+ kill_current_pipeline ();
+ UNBLOCK_CHILD (oset);
+#endif /* JOB_CONTROL */
+ last_command_exit_value = EXECUTION_FAILURE;
+ /* The unwind-protects installed below will take care
+ of closing all of the open file descriptors. */
+ throw_to_top_level ();
+ return (EXECUTION_FAILURE); /* XXX */
+ }
+
+ /* Here is a problem: with the new file close-on-exec
+ code, the read end of the pipe (fildes[0]) stays open
+ in the first process, so that process will never get a
+ SIGPIPE. There is no way to signal the first process
+ that it should close fildes[0] after forking, so it
+ remains open. No SIGPIPE is ever sent because there
+ is still a file descriptor open for reading connected
+ to the pipe. We take care of that here. This passes
+ around a bitmap of file descriptors that must be
+ closed after making a child process in execute_simple_command. */
+
+ /* We need fd_bitmap to be at least as big as fildes[0].
+ If fildes[0] is less than fds_to_close->size, then
+ use fds_to_close->size. */
+ new_bitmap_size = (fildes[0] < fds_to_close->size)
+ ? fds_to_close->size
+ : fildes[0] + 8;
+
+ fd_bitmap = new_fd_bitmap (new_bitmap_size);
+
+ /* Now copy the old information into the new bitmap. */
+ xbcopy ((char *)fds_to_close->bitmap, (char *)fd_bitmap->bitmap, fds_to_close->size);
+
+ /* And mark the pipe file descriptors to be closed. */
+ fd_bitmap->bitmap[fildes[0]] = 1;
+
+ /* In case there are pipe or out-of-processes errors, we
+ want all these file descriptors to be closed when
+ unwind-protects are run, and the storage used for the
+ bitmaps freed up. */
+ begin_unwind_frame ("pipe-file-descriptors");
+ add_unwind_protect (dispose_fd_bitmap, fd_bitmap);
+ add_unwind_protect (close_fd_bitmap, fd_bitmap);
+ if (prev >= 0)
+ add_unwind_protect (close, prev);
+ dummyfd = fildes[1];
+ add_unwind_protect (close, dummyfd);
+
+#if defined (JOB_CONTROL)
+ add_unwind_protect (restore_signal_mask, &oset);
+#endif /* JOB_CONTROL */
+
+ if (ignore_return && cmd->value.Connection->first)
+ cmd->value.Connection->first->flags |= CMD_IGNORE_RETURN;
+ execute_command_internal (cmd->value.Connection->first, asynchronous,
+ prev, fildes[1], fd_bitmap);
+
+ if (prev >= 0)
+ close (prev);
+
+ prev = fildes[0];
+ close (fildes[1]);
+
+ dispose_fd_bitmap (fd_bitmap);
+ discard_unwind_frame ("pipe-file-descriptors");
+
+ cmd = cmd->value.Connection->second;
+ }
+
+ /* Now execute the rightmost command in the pipeline. */
+ if (ignore_return && cmd)
+ cmd->flags |= CMD_IGNORE_RETURN;
+ exec_result = execute_command_internal (cmd, asynchronous, prev, pipe_out, fds_to_close);
+
+ if (prev >= 0)
+ close (prev);
+
+#if defined (JOB_CONTROL)
+ UNBLOCK_CHILD (oset);
+#endif
+
+ QUIT;
+ return (exec_result);
+}
+
+static int
+execute_connection (command, asynchronous, pipe_in, pipe_out, fds_to_close)
+ COMMAND *command;
+ int asynchronous, pipe_in, pipe_out;
+ struct fd_bitmap *fds_to_close;
+{
+ COMMAND *tc, *second;
+ int ignore_return, exec_result, was_error_trap, invert;
+ volatile int save_line_number;
+
+ ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0;
+
+ switch (command->value.Connection->connector)
+ {
+ /* Do the first command asynchronously. */
+ case '&':
+ tc = command->value.Connection->first;
+ if (tc == 0)
+ return (EXECUTION_SUCCESS);
+
+ if (ignore_return)
+ tc->flags |= CMD_IGNORE_RETURN;
+ tc->flags |= CMD_AMPERSAND;
+
+ /* If this shell was compiled without job control support,
+ if we are currently in a subshell via `( xxx )', or if job
+ control is not active then the standard input for an
+ asynchronous command is forced to /dev/null. */
+#if defined (JOB_CONTROL)
+ if ((subshell_environment || !job_control) && !stdin_redir)
+#else
+ if (!stdin_redir)
+#endif /* JOB_CONTROL */
+ tc->flags |= CMD_STDIN_REDIR;
+
+ exec_result = execute_command_internal (tc, 1, pipe_in, pipe_out, fds_to_close);
+ QUIT;
+
+ if (tc->flags & CMD_STDIN_REDIR)
+ tc->flags &= ~CMD_STDIN_REDIR;
+
+ second = command->value.Connection->second;
+ if (second)
+ {
+ if (ignore_return)
+ second->flags |= CMD_IGNORE_RETURN;
+
+ exec_result = execute_command_internal (second, asynchronous, pipe_in, pipe_out, fds_to_close);
+ }
+
+ break;
+
+ /* Just call execute command on both sides. */
+ case ';':
+ if (ignore_return)
+ {
+ if (command->value.Connection->first)
+ command->value.Connection->first->flags |= CMD_IGNORE_RETURN;
+ if (command->value.Connection->second)
+ command->value.Connection->second->flags |= CMD_IGNORE_RETURN;
+ }
+ executing_list++;
+ QUIT;
+ execute_command (command->value.Connection->first);
+ QUIT;
+ exec_result = execute_command_internal (command->value.Connection->second,
+ asynchronous, pipe_in, pipe_out,
+ fds_to_close);
+ executing_list--;
+ break;
+
+ case '|':
+ was_error_trap = signal_is_trapped (ERROR_TRAP) && signal_is_ignored (ERROR_TRAP) == 0;
+ invert = (command->flags & CMD_INVERT_RETURN) != 0;
+ ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0;
+
+ line_number_for_err_trap = line_number;
+ exec_result = execute_pipeline (command, asynchronous, pipe_in, pipe_out, fds_to_close);
+
+ if (was_error_trap && ignore_return == 0 && invert == 0 && exec_result != EXECUTION_SUCCESS)
+ {
+ last_command_exit_value = exec_result;
+ save_line_number = line_number;
+ line_number = line_number_for_err_trap;
+ run_error_trap ();
+ line_number = save_line_number;
+ }
+
+ if (ignore_return == 0 && invert == 0 && exit_immediately_on_error && exec_result != EXECUTION_SUCCESS)
+ {
+ last_command_exit_value = exec_result;
+ run_pending_traps ();
+ jump_to_top_level (ERREXIT);
+ }
+
+ break;
+
+ case AND_AND:
+ case OR_OR:
+ if (asynchronous)
+ {
+ /* If we have something like `a && b &' or `a || b &', run the
+ && or || stuff in a subshell. Force a subshell and just call
+ execute_command_internal again. Leave asynchronous on
+ so that we get a report from the parent shell about the
+ background job. */
+ command->flags |= CMD_FORCE_SUBSHELL;
+ exec_result = execute_command_internal (command, 1, pipe_in, pipe_out, fds_to_close);
+ break;
+ }
+
+ /* Execute the first command. If the result of that is successful
+ and the connector is AND_AND, or the result is not successful
+ and the connector is OR_OR, then execute the second command,
+ otherwise return. */
+
+ executing_list++;
+ if (command->value.Connection->first)
+ command->value.Connection->first->flags |= CMD_IGNORE_RETURN;
+
+ exec_result = execute_command (command->value.Connection->first);
+ QUIT;
+ if (((command->value.Connection->connector == AND_AND) &&
+ (exec_result == EXECUTION_SUCCESS)) ||
+ ((command->value.Connection->connector == OR_OR) &&
+ (exec_result != EXECUTION_SUCCESS)))
+ {
+ if (ignore_return && command->value.Connection->second)
+ command->value.Connection->second->flags |= CMD_IGNORE_RETURN;
+
+ exec_result = execute_command (command->value.Connection->second);
+ }
+ executing_list--;
+ break;
+
+ default:
+ command_error ("execute_connection", CMDERR_BADCONN, command->value.Connection->connector, 0);
+ jump_to_top_level (DISCARD);
+ exec_result = EXECUTION_FAILURE;
+ }
+
+ return exec_result;
+}
+
+#define REAP() \
+ do \
+ { \
+ if (!interactive_shell) \
+ reap_dead_jobs (); \
+ } \
+ while (0)
+
+/* Execute a FOR command. The syntax is: FOR word_desc IN word_list;
+ DO command; DONE */
+static int
+execute_for_command (for_command)
+ FOR_COM *for_command;
+{
+ register WORD_LIST *releaser, *list;
+ SHELL_VAR *v;
+ char *identifier;
+ int retval, save_line_number;
+#if 0
+ SHELL_VAR *old_value = (SHELL_VAR *)NULL; /* Remember the old value of x. */
+#endif
+
+ save_line_number = line_number;
+ if (check_identifier (for_command->name, 1) == 0)
+ {
+ if (posixly_correct && interactive_shell == 0)
+ {
+ last_command_exit_value = EX_BADUSAGE;
+ jump_to_top_level (ERREXIT);
+ }
+ return (EXECUTION_FAILURE);
+ }
+
+ loop_level++;
+ identifier = for_command->name->word;
+
+ list = releaser = expand_words_no_vars (for_command->map_list);
+
+ begin_unwind_frame ("for");
+ add_unwind_protect (dispose_words, releaser);
+
+#if 0
+ if (lexical_scoping)
+ {
+ old_value = copy_variable (find_variable (identifier));
+ if (old_value)
+ add_unwind_protect (dispose_variable, old_value);
+ }
+#endif
+
+ if (for_command->flags & CMD_IGNORE_RETURN)
+ for_command->action->flags |= CMD_IGNORE_RETURN;
+
+ for (retval = EXECUTION_SUCCESS; list; list = list->next)
+ {
+ QUIT;
+
+ line_number = for_command->line;
+
+ /* Remember what this command looks like, for debugger. */
+ command_string_index = 0;
+ print_for_command_head (for_command);
+
+ if (echo_command_at_execute)
+ xtrace_print_for_command_head (for_command);
+
+ /* Save this command unless it's a trap command and we're not running
+ a debug trap. */
+#if 0
+ if (signal_in_progress (DEBUG_TRAP) == 0 && (this_command_name == 0 || (STREQ (this_command_name, "trap") == 0)))
+#else
+ if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0)
+#endif
+ {
+ FREE (the_printed_command_except_trap);
+ the_printed_command_except_trap = savestring (the_printed_command);
+ }
+
+ retval = run_debug_trap ();
+#if defined (DEBUGGER)
+ /* In debugging mode, if the DEBUG trap returns a non-zero status, we
+ skip the command. */
+ if (debugging_mode && retval != EXECUTION_SUCCESS)
+ continue;
+#endif
+
+ this_command_name = (char *)NULL;
+ v = bind_variable (identifier, list->word->word, 0);
+ if (readonly_p (v) || noassign_p (v))
+ {
+ line_number = save_line_number;
+ if (readonly_p (v) && interactive_shell == 0 && posixly_correct)
+ {
+ last_command_exit_value = EXECUTION_FAILURE;
+ jump_to_top_level (FORCE_EOF);
+ }
+ else
+ {
+ dispose_words (releaser);
+ discard_unwind_frame ("for");
+ loop_level--;
+ return (EXECUTION_FAILURE);
+ }
+ }
+ retval = execute_command (for_command->action);
+ REAP ();
+ QUIT;
+
+ if (breaking)
+ {
+ breaking--;
+ break;
+ }
+
+ if (continuing)
+ {
+ continuing--;
+ if (continuing)
+ break;
+ }
+ }
+
+ loop_level--;
+ line_number = save_line_number;
+
+#if 0
+ if (lexical_scoping)
+ {
+ if (!old_value)
+ unbind_variable (identifier);
+ else
+ {
+ SHELL_VAR *new_value;
+
+ new_value = bind_variable (identifier, value_cell(old_value), 0);
+ new_value->attributes = old_value->attributes;
+ dispose_variable (old_value);
+ }
+ }
+#endif
+
+ dispose_words (releaser);
+ discard_unwind_frame ("for");
+ return (retval);
+}
+
+#if defined (ARITH_FOR_COMMAND)
+/* Execute an arithmetic for command. The syntax is
+
+ for (( init ; step ; test ))
+ do
+ body
+ done
+
+ The execution should be exactly equivalent to
+
+ eval \(\( init \)\)
+ while eval \(\( test \)\) ; do
+ body;
+ eval \(\( step \)\)
+ done
+*/
+static intmax_t
+eval_arith_for_expr (l, okp)
+ WORD_LIST *l;
+ int *okp;
+{
+ WORD_LIST *new;
+ intmax_t expresult;
+ int r;
+
+ new = expand_words_no_vars (l);
+ if (new)
+ {
+ if (echo_command_at_execute)
+ xtrace_print_arith_cmd (new);
+ this_command_name = "(("; /* )) for expression error messages */
+
+ command_string_index = 0;
+ print_arith_command (new);
+ if (signal_in_progress (DEBUG_TRAP) == 0)
+ {
+ FREE (the_printed_command_except_trap);
+ the_printed_command_except_trap = savestring (the_printed_command);
+ }
+
+ r = run_debug_trap ();
+ /* In debugging mode, if the DEBUG trap returns a non-zero status, we
+ skip the command. */
+#if defined (DEBUGGER)
+ if (debugging_mode == 0 || r == EXECUTION_SUCCESS)
+ expresult = evalexp (new->word->word, okp);
+ else
+ {
+ expresult = 0;
+ if (okp)
+ *okp = 1;
+ }
+#else
+ expresult = evalexp (new->word->word, okp);
+#endif
+ dispose_words (new);
+ }
+ else
+ {
+ expresult = 0;
+ if (okp)
+ *okp = 1;
+ }
+ return (expresult);
+}
+
+static int
+execute_arith_for_command (arith_for_command)
+ ARITH_FOR_COM *arith_for_command;
+{
+ intmax_t expresult;
+ int expok, body_status, arith_lineno, save_lineno;
+
+ body_status = EXECUTION_SUCCESS;
+ loop_level++;
+ save_lineno = line_number;
+
+ if (arith_for_command->flags & CMD_IGNORE_RETURN)
+ arith_for_command->action->flags |= CMD_IGNORE_RETURN;
+
+ this_command_name = "(("; /* )) for expression error messages */
+
+ /* save the starting line number of the command so we can reset
+ line_number before executing each expression -- for $LINENO
+ and the DEBUG trap. */
+ line_number = arith_lineno = arith_for_command->line;
+ if (variable_context && interactive_shell)
+ line_number -= function_line_number;
+
+ /* Evaluate the initialization expression. */
+ expresult = eval_arith_for_expr (arith_for_command->init, &expok);
+ if (expok == 0)
+ {
+ line_number = save_lineno;
+ return (EXECUTION_FAILURE);
+ }
+
+ while (1)
+ {
+ /* Evaluate the test expression. */
+ line_number = arith_lineno;
+ expresult = eval_arith_for_expr (arith_for_command->test, &expok);
+ line_number = save_lineno;
+
+ if (expok == 0)
+ {
+ body_status = EXECUTION_FAILURE;
+ break;
+ }
+ REAP ();
+ if (expresult == 0)
+ break;
+
+ /* Execute the body of the arithmetic for command. */
+ QUIT;
+ body_status = execute_command (arith_for_command->action);
+ QUIT;
+
+ /* Handle any `break' or `continue' commands executed by the body. */
+ if (breaking)
+ {
+ breaking--;
+ break;
+ }
+
+ if (continuing)
+ {
+ continuing--;
+ if (continuing)
+ break;
+ }
+
+ /* Evaluate the step expression. */
+ line_number = arith_lineno;
+ expresult = eval_arith_for_expr (arith_for_command->step, &expok);
+ line_number = save_lineno;
+
+ if (expok == 0)
+ {
+ body_status = EXECUTION_FAILURE;
+ break;
+ }
+ }
+
+ loop_level--;
+ line_number = save_lineno;
+
+ return (body_status);
+}
+#endif
+
+#if defined (SELECT_COMMAND)
+static int LINES, COLS, tabsize;
+
+#define RP_SPACE ") "
+#define RP_SPACE_LEN 2
+
+/* XXX - does not handle numbers > 1000000 at all. */
+#define NUMBER_LEN(s) \
+((s < 10) ? 1 \
+ : ((s < 100) ? 2 \
+ : ((s < 1000) ? 3 \
+ : ((s < 10000) ? 4 \
+ : ((s < 100000) ? 5 \
+ : 6)))))
+
+static int
+print_index_and_element (len, ind, list)
+ int len, ind;
+ WORD_LIST *list;
+{
+ register WORD_LIST *l;
+ register int i;
+
+ if (list == 0)
+ return (0);
+ for (i = ind, l = list; l && --i; l = l->next)
+ ;
+ fprintf (stderr, "%*d%s%s", len, ind, RP_SPACE, l->word->word);
+ return (STRLEN (l->word->word));
+}
+
+static void
+indent (from, to)
+ int from, to;
+{
+ while (from < to)
+ {
+ if ((to / tabsize) > (from / tabsize))
+ {
+ putc ('\t', stderr);
+ from += tabsize - from % tabsize;
+ }
+ else
+ {
+ putc (' ', stderr);
+ from++;
+ }
+ }
+}
+
+static void
+print_select_list (list, list_len, max_elem_len, indices_len)
+ WORD_LIST *list;
+ int list_len, max_elem_len, indices_len;
+{
+ int ind, row, elem_len, pos, cols, rows;
+ int first_column_indices_len, other_indices_len;
+
+ if (list == 0)
+ {
+ putc ('\n', stderr);
+ return;
+ }
+
+ cols = max_elem_len ? COLS / max_elem_len : 1;
+ if (cols == 0)
+ cols = 1;
+ rows = list_len ? list_len / cols + (list_len % cols != 0) : 1;
+ cols = list_len ? list_len / rows + (list_len % rows != 0) : 1;
+
+ if (rows == 1)
+ {
+ rows = cols;
+ cols = 1;
+ }
+
+ first_column_indices_len = NUMBER_LEN (rows);
+ other_indices_len = indices_len;
+
+ for (row = 0; row < rows; row++)
+ {
+ ind = row;
+ pos = 0;
+ while (1)
+ {
+ indices_len = (pos == 0) ? first_column_indices_len : other_indices_len;
+ elem_len = print_index_and_element (indices_len, ind + 1, list);
+ elem_len += indices_len + RP_SPACE_LEN;
+ ind += rows;
+ if (ind >= list_len)
+ break;
+ indent (pos + elem_len, pos + max_elem_len);
+ pos += max_elem_len;
+ }
+ putc ('\n', stderr);
+ }
+}
+
+/* Print the elements of LIST, one per line, preceded by an index from 1 to
+ LIST_LEN. Then display PROMPT and wait for the user to enter a number.
+ If the number is between 1 and LIST_LEN, return that selection. If EOF
+ is read, return a null string. If a blank line is entered, or an invalid
+ number is entered, the loop is executed again. */
+static char *
+select_query (list, list_len, prompt, print_menu)
+ WORD_LIST *list;
+ int list_len;
+ char *prompt;
+ int print_menu;
+{
+ int max_elem_len, indices_len, len;
+ intmax_t reply;
+ WORD_LIST *l;
+ char *repl_string, *t;
+
+#if 0
+ t = get_string_value ("LINES");
+ LINES = (t && *t) ? atoi (t) : 24;
+#endif
+ t = get_string_value ("COLUMNS");
+ COLS = (t && *t) ? atoi (t) : 80;
+
+#if 0
+ t = get_string_value ("TABSIZE");
+ tabsize = (t && *t) ? atoi (t) : 8;
+ if (tabsize <= 0)
+ tabsize = 8;
+#else
+ tabsize = 8;
+#endif
+
+ max_elem_len = 0;
+ for (l = list; l; l = l->next)
+ {
+ len = STRLEN (l->word->word);
+ if (len > max_elem_len)
+ max_elem_len = len;
+ }
+ indices_len = NUMBER_LEN (list_len);
+ max_elem_len += indices_len + RP_SPACE_LEN + 2;
+
+ while (1)
+ {
+ if (print_menu)
+ print_select_list (list, list_len, max_elem_len, indices_len);
+ fprintf (stderr, "%s", prompt);
+ fflush (stderr);
+ QUIT;
+
+ if (read_builtin ((WORD_LIST *)NULL) == EXECUTION_FAILURE)
+ {
+ putchar ('\n');
+ return ((char *)NULL);
+ }
+ repl_string = get_string_value ("REPLY");
+ if (*repl_string == 0)
+ {
+ print_menu = 1;
+ continue;
+ }
+ if (legal_number (repl_string, &reply) == 0)
+ return "";
+ if (reply < 1 || reply > list_len)
+ return "";
+
+ for (l = list; l && --reply; l = l->next)
+ ;
+ return (l->word->word);
+ }
+}
+
+/* Execute a SELECT command. The syntax is:
+ SELECT word IN list DO command_list DONE
+ Only `break' or `return' in command_list will terminate
+ the command. */
+static int
+execute_select_command (select_command)
+ SELECT_COM *select_command;
+{
+ WORD_LIST *releaser, *list;
+ SHELL_VAR *v;
+ char *identifier, *ps3_prompt, *selection;
+ int retval, list_len, show_menu, save_line_number;
+
+ if (check_identifier (select_command->name, 1) == 0)
+ return (EXECUTION_FAILURE);
+
+ save_line_number = line_number;
+ line_number = select_command->line;
+
+ command_string_index = 0;
+ print_select_command_head (select_command);
+
+ if (echo_command_at_execute)
+ xtrace_print_select_command_head (select_command);
+
+#if 0
+ if (signal_in_progress (DEBUG_TRAP) == 0 && (this_command_name == 0 || (STREQ (this_command_name, "trap") == 0)))
+#else
+ if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0)
+#endif
+ {
+ FREE (the_printed_command_except_trap);
+ the_printed_command_except_trap = savestring (the_printed_command);
+ }
+
+ retval = run_debug_trap ();
+#if defined (DEBUGGER)
+ /* In debugging mode, if the DEBUG trap returns a non-zero status, we
+ skip the command. */
+ if (debugging_mode && retval != EXECUTION_SUCCESS)
+ return (EXECUTION_SUCCESS);
+#endif
+
+ loop_level++;
+ identifier = select_command->name->word;
+
+ /* command and arithmetic substitution, parameter and variable expansion,
+ word splitting, pathname expansion, and quote removal. */
+ list = releaser = expand_words_no_vars (select_command->map_list);
+ list_len = list_length (list);
+ if (list == 0 || list_len == 0)
+ {
+ if (list)
+ dispose_words (list);
+ line_number = save_line_number;
+ return (EXECUTION_SUCCESS);
+ }
+
+ begin_unwind_frame ("select");
+ add_unwind_protect (dispose_words, releaser);
+
+ if (select_command->flags & CMD_IGNORE_RETURN)
+ select_command->action->flags |= CMD_IGNORE_RETURN;
+
+ retval = EXECUTION_SUCCESS;
+ show_menu = 1;
+
+ while (1)
+ {
+ line_number = select_command->line;
+ ps3_prompt = get_string_value ("PS3");
+ if (ps3_prompt == 0)
+ ps3_prompt = "#? ";
+
+ QUIT;
+ selection = select_query (list, list_len, ps3_prompt, show_menu);
+ QUIT;
+ if (selection == 0)
+ {
+ /* select_query returns EXECUTION_FAILURE if the read builtin
+ fails, so we want to return failure in this case. */
+ retval = EXECUTION_FAILURE;
+ break;
+ }
+
+ v = bind_variable (identifier, selection, 0);
+ if (readonly_p (v) || noassign_p (v))
+ {
+ if (readonly_p (v) && interactive_shell == 0 && posixly_correct)
+ {
+ last_command_exit_value = EXECUTION_FAILURE;
+ jump_to_top_level (FORCE_EOF);
+ }
+ else
+ {
+ dispose_words (releaser);
+ discard_unwind_frame ("select");
+ loop_level--;
+ line_number = save_line_number;
+ return (EXECUTION_FAILURE);
+ }
+ }
+
+ retval = execute_command (select_command->action);
+
+ REAP ();
+ QUIT;
+
+ if (breaking)
+ {
+ breaking--;
+ break;
+ }
+
+ if (continuing)
+ {
+ continuing--;
+ if (continuing)
+ break;
+ }
+
+#if defined (KSH_COMPATIBLE_SELECT)
+ show_menu = 0;
+ selection = get_string_value ("REPLY");
+ if (selection && *selection == '\0')
+ show_menu = 1;
+#endif
+ }
+
+ loop_level--;
+ line_number = save_line_number;
+
+ dispose_words (releaser);
+ discard_unwind_frame ("select");
+ return (retval);
+}
+#endif /* SELECT_COMMAND */
+
+/* Execute a CASE command. The syntax is: CASE word_desc IN pattern_list ESAC.
+ The pattern_list is a linked list of pattern clauses; each clause contains
+ some patterns to compare word_desc against, and an associated command to
+ execute. */
+static int
+execute_case_command (case_command)
+ CASE_COM *case_command;
+{
+ register WORD_LIST *list;
+ WORD_LIST *wlist, *es;
+ PATTERN_LIST *clauses;
+ char *word, *pattern;
+ int retval, match, ignore_return, save_line_number;
+
+ save_line_number = line_number;
+ line_number = case_command->line;
+
+ command_string_index = 0;
+ print_case_command_head (case_command);
+
+ if (echo_command_at_execute)
+ xtrace_print_case_command_head (case_command);
+
+#if 0
+ if (signal_in_progress (DEBUG_TRAP) == 0 && (this_command_name == 0 || (STREQ (this_command_name, "trap") == 0)))
+#else
+ if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0)
+#endif
+ {
+ FREE (the_printed_command_except_trap);
+ the_printed_command_except_trap = savestring (the_printed_command);
+ }
+
+ retval = run_debug_trap();
+#if defined (DEBUGGER)
+ /* In debugging mode, if the DEBUG trap returns a non-zero status, we
+ skip the command. */
+ if (debugging_mode && retval != EXECUTION_SUCCESS)
+ {
+ line_number = save_line_number;
+ return (EXECUTION_SUCCESS);
+ }
+#endif
+
+ wlist = expand_word_unsplit (case_command->word, 0);
+ word = wlist ? string_list (wlist) : savestring ("");
+ dispose_words (wlist);
+
+ retval = EXECUTION_SUCCESS;
+ ignore_return = case_command->flags & CMD_IGNORE_RETURN;
+
+ begin_unwind_frame ("case");
+ add_unwind_protect ((Function *)xfree, word);
+
+#define EXIT_CASE() goto exit_case_command
+
+ for (clauses = case_command->clauses; clauses; clauses = clauses->next)
+ {
+ QUIT;
+ for (list = clauses->patterns; list; list = list->next)
+ {
+ es = expand_word_leave_quoted (list->word, 0);
+
+ if (es && es->word && es->word->word && *(es->word->word))
+ pattern = quote_string_for_globbing (es->word->word, QGLOB_CVTNULL);
+ else
+ {
+ pattern = (char *)xmalloc (1);
+ pattern[0] = '\0';
+ }
+
+ /* Since the pattern does not undergo quote removal (as per
+ Posix.2, section 3.9.4.3), the strmatch () call must be able
+ to recognize backslashes as escape characters. */
+ match = strmatch (pattern, word, FNMATCH_EXTFLAG|FNMATCH_IGNCASE) != FNM_NOMATCH;
+ free (pattern);
+
+ dispose_words (es);
+
+ if (match)
+ {
+ do
+ {
+ if (clauses->action && ignore_return)
+ clauses->action->flags |= CMD_IGNORE_RETURN;
+ retval = execute_command (clauses->action);
+ }
+ while ((clauses->flags & CASEPAT_FALLTHROUGH) && (clauses = clauses->next));
+ if (clauses == 0 || (clauses->flags & CASEPAT_TESTNEXT) == 0)
+ EXIT_CASE ();
+ else
+ break;
+ }
+
+ QUIT;
+ }
+ }
+
+exit_case_command:
+ free (word);
+ discard_unwind_frame ("case");
+ line_number = save_line_number;
+ return (retval);
+}
+
+#define CMD_WHILE 0
+#define CMD_UNTIL 1
+
+/* The WHILE command. Syntax: WHILE test DO action; DONE.
+ Repeatedly execute action while executing test produces
+ EXECUTION_SUCCESS. */
+static int
+execute_while_command (while_command)
+ WHILE_COM *while_command;
+{
+ return (execute_while_or_until (while_command, CMD_WHILE));
+}
+
+/* UNTIL is just like WHILE except that the test result is negated. */
+static int
+execute_until_command (while_command)
+ WHILE_COM *while_command;
+{
+ return (execute_while_or_until (while_command, CMD_UNTIL));
+}
+
+/* The body for both while and until. The only difference between the
+ two is that the test value is treated differently. TYPE is
+ CMD_WHILE or CMD_UNTIL. The return value for both commands should
+ be EXECUTION_SUCCESS if no commands in the body are executed, and
+ the status of the last command executed in the body otherwise. */
+static int
+execute_while_or_until (while_command, type)
+ WHILE_COM *while_command;
+ int type;
+{
+ int return_value, body_status;
+
+ body_status = EXECUTION_SUCCESS;
+ loop_level++;
+
+ while_command->test->flags |= CMD_IGNORE_RETURN;
+ if (while_command->flags & CMD_IGNORE_RETURN)
+ while_command->action->flags |= CMD_IGNORE_RETURN;
+
+ while (1)
+ {
+ return_value = execute_command (while_command->test);
+ REAP ();
+
+ /* Need to handle `break' in the test when we would break out of the
+ loop. The job control code will set `breaking' to loop_level
+ when a job in a loop is stopped with SIGTSTP. If the stopped job
+ is in the loop test, `breaking' will not be reset unless we do
+ this, and the shell will cease to execute commands. */
+ if (type == CMD_WHILE && return_value != EXECUTION_SUCCESS)
+ {
+ if (breaking)
+ breaking--;
+ break;
+ }
+ if (type == CMD_UNTIL && return_value == EXECUTION_SUCCESS)
+ {
+ if (breaking)
+ breaking--;
+ break;
+ }
+
+ QUIT;
+ body_status = execute_command (while_command->action);
+ QUIT;
+
+ if (breaking)
+ {
+ breaking--;
+ break;
+ }
+
+ if (continuing)
+ {
+ continuing--;
+ if (continuing)
+ break;
+ }
+ }
+ loop_level--;
+
+ return (body_status);
+}
+
+/* IF test THEN command [ELSE command].
+ IF also allows ELIF in the place of ELSE IF, but
+ the parser makes *that* stupidity transparent. */
+static int
+execute_if_command (if_command)
+ IF_COM *if_command;
+{
+ int return_value, save_line_number;
+
+ save_line_number = line_number;
+ if_command->test->flags |= CMD_IGNORE_RETURN;
+ return_value = execute_command (if_command->test);
+ line_number = save_line_number;
+
+ if (return_value == EXECUTION_SUCCESS)
+ {
+ QUIT;
+
+ if (if_command->true_case && (if_command->flags & CMD_IGNORE_RETURN))
+ if_command->true_case->flags |= CMD_IGNORE_RETURN;
+
+ return (execute_command (if_command->true_case));
+ }
+ else
+ {
+ QUIT;
+
+ if (if_command->false_case && (if_command->flags & CMD_IGNORE_RETURN))
+ if_command->false_case->flags |= CMD_IGNORE_RETURN;
+
+ return (execute_command (if_command->false_case));
+ }
+}
+
+#if defined (DPAREN_ARITHMETIC)
+static int
+execute_arith_command (arith_command)
+ ARITH_COM *arith_command;
+{
+ int expok, save_line_number, retval;
+ intmax_t expresult;
+ WORD_LIST *new;
+ char *exp;
+
+ expresult = 0;
+
+ save_line_number = line_number;
+ this_command_name = "(("; /* )) */
+ line_number = arith_command->line;
+ /* If we're in a function, update the line number information. */
+ if (variable_context && interactive_shell)
+ line_number -= function_line_number;
+
+ command_string_index = 0;
+ print_arith_command (arith_command->exp);
+
+ if (signal_in_progress (DEBUG_TRAP) == 0)
+ {
+ FREE (the_printed_command_except_trap);
+ the_printed_command_except_trap = savestring (the_printed_command);
+ }
+
+ /* Run the debug trap before each arithmetic command, but do it after we
+ update the line number information and before we expand the various
+ words in the expression. */
+ retval = run_debug_trap ();
+#if defined (DEBUGGER)
+ /* In debugging mode, if the DEBUG trap returns a non-zero status, we
+ skip the command. */
+ if (debugging_mode && retval != EXECUTION_SUCCESS)
+ {
+ line_number = save_line_number;
+ return (EXECUTION_SUCCESS);
+ }
+#endif
+
+ new = expand_words_no_vars (arith_command->exp);
+
+ /* If we're tracing, make a new word list with `((' at the front and `))'
+ at the back and print it. */
+ if (echo_command_at_execute)
+ xtrace_print_arith_cmd (new);
+
+ if (new)
+ {
+ exp = new->next ? string_list (new) : new->word->word;
+ expresult = evalexp (exp, &expok);
+ line_number = save_line_number;
+ if (exp != new->word->word)
+ free (exp);
+ dispose_words (new);
+ }
+ else
+ {
+ expresult = 0;
+ expok = 1;
+ }
+
+ if (expok == 0)
+ return (EXECUTION_FAILURE);
+
+ return (expresult == 0 ? EXECUTION_FAILURE : EXECUTION_SUCCESS);
+}
+#endif /* DPAREN_ARITHMETIC */
+
+#if defined (COND_COMMAND)
+
+static char * const nullstr = "";
+
+static int
+execute_cond_node (cond)
+ COND_COM *cond;
+{
+ int result, invert, patmatch, rmatch, mflags, ignore;
+ char *arg1, *arg2;
+
+ invert = (cond->flags & CMD_INVERT_RETURN);
+ ignore = (cond->flags & CMD_IGNORE_RETURN);
+ if (ignore)
+ {
+ if (cond->left)
+ cond->left->flags |= CMD_IGNORE_RETURN;
+ if (cond->right)
+ cond->right->flags |= CMD_IGNORE_RETURN;
+ }
+
+ if (cond->type == COND_EXPR)
+ result = execute_cond_node (cond->left);
+ else if (cond->type == COND_OR)
+ {
+ result = execute_cond_node (cond->left);
+ if (result != EXECUTION_SUCCESS)
+ result = execute_cond_node (cond->right);
+ }
+ else if (cond->type == COND_AND)
+ {
+ result = execute_cond_node (cond->left);
+ if (result == EXECUTION_SUCCESS)
+ result = execute_cond_node (cond->right);
+ }
+ else if (cond->type == COND_UNARY)
+ {
+ if (ignore)
+ comsub_ignore_return++;
+ arg1 = cond_expand_word (cond->left->op, 0);
+ if (ignore)
+ comsub_ignore_return--;
+ if (arg1 == 0)
+ arg1 = nullstr;
+ if (echo_command_at_execute)
+ xtrace_print_cond_term (cond->type, invert, cond->op, arg1, (char *)NULL);
+ result = unary_test (cond->op->word, arg1) ? EXECUTION_SUCCESS : EXECUTION_FAILURE;
+ if (arg1 != nullstr)
+ free (arg1);
+ }
+ else if (cond->type == COND_BINARY)
+ {
+ rmatch = 0;
+ patmatch = ((cond->op->word[1] == '=') && (cond->op->word[2] == '\0') &&
+ (cond->op->word[0] == '!' || cond->op->word[0] == '=') ||
+ (cond->op->word[0] == '=' && cond->op->word[1] == '\0'));
+#if defined (COND_REGEXP)
+ rmatch = (cond->op->word[0] == '=' && cond->op->word[1] == '~' &&
+ cond->op->word[2] == '\0');
+#endif
+
+ if (ignore)
+ comsub_ignore_return++;
+ arg1 = cond_expand_word (cond->left->op, 0);
+ if (ignore)
+ comsub_ignore_return--;
+ if (arg1 == 0)
+ arg1 = nullstr;
+ if (ignore)
+ comsub_ignore_return++;
+ arg2 = cond_expand_word (cond->right->op,
+ (rmatch && shell_compatibility_level > 31) ? 2 : (patmatch ? 1 : 0));
+ if (ignore)
+ comsub_ignore_return--;
+ if (arg2 == 0)
+ arg2 = nullstr;
+
+ if (echo_command_at_execute)
+ xtrace_print_cond_term (cond->type, invert, cond->op, arg1, arg2);
+
+#if defined (COND_REGEXP)
+ if (rmatch)
+ {
+ mflags = SHMAT_PWARN;
+#if defined (ARRAY_VARS)
+ mflags |= SHMAT_SUBEXP;
+#endif
+
+ result = sh_regmatch (arg1, arg2, mflags);
+ }
+ else
+#endif /* COND_REGEXP */
+ {
+ int oe;
+ oe = extended_glob;
+ extended_glob = 1;
+ result = binary_test (cond->op->word, arg1, arg2, TEST_PATMATCH|TEST_ARITHEXP|TEST_LOCALE)
+ ? EXECUTION_SUCCESS
+ : EXECUTION_FAILURE;
+ extended_glob = oe;
+ }
+ if (arg1 != nullstr)
+ free (arg1);
+ if (arg2 != nullstr)
+ free (arg2);
+ }
+ else
+ {
+ command_error ("execute_cond_node", CMDERR_BADTYPE, cond->type, 0);
+ jump_to_top_level (DISCARD);
+ result = EXECUTION_FAILURE;
+ }
+
+ if (invert)
+ result = (result == EXECUTION_SUCCESS) ? EXECUTION_FAILURE : EXECUTION_SUCCESS;
+
+ return result;
+}
+
+static int
+execute_cond_command (cond_command)
+ COND_COM *cond_command;
+{
+ int retval, save_line_number;
+
+ retval = EXECUTION_SUCCESS;
+ save_line_number = line_number;
+
+ this_command_name = "[[";
+ line_number = cond_command->line;
+ /* If we're in a function, update the line number information. */
+ if (variable_context && interactive_shell)
+ line_number -= function_line_number;
+ command_string_index = 0;
+ print_cond_command (cond_command);
+
+ if (signal_in_progress (DEBUG_TRAP) == 0)
+ {
+ FREE (the_printed_command_except_trap);
+ the_printed_command_except_trap = savestring (the_printed_command);
+ }
+
+ /* Run the debug trap before each conditional command, but do it after we
+ update the line number information. */
+ retval = run_debug_trap ();
+#if defined (DEBUGGER)
+ /* In debugging mode, if the DEBUG trap returns a non-zero status, we
+ skip the command. */
+ if (debugging_mode && retval != EXECUTION_SUCCESS)
+ {
+ line_number = save_line_number;
+ return (EXECUTION_SUCCESS);
+ }
+#endif
+
+#if 0
+ debug_print_cond_command (cond_command);
+#endif
+
+ last_command_exit_value = retval = execute_cond_node (cond_command);
+ line_number = save_line_number;
+ return (retval);
+}
+#endif /* COND_COMMAND */
+
+static void
+bind_lastarg (arg)
+ char *arg;
+{
+ SHELL_VAR *var;
+
+ if (arg == 0)
+ arg = "";
+ var = bind_variable ("_", arg, 0);
+ VUNSETATTR (var, att_exported);
+}
+
+/* Execute a null command. Fork a subshell if the command uses pipes or is
+ to be run asynchronously. This handles all the side effects that are
+ supposed to take place. */
+static int
+execute_null_command (redirects, pipe_in, pipe_out, async)
+ REDIRECT *redirects;
+ int pipe_in, pipe_out, async;
+{
+ int r;
+ int forcefork;
+ REDIRECT *rd;
+
+ for (forcefork = 0, rd = redirects; rd; rd = rd->next)
+ forcefork += rd->rflags & REDIR_VARASSIGN;
+
+ if (forcefork || pipe_in != NO_PIPE || pipe_out != NO_PIPE || async)
+ {
+ /* We have a null command, but we really want a subshell to take
+ care of it. Just fork, do piping and redirections, and exit. */
+ if (make_child ((char *)NULL, async) == 0)
+ {
+ /* Cancel traps, in trap.c. */
+ restore_original_signals (); /* XXX */
+
+ do_piping (pipe_in, pipe_out);
+
+#if defined (COPROCESS_SUPPORT)
+ coproc_closeall ();
+#endif
+
+ subshell_environment = 0;
+ if (async)
+ subshell_environment |= SUBSHELL_ASYNC;
+ if (pipe_in != NO_PIPE || pipe_out != NO_PIPE)
+ subshell_environment |= SUBSHELL_PIPE;
+
+ if (do_redirections (redirects, RX_ACTIVE) == 0)
+ exit (EXECUTION_SUCCESS);
+ else
+ exit (EXECUTION_FAILURE);
+ }
+ else
+ {
+ close_pipes (pipe_in, pipe_out);
+#if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD)
+ unlink_fifo_list ();
+#endif
+ return (EXECUTION_SUCCESS);
+ }
+ }
+ else
+ {
+ /* Even if there aren't any command names, pretend to do the
+ redirections that are specified. The user expects the side
+ effects to take place. If the redirections fail, then return
+ failure. Otherwise, if a command substitution took place while
+ expanding the command or a redirection, return the value of that
+ substitution. Otherwise, return EXECUTION_SUCCESS. */
+
+ r = do_redirections (redirects, RX_ACTIVE|RX_UNDOABLE);
+ cleanup_redirects (redirection_undo_list);
+ redirection_undo_list = (REDIRECT *)NULL;
+
+ if (r != 0)
+ return (EXECUTION_FAILURE);
+ else if (last_command_subst_pid != NO_PID)
+ return (last_command_exit_value);
+ else
+ return (EXECUTION_SUCCESS);
+ }
+}
+
+/* This is a hack to suppress word splitting for assignment statements
+ given as arguments to builtins with the ASSIGNMENT_BUILTIN flag set. */
+static void
+fix_assignment_words (words)
+ WORD_LIST *words;
+{
+ WORD_LIST *w;
+ struct builtin *b;
+ int assoc;
+
+ if (words == 0)
+ return;
+
+ b = 0;
+ assoc = 0;
+
+ for (w = words; w; w = w->next)
+ if (w->word->flags & W_ASSIGNMENT)
+ {
+ if (b == 0)
+ {
+ b = builtin_address_internal (words->word->word, 0);
+ if (b == 0 || (b->flags & ASSIGNMENT_BUILTIN) == 0)
+ return;
+ else if (b && (b->flags & ASSIGNMENT_BUILTIN))
+ words->word->flags |= W_ASSNBLTIN;
+ }
+ w->word->flags |= (W_NOSPLIT|W_NOGLOB|W_TILDEEXP|W_ASSIGNARG);
+#if defined (ARRAY_VARS)
+ if (assoc)
+ w->word->flags |= W_ASSIGNASSOC;
+#endif
+ }
+#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, 'A'))
+ {
+ if (b == 0)
+ {
+ b = builtin_address_internal (words->word->word, 0);
+ if (b == 0 || (b->flags & ASSIGNMENT_BUILTIN) == 0)
+ return;
+ else if (b && (b->flags & ASSIGNMENT_BUILTIN))
+ words->word->flags |= W_ASSNBLTIN;
+ }
+ if (words->word->flags & W_ASSNBLTIN)
+ assoc = 1;
+ }
+#endif
+}
+
+/* Return 1 if the file found by searching $PATH for PATHNAME, defaulting
+ to PATHNAME, is a directory. Used by the autocd code below. */
+static int
+is_dirname (pathname)
+ char *pathname;
+{
+ char *temp;
+ temp = search_for_command (pathname);
+ return (temp ? file_isdir (temp) : file_isdir (pathname));
+}
+
+/* The meaty part of all the executions. We have to start hacking the
+ real execution of commands here. Fork a process, set things up,
+ execute the command. */
+static int
+execute_simple_command (simple_command, pipe_in, pipe_out, async, fds_to_close)
+ SIMPLE_COM *simple_command;
+ int pipe_in, pipe_out, async;
+ struct fd_bitmap *fds_to_close;
+{
+ WORD_LIST *words, *lastword;
+ char *command_line, *lastarg, *temp;
+ int first_word_quoted, result, builtin_is_special, already_forked, dofork;
+ pid_t old_last_async_pid;
+ sh_builtin_func_t *builtin;
+ SHELL_VAR *func;
+
+ result = EXECUTION_SUCCESS;
+ special_builtin_failed = builtin_is_special = 0;
+ command_line = (char *)0;
+
+ /* If we're in a function, update the line number information. */
+ if (variable_context && interactive_shell && sourcelevel == 0)
+ line_number -= function_line_number;
+
+ /* Remember what this command line looks like at invocation. */
+ command_string_index = 0;
+ print_simple_command (simple_command);
+
+#if 0
+ if (signal_in_progress (DEBUG_TRAP) == 0 && (this_command_name == 0 || (STREQ (this_command_name, "trap") == 0)))
+#else
+ if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0)
+#endif
+ {
+ FREE (the_printed_command_except_trap);
+ the_printed_command_except_trap = the_printed_command ? savestring (the_printed_command) : (char *)0;
+ }
+
+ /* Run the debug trap before each simple command, but do it after we
+ update the line number information. */
+ result = run_debug_trap ();
+#if defined (DEBUGGER)
+ /* In debugging mode, if the DEBUG trap returns a non-zero status, we
+ skip the command. */
+ if (debugging_mode && result != EXECUTION_SUCCESS)
+ return (EXECUTION_SUCCESS);
+#endif
+
+ first_word_quoted =
+ simple_command->words ? (simple_command->words->word->flags & W_QUOTED) : 0;
+
+ last_command_subst_pid = NO_PID;
+ old_last_async_pid = last_asynchronous_pid;
+
+ already_forked = dofork = 0;
+
+ /* If we're in a pipeline or run in the background, set DOFORK so we
+ make the child early, before word expansion. This keeps assignment
+ statements from affecting the parent shell's environment when they
+ should not. */
+ dofork = pipe_in != NO_PIPE || pipe_out != NO_PIPE || async;
+
+ /* Something like `%2 &' should restart job 2 in the background, not cause
+ the shell to fork here. */
+ if (dofork && pipe_in == NO_PIPE && pipe_out == NO_PIPE &&
+ simple_command->words && simple_command->words->word &&
+ simple_command->words->word->word &&
+ (simple_command->words->word->word[0] == '%'))
+ dofork = 0;
+
+ if (dofork)
+ {
+ /* Do this now, because execute_disk_command will do it anyway in the
+ vast majority of cases. */
+ maybe_make_export_env ();
+
+ /* Don't let a DEBUG trap overwrite the command string to be saved with
+ the process/job associated with this child. */
+ if (make_child (savestring (the_printed_command_except_trap), async) == 0)
+ {
+ already_forked = 1;
+ simple_command->flags |= CMD_NO_FORK;
+
+ subshell_environment = SUBSHELL_FORK;
+ if (pipe_in != NO_PIPE || pipe_out != NO_PIPE)
+ subshell_environment |= SUBSHELL_PIPE;
+ if (async)
+ subshell_environment |= SUBSHELL_ASYNC;
+
+ /* We need to do this before piping to handle some really
+ pathological cases where one of the pipe file descriptors
+ is < 2. */
+ if (fds_to_close)
+ close_fd_bitmap (fds_to_close);
+
+ do_piping (pipe_in, pipe_out);
+ pipe_in = pipe_out = NO_PIPE;
+#if defined (COPROCESS_SUPPORT)
+ coproc_closeall ();
+#endif
+
+ last_asynchronous_pid = old_last_async_pid;
+ }
+ else
+ {
+ close_pipes (pipe_in, pipe_out);
+#if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD)
+ unlink_fifo_list ();
+#endif
+ command_line = (char *)NULL; /* don't free this. */
+ bind_lastarg ((char *)NULL);
+ return (result);
+ }
+ }
+
+ /* If we are re-running this as the result of executing the `command'
+ builtin, do not expand the command words a second time. */
+ if ((simple_command->flags & CMD_INHIBIT_EXPANSION) == 0)
+ {
+ current_fds_to_close = fds_to_close;
+ fix_assignment_words (simple_command->words);
+ /* Pass the ignore return flag down to command substitutions */
+ if (simple_command->flags & CMD_IGNORE_RETURN) /* XXX */
+ comsub_ignore_return++;
+ words = expand_words (simple_command->words);
+ if (simple_command->flags & CMD_IGNORE_RETURN)
+ comsub_ignore_return--;
+ current_fds_to_close = (struct fd_bitmap *)NULL;
+ }
+ else
+ words = copy_word_list (simple_command->words);
+
+ /* It is possible for WORDS not to have anything left in it.
+ Perhaps all the words consisted of `$foo', and there was
+ no variable `$foo'. */
+ if (words == 0)
+ {
+ this_command_name = 0;
+ result = execute_null_command (simple_command->redirects,
+ pipe_in, pipe_out,
+ already_forked ? 0 : async);
+ if (already_forked)
+ exit (result);
+ else
+ {
+ bind_lastarg ((char *)NULL);
+ set_pipestatus_from_exit (result);
+ return (result);
+ }
+ }
+
+ lastarg = (char *)NULL;
+
+ begin_unwind_frame ("simple-command");
+
+ if (echo_command_at_execute)
+ xtrace_print_word_list (words, 1);
+
+ builtin = (sh_builtin_func_t *)NULL;
+ func = (SHELL_VAR *)NULL;
+ if ((simple_command->flags & CMD_NO_FUNCTIONS) == 0)
+ {
+ /* Posix.2 says special builtins are found before functions. We
+ don't set builtin_is_special anywhere other than here, because
+ this path is followed only when the `command' builtin is *not*
+ being used, and we don't want to exit the shell if a special
+ builtin executed with `command builtin' fails. `command' is not
+ a special builtin. */
+ if (posixly_correct)
+ {
+ builtin = find_special_builtin (words->word->word);
+ if (builtin)
+ builtin_is_special = 1;
+ }
+ if (builtin == 0)
+ func = find_function (words->word->word);
+ }
+
+ /* In POSIX mode, assignment errors in the temporary environment cause a
+ non-interactive shell to exit. */
+ if (builtin_is_special && interactive_shell == 0 && tempenv_assign_error)
+ {
+ last_command_exit_value = EXECUTION_FAILURE;
+ jump_to_top_level (ERREXIT);
+ }
+
+ add_unwind_protect (dispose_words, words);
+ QUIT;
+
+ /* Bind the last word in this command to "$_" after execution. */
+ for (lastword = words; lastword->next; lastword = lastword->next)
+ ;
+ lastarg = lastword->word->word;
+
+#if defined (JOB_CONTROL)
+ /* Is this command a job control related thing? */
+ if (words->word->word[0] == '%' && already_forked == 0)
+ {
+ this_command_name = async ? "bg" : "fg";
+ last_shell_builtin = this_shell_builtin;
+ this_shell_builtin = builtin_address (this_command_name);
+ result = (*this_shell_builtin) (words);
+ goto return_result;
+ }
+
+ /* One other possiblilty. The user may want to resume an existing job.
+ If they do, find out whether this word is a candidate for a running
+ job. */
+ if (job_control && already_forked == 0 && async == 0 &&
+ !first_word_quoted &&
+ !words->next &&
+ words->word->word[0] &&
+ !simple_command->redirects &&
+ pipe_in == NO_PIPE &&
+ pipe_out == NO_PIPE &&
+ (temp = get_string_value ("auto_resume")))
+ {
+ int job, jflags, started_status;
+
+ jflags = JM_STOPPED|JM_FIRSTMATCH;
+ if (STREQ (temp, "exact"))
+ jflags |= JM_EXACT;
+ else if (STREQ (temp, "substring"))
+ jflags |= JM_SUBSTRING;
+ else
+ jflags |= JM_PREFIX;
+ job = get_job_by_name (words->word->word, jflags);
+ if (job != NO_JOB)
+ {
+ run_unwind_frame ("simple-command");
+ this_command_name = "fg";
+ last_shell_builtin = this_shell_builtin;
+ this_shell_builtin = builtin_address ("fg");
+
+ started_status = start_job (job, 1);
+ return ((started_status < 0) ? EXECUTION_FAILURE : started_status);
+ }
+ }
+#endif /* JOB_CONTROL */
+
+run_builtin:
+ /* Remember the name of this command globally. */
+ this_command_name = words->word->word;
+
+ QUIT;
+
+ /* This command could be a shell builtin or a user-defined function.
+ We have already found special builtins by this time, so we do not
+ set builtin_is_special. If this is a function or builtin, and we
+ have pipes, then fork a subshell in here. Otherwise, just execute
+ the command directly. */
+ if (func == 0 && builtin == 0)
+ builtin = find_shell_builtin (this_command_name);
+
+ last_shell_builtin = this_shell_builtin;
+ this_shell_builtin = builtin;
+
+ if (builtin || func)
+ {
+ if (builtin)
+ unwind_protect_int (executing_builtin); /* modified in execute_builtin */
+ if (already_forked)
+ {
+ /* reset_terminating_signals (); */ /* XXX */
+ /* Cancel traps, in trap.c. */
+ restore_original_signals ();
+
+ if (async)
+ {
+ if ((simple_command->flags & CMD_STDIN_REDIR) &&
+ pipe_in == NO_PIPE &&
+ (stdin_redirects (simple_command->redirects) == 0))
+ async_redirect_stdin ();
+ setup_async_signals ();
+ }
+
+ subshell_level++;
+ execute_subshell_builtin_or_function
+ (words, simple_command->redirects, builtin, func,
+ pipe_in, pipe_out, async, fds_to_close,
+ simple_command->flags);
+ subshell_level--;
+ }
+ else
+ {
+ result = execute_builtin_or_function
+ (words, builtin, func, simple_command->redirects, fds_to_close,
+ simple_command->flags);
+ if (builtin)
+ {
+ if (result > EX_SHERRBASE)
+ {
+ result = builtin_status (result);
+ if (builtin_is_special)
+ special_builtin_failed = 1;
+ }
+ /* In POSIX mode, if there are assignment statements preceding
+ a special builtin, they persist after the builtin
+ completes. */
+ if (posixly_correct && builtin_is_special && temporary_env)
+ merge_temporary_env ();
+ }
+ else /* function */
+ {
+ if (result == EX_USAGE)
+ result = EX_BADUSAGE;
+ else if (result > EX_SHERRBASE)
+ result = EXECUTION_FAILURE;
+ }
+
+ set_pipestatus_from_exit (result);
+
+ goto return_result;
+ }
+ }
+
+ if (autocd && interactive && words->word && is_dirname (words->word->word))
+ {
+ words = make_word_list (make_word ("cd"), words);
+ xtrace_print_word_list (words, 0);
+ goto run_builtin;
+ }
+
+ if (command_line == 0)
+ command_line = savestring (the_printed_command_except_trap);
+
+#if defined (PROCESS_SUBSTITUTION)
+ if ((subshell_environment & SUBSHELL_COMSUB) && (simple_command->flags & CMD_NO_FORK) && fifos_pending() > 0)
+ simple_command->flags &= ~CMD_NO_FORK;
+#endif
+
+ execute_disk_command (words, simple_command->redirects, command_line,
+ pipe_in, pipe_out, async, fds_to_close,
+ simple_command->flags);
+
+ return_result:
+ bind_lastarg (lastarg);
+ FREE (command_line);
+ dispose_words (words);
+ discard_unwind_frame ("simple-command");
+ this_command_name = (char *)NULL; /* points to freed memory now */
+ return (result);
+}
+
+/* Translate the special builtin exit statuses. We don't really need a
+ function for this; it's a placeholder for future work. */
+static int
+builtin_status (result)
+ int result;
+{
+ int r;
+
+ switch (result)
+ {
+ case EX_USAGE:
+ r = EX_BADUSAGE;
+ break;
+ case EX_REDIRFAIL:
+ case EX_BADSYNTAX:
+ case EX_BADASSIGN:
+ case EX_EXPFAIL:
+ r = EXECUTION_FAILURE;
+ break;
+ default:
+ r = EXECUTION_SUCCESS;
+ break;
+ }
+ return (r);
+}
+
+static int
+execute_builtin (builtin, words, flags, subshell)
+ sh_builtin_func_t *builtin;
+ WORD_LIST *words;
+ int flags, subshell;
+{
+ int old_e_flag, result, eval_unwind;
+ int isbltinenv;
+ char *error_trap;
+
+#if 0
+ /* XXX -- added 12/11 */
+ terminate_immediately++;
+#endif
+
+ error_trap = 0;
+ old_e_flag = exit_immediately_on_error;
+ /* The eval builtin calls parse_and_execute, which does not know about
+ the setting of flags, and always calls the execution functions with
+ flags that will exit the shell on an error if -e is set. If the
+ eval builtin is being called, and we're supposed to ignore the exit
+ value of the command, we turn the -e flag off ourselves and disable
+ the ERR trap, then restore them when the command completes. This is
+ also a problem (as below) for the command and source/. builtins. */
+ if (subshell == 0 && (flags & CMD_IGNORE_RETURN) &&
+ (builtin == eval_builtin || builtin == command_builtin || builtin == source_builtin))
+ {
+ begin_unwind_frame ("eval_builtin");
+ unwind_protect_int (exit_immediately_on_error);
+ error_trap = TRAP_STRING (ERROR_TRAP);
+ if (error_trap)
+ {
+ error_trap = savestring (error_trap);
+ add_unwind_protect (xfree, error_trap);
+ add_unwind_protect (set_error_trap, error_trap);
+ restore_default_signal (ERROR_TRAP);
+ }
+ exit_immediately_on_error = 0;
+ eval_unwind = 1;
+ }
+ else
+ eval_unwind = 0;
+
+ /* The temporary environment for a builtin is supposed to apply to
+ all commands executed by that builtin. Currently, this is a
+ problem only with the `unset', `source' and `eval' builtins. */
+
+ isbltinenv = (builtin == source_builtin || builtin == eval_builtin || builtin == unset_builtin);
+
+ if (isbltinenv)
+ {
+ if (subshell == 0)
+ begin_unwind_frame ("builtin_env");
+
+ if (temporary_env)
+ {
+ push_scope (VC_BLTNENV, temporary_env);
+ if (subshell == 0)
+ add_unwind_protect (pop_scope, (flags & CMD_COMMAND_BUILTIN) ? 0 : "1");
+ temporary_env = (HASH_TABLE *)NULL;
+ }
+ }
+
+ /* `return' does a longjmp() back to a saved environment in execute_function.
+ If a variable assignment list preceded the command, and the shell is
+ running in POSIX mode, we need to merge that into the shell_variables
+ table, since `return' is a POSIX special builtin. */
+ if (posixly_correct && subshell == 0 && builtin == return_builtin && temporary_env)
+ {
+ begin_unwind_frame ("return_temp_env");
+ add_unwind_protect (merge_temporary_env, (char *)NULL);
+ }
+
+ executing_builtin++;
+ result = ((*builtin) (words->next));
+
+ /* This shouldn't happen, but in case `return' comes back instead of
+ longjmp'ing, we need to unwind. */
+ if (posixly_correct && subshell == 0 && builtin == return_builtin && temporary_env)
+ discard_unwind_frame ("return_temp_env");
+
+ if (subshell == 0 && isbltinenv)
+ run_unwind_frame ("builtin_env");
+
+ if (eval_unwind)
+ {
+ exit_immediately_on_error += old_e_flag;
+ if (error_trap)
+ {
+ set_error_trap (error_trap);
+ xfree (error_trap);
+ }
+ discard_unwind_frame ("eval_builtin");
+ }
+
+#if 0
+ /* XXX -- added 12/11 */
+ terminate_immediately--;
+#endif
+
+ return (result);
+}
+
+static int
+execute_function (var, words, flags, fds_to_close, async, subshell)
+ SHELL_VAR *var;
+ WORD_LIST *words;
+ int flags;
+ struct fd_bitmap *fds_to_close;
+ int async, subshell;
+{
+ int return_val, result;
+ COMMAND *tc, *fc, *save_current;
+ char *debug_trap, *error_trap, *return_trap;
+#if defined (ARRAY_VARS)
+ SHELL_VAR *funcname_v, *nfv, *bash_source_v, *bash_lineno_v;
+ ARRAY *funcname_a, *bash_source_a, *bash_lineno_a;
+#endif
+ FUNCTION_DEF *shell_fn;
+ char *sfile, *t;
+
+ USE_VAR(fc);
+
+#if 0 /* for bash-4.2 */
+ if (funcnest_max > 0 && funcnest >= funcnest_max)
+ {
+ internal_error ("%s: maximum function nesting level exceeded (%d)", var->name, funcnest);
+ jump_to_top_level (DISCARD);
+ }
+#endif
+
+#if defined (ARRAY_VARS)
+ GET_ARRAY_FROM_VAR ("FUNCNAME", funcname_v, funcname_a);
+ GET_ARRAY_FROM_VAR ("BASH_SOURCE", bash_source_v, bash_source_a);
+ GET_ARRAY_FROM_VAR ("BASH_LINENO", bash_lineno_v, bash_lineno_a);
+#endif
+
+ tc = (COMMAND *)copy_command (function_cell (var));
+ if (tc && (flags & CMD_IGNORE_RETURN))
+ tc->flags |= CMD_IGNORE_RETURN;
+
+ if (subshell == 0)
+ {
+ begin_unwind_frame ("function_calling");
+ push_context (var->name, subshell, temporary_env);
+ add_unwind_protect (pop_context, (char *)NULL);
+ unwind_protect_int (line_number);
+ unwind_protect_int (return_catch_flag);
+ unwind_protect_jmp_buf (return_catch);
+ add_unwind_protect (dispose_command, (char *)tc);
+ unwind_protect_pointer (this_shell_function);
+ unwind_protect_int (loop_level);
+ unwind_protect_int (funcnest);
+ }
+ else
+ push_context (var->name, subshell, temporary_env); /* don't unwind-protect for subshells */
+
+ temporary_env = (HASH_TABLE *)NULL;
+
+ this_shell_function = var;
+ make_funcname_visible (1);
+
+ debug_trap = TRAP_STRING(DEBUG_TRAP);
+ error_trap = TRAP_STRING(ERROR_TRAP);
+ return_trap = TRAP_STRING(RETURN_TRAP);
+
+ /* The order of the unwind protects for debug_trap, error_trap and
+ return_trap is important here! unwind-protect commands are run
+ in reverse order of registration. If this causes problems, take
+ out the xfree unwind-protect calls and live with the small memory leak. */
+
+ /* function_trace_mode != 0 means that all functions inherit the DEBUG trap.
+ if the function has the trace attribute set, it inherits the DEBUG trap */
+ if (debug_trap && ((trace_p (var) == 0) && function_trace_mode == 0))
+ {
+ if (subshell == 0)
+ {
+ debug_trap = savestring (debug_trap);
+ add_unwind_protect (xfree, debug_trap);
+ add_unwind_protect (set_debug_trap, debug_trap);
+ }
+ restore_default_signal (DEBUG_TRAP);
+ }
+
+ /* error_trace_mode != 0 means that functions inherit the ERR trap. */
+ if (error_trap && error_trace_mode == 0)
+ {
+ if (subshell == 0)
+ {
+ error_trap = savestring (error_trap);
+ add_unwind_protect (xfree, error_trap);
+ add_unwind_protect (set_error_trap, error_trap);
+ }
+ restore_default_signal (ERROR_TRAP);
+ }
+
+ /* Shell functions inherit the RETURN trap if function tracing is on
+ globally or on individually for this function. */
+#if 0
+ if (return_trap && ((trace_p (var) == 0) && function_trace_mode == 0))
+#else
+ if (return_trap && (signal_in_progress (DEBUG_TRAP) || ((trace_p (var) == 0) && function_trace_mode == 0)))
+#endif
+ {
+ if (subshell == 0)
+ {
+ return_trap = savestring (return_trap);
+ add_unwind_protect (xfree, return_trap);
+ add_unwind_protect (set_return_trap, return_trap);
+ }
+ restore_default_signal (RETURN_TRAP);
+ }
+
+ funcnest++;
+#if defined (ARRAY_VARS)
+ /* This is quite similar to the code in shell.c and elsewhere. */
+ shell_fn = find_function_def (this_shell_function->name);
+ sfile = shell_fn ? shell_fn->source_file : "";
+ array_push (funcname_a, this_shell_function->name);
+
+ array_push (bash_source_a, sfile);
+ t = itos (executing_line_number ());
+ array_push (bash_lineno_a, t);
+ free (t);
+#endif
+
+ /* The temporary environment for a function is supposed to apply to
+ all commands executed within the function body. */
+
+ remember_args (words->next, 1);
+
+ /* Update BASH_ARGV and BASH_ARGC */
+ if (debugging_mode)
+ push_args (words->next);
+
+ /* Number of the line on which the function body starts. */
+ line_number = function_line_number = tc->line;
+
+#if defined (JOB_CONTROL)
+ if (subshell)
+ stop_pipeline (async, (COMMAND *)NULL);
+#endif
+
+ fc = tc;
+
+ return_catch_flag++;
+ return_val = setjmp (return_catch);
+
+ if (return_val)
+ {
+ result = return_catch_value;
+ /* Run the RETURN trap in the function's context. */
+ save_current = currently_executing_command;
+ run_return_trap ();
+ currently_executing_command = save_current;
+ }
+ else
+ {
+ /* Run the debug trap here so we can trap at the start of a function's
+ execution rather than the execution of the body's first command. */
+ showing_function_line = 1;
+ save_current = currently_executing_command;
+ result = run_debug_trap ();
+#if defined (DEBUGGER)
+ /* In debugging mode, if the DEBUG trap returns a non-zero status, we
+ skip the command. */
+ if (debugging_mode == 0 || result == EXECUTION_SUCCESS)
+ {
+ showing_function_line = 0;
+ currently_executing_command = save_current;
+ result = execute_command_internal (fc, 0, NO_PIPE, NO_PIPE, fds_to_close);
+
+ /* Run the RETURN trap in the function's context */
+ save_current = currently_executing_command;
+ run_return_trap ();
+ currently_executing_command = save_current;
+ }
+#else
+ result = execute_command_internal (fc, 0, NO_PIPE, NO_PIPE, fds_to_close);
+
+ save_current = currently_executing_command;
+ run_return_trap ();
+ currently_executing_command = save_current;
+#endif
+ showing_function_line = 0;
+ }
+
+ /* Restore BASH_ARGC and BASH_ARGV */
+ if (debugging_mode)
+ pop_args ();
+
+ if (subshell == 0)
+ run_unwind_frame ("function_calling");
+
+#if defined (ARRAY_VARS)
+ /* These two variables cannot be unset, and cannot be affected by the
+ function. */
+ array_pop (bash_source_a);
+ array_pop (bash_lineno_a);
+
+ /* FUNCNAME can be unset, and so can potentially be changed by the
+ function. */
+ GET_ARRAY_FROM_VAR ("FUNCNAME", nfv, funcname_a);
+ if (nfv == funcname_v)
+ array_pop (funcname_a);
+#endif
+
+ if (variable_context == 0 || this_shell_function == 0)
+ {
+ make_funcname_visible (0);
+#if defined (PROCESS_SUBSTITUTION)
+ unlink_fifo_list ();
+#endif
+ }
+
+ return (result);
+}
+
+/* A convenience routine for use by other parts of the shell to execute
+ a particular shell function. */
+int
+execute_shell_function (var, words)
+ SHELL_VAR *var;
+ WORD_LIST *words;
+{
+ int ret;
+ struct fd_bitmap *bitmap;
+
+ bitmap = new_fd_bitmap (FD_BITMAP_DEFAULT_SIZE);
+ begin_unwind_frame ("execute-shell-function");
+ add_unwind_protect (dispose_fd_bitmap, (char *)bitmap);
+
+ ret = execute_function (var, words, 0, bitmap, 0, 0);
+
+ dispose_fd_bitmap (bitmap);
+ discard_unwind_frame ("execute-shell-function");
+
+ return ret;
+}
+
+/* Execute a shell builtin or function in a subshell environment. This
+ routine does not return; it only calls exit(). If BUILTIN is non-null,
+ it points to a function to call to execute a shell builtin; otherwise
+ VAR points at the body of a function to execute. WORDS is the arguments
+ to the command, REDIRECTS specifies redirections to perform before the
+ command is executed. */
+static void
+execute_subshell_builtin_or_function (words, redirects, builtin, var,
+ pipe_in, pipe_out, async, fds_to_close,
+ flags)
+ WORD_LIST *words;
+ REDIRECT *redirects;
+ sh_builtin_func_t *builtin;
+ SHELL_VAR *var;
+ int pipe_in, pipe_out, async;
+ struct fd_bitmap *fds_to_close;
+ int flags;
+{
+ int result, r, funcvalue;
+#if defined (JOB_CONTROL)
+ int jobs_hack;
+
+ jobs_hack = (builtin == jobs_builtin) &&
+ ((subshell_environment & SUBSHELL_ASYNC) == 0 || pipe_out != NO_PIPE);
+#endif
+
+ /* A subshell is neither a login shell nor interactive. */
+ login_shell = interactive = 0;
+
+ if (async)
+ subshell_environment |= SUBSHELL_ASYNC;
+ if (pipe_in != NO_PIPE || pipe_out != NO_PIPE)
+ subshell_environment |= SUBSHELL_PIPE;
+
+ maybe_make_export_env (); /* XXX - is this needed? */
+
+#if defined (JOB_CONTROL)
+ /* Eradicate all traces of job control after we fork the subshell, so
+ all jobs begun by this subshell are in the same process group as
+ the shell itself. */
+
+ /* Allow the output of `jobs' to be piped. */
+ if (jobs_hack)
+ kill_current_pipeline ();
+ else
+ without_job_control ();
+
+ set_sigchld_handler ();
+#endif /* JOB_CONTROL */
+
+ set_sigint_handler ();
+
+ if (fds_to_close)
+ close_fd_bitmap (fds_to_close);
+
+ do_piping (pipe_in, pipe_out);
+
+ if (do_redirections (redirects, RX_ACTIVE) != 0)
+ exit (EXECUTION_FAILURE);
+
+ if (builtin)
+ {
+ /* Give builtins a place to jump back to on failure,
+ so we don't go back up to main(). */
+ result = setjmp (top_level);
+
+ /* Give the return builtin a place to jump to when executed in a subshell
+ or pipeline */
+ funcvalue = 0;
+ if (return_catch_flag && builtin == return_builtin)
+ funcvalue = setjmp (return_catch);
+
+ if (result == EXITPROG)
+ exit (last_command_exit_value);
+ else if (result)
+ exit (EXECUTION_FAILURE);
+ else if (funcvalue)
+ exit (return_catch_value);
+ else
+ {
+ r = execute_builtin (builtin, words, flags, 1);
+ fflush (stdout);
+ if (r == EX_USAGE)
+ r = EX_BADUSAGE;
+ exit (r);
+ }
+ }
+ else
+ {
+ r = execute_function (var, words, flags, fds_to_close, async, 1);
+ fflush (stdout);
+ exit (r);
+ }
+}
+
+/* Execute a builtin or function in the current shell context. If BUILTIN
+ is non-null, it is the builtin command to execute, otherwise VAR points
+ to the body of a function. WORDS are the command's arguments, REDIRECTS
+ are the redirections to perform. FDS_TO_CLOSE is the usual bitmap of
+ file descriptors to close.
+
+ If BUILTIN is exec_builtin, the redirections specified in REDIRECTS are
+ not undone before this function returns. */
+static int
+execute_builtin_or_function (words, builtin, var, redirects,
+ fds_to_close, flags)
+ WORD_LIST *words;
+ sh_builtin_func_t *builtin;
+ SHELL_VAR *var;
+ REDIRECT *redirects;
+ struct fd_bitmap *fds_to_close;
+ int flags;
+{
+ int result;
+ REDIRECT *saved_undo_list;
+
+ if (do_redirections (redirects, RX_ACTIVE|RX_UNDOABLE) != 0)
+ {
+ cleanup_redirects (redirection_undo_list);
+ redirection_undo_list = (REDIRECT *)NULL;
+ dispose_exec_redirects ();
+ return (EX_REDIRFAIL); /* was EXECUTION_FAILURE */
+ }
+
+ saved_undo_list = redirection_undo_list;
+
+ /* Calling the "exec" builtin changes redirections forever. */
+ if (builtin == exec_builtin)
+ {
+ dispose_redirects (saved_undo_list);
+ saved_undo_list = exec_redirection_undo_list;
+ exec_redirection_undo_list = (REDIRECT *)NULL;
+ }
+ else
+ dispose_exec_redirects ();
+
+ if (saved_undo_list)
+ {
+ begin_unwind_frame ("saved redirects");
+ add_unwind_protect (cleanup_redirects, (char *)saved_undo_list);
+ }
+
+ redirection_undo_list = (REDIRECT *)NULL;
+
+ if (builtin)
+ result = execute_builtin (builtin, words, flags, 0);
+ else
+ result = execute_function (var, words, flags, fds_to_close, 0, 0);
+
+ /* We do this before undoing the effects of any redirections. */
+ fflush (stdout);
+ fpurge (stdout);
+ if (ferror (stdout))
+ clearerr (stdout);
+
+ /* If we are executing the `command' builtin, but this_shell_builtin is
+ set to `exec_builtin', we know that we have something like
+ `command exec [redirection]', since otherwise `exec' would have
+ overwritten the shell and we wouldn't get here. In this case, we
+ want to behave as if the `command' builtin had not been specified
+ and preserve the redirections. */
+ if (builtin == command_builtin && this_shell_builtin == exec_builtin)
+ {
+ if (saved_undo_list)
+ dispose_redirects (saved_undo_list);
+ redirection_undo_list = exec_redirection_undo_list;
+ saved_undo_list = exec_redirection_undo_list = (REDIRECT *)NULL;
+ discard_unwind_frame ("saved_redirects");
+ }
+
+ if (saved_undo_list)
+ {
+ redirection_undo_list = saved_undo_list;
+ discard_unwind_frame ("saved redirects");
+ }
+
+ if (redirection_undo_list)
+ {
+ cleanup_redirects (redirection_undo_list);
+ redirection_undo_list = (REDIRECT *)NULL;
+ }
+
+ return (result);
+}
+
+void
+setup_async_signals ()
+{
+#if defined (__BEOS__)
+ set_signal_handler (SIGHUP, SIG_IGN); /* they want csh-like behavior */
+#endif
+
+#if defined (JOB_CONTROL)
+ if (job_control == 0)
+#endif
+ {
+ set_signal_handler (SIGINT, SIG_IGN);
+ set_signal_ignored (SIGINT);
+ set_signal_handler (SIGQUIT, SIG_IGN);
+ set_signal_ignored (SIGQUIT);
+ }
+}
+
+/* Execute a simple command that is hopefully defined in a disk file
+ somewhere.
+
+ 1) fork ()
+ 2) connect pipes
+ 3) look up the command
+ 4) do redirections
+ 5) execve ()
+ 6) If the execve failed, see if the file has executable mode set.
+ If so, and it isn't a directory, then execute its contents as
+ a shell script.
+
+ Note that the filename hashing stuff has to take place up here,
+ in the parent. This is probably why the Bourne style shells
+ don't handle it, since that would require them to go through
+ this gnarly hair, for no good reason.
+
+ NOTE: callers expect this to fork or exit(). */
+
+/* Name of a shell function to call when a command name is not found. */
+#ifndef NOTFOUND_HOOK
+# define NOTFOUND_HOOK "command_not_found_handle"
+#endif
+
+static void
+execute_disk_command (words, redirects, command_line, pipe_in, pipe_out,
+ async, fds_to_close, cmdflags)
+ WORD_LIST *words;
+ REDIRECT *redirects;
+ char *command_line;
+ int pipe_in, pipe_out, async;
+ struct fd_bitmap *fds_to_close;
+ int cmdflags;
+{
+ char *pathname, *command, **args;
+ int nofork;
+ pid_t pid;
+ SHELL_VAR *hookf;
+ WORD_LIST *wl;
+
+ nofork = (cmdflags & CMD_NO_FORK); /* Don't fork, just exec, if no pipes */
+ pathname = words->word->word;
+
+#if defined (RESTRICTED_SHELL)
+ command = (char *)NULL;
+ if (restricted && mbschr (pathname, '/'))
+ {
+ internal_error (_("%s: restricted: cannot specify `/' in command names"),
+ pathname);
+ last_command_exit_value = EXECUTION_FAILURE;
+
+ /* If we're not going to fork below, we must already be in a child
+ process or a context in which it's safe to call exit(2). */
+ if (nofork && pipe_in == NO_PIPE && pipe_out == NO_PIPE)
+ exit (last_command_exit_value);
+ else
+ goto parent_return;
+ }
+#endif /* RESTRICTED_SHELL */
+
+ command = search_for_command (pathname);
+
+ if (command)
+ {
+ maybe_make_export_env ();
+ put_command_name_into_env (command);
+ }
+
+ /* We have to make the child before we check for the non-existence
+ of COMMAND, since we want the error messages to be redirected. */
+ /* If we can get away without forking and there are no pipes to deal with,
+ don't bother to fork, just directly exec the command. */
+ if (nofork && pipe_in == NO_PIPE && pipe_out == NO_PIPE)
+ pid = 0;
+ else
+ pid = make_child (savestring (command_line), async);
+
+ if (pid == 0)
+ {
+ int old_interactive;
+
+#if 0
+ /* This has been disabled for the time being. */
+#if !defined (ARG_MAX) || ARG_MAX >= 10240
+ if (posixly_correct == 0)
+ put_gnu_argv_flags_into_env ((long)getpid (), glob_argv_flags);
+#endif
+#endif
+
+ /* Cancel traps, in trap.c. */
+ restore_original_signals ();
+
+ /* restore_original_signals may have undone the work done
+ by make_child to ensure that SIGINT and SIGQUIT are ignored
+ in asynchronous children. */
+ if (async)
+ {
+ if ((cmdflags & CMD_STDIN_REDIR) &&
+ pipe_in == NO_PIPE &&
+ (stdin_redirects (redirects) == 0))
+ async_redirect_stdin ();
+ setup_async_signals ();
+ }
+
+ /* This functionality is now provided by close-on-exec of the
+ file descriptors manipulated by redirection and piping.
+ Some file descriptors still need to be closed in all children
+ because of the way bash does pipes; fds_to_close is a
+ bitmap of all such file descriptors. */
+ if (fds_to_close)
+ close_fd_bitmap (fds_to_close);
+
+ do_piping (pipe_in, pipe_out);
+
+ old_interactive = interactive;
+ if (async)
+ interactive = 0;
+
+ subshell_environment = SUBSHELL_FORK;
+
+ if (redirects && (do_redirections (redirects, RX_ACTIVE) != 0))
+ {
+#if defined (PROCESS_SUBSTITUTION)
+ /* Try to remove named pipes that may have been created as the
+ result of redirections. */
+ unlink_fifo_list ();
+#endif /* PROCESS_SUBSTITUTION */
+ exit (EXECUTION_FAILURE);
+ }
+
+ if (async)
+ interactive = old_interactive;
+
+ if (command == 0)
+ {
+ hookf = find_function (NOTFOUND_HOOK);
+ if (hookf == 0)
+ {
+ internal_error (_("%s: command not found"), pathname);
+ exit (EX_NOTFOUND); /* Posix.2 says the exit status is 127 */
+ }
+
+ wl = make_word_list (make_word (NOTFOUND_HOOK), words);
+ exit (execute_shell_function (hookf, wl));
+ }
+
+ /* Execve expects the command name to be in args[0]. So we
+ leave it there, in the same format that the user used to
+ type it in. */
+ args = strvec_from_word_list (words, 0, 0, (int *)NULL);
+ exit (shell_execve (command, args, export_env));
+ }
+ else
+ {
+parent_return:
+ /* Make sure that the pipes are closed in the parent. */
+ close_pipes (pipe_in, pipe_out);
+#if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD)
+ if (variable_context == 0)
+ unlink_fifo_list ();
+#endif
+ FREE (command);
+ }
+}
+
+/* CPP defines to decide whether a particular index into the #! line
+ corresponds to a valid interpreter name or argument character, or
+ whitespace. The MSDOS define is to allow \r to be treated the same
+ as \n. */
+
+#if !defined (MSDOS)
+# define STRINGCHAR(ind) \
+ (ind < sample_len && !whitespace (sample[ind]) && sample[ind] != '\n')
+# define WHITECHAR(ind) \
+ (ind < sample_len && whitespace (sample[ind]))
+#else /* MSDOS */
+# define STRINGCHAR(ind) \
+ (ind < sample_len && !whitespace (sample[ind]) && sample[ind] != '\n' && sample[ind] != '\r')
+# define WHITECHAR(ind) \
+ (ind < sample_len && whitespace (sample[ind]))
+#endif /* MSDOS */
+
+static char *
+getinterp (sample, sample_len, endp)
+ char *sample;
+ int sample_len, *endp;
+{
+ register int i;
+ char *execname;
+ int start;
+
+ /* Find the name of the interpreter to exec. */
+ for (i = 2; i < sample_len && whitespace (sample[i]); i++)
+ ;
+
+ for (start = i; STRINGCHAR(i); i++)
+ ;
+
+ execname = substring (sample, start, i);
+
+ if (endp)
+ *endp = i;
+ return execname;
+}
+
+#if !defined (HAVE_HASH_BANG_EXEC)
+/* If the operating system on which we're running does not handle
+ the #! executable format, then help out. SAMPLE is the text read
+ from the file, SAMPLE_LEN characters. COMMAND is the name of
+ the script; it and ARGS, the arguments given by the user, will
+ become arguments to the specified interpreter. ENV is the environment
+ to pass to the interpreter.
+
+ The word immediately following the #! is the interpreter to execute.
+ A single argument to the interpreter is allowed. */
+
+static int
+execute_shell_script (sample, sample_len, command, args, env)
+ char *sample;
+ int sample_len;
+ char *command;
+ char **args, **env;
+{
+ char *execname, *firstarg;
+ int i, start, size_increment, larry;
+
+ /* Find the name of the interpreter to exec. */
+ execname = getinterp (sample, sample_len, &i);
+ size_increment = 1;
+
+ /* Now the argument, if any. */
+ for (firstarg = (char *)NULL, start = i; WHITECHAR(i); i++)
+ ;
+
+ /* If there is more text on the line, then it is an argument for the
+ interpreter. */
+
+ if (STRINGCHAR(i))
+ {
+ for (start = i; STRINGCHAR(i); i++)
+ ;
+ firstarg = substring ((char *)sample, start, i);
+ size_increment = 2;
+ }
+
+ larry = strvec_len (args) + size_increment;
+ args = strvec_resize (args, larry + 1);
+
+ for (i = larry - 1; i; i--)
+ args[i] = args[i - size_increment];
+
+ args[0] = execname;
+ if (firstarg)
+ {
+ args[1] = firstarg;
+ args[2] = command;
+ }
+ else
+ args[1] = command;
+
+ args[larry] = (char *)NULL;
+
+ return (shell_execve (execname, args, env));
+}
+#undef STRINGCHAR
+#undef WHITECHAR
+
+#endif /* !HAVE_HASH_BANG_EXEC */
+
+static void
+initialize_subshell ()
+{
+#if defined (ALIAS)
+ /* Forget about any aliases that we knew of. We are in a subshell. */
+ delete_all_aliases ();
+#endif /* ALIAS */
+
+#if defined (HISTORY)
+ /* Forget about the history lines we have read. This is a non-interactive
+ subshell. */
+ history_lines_this_session = 0;
+#endif
+
+#if defined (JOB_CONTROL)
+ /* Forget about the way job control was working. We are in a subshell. */
+ without_job_control ();
+ set_sigchld_handler ();
+ init_job_stats ();
+#endif /* JOB_CONTROL */
+
+ /* Reset the values of the shell flags and options. */
+ reset_shell_flags ();
+ reset_shell_options ();
+ reset_shopt_options ();
+
+ /* Zero out builtin_env, since this could be a shell script run from a
+ sourced file with a temporary environment supplied to the `source/.'
+ builtin. Such variables are not supposed to be exported (empirical
+ testing with sh and ksh). Just throw it away; don't worry about a
+ memory leak. */
+ if (vc_isbltnenv (shell_variables))
+ shell_variables = shell_variables->down;
+
+ clear_unwind_protect_list (0);
+ /* XXX -- are there other things we should be resetting here? */
+ parse_and_execute_level = 0; /* nothing left to restore it */
+
+ /* We're no longer inside a shell function. */
+ variable_context = return_catch_flag = funcnest = 0;
+
+ executing_list = 0; /* XXX */
+
+ /* If we're not interactive, close the file descriptor from which we're
+ reading the current shell script. */
+ if (interactive_shell == 0)
+ unset_bash_input (0);
+}
+
+#if defined (HAVE_SETOSTYPE) && defined (_POSIX_SOURCE)
+# define SETOSTYPE(x) __setostype(x)
+#else
+# define SETOSTYPE(x)
+#endif
+
+#define READ_SAMPLE_BUF(file, buf, len) \
+ do \
+ { \
+ fd = open(file, O_RDONLY); \
+ if (fd >= 0) \
+ { \
+ len = read (fd, buf, 80); \
+ close (fd); \
+ } \
+ else \
+ len = -1; \
+ } \
+ while (0)
+
+/* Call execve (), handling interpreting shell scripts, and handling
+ exec failures. */
+int
+shell_execve (command, args, env)
+ char *command;
+ char **args, **env;
+{
+ int larray, i, fd;
+ char sample[80];
+ int sample_len;
+
+ SETOSTYPE (0); /* Some systems use for USG/POSIX semantics */
+ execve (command, args, env);
+ i = errno; /* error from execve() */
+ CHECK_TERMSIG;
+ SETOSTYPE (1);
+
+ /* If we get to this point, then start checking out the file.
+ Maybe it is something we can hack ourselves. */
+ if (i != ENOEXEC)
+ {
+ if (file_isdir (command))
+ internal_error (_("%s: is a directory"), command);
+ else if (executable_file (command) == 0)
+ {
+ errno = i;
+ file_error (command);
+ }
+ /* errors not involving the path argument to execve. */
+ else if (i == E2BIG || i == ENOMEM)
+ {
+ errno = i;
+ file_error (command);
+ }
+ else
+ {
+ /* The file has the execute bits set, but the kernel refuses to
+ run it for some reason. See why. */
+#if defined (HAVE_HASH_BANG_EXEC)
+ READ_SAMPLE_BUF (command, sample, sample_len);
+ if (sample_len > 2 && sample[0] == '#' && sample[1] == '!')
+ {
+ char *interp;
+ int ilen;
+
+ interp = getinterp (sample, sample_len, (int *)NULL);
+ ilen = strlen (interp);
+ errno = i;
+ if (interp[ilen - 1] == '\r')
+ {
+ interp = xrealloc (interp, ilen + 2);
+ interp[ilen - 1] = '^';
+ interp[ilen] = 'M';
+ interp[ilen + 1] = '\0';
+ }
+ sys_error (_("%s: %s: bad interpreter"), command, interp ? interp : "");
+ FREE (interp);
+ return (EX_NOEXEC);
+ }
+#endif
+ errno = i;
+ file_error (command);
+ }
+ return ((i == ENOENT) ? EX_NOTFOUND : EX_NOEXEC); /* XXX Posix.2 says that exit status is 126 */
+ }
+
+ /* This file is executable.
+ If it begins with #!, then help out people with losing operating
+ systems. Otherwise, check to see if it is a binary file by seeing
+ if the contents of the first line (or up to 80 characters) are in the
+ ASCII set. If it's a text file, execute the contents as shell commands,
+ otherwise return 126 (EX_BINARY_FILE). */
+ READ_SAMPLE_BUF (command, sample, sample_len);
+
+ if (sample_len == 0)
+ return (EXECUTION_SUCCESS);
+
+ /* Is this supposed to be an executable script?
+ If so, the format of the line is "#! interpreter [argument]".
+ A single argument is allowed. The BSD kernel restricts
+ the length of the entire line to 32 characters (32 bytes
+ being the size of the BSD exec header), but we allow 80
+ characters. */
+ if (sample_len > 0)
+ {
+#if !defined (HAVE_HASH_BANG_EXEC)
+ if (sample_len > 2 && sample[0] == '#' && sample[1] == '!')
+ return (execute_shell_script (sample, sample_len, command, args, env));
+ else
+#endif
+ if (check_binary_file (sample, sample_len))
+ {
+ internal_error (_("%s: cannot execute binary file"), command);
+ return (EX_BINARY_FILE);
+ }
+ }
+
+ /* We have committed to attempting to execute the contents of this file
+ as shell commands. */
+
+ initialize_subshell ();
+
+ set_sigint_handler ();
+
+ /* Insert the name of this shell into the argument list. */
+ larray = strvec_len (args) + 1;
+ args = strvec_resize (args, larray + 1);
+
+ for (i = larray - 1; i; i--)
+ args[i] = args[i - 1];
+
+ args[0] = exec_argv0 ? shell_name : exec_argv0;
+ exec_argv0 = (char *)NULL;
+ args[1] = command;
+ args[larray] = (char *)NULL;
+
+ if (args[0][0] == '-')
+ args[0]++;
+
+#if defined (RESTRICTED_SHELL)
+ if (restricted)
+ change_flag ('r', FLAG_OFF);
+#endif
+
+ if (subshell_argv)
+ {
+ /* Can't free subshell_argv[0]; that is shell_name. */
+ for (i = 1; i < subshell_argc; i++)
+ free (subshell_argv[i]);
+ free (subshell_argv);
+ }
+
+ dispose_command (currently_executing_command); /* XXX */
+ currently_executing_command = (COMMAND *)NULL;
+
+ subshell_argc = larray;
+ subshell_argv = args;
+ subshell_envp = env;
+
+ unbind_args (); /* remove the positional parameters */
+
+ longjmp (subshell_top_level, 1);
+ /*NOTREACHED*/
+}
+
+static int
+execute_intern_function (name, function)
+ WORD_DESC *name;
+ COMMAND *function;
+{
+ SHELL_VAR *var;
+
+ if (check_identifier (name, posixly_correct) == 0)
+ {
+ if (posixly_correct && interactive_shell == 0)
+ {
+ last_command_exit_value = EX_BADUSAGE;
+ jump_to_top_level (ERREXIT);
+ }
+ return (EXECUTION_FAILURE);
+ }
+
+ var = find_function (name->word);
+ if (var && (readonly_p (var) || noassign_p (var)))
+ {
+ if (readonly_p (var))
+ internal_error (_("%s: readonly function"), var->name);
+ return (EXECUTION_FAILURE);
+ }
+
+ bind_function (name->word, function);
+ return (EXECUTION_SUCCESS);
+}
+
+#if defined (INCLUDE_UNUSED)
+#if defined (PROCESS_SUBSTITUTION)
+void
+close_all_files ()
+{
+ register int i, fd_table_size;
+
+ fd_table_size = getdtablesize ();
+ if (fd_table_size > 256) /* clamp to a reasonable value */
+ fd_table_size = 256;
+
+ for (i = 3; i < fd_table_size; i++)
+ close (i);
+}
+#endif /* PROCESS_SUBSTITUTION */
+#endif
+
+static void
+close_pipes (in, out)
+ int in, out;
+{
+ if (in >= 0)
+ close (in);
+ if (out >= 0)
+ close (out);
+}
+
+static void
+dup_error (oldd, newd)
+ int oldd, newd;
+{
+ sys_error (_("cannot duplicate fd %d to fd %d"), oldd, newd);
+}
+
+/* Redirect input and output to be from and to the specified pipes.
+ NO_PIPE and REDIRECT_BOTH are handled correctly. */
+static void
+do_piping (pipe_in, pipe_out)
+ int pipe_in, pipe_out;
+{
+ if (pipe_in != NO_PIPE)
+ {
+ if (dup2 (pipe_in, 0) < 0)
+ dup_error (pipe_in, 0);
+ if (pipe_in > 0)
+ close (pipe_in);
+ }
+ if (pipe_out != NO_PIPE)
+ {
+ if (pipe_out != REDIRECT_BOTH)
+ {
+ if (dup2 (pipe_out, 1) < 0)
+ dup_error (pipe_out, 1);
+ if (pipe_out == 0 || pipe_out > 1)
+ close (pipe_out);
+ }
+ else
+ {
+ if (dup2 (1, 2) < 0)
+ dup_error (1, 2);
+ }
+ }
+}
WAIT s;
register PROCESS *child;
sigset_t set, oset;
- register PROCESS *p;
/* In the case that this code is interrupted, and we longjmp () out of it,
we are relying on the code in throw_to_top_level () to restore the
extern int errno;
#endif /* !errno */
+#if !defined (HAVE_KILLPG)
+extern int killpg __P((pid_t, int));
+#endif
+
#define DEFAULT_CHILD_MAX 32
#if !defined (DEBUG)
#define MAX_JOBS_IN_ARRAY 4096 /* production */
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 compspec for that command. This allows a set of
+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.
--- /dev/null
+@comment %**start of header (This is for running Texinfo on a region.)
+@setfilename rluser.info
+@comment %**end of header (This is for running Texinfo on a region.)
+
+@ignore
+This file documents the end user interface to the GNU command line
+editing features. It is to be an appendix to manuals for programs which
+use these features. There is a document entitled "readline.texinfo"
+which contains both end-user and programmer documentation for the
+GNU Readline Library.
+
+Copyright (C) 1988--2009 Free Software Foundation, Inc.
+
+Authored by Brian Fox and Chet Ramey.
+
+Permission is granted to process this file through Tex and print the
+results, provided the printed document carries copying permission notice
+identical to this one except for the removal of this paragraph (this
+paragraph not being relevant to the printed manual).
+
+Permission is granted to make and distribute verbatim copies of this manual
+provided the copyright notice and this permission notice are preserved on
+all copies.
+
+Permission is granted to copy and distribute modified versions of this
+manual under the conditions for verbatim copying, provided also that the
+GNU Copyright statement is available to the distributee, and provided that
+the entire resulting derived work is distributed under the terms of a
+permission notice identical to this one.
+
+Permission is granted to copy and distribute translations of this manual
+into another language, under the above conditions for modified versions.
+@end ignore
+
+@comment If you are including this manual as an appendix, then set the
+@comment variable readline-appendix.
+
+@ifclear BashFeatures
+@defcodeindex bt
+@end ifclear
+
+@node Command Line Editing
+@chapter Command Line Editing
+
+This chapter describes the basic features of the @sc{gnu}
+command line editing interface.
+@ifset BashFeatures
+Command line editing is provided by the Readline library, which is
+used by several different programs, including Bash.
+Command line editing is enabled by default when using an interactive shell,
+unless the @option{--noediting} option is supplied at shell invocation.
+Line editing is also used when using the @option{-e} option to the
+@code{read} builtin command (@pxref{Bash Builtins}).
+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 @option{-o emacs} or
+@option{-o vi} options to the @code{set} builtin command
+(@pxref{The Set Builtin}), or disabled using the @option{+o emacs} or
+@option{+o vi} options to @code{set}.
+@end ifset
+
+@menu
+* Introduction and Notation:: Notation used in this text.
+* Readline Interaction:: The minimum set of commands for editing a line.
+* Readline Init File:: Customizing Readline from a user's view.
+* Bindable Readline Commands:: A description of most of the Readline commands
+ available for binding
+* Readline vi Mode:: A short description of how to make Readline
+ behave like the vi editor.
+@ifset BashFeatures
+* Programmable Completion:: How to specify the possible completions for
+ a specific command.
+* Programmable Completion Builtins:: Builtin commands to specify how to
+ complete arguments for a particular command.
+@end ifset
+@end menu
+
+@node Introduction and Notation
+@section Introduction to Line Editing
+
+The following paragraphs describe the notation used to represent
+keystrokes.
+
+The text @kbd{C-k} is read as `Control-K' and describes the character
+produced when the @key{k} key is pressed while the Control key
+is depressed.
+
+The text @kbd{M-k} is read as `Meta-K' and describes the character
+produced when the Meta key (if you have one) is depressed, and the @key{k}
+key is pressed.
+The Meta key is labeled @key{ALT} on many keyboards.
+On keyboards with two keys labeled @key{ALT} (usually to either side of
+the space bar), the @key{ALT} on the left side is generally set to
+work as a Meta key.
+The @key{ALT} key on the right may also be configured to work as a
+Meta key or may be configured as some other modifier, such as a
+Compose key for typing accented characters.
+
+If you do not have a Meta or @key{ALT} key, or another key working as
+a Meta key, the identical keystroke can be generated by typing @key{ESC}
+@emph{first}, and then typing @key{k}.
+Either process is known as @dfn{metafying} the @key{k} key.
+
+The text @kbd{M-C-k} is read as `Meta-Control-k' and describes the
+character produced by @dfn{metafying} @kbd{C-k}.
+
+In addition, several keys have their own names. Specifically,
+@key{DEL}, @key{ESC}, @key{LFD}, @key{SPC}, @key{RET}, and @key{TAB} all
+stand for themselves when seen in this text, or in an init file
+(@pxref{Readline Init File}).
+If your keyboard lacks a @key{LFD} key, typing @key{C-j} will
+produce the desired character.
+The @key{RET} key may be labeled @key{Return} or @key{Enter} on
+some keyboards.
+
+@node Readline Interaction
+@section Readline Interaction
+@cindex interaction, readline
+
+Often during an interactive session you type in a long line of text,
+only to notice that the first word on the line is misspelled. The
+Readline library gives you a set of commands for manipulating the text
+as you type it in, allowing you to just fix your typo, and not forcing
+you to retype the majority of the line. Using these editing commands,
+you move the cursor to the place that needs correction, and delete or
+insert the text of the corrections. Then, when you are satisfied with
+the line, you simply press @key{RET}. You do not have to be at the
+end of the line to press @key{RET}; the entire line is accepted
+regardless of the location of the cursor within the line.
+
+@menu
+* Readline Bare Essentials:: The least you need to know about Readline.
+* Readline Movement Commands:: Moving about the input line.
+* Readline Killing Commands:: How to delete text, and how to get it back!
+* Readline Arguments:: Giving numeric arguments to commands.
+* Searching:: Searching through previous lines.
+@end menu
+
+@node Readline Bare Essentials
+@subsection Readline Bare Essentials
+@cindex notation, readline
+@cindex command editing
+@cindex editing command lines
+
+In order to enter characters into the line, simply type them. The typed
+character appears where the cursor was, and then the cursor moves one
+space to the right. If you mistype a character, you can use your
+erase character to back up and delete the mistyped character.
+
+Sometimes you may mistype a character, and
+not notice the error until you have typed several other characters. In
+that case, you can type @kbd{C-b} to move the cursor to the left, and then
+correct your mistake. Afterwards, you can move the cursor to the right
+with @kbd{C-f}.
+
+When you add text in the middle of a line, you will notice that characters
+to the right of the cursor are `pushed over' to make room for the text
+that you have inserted. Likewise, when you delete text behind the cursor,
+characters to the right of the cursor are `pulled back' to fill in the
+blank space created by the removal of the text. A list of the bare
+essentials for editing the text of an input line follows.
+
+@table @asis
+@item @kbd{C-b}
+Move back one character.
+@item @kbd{C-f}
+Move forward one character.
+@item @key{DEL} or @key{Backspace}
+Delete the character to the left of the cursor.
+@item @kbd{C-d}
+Delete the character underneath the cursor.
+@item @w{Printing characters}
+Insert the character into the line at the cursor.
+@item @kbd{C-_} or @kbd{C-x C-u}
+Undo the last editing command. You can undo all the way back to an
+empty line.
+@end table
+
+@noindent
+(Depending on your configuration, the @key{Backspace} key be set to
+delete the character to the left of the cursor and the @key{DEL} key set
+to delete the character underneath the cursor, like @kbd{C-d}, rather
+than the character to the left of the cursor.)
+
+@node Readline Movement Commands
+@subsection Readline Movement Commands
+
+
+The above table describes the most basic keystrokes that you need
+in order to do editing of the input line. For your convenience, many
+other commands have been added in addition to @kbd{C-b}, @kbd{C-f},
+@kbd{C-d}, and @key{DEL}. Here are some commands for moving more rapidly
+about the line.
+
+@table @kbd
+@item C-a
+Move to the start of the line.
+@item C-e
+Move to the end of the line.
+@item M-f
+Move forward a word, where a word is composed of letters and digits.
+@item M-b
+Move backward a word.
+@item C-l
+Clear the screen, reprinting the current line at the top.
+@end table
+
+Notice how @kbd{C-f} moves forward a character, while @kbd{M-f} moves
+forward a word. It is a loose convention that control keystrokes
+operate on characters while meta keystrokes operate on words.
+
+@node Readline Killing Commands
+@subsection Readline Killing Commands
+
+@cindex killing text
+@cindex yanking text
+
+@dfn{Killing} text means to delete the text from the line, but to save
+it away for later use, usually by @dfn{yanking} (re-inserting)
+it back into the line.
+(`Cut' and `paste' are more recent jargon for `kill' and `yank'.)
+
+If the description for a command says that it `kills' text, then you can
+be sure that you can get the text back in a different (or the same)
+place later.
+
+When you use a kill command, the text is saved in a @dfn{kill-ring}.
+Any number of consecutive kills save all of the killed text together, so
+that when you yank it back, you get it all. The kill
+ring is not line specific; the text that you killed on a previously
+typed line is available to be yanked back later, when you are typing
+another line.
+@cindex kill ring
+
+Here is the list of commands for killing text.
+
+@table @kbd
+@item C-k
+Kill the text from the current cursor position to the end of the line.
+
+@item M-d
+Kill from the cursor 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 @kbd{M-f}.
+
+@item M-@key{DEL}
+Kill from the cursor the start of the current word, or, if between
+words, to the start of the previous word.
+Word boundaries are the same as those used by @kbd{M-b}.
+
+@item C-w
+Kill from the cursor to the previous whitespace. This is different than
+@kbd{M-@key{DEL}} because the word boundaries differ.
+
+@end table
+
+Here is how to @dfn{yank} the text back into the line. Yanking
+means to copy the most-recently-killed text from the kill buffer.
+
+@table @kbd
+@item C-y
+Yank the most recently killed text back into the buffer at the cursor.
+
+@item M-y
+Rotate the kill-ring, and yank the new top. You can only do this if
+the prior command is @kbd{C-y} or @kbd{M-y}.
+@end table
+
+@node Readline Arguments
+@subsection Readline Arguments
+
+You can pass numeric arguments to Readline commands. Sometimes the
+argument acts as a repeat count, other times it is the @i{sign} of the
+argument that is significant. If you pass a negative argument to a
+command which normally acts in a forward direction, that command will
+act in a backward direction. For example, to kill text back to the
+start of the line, you might type @samp{M-- C-k}.
+
+The general way to pass numeric arguments to a command is to type meta
+digits before the command. If the first `digit' typed is a minus
+sign (@samp{-}), then the sign of the argument will be negative. Once
+you have typed one meta digit to get the argument started, you can type
+the remainder of the digits, and then the command. For example, to give
+the @kbd{C-d} command an argument of 10, you could type @samp{M-1 0 C-d},
+which will delete the next ten characters on the input line.
+
+@node Searching
+@subsection Searching for Commands in the History
+
+Readline provides commands for searching through the command history
+@ifset BashFeatures
+(@pxref{Bash History Facilities})
+@end ifset
+for lines containing a specified string.
+There are two search modes: @dfn{incremental} and @dfn{non-incremental}.
+
+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.
+To search backward in the history for a particular string, type
+@kbd{C-r}. Typing @kbd{C-s} searches forward through the history.
+The characters present in the value of the @code{isearch-terminators} variable
+are used to terminate an incremental search.
+If that variable has not been assigned a value, the @key{ESC} and
+@kbd{C-J} characters will terminate an incremental search.
+@kbd{C-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.
+
+To find other matching entries in the history list, type @kbd{C-r} or
+@kbd{C-s} 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 @key{RET} will terminate the search and accept
+the line, thereby executing the command from the history list.
+A movement command will terminate the search, make the last line found
+the current line, and begin editing.
+
+Readline remembers the last incremental search string. If two
+@kbd{C-r}s are typed without any intervening characters defining a new
+search string, any remembered search string is used.
+
+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.
+
+@node Readline Init File
+@section Readline Init File
+@cindex initialization file, readline
+
+Although the Readline library comes with a set of Emacs-like
+keybindings installed by default, it is possible to use a different set
+of keybindings.
+Any user can customize programs that use Readline by putting
+commands in an @dfn{inputrc} file, conventionally in his home directory.
+The name of this
+@ifset BashFeatures
+file is taken from the value of the shell variable @env{INPUTRC}. If
+@end ifset
+@ifclear BashFeatures
+file is taken from the value of the environment variable @env{INPUTRC}. If
+@end ifclear
+that variable is unset, the default is @file{~/.inputrc}. If that
+file does not exist or cannot be read, the ultimate default is
+@file{/etc/inputrc}.
+
+When a program which uses the Readline library starts up, the
+init file is read, and the key bindings are set.
+
+In addition, the @code{C-x C-r} command re-reads this init file, thus
+incorporating any changes that you might have made to it.
+
+@menu
+* Readline Init File Syntax:: Syntax for the commands in the inputrc file.
+
+* Conditional Init Constructs:: Conditional key bindings in the inputrc file.
+
+* Sample Init File:: An example inputrc file.
+@end menu
+
+@node Readline Init File Syntax
+@subsection Readline Init File Syntax
+
+There are only a few basic constructs allowed in the
+Readline init file. Blank lines are ignored.
+Lines beginning with a @samp{#} are comments.
+Lines beginning with a @samp{$} indicate conditional
+constructs (@pxref{Conditional Init Constructs}). Other lines
+denote variable settings and key bindings.
+
+@table @asis
+@item Variable Settings
+You can modify the run-time behavior of Readline by
+altering the values of variables in Readline
+using the @code{set} command within the init file.
+The syntax is simple:
+
+@example
+set @var{variable} @var{value}
+@end example
+
+@noindent
+Here, for example, is how to
+change from the default Emacs-like key binding to use
+@code{vi} line editing commands:
+
+@example
+set editing-mode vi
+@end example
+
+Variable names and values, where appropriate, are recognized without regard
+to case. Unrecognized variable names are ignored.
+
+Boolean variables (those that can be set to on or off) are set to on if
+the value is null or empty, @var{on} (case-insensitive), or 1. Any other
+value results in the variable being set to off.
+
+@ifset BashFeatures
+The @w{@code{bind -V}} command lists the current Readline variable names
+and values. @xref{Bash Builtins}.
+@end ifset
+
+A great deal of run-time behavior is changeable with the following
+variables.
+
+@cindex variables, readline
+@table @code
+
+@item bell-style
+@vindex bell-style
+Controls what happens when Readline wants to ring the terminal bell.
+If set to @samp{none}, Readline never rings the bell. If set to
+@samp{visible}, Readline uses a visible bell if one is available.
+If set to @samp{audible} (the default), Readline attempts to ring
+the terminal's bell.
+
+@item bind-tty-special-chars
+@vindex bind-tty-special-chars
+If set to @samp{on}, Readline attempts to bind the control characters
+treated specially by the kernel's terminal driver to their Readline
+equivalents.
+
+@item comment-begin
+@vindex comment-begin
+The string to insert at the beginning of the line when the
+@code{insert-comment} command is executed. The default value
+is @code{"#"}.
+
+@item completion-ignore-case
+If set to @samp{on}, Readline performs filename matching and completion
+in a case-insensitive fashion.
+The default value is @samp{off}.
+
+@item completion-prefix-display-length
+@vindex completion-prefix-display-length
+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.
+
+@item completion-query-items
+@vindex completion-query-items
+The number of possible completions that determines when the user is
+asked whether the list of possibilities should be displayed.
+If the number of possible completions is greater than this value,
+Readline will ask the user whether or not he wishes to view
+them; otherwise, they are simply listed.
+This variable must be set to an integer value greater than or equal to 0.
+A negative value means Readline should never ask.
+The default limit is @code{100}.
+
+@item convert-meta
+@vindex convert-meta
+If set to @samp{on}, Readline will convert characters with the
+eighth bit set to an @sc{ascii} key sequence by stripping the eighth
+bit and prefixing an @key{ESC} character, converting them to a
+meta-prefixed key sequence. The default value is @samp{on}.
+
+@item disable-completion
+@vindex disable-completion
+If set to @samp{On}, Readline will inhibit word completion.
+Completion characters will be inserted into the line as if they had
+been mapped to @code{self-insert}. The default is @samp{off}.
+
+@item editing-mode
+@vindex editing-mode
+The @code{editing-mode} variable controls which default set of
+key bindings is used. By default, Readline starts up in Emacs editing
+mode, where the keystrokes are most similar to Emacs. This variable can be
+set to either @samp{emacs} or @samp{vi}.
+
+@item echo-control-characters
+When set to @samp{on}, on operating systems that indicate they support it,
+readline echoes a character corresponding to a signal generated from the
+keyboard. The default is @samp{on}.
+
+@item enable-keypad
+@vindex enable-keypad
+When set to @samp{on}, Readline will try to enable the application
+keypad when it is called. Some systems need this to enable the
+arrow keys. The default is @samp{off}.
+
+@item enable-meta-key
+When set to @samp{on}, 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.
+The default is @samp{on}.
+
+@item expand-tilde
+@vindex expand-tilde
+If set to @samp{on}, tilde expansion is performed when Readline
+attempts word completion. The default is @samp{off}.
+
+@item history-preserve-point
+@vindex history-preserve-point
+If set to @samp{on}, the history code attempts to place the point (the
+current cursor position) at the
+same location on each history line retrieved with @code{previous-history}
+or @code{next-history}. The default is @samp{off}.
+
+@item history-size
+@vindex history-size
+Set the maximum number of history entries saved in the history list. If
+set to zero, the number of entries in the history list is not limited.
+
+@item horizontal-scroll-mode
+@vindex horizontal-scroll-mode
+This variable can be set to either @samp{on} or @samp{off}. Setting it
+to @samp{on} means that the text of the lines being edited will scroll
+horizontally on a single screen line when they are longer than the width
+of the screen, instead of wrapping onto a new screen line. By default,
+this variable is set to @samp{off}.
+
+@item input-meta
+@vindex input-meta
+@vindex meta-flag
+If set to @samp{on}, Readline will enable eight-bit input (it
+will not clear the eighth bit in the characters it reads),
+regardless of what the terminal claims it can support. The
+default value is @samp{off}. The name @code{meta-flag} is a
+synonym for this variable.
+
+@item isearch-terminators
+@vindex isearch-terminators
+The string of characters that should terminate an incremental search without
+subsequently executing the character as a command (@pxref{Searching}).
+If this variable has not been given a value, the characters @key{ESC} and
+@kbd{C-J} will terminate an incremental search.
+
+@item keymap
+@vindex keymap
+Sets Readline's idea of the current keymap for key binding commands.
+Acceptable @code{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}. The default value is @code{emacs}.
+The value of the @code{editing-mode} variable also affects the
+default keymap.
+
+@item mark-directories
+If set to @samp{on}, completed directory names have a slash
+appended. The default is @samp{on}.
+
+@item mark-modified-lines
+@vindex mark-modified-lines
+This variable, when set to @samp{on}, causes Readline to display an
+asterisk (@samp{*}) at the start of history lines which have been modified.
+This variable is @samp{off} by default.
+
+@item mark-symlinked-directories
+@vindex mark-symlinked-directories
+If set to @samp{on}, completed names which are symbolic links
+to directories have a slash appended (subject to the value of
+@code{mark-directories}).
+The default is @samp{off}.
+
+@item match-hidden-files
+@vindex match-hidden-files
+This variable, when set to @samp{on}, causes Readline to match files whose
+names begin with a @samp{.} (hidden files) when performing filename
+completion, unless the leading @samp{.} is
+supplied by the user in the filename to be completed.
+This variable is @samp{on} by default.
+
+@item output-meta
+@vindex output-meta
+If set to @samp{on}, Readline will display characters with the
+eighth bit set directly rather than as a meta-prefixed escape
+sequence. The default is @samp{off}.
+
+@item page-completions
+@vindex page-completions
+If set to @samp{on}, Readline uses an internal @code{more}-like pager
+to display a screenful of possible completions at a time.
+This variable is @samp{on} by default.
+
+@item print-completions-horizontally
+If set to @samp{on}, Readline will display completions with matches
+sorted horizontally in alphabetical order, rather than down the screen.
+The default is @samp{off}.
+
+@item revert-all-at-newline
+@vindex revert-all-at-newline
+If set to @samp{on}, Readline will undo all changes to history lines
+before returning when @code{accept-line} is executed. By default,
+history lines may be modified and retain individual undo lists across
+calls to @code{readline}. The default is @samp{off}.
+
+@item show-all-if-ambiguous
+@vindex show-all-if-ambiguous
+This alters the default behavior of the completion functions. If
+set to @samp{on},
+words which have more than one possible completion cause the
+matches to be listed immediately instead of ringing the bell.
+The default value is @samp{off}.
+
+@item show-all-if-unmodified
+@vindex show-all-if-unmodified
+This alters the default behavior of the completion functions in
+a fashion similar to @var{show-all-if-ambiguous}.
+If set to @samp{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.
+The default value is @samp{off}.
+
+@item skip-completed-text
+@vindex skip-completed-text
+If set to @samp{on}, 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.
+For instance, if this is enabled, attempting completion when the cursor
+is after the @samp{e} in @samp{Makefile} will result in @samp{Makefile}
+rather than @samp{Makefilefile}, assuming there is a single possible
+completion.
+The default value is @samp{off}.
+
+@item visible-stats
+@vindex visible-stats
+If set to @samp{on}, a character denoting a file's type
+is appended to the filename when listing possible
+completions. The default is @samp{off}.
+
+@end table
+
+@item Key Bindings
+The syntax for controlling key bindings in the init file is
+simple. First you need to find the name of the command that you
+want to change. The following sections contain tables of the command
+name, the default keybinding, if any, and a short description of what
+the command does.
+
+Once you know the name of the command, simply place on a line
+in the init file the name of the key
+you wish to bind the command to, a colon, and then the name of the
+command.
+There can be no space between the key name and the colon -- that will be
+interpreted as part of the key name.
+The name of the key can be expressed in different ways, depending on
+what you find most comfortable.
+
+In addition to command names, readline allows keys to be bound
+to a string that is inserted when the key is pressed (a @var{macro}).
+
+@ifset BashFeatures
+The @w{@code{bind -p}} command displays Readline function names and
+bindings in a format that can put directly into an initialization file.
+@xref{Bash Builtins}.
+@end ifset
+
+@table @asis
+@item @w{@var{keyname}: @var{function-name} or @var{macro}}
+@var{keyname} is the name of a key spelled out in English. For example:
+@example
+Control-u: universal-argument
+Meta-Rubout: backward-kill-word
+Control-o: "> output"
+@end example
+
+In the above example, @kbd{C-u} is bound to the function
+@code{universal-argument},
+@kbd{M-DEL} is bound to the function @code{backward-kill-word}, and
+@kbd{C-o} is bound to run the macro
+expressed on the right hand side (that is, to insert the text
+@samp{> output} into the line).
+
+A number of symbolic character names are recognized while
+processing this key binding syntax:
+@var{DEL},
+@var{ESC},
+@var{ESCAPE},
+@var{LFD},
+@var{NEWLINE},
+@var{RET},
+@var{RETURN},
+@var{RUBOUT},
+@var{SPACE},
+@var{SPC},
+and
+@var{TAB}.
+
+@item @w{"@var{keyseq}": @var{function-name} or @var{macro}}
+@var{keyseq} differs from @var{keyname} above in that strings
+denoting an entire key sequence can be specified, by placing
+the key sequence in double quotes. Some @sc{gnu} Emacs style key
+escapes can be used, as in the following example, but the
+special character names are not recognized.
+
+@example
+"\C-u": universal-argument
+"\C-x\C-r": re-read-init-file
+"\e[11~": "Function Key 1"
+@end example
+
+In the above example, @kbd{C-u} is again bound to the function
+@code{universal-argument} (just as it was in the first example),
+@samp{@kbd{C-x} @kbd{C-r}} is bound to the function @code{re-read-init-file},
+and @samp{@key{ESC} @key{[} @key{1} @key{1} @key{~}} is bound to insert
+the text @samp{Function Key 1}.
+
+@end table
+
+The following @sc{gnu} Emacs style escape sequences are available when
+specifying key sequences:
+
+@table @code
+@item @kbd{\C-}
+control prefix
+@item @kbd{\M-}
+meta prefix
+@item @kbd{\e}
+an escape character
+@item @kbd{\\}
+backslash
+@item @kbd{\"}
+@key{"}, a double quotation mark
+@item @kbd{\'}
+@key{'}, a single quote or apostrophe
+@end table
+
+In addition to the @sc{gnu} Emacs style escape sequences, a second
+set of backslash escapes is available:
+
+@table @code
+@item \a
+alert (bell)
+@item \b
+backspace
+@item \d
+delete
+@item \f
+form feed
+@item \n
+newline
+@item \r
+carriage return
+@item \t
+horizontal tab
+@item \v
+vertical tab
+@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)
+@end table
+
+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 @samp{"} and @samp{'}.
+For example, the following binding will make @samp{@kbd{C-x} \}
+insert a single @samp{\} into the line:
+@example
+"\C-x\\": "\\"
+@end example
+
+@end table
+
+@node Conditional Init Constructs
+@subsection Conditional Init Constructs
+
+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.
+
+@table @code
+@item $if
+The @code{$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.
+
+@table @code
+@item mode
+The @code{mode=} form of the @code{$if} directive is used to test
+whether Readline is in @code{emacs} or @code{vi} mode.
+This may be used in conjunction
+with the @samp{set keymap} command, for instance, to set bindings in
+the @code{emacs-standard} and @code{emacs-ctlx} keymaps only if
+Readline is starting out in @code{emacs} mode.
+
+@item term
+The @code{term=} form may be used to include terminal-specific
+key bindings, perhaps to bind the key sequences output by the
+terminal's function keys. The word on the right side of the
+@samp{=} is tested against both the full name of the terminal and
+the portion of the terminal name before the first @samp{-}. This
+allows @code{sun} to match both @code{sun} and @code{sun-cmd},
+for instance.
+
+@item application
+The @var{application} construct is used to include
+application-specific settings. Each program using the Readline
+library sets the @var{application name}, and you can test for
+a particular value.
+This could be used to bind key sequences to functions useful for
+a specific program. For instance, the following command adds a
+key sequence that quotes the current or previous word in Bash:
+@example
+$if Bash
+# Quote the current or previous word
+"\C-xq": "\eb\"\ef\""
+$endif
+@end example
+@end table
+
+@item $endif
+This command, as seen in the previous example, terminates an
+@code{$if} command.
+
+@item $else
+Commands in this branch of the @code{$if} directive are executed if
+the test fails.
+
+@item $include
+This directive takes a single filename as an argument and reads commands
+and bindings from that file.
+For example, the following directive reads from @file{/etc/inputrc}:
+@example
+$include /etc/inputrc
+@end example
+@end table
+
+@node Sample Init File
+@subsection Sample Init File
+
+Here is an example of an @var{inputrc} file. This illustrates key
+binding, variable assignment, and conditional syntax.
+
+@example
+@page
+# This file controls the behaviour of line input editing for
+# programs that use the GNU Readline library. Existing
+# programs include FTP, Bash, and GDB.
+#
+# You can re-read the inputrc file with C-x C-r.
+# Lines beginning with '#' are comments.
+#
+# First, include any systemwide bindings and variable
+# assignments from /etc/Inputrc
+$include /etc/Inputrc
+
+#
+# Set various bindings for emacs mode.
+
+set editing-mode emacs
+
+$if mode=emacs
+
+Meta-Control-h: backward-kill-word Text after the function name is ignored
+
+#
+# Arrow keys in keypad mode
+#
+#"\M-OD": backward-char
+#"\M-OC": forward-char
+#"\M-OA": previous-history
+#"\M-OB": next-history
+#
+# Arrow keys in ANSI mode
+#
+"\M-[D": backward-char
+"\M-[C": forward-char
+"\M-[A": previous-history
+"\M-[B": next-history
+#
+# Arrow keys in 8 bit keypad mode
+#
+#"\M-\C-OD": backward-char
+#"\M-\C-OC": forward-char
+#"\M-\C-OA": previous-history
+#"\M-\C-OB": next-history
+#
+# Arrow keys in 8 bit ANSI mode
+#
+#"\M-\C-[D": backward-char
+#"\M-\C-[C": forward-char
+#"\M-\C-[A": previous-history
+#"\M-\C-[B": next-history
+
+C-q: quoted-insert
+
+$endif
+
+# An old-style binding. This happens to be the default.
+TAB: complete
+
+# Macros that are convenient for shell interaction
+$if Bash
+# edit the path
+"\C-xp": "PATH=$@{PATH@}\e\C-e\C-a\ef\C-f"
+# prepare to type a quoted word --
+# insert open and close double quotes
+# and move to just after the open quote
+"\C-x\"": "\"\"\C-b"
+# insert a backslash (testing backslash escapes
+# in sequences and macros)
+"\C-x\\": "\\"
+# Quote the current or previous word
+"\C-xq": "\eb\"\ef\""
+# Add a binding to refresh the line, which is unbound
+"\C-xr": redraw-current-line
+# Edit variable on current line.
+"\M-\C-v": "\C-a\C-k$\C-y\M-\C-e\C-a\C-y="
+$endif
+
+# use a visible bell if one is available
+set bell-style visible
+
+# don't strip characters to 7 bits when reading
+set input-meta on
+
+# allow iso-latin1 characters to be inserted rather
+# than converted to prefix-meta sequences
+set convert-meta off
+
+# display characters with the eighth bit set directly
+# rather than as meta-prefixed characters
+set output-meta on
+
+# if there are more than 150 possible completions for
+# a word, ask the user if he wants to see all of them
+set completion-query-items 150
+
+# For FTP
+$if Ftp
+"\C-xg": "get \M-?"
+"\C-xt": "put \M-?"
+"\M-.": yank-last-arg
+$endif
+@end example
+
+@node Bindable Readline Commands
+@section Bindable Readline Commands
+
+@menu
+* Commands For Moving:: Moving about the line.
+* Commands For History:: Getting at previous lines.
+* Commands For Text:: Commands for changing text.
+* Commands For Killing:: Commands for killing and yanking.
+* Numeric Arguments:: Specifying numeric arguments, repeat counts.
+* Commands For Completion:: Getting Readline to do the typing for you.
+* Keyboard Macros:: Saving and re-executing typed characters
+* Miscellaneous Commands:: Other miscellaneous commands.
+@end menu
+
+This section describes Readline commands that may be bound to key
+sequences.
+@ifset BashFeatures
+You can list your key bindings by executing
+@w{@code{bind -P}} or, for a more terse format, suitable for an
+@var{inputrc} file, @w{@code{bind -p}}. (@xref{Bash Builtins}.)
+@end ifset
+Command names without an accompanying key sequence are unbound by default.
+
+In the following descriptions, @dfn{point} refers to the current cursor
+position, and @dfn{mark} refers to a cursor position saved by the
+@code{set-mark} command.
+The text between the point and mark is referred to as the @dfn{region}.
+
+@node Commands For Moving
+@subsection Commands For Moving
+@ftable @code
+@item beginning-of-line (C-a)
+Move to the start of the current line.
+
+@item end-of-line (C-e)
+Move to the end of the line.
+
+@item forward-char (C-f)
+Move forward a character.
+
+@item backward-char (C-b)
+Move back a character.
+
+@item forward-word (M-f)
+Move forward to the end of the next word.
+Words are composed of letters and digits.
+
+@item backward-word (M-b)
+Move back to the start of the current or previous word.
+Words are composed of letters and digits.
+
+@ifset BashFeatures
+@item shell-forward-word ()
+Move forward to the end of the next word.
+Words are delimited by non-quoted shell metacharacters.
+
+@item shell-backward-word ()
+Move back to the start of the current or previous word.
+Words are delimited by non-quoted shell metacharacters.
+@end ifset
+
+@item clear-screen (C-l)
+Clear the screen and redraw the current line,
+leaving the current line at the top of the screen.
+
+@item redraw-current-line ()
+Refresh the current line. By default, this is unbound.
+
+@end ftable
+
+@node Commands For History
+@subsection Commands For Manipulating The History
+
+@ftable @code
+@item accept-line (Newline or Return)
+@ifset BashFeatures
+Accept the line regardless of where the cursor is.
+If this line is
+non-empty, add it to the history list according to the setting of
+the @env{HISTCONTROL} and @env{HISTIGNORE} variables.
+If this line is a modified history line, then restore the history line
+to its original state.
+@end ifset
+@ifclear BashFeatures
+Accept the line regardless of where the cursor is.
+If this line is
+non-empty, it may be added to the history list for future recall with
+@code{add_history()}.
+If this line is a modified history line, the history line is restored
+to its original state.
+@end ifclear
+
+@item previous-history (C-p)
+Move `back' through the history list, fetching the previous command.
+
+@item next-history (C-n)
+Move `forward' through the history list, fetching the next command.
+
+@item beginning-of-history (M-<)
+Move to the first line in the history.
+
+@item end-of-history (M->)
+Move to the end of the input history, i.e., the line currently
+being entered.
+
+@item 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.
+
+@item forward-search-history (C-s)
+Search forward starting at the current line and moving `down' through
+the the history as necessary. This is an incremental search.
+
+@item non-incremental-reverse-search-history (M-p)
+Search backward starting at the current line and moving `up'
+through the history as necessary using a non-incremental search
+for a string supplied by the user.
+
+@item non-incremental-forward-search-history (M-n)
+Search forward starting at the current line and moving `down'
+through the the history as necessary using a non-incremental search
+for a string supplied by the user.
+
+@item 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.
+By default, this command is unbound.
+
+@item 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. By default, this command is unbound.
+
+@item 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 @var{n},
+insert the @var{n}th word from the previous command (the words
+in the previous command begin with word 0). A negative argument
+inserts the @var{n}th word from the end of the previous command.
+Once the argument @var{n} is computed, the argument is extracted
+as if the @samp{!@var{n}} history expansion had been specified.
+
+@item yank-last-arg (M-. or M-_)
+Insert last argument to the previous command (the last word of the
+previous history entry). With an
+argument, behave exactly like @code{yank-nth-arg}.
+Successive calls to @code{yank-last-arg} move back through the history
+list, inserting the last argument of each line in turn.
+The history expansion facilities are used to extract the last argument,
+as if the @samp{!$} history expansion had been specified.
+
+@end ftable
+
+@node Commands For Text
+@subsection Commands For Changing Text
+
+@ftable @code
+@item delete-char (C-d)
+Delete the character at point. If point is at the
+beginning of the line, there are no characters in the line, and
+the last character typed was not bound to @code{delete-char}, then
+return @sc{eof}.
+
+@item backward-delete-char (Rubout)
+Delete the character behind the cursor. A numeric argument means
+to kill the characters instead of deleting them.
+
+@item 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. By default, this is not bound to a key.
+
+@item quoted-insert (C-q or C-v)
+Add the next character typed to the line verbatim. This is
+how to insert key sequences like @kbd{C-q}, for example.
+
+@ifclear BashFeatures
+@item tab-insert (M-@key{TAB})
+Insert a tab character.
+@end ifclear
+
+@item self-insert (a, b, A, 1, !, @dots{})
+Insert yourself.
+
+@item transpose-chars (C-t)
+Drag the character before the cursor forward over
+the character at the cursor, moving the
+cursor forward as well. If the insertion point
+is at the end of the line, then this
+transposes the last two characters of the line.
+Negative arguments have no effect.
+
+@item transpose-words (M-t)
+Drag the word before point past the word after point,
+moving point past that word as well.
+If the insertion point is at the end of the line, this transposes
+the last two words on the line.
+
+@item upcase-word (M-u)
+Uppercase the current (or following) word. With a negative argument,
+uppercase the previous word, but do not move the cursor.
+
+@item downcase-word (M-l)
+Lowercase the current (or following) word. With a negative argument,
+lowercase the previous word, but do not move the cursor.
+
+@item capitalize-word (M-c)
+Capitalize the current (or following) word. With a negative argument,
+capitalize the previous word, but do not move the cursor.
+
+@item 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
+@code{emacs} mode; @code{vi} mode does overwrite differently.
+Each call to @code{readline()} starts in insert mode.
+
+In overwrite mode, characters bound to @code{self-insert} replace
+the text at point rather than pushing the text to the right.
+Characters bound to @code{backward-delete-char} replace the character
+before point with a space.
+
+By default, this command is unbound.
+
+@end ftable
+
+@node Commands For Killing
+@subsection Killing And Yanking
+
+@ftable @code
+
+@item kill-line (C-k)
+Kill the text from point to the end of the line.
+
+@item backward-kill-line (C-x Rubout)
+Kill backward to the beginning of the line.
+
+@item unix-line-discard (C-u)
+Kill backward from the cursor to the beginning of the current line.
+
+@item kill-whole-line ()
+Kill all characters on the current line, no matter where point is.
+By default, this is unbound.
+
+@item 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 @code{forward-word}.
+
+@item backward-kill-word (M-@key{DEL})
+Kill the word behind point.
+Word boundaries are the same as @code{backward-word}.
+
+@ifset BashFeatures
+@item 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 @code{shell-forward-word}.
+
+@item backward-kill-word ()
+Kill the word behind point.
+Word boundaries are the same as @code{shell-backward-word}.
+@end ifset
+
+@item 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.
+
+@item 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.
+
+@item delete-horizontal-space ()
+Delete all spaces and tabs around point. By default, this is unbound.
+
+@item kill-region ()
+Kill the text in the current region.
+By default, this command is unbound.
+
+@item copy-region-as-kill ()
+Copy the text in the region to the kill buffer, so it can be yanked
+right away. By default, this command is unbound.
+
+@item copy-backward-word ()
+Copy the word before point to the kill buffer.
+The word boundaries are the same as @code{backward-word}.
+By default, this command is unbound.
+
+@item copy-forward-word ()
+Copy the word following point to the kill buffer.
+The word boundaries are the same as @code{forward-word}.
+By default, this command is unbound.
+
+@item yank (C-y)
+Yank the top of the kill ring into the buffer at point.
+
+@item yank-pop (M-y)
+Rotate the kill-ring, and yank the new top. You can only do this if
+the prior command is @code{yank} or @code{yank-pop}.
+@end ftable
+
+@node Numeric Arguments
+@subsection Specifying Numeric Arguments
+@ftable @code
+
+@item digit-argument (@kbd{M-0}, @kbd{M-1}, @dots{} @kbd{M--})
+Add this digit to the argument already accumulating, or start a new
+argument. @kbd{M--} starts a negative argument.
+
+@item 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 @code{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.
+By default, this is not bound to a key.
+@end ftable
+
+@node Commands For Completion
+@subsection Letting Readline Type For You
+
+@ftable @code
+@item complete (@key{TAB})
+Attempt to perform completion on the text before point.
+The actual completion performed is application-specific.
+@ifset BashFeatures
+Bash attempts completion treating the text as a variable (if the
+text begins with @samp{$}), username (if the text begins with
+@samp{~}), hostname (if the text begins with @samp{@@}), or
+command (including aliases and functions) in turn. If none
+of these produces a match, filename completion is attempted.
+@end ifset
+@ifclear BashFeatures
+The default is filename completion.
+@end ifclear
+
+@item possible-completions (M-?)
+List the possible completions of the text before point.
+
+@item insert-completions (M-*)
+Insert all completions of the text before point that would have
+been generated by @code{possible-completions}.
+
+@item menu-complete ()
+Similar to @code{complete}, but replaces the word to be completed
+with a single match from the list of possible completions.
+Repeated execution of @code{menu-complete} 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 @code{bell-style})
+and the original text is restored.
+An argument of @var{n} moves @var{n} 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 @key{TAB}, but is unbound
+by default.
+
+@item menu-complete-backward ()
+Identical to @code{menu-complete}, but moves backward through the list
+of possible completions, as if @code{menu-complete} had been given a
+negative argument.
+
+@item delete-char-or-list ()
+Deletes the character under the cursor if not at the beginning or
+end of the line (like @code{delete-char}).
+If at the end of the line, behaves identically to
+@code{possible-completions}.
+This command is unbound by default.
+
+@ifset BashFeatures
+@item complete-filename (M-/)
+Attempt filename completion on the text before point.
+
+@item possible-filename-completions (C-x /)
+List the possible completions of the text before point,
+treating it as a filename.
+
+@item complete-username (M-~)
+Attempt completion on the text before point, treating
+it as a username.
+
+@item possible-username-completions (C-x ~)
+List the possible completions of the text before point,
+treating it as a username.
+
+@item complete-variable (M-$)
+Attempt completion on the text before point, treating
+it as a shell variable.
+
+@item possible-variable-completions (C-x $)
+List the possible completions of the text before point,
+treating it as a shell variable.
+
+@item complete-hostname (M-@@)
+Attempt completion on the text before point, treating
+it as a hostname.
+
+@item possible-hostname-completions (C-x @@)
+List the possible completions of the text before point,
+treating it as a hostname.
+
+@item 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.
+
+@item possible-command-completions (C-x !)
+List the possible completions of the text before point,
+treating it as a command name.
+
+@item dynamic-complete-history (M-@key{TAB})
+Attempt completion on the text before point, comparing
+the text against lines from the history list for possible
+completion matches.
+
+@item dabbrev-expand ()
+Attempt menu completion on the text before point, comparing
+the text against lines from the history list for possible
+completion matches.
+
+@item 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
+(@pxref{Brace Expansion}).
+
+@end ifset
+@end ftable
+
+@node Keyboard Macros
+@subsection Keyboard Macros
+@ftable @code
+
+@item start-kbd-macro (C-x ()
+Begin saving the characters typed into the current keyboard macro.
+
+@item end-kbd-macro (C-x ))
+Stop saving the characters typed into the current keyboard macro
+and save the definition.
+
+@item 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.
+
+@end ftable
+
+@node Miscellaneous Commands
+@subsection Some Miscellaneous Commands
+@ftable @code
+
+@item re-read-init-file (C-x C-r)
+Read in the contents of the @var{inputrc} file, and incorporate
+any bindings or variable assignments found there.
+
+@item abort (C-g)
+Abort the current editing command and
+ring the terminal's bell (subject to the setting of
+@code{bell-style}).
+
+@item do-uppercase-version (M-a, M-b, M-@var{x}, @dots{})
+If the metafied character @var{x} is lowercase, run the command
+that is bound to the corresponding uppercase character.
+
+@item prefix-meta (@key{ESC})
+Metafy the next character typed. This is for keyboards
+without a meta key. Typing @samp{@key{ESC} f} is equivalent to typing
+@kbd{M-f}.
+
+@item undo (C-_ or C-x C-u)
+Incremental undo, separately remembered for each line.
+
+@item revert-line (M-r)
+Undo all changes made to this line. This is like executing the @code{undo}
+command enough times to get back to the beginning.
+
+@ifset BashFeatures
+@item tilde-expand (M-&)
+@end ifset
+@ifclear BashFeatures
+@item tilde-expand (M-~)
+@end ifclear
+Perform tilde expansion on the current word.
+
+@item set-mark (C-@@)
+Set the mark to the point. If a
+numeric argument is supplied, the mark is set to that position.
+
+@item 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.
+
+@item 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.
+
+@item 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.
+
+@item 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-[.
+
+@item insert-comment (M-#)
+Without a numeric argument, the value of the @code{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 @code{comment-begin}, the value is inserted, otherwise
+the characters in @code{comment-begin} are deleted from the beginning of
+the line.
+In either case, the line is accepted as if a newline had been typed.
+@ifset BashFeatures
+The default value of @code{comment-begin} 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.
+@end ifset
+
+@item 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 @var{inputrc} file. This command is unbound by default.
+
+@item dump-variables ()
+Print all of the settable 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 @var{inputrc} file. This command is unbound by default.
+
+@item 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 @var{inputrc} file. This command is unbound by default.
+
+@ifset BashFeatures
+@item 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 file names for possible completions.
+
+@item glob-expand-word (C-x *)
+The word before point is treated as a pattern for pathname expansion,
+and the list of matching file names is inserted, replacing the word.
+If a numeric argument is supplied, a @samp{*} is appended before
+pathname expansion.
+
+@item glob-list-expansions (C-x g)
+The list of expansions that would have been generated by
+@code{glob-expand-word} is displayed, and the line is redrawn.
+If a numeric argument is supplied, a @samp{*} is appended before
+pathname expansion.
+
+@item display-shell-version (C-x C-v)
+Display version information about the current instance of Bash.
+
+@item 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 (@pxref{Shell Expansions}).
+
+@item history-expand-line (M-^)
+Perform history expansion on the current line.
+
+@item magic-space ()
+Perform history expansion on the current line and insert a space
+(@pxref{History Interaction}).
+
+@item alias-expand-line ()
+Perform alias expansion on the current line (@pxref{Aliases}).
+
+@item history-and-alias-expand-line ()
+Perform history and alias expansion on the current line.
+
+@item insert-last-argument (M-. or M-_)
+A synonym for @code{yank-last-arg}.
+
+@item 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.
+
+@item edit-and-execute-command (C-xC-e)
+Invoke an editor on the current command line, and execute the result as shell
+commands.
+Bash attempts to invoke
+@code{$VISUAL}, @code{$EDITOR}, and @code{emacs}
+as the editor, in that order.
+
+@end ifset
+
+@ifclear BashFeatures
+@item emacs-editing-mode (C-e)
+When in @code{vi} command mode, this causes a switch to @code{emacs}
+editing mode.
+
+@item vi-editing-mode (M-C-j)
+When in @code{emacs} editing mode, this causes a switch to @code{vi}
+editing mode.
+
+@end ifclear
+
+@end ftable
+
+@node Readline vi Mode
+@section Readline vi Mode
+
+While the Readline library does not have a full set of @code{vi}
+editing functions, it does contain enough to allow simple editing
+of the line. The Readline @code{vi} mode behaves as specified in
+the @sc{posix} 1003.2 standard.
+
+@ifset BashFeatures
+In order to switch interactively between @code{emacs} and @code{vi}
+editing modes, use the @samp{set -o emacs} and @samp{set -o vi}
+commands (@pxref{The Set Builtin}).
+@end ifset
+@ifclear BashFeatures
+In order to switch interactively between @code{emacs} and @code{vi}
+editing modes, use the command @kbd{M-C-j} (bound to emacs-editing-mode
+when in @code{vi} mode and to vi-editing-mode in @code{emacs} mode).
+@end ifclear
+The Readline default is @code{emacs} mode.
+
+When you enter a line in @code{vi} mode, you are already placed in
+`insertion' mode, as if you had typed an @samp{i}. Pressing @key{ESC}
+switches you into `command' mode, where you can edit the text of the
+line with the standard @code{vi} movement keys, move to previous
+history lines with @samp{k} and subsequent lines with @samp{j}, and
+so forth.
+
+@ifset BashFeatures
+@node Programmable Completion
+@section Programmable Completion
+@cindex programmable completion
+
+When word completion is attempted for an argument to a command for
+which a completion specification (a @var{compspec}) has been defined
+using the @code{complete} builtin (@pxref{Programmable Completion Builtins}),
+the programmable completion facilities are invoked.
+
+First, the command name is identified.
+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 the empty string (completion attempted at the
+beginning of an empty line), any compspec defined with
+the @option{-E} option to @code{complete} is used.
+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 @option{-D} option to @code{complete} is used as the default.
+
+Once a compspec has been found, it is used to generate the list of
+matching words.
+If a compspec is not found, the default Bash completion
+described above (@pxref{Commands For Completion}) is performed.
+
+First, the actions specified by the compspec are used.
+Only matches which are prefixed by the word being completed are
+returned.
+When the @option{-f} or @option{-d} option is used for filename or
+directory name completion, the shell variable @env{FIGNORE} is
+used to filter the matches.
+@xref{Bash Variables}, for a description of @env{FIGNORE}.
+
+Any completions specified by a filename expansion pattern to the
+@option{-G} option are generated next.
+The words generated by the pattern need not match the word being completed.
+The @env{GLOBIGNORE} shell variable is not used to filter the matches,
+but the @env{FIGNORE} shell variable is used.
+
+Next, the string specified as the argument to the @option{-W} option
+is considered.
+The string is first split using the characters in the @env{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 (@pxref{Shell Expansions}).
+The results are split using the rules described above
+(@pxref{Word Splitting}).
+The results of the expansion are prefix-matched against the word being
+completed, and the matching words become the possible completions.
+
+After these matches have been generated, any shell function or command
+specified with the @option{-F} and @option{-C} options is invoked.
+When the command or function is invoked, the @env{COMP_LINE},
+@env{COMP_POINT}, @env{COMP_KEY}, and @env{COMP_TYPE} variables are
+assigned values as described above (@pxref{Bash Variables}).
+If a shell function is being invoked, the @env{COMP_WORDS} and
+@env{COMP_CWORD} variables are also set.
+When the function or command is invoked, the first argument is the
+name of the command whose arguments are being completed, the
+second argument is the word being completed, and the third argument
+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.
+
+Any function specified with @option{-F} is invoked first.
+The function may use any of the shell facilities, including the
+@code{compgen} and @code{compopt} builtins described below
+(@pxref{Programmable Completion Builtins}), to generate the matches.
+It must put the possible completions in the @env{COMPREPLY} array
+variable.
+
+Next, any command specified with the @option{-C} 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.
+
+After all of the possible completions are generated, any filter
+specified with the @option{-X} option is applied to the list.
+The filter is a pattern as used for pathname expansion; a @samp{&}
+in the pattern is replaced with the text of the word being completed.
+A literal @samp{&} 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 @samp{!} negates the pattern; in this case any completion
+not matching the pattern will be removed.
+
+Finally, any prefix and suffix specified with the @option{-P} and @option{-S}
+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.
+
+If the previously-applied actions do not generate any matches, and the
+@option{-o dirnames} option was supplied to @code{complete} when the
+compspec was defined, directory name completion is attempted.
+
+If the @option{-o plusdirs} option was supplied to @code{complete} when
+the compspec was defined, directory name completion is attempted and any
+matches are added to the results of the other actions.
+
+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 Bash completions are not attempted, and the Readline default
+of filename completion is disabled.
+If the @option{-o bashdefault} option was supplied to @code{complete} when
+the compspec was defined, the default Bash completions are attempted
+if the compspec generates no matches.
+If the @option{-o default} option was supplied to @code{complete} when the
+compspec was defined, Readline's default completion will be performed
+if the compspec (and, if attempted, the default Bash completions)
+generate no matches.
+
+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 @var{mark-directories} Readline variable, regardless
+of the setting of the @var{mark-symlinked-directories} Readline variable.
+
+There is some support for dynamically modifying completions. This is
+most useful when used in combination with a default completion specified
+with @option{-D}. 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 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.
+
+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:
+
+@example
+_completion_loader()
+@{
+ . "/etc/bash_completion.d/$1.sh" >/dev/null 2>&1 && return 124
+@}
+complete -D -F _completion_loader
+@end example
+
+@node Programmable Completion Builtins
+@section Programmable Completion Builtins
+@cindex completion builtins
+
+Two builtin commands are available to manipulate the programmable completion
+facilities.
+
+@table @code
+@item compgen
+@btindex compgen
+@example
+@code{compgen [@var{option}] [@var{word}]}
+@end example
+
+Generate possible completion matches for @var{word} according to
+the @var{option}s, which may be any option accepted by the
+@code{complete}
+builtin with the exception of @option{-p} and @option{-r}, and write
+the matches to the standard output.
+When using the @option{-F} or @option{-C} options, the various shell variables
+set by the programmable completion facilities, while available, will not
+have useful values.
+
+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 @var{word} is specified, only those completions matching @var{word}
+will be displayed.
+
+The return value is true unless an invalid option is supplied, or no
+matches were generated.
+
+@item complete
+@btindex complete
+@example
+@code{complete [-abcdefgjksuv] [-o @var{comp-option}] [-DE] [-A @var{action}] [-G @var{globpat}] [-W @var{wordlist}]
+[-F @var{function}] [-C @var{command}] [-X @var{filterpat}]
+[-P @var{prefix}] [-S @var{suffix}] @var{name} [@var{name} @dots{}]}
+@code{complete -pr [-DE] [@var{name} @dots{}]}
+@end example
+
+Specify how arguments to each @var{name} should be completed.
+If the @option{-p} 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 @option{-r} option removes a completion specification for
+each @var{name}, or, if no @var{name}s are supplied, all
+completion specifications.
+The @option{-D} 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 @option{-E} option indicates that the remaining options and actions should
+apply to ``empty'' command completion; that is, completion attempted on a
+blank line.
+
+The process of applying these completion specifications when word completion
+is attempted is described above (@pxref{Programmable Completion}). The
+@option{-D} option takes precedence over @option{-E}.
+
+Other options, if specified, have the following meanings.
+The arguments to the @option{-G}, @option{-W}, and @option{-X} options
+(and, if necessary, the @option{-P} and @option{-S} options)
+should be quoted to protect them from expansion before the
+@code{complete} builtin is invoked.
+
+
+@table @code
+@item -o @var{comp-option}
+The @var{comp-option} controls several aspects of the compspec's behavior
+beyond the simple generation of completions.
+@var{comp-option} may be one of:
+
+@table @code
+
+@item bashdefault
+Perform the rest of the default Bash completions if the compspec
+generates no matches.
+
+@item default
+Use Readline's default filename completion if the compspec generates
+no matches.
+
+@item dirnames
+Perform directory name completion if the compspec generates no matches.
+
+@item 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).
+This option is intended to be used with shell functions specified
+with @option{-F}.
+
+@item nospace
+Tell Readline not to append a space (the default) to words completed at
+the end of the line.
+
+@item 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.
+
+@end table
+
+@item -A @var{action}
+The @var{action} may be one of the following to generate a list of possible
+completions:
+
+@table @code
+@item alias
+Alias names. May also be specified as @option{-a}.
+
+@item arrayvar
+Array variable names.
+
+@item binding
+Readline key binding names (@pxref{Bindable Readline Commands}).
+
+@item builtin
+Names of shell builtin commands. May also be specified as @option{-b}.
+
+@item command
+Command names. May also be specified as @option{-c}.
+
+@item directory
+Directory names. May also be specified as @option{-d}.
+
+@item disabled
+Names of disabled shell builtins.
+
+@item enabled
+Names of enabled shell builtins.
+
+@item export
+Names of exported shell variables. May also be specified as @option{-e}.
+
+@item file
+File names. May also be specified as @option{-f}.
+
+@item function
+Names of shell functions.
+
+@item group
+Group names. May also be specified as @option{-g}.
+
+@item helptopic
+Help topics as accepted by the @code{help} builtin (@pxref{Bash Builtins}).
+
+@item hostname
+Hostnames, as taken from the file specified by the
+@env{HOSTFILE} shell variable (@pxref{Bash Variables}).
+
+@item job
+Job names, if job control is active. May also be specified as @option{-j}.
+
+@item keyword
+Shell reserved words. May also be specified as @option{-k}.
+
+@item running
+Names of running jobs, if job control is active.
+
+@item service
+Service names. May also be specified as @option{-s}.
+
+@item setopt
+Valid arguments for the @option{-o} option to the @code{set} builtin
+(@pxref{The Set Builtin}).
+
+@item shopt
+Shell option names as accepted by the @code{shopt} builtin
+(@pxref{Bash Builtins}).
+
+@item signal
+Signal names.
+
+@item stopped
+Names of stopped jobs, if job control is active.
+
+@item user
+User names. May also be specified as @option{-u}.
+
+@item variable
+Names of all shell variables. May also be specified as @option{-v}.
+@end table
+
+@item -C @var{command}
+@var{command} is executed in a subshell environment, and its output is
+used as the possible completions.
+
+@item -F @var{function}
+The shell function @var{function} is executed in the current shell
+environment.
+When it finishes, the possible completions are retrieved from the value
+of the @env{COMPREPLY} array variable.
+
+@item -G @var{globpat}
+The filename expansion pattern @var{globpat} is expanded to generate
+the possible completions.
+
+@item -P @var{prefix}
+@var{prefix} is added at the beginning of each possible completion
+after all other options have been applied.
+
+@item -S @var{suffix}
+@var{suffix} is appended to each possible completion
+after all other options have been applied.
+
+@item -W @var{wordlist}
+The @var{wordlist} is split using the characters in the
+@env{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.
+
+@item -X @var{filterpat}
+@var{filterpat} is a pattern as used for filename expansion.
+It is applied to the list of possible completions generated by the
+preceding options and arguments, and each completion matching
+@var{filterpat} is removed from the list.
+A leading @samp{!} in @var{filterpat} negates the pattern; in this
+case, any completion not matching @var{filterpat} is removed.
+@end table
+
+The return value is true unless an invalid option is supplied, an option
+other than @option{-p} or @option{-r} is supplied without a @var{name}
+argument, an attempt is made to remove a completion specification for
+a @var{name} for which no specification exists, or
+an error occurs adding a completion specification.
+
+@item compopt
+@btindex compopt
+@example
+@code{compopt} [-o @var{option}] [-DE] [+o @var{option}] [@var{name}]
+@end example
+Modify completion options for each @var{name} according to the
+@var{option}s, or for the currently-executing completion if no @var{name}s
+are supplied.
+If no @var{option}s are given, display the completion options for each
+@var{name} or the current completion.
+The possible values of @var{option} are those valid for the @code{complete}
+builtin described above.
+The @option{-D} 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 @option{-E} option indicates that the remaining options should
+apply to ``empty'' command completion; that is, completion attempted on a
+blank line.
+
+The @option{-D} option takes precedence over @option{-E}.
+
+The return value is true unless an invalid option is supplied, an attempt
+is made to modify the options for a @var{name} for which no completion
+specification exists, or an output error occurs.
+
+@end table
+
+@end ifset
}
else if (c == '\\' && remove_quoted_newline)
{
+ QUIT;
peekc = yy_getc ();
if (peekc == '\n')
{
# Set of available languages.
-en@quot en@boldquot af bg ca cs de eo es et fi fr ga hu id ja lt nl pl pt_BR ro ru sk sv tr vi zh_TW
+en@quot en@boldquot af bg ca cs de eo es et fi fr ga hu id ja lt nl pl pt_BR ro ru sk sv tr vi zh_CN zh_TW
--- /dev/null
+# Chinese (Simplified) translation for bash package
+# Copyright (C) 2010 Free Software Foundation, Inc.
+# This file is distributed under the same license as the bash package.
+# Xin Ye <alyex.ye@gmail.com>, 2010
+#
+msgid ""
+msgstr ""
+"Project-Id-Version: bash 4.1\n"
+"Report-Msgid-Bugs-To: \n"
+"POT-Creation-Date: 2009-12-30 08:25-0500\n"
+"PO-Revision-Date: 2010-01-28 10:27+0800\n"
+"Last-Translator: Xin Ye <alyex.ye@gmail.com>\n"
+"Language-Team: Chinese (simplified) <i18n-zh@googlegroups.com>\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=utf-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"Plural-Forms: nplurals=1; plural=0;\n"
+
+#: arrayfunc.c:50
+msgid "bad array subscript"
+msgstr "坏的数组下标"
+
+#: arrayfunc.c:313 builtins/declare.def:481
+#, c-format
+msgid "%s: cannot convert indexed to associative array"
+msgstr "%s: 无法将索引数组转化为关联数组"
+
+#: arrayfunc.c:480
+#, c-format
+msgid "%s: invalid associative array key"
+msgstr "%s: 无效的关联数组键"
+
+#: arrayfunc.c:482
+#, c-format
+msgid "%s: cannot assign to non-numeric index"
+msgstr "%s: 无法为非数字的索引赋值"
+
+#: arrayfunc.c:518
+#, c-format
+msgid "%s: %s: must use subscript when assigning associative array"
+msgstr "%s: %s: 为关联数组赋值时必须使用下标"
+
+#: bashhist.c:383
+#, c-format
+msgid "%s: cannot create: %s"
+msgstr "%s: 无法创建: %s"
+
+#: bashline.c:3457
+msgid "bash_execute_unix_command: cannot find keymap for command"
+msgstr "bash_execute_unix_command: 无法为命令找到键映射"
+
+#: bashline.c:3543
+#, c-format
+msgid "%s: first non-whitespace character is not `\"'"
+msgstr "%s: 第一个非空字符不是 `\"'"
+
+#: bashline.c:3572
+#, c-format
+msgid "no closing `%c' in %s"
+msgstr "%2$s 中没有闭合的 `%1$c'"
+
+#: bashline.c:3606
+#, c-format
+msgid "%s: missing colon separator"
+msgstr "%s: 缺少冒号分隔符"
+
+#: builtins/alias.def:132
+#, c-format
+msgid "`%s': invalid alias name"
+msgstr "`%s': 无效的别名"
+
+#: builtins/bind.def:120 builtins/bind.def:123
+msgid "line editing not enabled"
+msgstr "行编辑未启用"
+
+#: builtins/bind.def:206
+#, c-format
+msgid "`%s': invalid keymap name"
+msgstr "`%s': 无效的键映射名"
+
+#: builtins/bind.def:245
+#, c-format
+msgid "%s: cannot read: %s"
+msgstr "%s: 无法读取: %s"
+
+#: builtins/bind.def:260
+#, c-format
+msgid "`%s': cannot unbind"
+msgstr "`%s': 无法解除绑定"
+
+#: builtins/bind.def:295 builtins/bind.def:325
+#, c-format
+msgid "`%s': unknown function name"
+msgstr "`%s': 未知函数名"
+
+#: builtins/bind.def:303
+#, c-format
+msgid "%s is not bound to any keys.\n"
+msgstr "%s 未与任何键绑定。\n"
+
+#: builtins/bind.def:307
+#, c-format
+msgid "%s can be invoked via "
+msgstr ""
+
+#: builtins/break.def:77 builtins/break.def:117
+msgid "loop count"
+msgstr "循环计数"
+
+#: builtins/break.def:137
+msgid "only meaningful in a `for', `while', or `until' loop"
+msgstr "仅在`for', `while', 或者`until' 循环中有意义"
+
+#: builtins/caller.def:133
+msgid ""
+"Returns the context of the current subroutine call.\n"
+" \n"
+" Without EXPR, returns "
+msgstr ""
+"返回当前子例程调用的上下文\n"
+" \n"
+" 不带 EXPR 时, 返回"
+
+#: builtins/caller.def:135
+msgid ""
+". With EXPR, returns\n"
+" "
+msgstr ""
+". 带有 EXPR 时, 返回\n"
+" "
+
+#: builtins/caller.def:136
+msgid ""
+"; this extra information can be used to\n"
+" provide a stack trace.\n"
+" \n"
+" The value of EXPR indicates how many call frames to go back before the\n"
+" current one; the top frame is frame 0."
+msgstr ""
+
+#: builtins/cd.def:215
+msgid "HOME not set"
+msgstr "HOME 未设定"
+
+#: builtins/cd.def:227
+msgid "OLDPWD not set"
+msgstr "OLDPWD 未设定"
+
+#: builtins/common.c:101
+#, c-format
+msgid "line %d: "
+msgstr "第 %d 行:"
+
+#: builtins/common.c:139 error.c:261
+#, c-format
+msgid "warning: "
+msgstr "警告:"
+
+#: builtins/common.c:153
+#, c-format
+msgid "%s: usage: "
+msgstr "%s: 用法:"
+
+#: builtins/common.c:166 test.c:827
+msgid "too many arguments"
+msgstr "参数太多"
+
+#: builtins/common.c:191 shell.c:499 shell.c:782
+#, c-format
+msgid "%s: option requires an argument"
+msgstr "%s: 选项需要一个参数"
+
+#: builtins/common.c:198
+#, c-format
+msgid "%s: numeric argument required"
+msgstr "%s: 需要数字参数"
+
+#: builtins/common.c:205
+#, c-format
+msgid "%s: not found"
+msgstr "%s: 未找到"
+
+#: builtins/common.c:214 shell.c:795
+#, c-format
+msgid "%s: invalid option"
+msgstr "%s: 无效选项"
+
+#: builtins/common.c:221
+#, c-format
+msgid "%s: invalid option name"
+msgstr "%s: 无效的选项名"
+
+#: builtins/common.c:228 general.c:231 general.c:236
+#, c-format
+msgid "`%s': not a valid identifier"
+msgstr "`%s': 不是有效的标识符"
+
+#: builtins/common.c:238
+msgid "invalid octal number"
+msgstr "无效的八进制数"
+
+#: builtins/common.c:240
+msgid "invalid hex number"
+msgstr "无效的十六进制数"
+
+#: builtins/common.c:242 expr.c:1256
+msgid "invalid number"
+msgstr "无效数字"
+
+#: builtins/common.c:250
+#, c-format
+msgid "%s: invalid signal specification"
+msgstr "%s: 无效的信号声明"
+
+#: builtins/common.c:257
+#, c-format
+msgid "`%s': not a pid or valid job spec"
+msgstr "`%s': 不是有效的进程号或者任务声明"
+
+#: builtins/common.c:264 error.c:454
+#, c-format
+msgid "%s: readonly variable"
+msgstr "%s: 只读变量"
+
+#: builtins/common.c:272
+#, c-format
+msgid "%s: %s out of range"
+msgstr "%s: %s 越界"
+
+#: builtins/common.c:272 builtins/common.c:274
+msgid "argument"
+msgstr "参数"
+
+#: builtins/common.c:274
+#, c-format
+msgid "%s out of range"
+msgstr "%s 越界"
+
+#: builtins/common.c:282
+#, c-format
+msgid "%s: no such job"
+msgstr "%s: 无此任务"
+
+#: builtins/common.c:290
+#, c-format
+msgid "%s: no job control"
+msgstr "%s: 无任务控制"
+
+#: builtins/common.c:292
+msgid "no job control"
+msgstr "无任务控制"
+
+#: builtins/common.c:302
+#, c-format
+msgid "%s: restricted"
+msgstr "%s: 受限的"
+
+#: builtins/common.c:304
+msgid "restricted"
+msgstr "受限的"
+
+#: builtins/common.c:312
+#, c-format
+msgid "%s: not a shell builtin"
+msgstr "%s: 不是shell内建"
+
+#: builtins/common.c:321
+#, c-format
+msgid "write error: %s"
+msgstr "写错误: %s"
+
+#: builtins/common.c:329
+#, c-format
+msgid "error setting terminal attributes: %s"
+msgstr "设定终端属性时出错: %s"
+
+#: builtins/common.c:331
+#, c-format
+msgid "error getting terminal attributes: %s"
+msgstr "获取终端属性时出错: %s"
+
+#: builtins/common.c:563
+#, c-format
+msgid "%s: error retrieving current directory: %s: %s\n"
+msgstr "%s: 获取当前目录时出错: %s: %s\n"
+
+#: builtins/common.c:629 builtins/common.c:631
+#, c-format
+msgid "%s: ambiguous job spec"
+msgstr "%s: 模糊的任务声明"
+
+#: builtins/complete.def:276
+#, c-format
+msgid "%s: invalid action name"
+msgstr "%s: 无效的动作名"
+
+#: builtins/complete.def:449 builtins/complete.def:644
+#: builtins/complete.def:853
+#, c-format
+msgid "%s: no completion specification"
+msgstr "%s: 没有补完声名"
+
+#: builtins/complete.def:696
+msgid "warning: -F option may not work as you expect"
+msgstr "警告: -F 选项可能不像您预期的那样工作"
+
+#: builtins/complete.def:698
+msgid "warning: -C option may not work as you expect"
+msgstr "警告: -C 选项可能不像您预期的那样工作"
+
+#: builtins/complete.def:826
+msgid "not currently executing completion function"
+msgstr "目前不在执行补完功能"
+
+#: builtins/declare.def:122
+msgid "can only be used in a function"
+msgstr "只能在函数中使用"
+
+#: builtins/declare.def:360
+msgid "cannot use `-f' to make functions"
+msgstr "无法用 `-f' 生成函数"
+
+#: builtins/declare.def:372 execute_cmd.c:4937
+#, c-format
+msgid "%s: readonly function"
+msgstr "%s: 只读函数"
+
+#: builtins/declare.def:468
+#, c-format
+msgid "%s: cannot destroy array variables in this way"
+msgstr "%s: 无法以这种方式摧毁数组变量"
+
+#: builtins/declare.def:475
+#, c-format
+msgid "%s: cannot convert associative to indexed array"
+msgstr "%s: 无法将关联数组转化为索引数组"
+
+#: builtins/enable.def:137 builtins/enable.def:145
+msgid "dynamic loading not available"
+msgstr "动态加载不可用"
+
+#: builtins/enable.def:312
+#, c-format
+msgid "cannot open shared object %s: %s"
+msgstr "无法打开共享对象 %s: %s"
+
+#: builtins/enable.def:335
+#, c-format
+msgid "cannot find %s in shared object %s: %s"
+msgstr "无法在共享对象 %2$s 中找到 %1$s: %3$s"
+
+#: builtins/enable.def:459
+#, c-format
+msgid "%s: not dynamically loaded"
+msgstr "%s: 不是动态加载"
+
+#: builtins/enable.def:474
+#, c-format
+msgid "%s: cannot delete: %s"
+msgstr "%s: 无法删除: %s"
+
+#: builtins/evalfile.c:134 builtins/hash.def:169 execute_cmd.c:4794
+#: shell.c:1452
+#, c-format
+msgid "%s: is a directory"
+msgstr "%s: 是一个目录"
+
+#: builtins/evalfile.c:139
+#, c-format
+msgid "%s: not a regular file"
+msgstr "%s: 不是常规文件"
+
+#: builtins/evalfile.c:147
+#, c-format
+msgid "%s: file is too large"
+msgstr "%s: 文件太大"
+
+#: builtins/evalfile.c:185 builtins/evalfile.c:203 execute_cmd.c:4864
+#: shell.c:1462
+#, c-format
+msgid "%s: cannot execute binary file"
+msgstr "%s: 无法执行二进制文件"
+
+#: builtins/exec.def:212
+#, c-format
+msgid "%s: cannot execute: %s"
+msgstr "%s: 无法执行: %s"
+
+#: builtins/exit.def:65
+#, c-format
+msgid "logout\n"
+msgstr "登出\n"
+
+#: builtins/exit.def:88
+msgid "not login shell: use `exit'"
+msgstr "不是登录shell: 使用 `exit'"
+
+#: builtins/exit.def:120
+#, c-format
+msgid "There are stopped jobs.\n"
+msgstr "有停止的任务。\n"
+
+#: builtins/exit.def:122
+#, c-format
+msgid "There are running jobs.\n"
+msgstr "有运行中的任务。\n"
+
+#: builtins/fc.def:262
+msgid "no command found"
+msgstr "未找到命令"
+
+#: builtins/fc.def:349
+msgid "history specification"
+msgstr "历史声明"
+
+#: builtins/fc.def:370
+#, c-format
+msgid "%s: cannot open temp file: %s"
+msgstr "%s: 无法打开临时文件: %s"
+
+#: builtins/fg_bg.def:149 builtins/jobs.def:282
+msgid "current"
+msgstr "当前"
+
+#: builtins/fg_bg.def:158
+#, c-format
+msgid "job %d started without job control"
+msgstr "不带任务控制的情况下启动了任务 %d"
+
+#: builtins/getopt.c:110
+#, c-format
+msgid "%s: illegal option -- %c\n"
+msgstr "%s: 非法选项 -- %c\n"
+
+#: builtins/getopt.c:111
+#, c-format
+msgid "%s: option requires an argument -- %c\n"
+msgstr "%s: 选项需要一个参数 -- %c\n"
+
+#: builtins/hash.def:92
+msgid "hashing disabled"
+msgstr ""
+
+#: builtins/hash.def:138
+#, c-format
+msgid "%s: hash table empty\n"
+msgstr ""
+
+#: builtins/hash.def:244
+#, c-format
+msgid "hits\tcommand\n"
+msgstr ""
+
+#: builtins/help.def:130
+#, c-format
+msgid "Shell commands matching keyword `"
+msgid_plural "Shell commands matching keywords `"
+msgstr[0] "Shell命令匹配关键字`"
+
+#: builtins/help.def:168
+#, c-format
+msgid "no help topics match `%s'. Try `help help' or `man -k %s' or `info %s'."
+msgstr "没有与 `%s' 匹配的帮助主题。尝试 `help help' 或者 `man -k %s' 或者 `info %s'。"
+
+#: builtins/help.def:185
+#, c-format
+msgid "%s: cannot open: %s"
+msgstr "%s: 无法打开: %s"
+
+#: builtins/help.def:337
+#, c-format
+msgid ""
+"These shell commands are defined internally. Type `help' to see this list.\n"
+"Type `help name' to find out more about the function `name'.\n"
+"Use `info bash' to find out more about the shell in general.\n"
+"Use `man -k' or `info' to find out more about commands not in this list.\n"
+"\n"
+"A star (*) next to a name means that the command is disabled.\n"
+"\n"
+msgstr ""
+
+#: builtins/history.def:154
+msgid "cannot use more than one of -anrw"
+msgstr "最多只能使用 -anrw 选项中的一个"
+
+#: builtins/history.def:186
+msgid "history position"
+msgstr "历史位置"
+
+#: builtins/history.def:365
+#, c-format
+msgid "%s: history expansion failed"
+msgstr "%s: 历史扩展失败"
+
+#: builtins/inlib.def:71
+#, c-format
+msgid "%s: inlib failed"
+msgstr ""
+
+#: builtins/jobs.def:109
+msgid "no other options allowed with `-x'"
+msgstr "其他选项不能与 `-x' 同时使用"
+
+#: builtins/kill.def:200
+#, c-format
+msgid "%s: arguments must be process or job IDs"
+msgstr "%s: 参数必须是进程或任务 ID"
+
+#: builtins/kill.def:263
+msgid "Unknown error"
+msgstr "未知错误"
+
+#: builtins/let.def:95 builtins/let.def:120 expr.c:501 expr.c:516
+msgid "expression expected"
+msgstr "期待表达式"
+
+#: builtins/mapfile.def:165
+#, c-format
+msgid "%s: not an indexed array"
+msgstr "%s: 不是一个索引数组"
+
+#: builtins/mapfile.def:249 builtins/read.def:279
+#, c-format
+msgid "%s: invalid file descriptor specification"
+msgstr "%s: 无效的文件描述符声明"
+
+#: builtins/mapfile.def:257 builtins/read.def:286
+#, c-format
+msgid "%d: invalid file descriptor: %s"
+msgstr "%d: 无效的文件描述符: %s"
+
+#: builtins/mapfile.def:266 builtins/mapfile.def:304
+#, c-format
+msgid "%s: invalid line count"
+msgstr "%s: 无效的行数"
+
+#: builtins/mapfile.def:277
+#, c-format
+msgid "%s: invalid array origin"
+msgstr ""
+
+#: builtins/mapfile.def:294
+#, c-format
+msgid "%s: invalid callback quantum"
+msgstr ""
+
+#: builtins/mapfile.def:326
+msgid "empty array variable name"
+msgstr "空数组变量名"
+
+#: builtins/mapfile.def:347
+msgid "array variable support required"
+msgstr "需要数组变量支持"
+
+#: builtins/printf.def:374
+#, c-format
+msgid "`%s': missing format character"
+msgstr "`%s': 缺少格式字符"
+
+#: builtins/printf.def:551
+#, c-format
+msgid "`%c': invalid format character"
+msgstr "`%c': 无效格式字符"
+
+#: builtins/printf.def:578
+#, c-format
+msgid "warning: %s: %s"
+msgstr "警告: %s: %s"
+
+#: builtins/printf.def:757
+msgid "missing hex digit for \\x"
+msgstr ""
+
+#: builtins/pushd.def:195
+msgid "no other directory"
+msgstr "无其他目录"
+
+#: builtins/pushd.def:462
+msgid "<no current directory>"
+msgstr "<无当前目录>"
+
+#: builtins/pushd.def:506
+msgid "directory stack empty"
+msgstr "目录栈为空"
+
+#: builtins/pushd.def:508
+msgid "directory stack index"
+msgstr "目录栈索引"
+
+#: builtins/pushd.def:683
+msgid ""
+"Display the list of currently remembered directories. Directories\n"
+" find their way onto the list with the `pushd' command; you can get\n"
+" back up through the list with the `popd' command.\n"
+" \n"
+" Options:\n"
+" -c\tclear the directory stack by deleting all of the elements\n"
+" -l\tdo not print tilde-prefixed versions of directories relative\n"
+" \tto your home directory\n"
+" -p\tprint the directory stack with one entry per line\n"
+" -v\tprint the directory stack with one entry per line prefixed\n"
+" \twith its position in the stack\n"
+" \n"
+" Arguments:\n"
+" +N\tDisplays the Nth entry counting from the left of the list shown by\n"
+" \tdirs when invoked without options, starting with zero.\n"
+" \n"
+" -N\tDisplays the Nth entry counting from the right of the list shown by\n"
+"\tdirs when invoked without options, starting with zero."
+msgstr ""
+
+#: builtins/pushd.def:705
+msgid ""
+"Adds a directory to the top of the directory stack, or rotates\n"
+" the stack, making the new top of the stack the current working\n"
+" directory. With no arguments, exchanges the top two directories.\n"
+" \n"
+" Options:\n"
+" -n\tSuppresses the normal change of directory when adding\n"
+" \tdirectories to the stack, so only the stack is manipulated.\n"
+" \n"
+" Arguments:\n"
+" +N\tRotates the stack so that the Nth directory (counting\n"
+" \tfrom the left of the list shown by `dirs', starting with\n"
+" \tzero) is at the top.\n"
+" \n"
+" -N\tRotates the stack so that the Nth directory (counting\n"
+" \tfrom the right of the list shown by `dirs', starting with\n"
+" \tzero) is at the top.\n"
+" \n"
+" dir\tAdds DIR to the directory stack at the top, making it the\n"
+" \tnew current working directory.\n"
+" \n"
+" The `dirs' builtin displays the directory stack."
+msgstr ""
+
+#: builtins/pushd.def:730
+msgid ""
+"Removes entries from the directory stack. With no arguments, removes\n"
+" the top directory from the stack, and changes to the new top directory.\n"
+" \n"
+" Options:\n"
+" -n\tSuppresses the normal change of directory when removing\n"
+" \tdirectories from the stack, so only the stack is manipulated.\n"
+" \n"
+" Arguments:\n"
+" +N\tRemoves the Nth entry counting from the left of the list\n"
+" \tshown by `dirs', starting with zero. For example: `popd +0'\n"
+" \tremoves the first directory, `popd +1' the second.\n"
+" \n"
+" -N\tRemoves the Nth entry counting from the right of the list\n"
+" \tshown by `dirs', starting with zero. For example: `popd -0'\n"
+" \tremoves the last directory, `popd -1' the next to last.\n"
+" \n"
+" The `dirs' builtin displays the directory stack."
+msgstr ""
+
+#: builtins/read.def:252
+#, c-format
+msgid "%s: invalid timeout specification"
+msgstr "%s: 无效的超时声明"
+
+#: builtins/read.def:588
+#, c-format
+msgid "read error: %d: %s"
+msgstr "读错误: %d: %s"
+
+#: builtins/return.def:73
+msgid "can only `return' from a function or sourced script"
+msgstr "只能从函数或者源脚本`返回'"
+
+#: builtins/set.def:768
+msgid "cannot simultaneously unset a function and a variable"
+msgstr "无法同时反设定一个函数和一个变量"
+
+#: builtins/set.def:805
+#, c-format
+msgid "%s: cannot unset"
+msgstr "%s: 无法反设定"
+
+#: builtins/set.def:812
+#, c-format
+msgid "%s: cannot unset: readonly %s"
+msgstr "%s: 无法反设定: 只读 %s"
+
+#: builtins/set.def:823
+#, c-format
+msgid "%s: not an array variable"
+msgstr "%s: 不是数组变量"
+
+#: builtins/setattr.def:186
+#, c-format
+msgid "%s: not a function"
+msgstr "%s: 不是函数"
+
+#: builtins/shift.def:71 builtins/shift.def:77
+msgid "shift count"
+msgstr ""
+
+#: builtins/shopt.def:260
+msgid "cannot set and unset shell options simultaneously"
+msgstr "无法同时设定和反设定 shell 选项"
+
+#: builtins/shopt.def:325
+#, c-format
+msgid "%s: invalid shell option name"
+msgstr "%s: 无效的 shell 选项名"
+
+#: builtins/source.def:128
+msgid "filename argument required"
+msgstr "需要文件名参数"
+
+#: builtins/source.def:153
+#, c-format
+msgid "%s: file not found"
+msgstr "%s: 没有找到文件"
+
+#: builtins/suspend.def:101
+msgid "cannot suspend"
+msgstr "无法挂起"
+
+#: builtins/suspend.def:111
+#, fuzzy
+msgid "cannot suspend a login shell"
+msgstr "无法挂起一个登录shell"
+
+#: builtins/type.def:234
+#, c-format
+msgid "%s is aliased to `%s'\n"
+msgstr "%s 是 `%s' 的别名\n"
+
+#: builtins/type.def:255
+#, c-format
+msgid "%s is a shell keyword\n"
+msgstr "%s 是 shell 关键字\n"
+
+#: builtins/type.def:274
+#, c-format
+msgid "%s is a function\n"
+msgstr "%s 是函数\n"
+
+#: builtins/type.def:296
+#, c-format
+msgid "%s is a shell builtin\n"
+msgstr "%s 是 shell 内嵌\n"
+
+#: builtins/type.def:317 builtins/type.def:391
+#, c-format
+msgid "%s is %s\n"
+msgstr "%s 是 %s\n"
+
+#: builtins/type.def:337
+#, c-format
+msgid "%s is hashed (%s)\n"
+msgstr ""
+
+#: builtins/ulimit.def:372
+#, c-format
+msgid "%s: invalid limit argument"
+msgstr ""
+
+#: builtins/ulimit.def:398
+#, c-format
+msgid "`%c': bad command"
+msgstr "`%c': 坏的命令"
+
+#: builtins/ulimit.def:427
+#, c-format
+msgid "%s: cannot get limit: %s"
+msgstr ""
+
+#: builtins/ulimit.def:453
+msgid "limit"
+msgstr ""
+
+#: builtins/ulimit.def:465 builtins/ulimit.def:765
+#, c-format
+msgid "%s: cannot modify limit: %s"
+msgstr ""
+
+#: builtins/umask.def:118
+msgid "octal number"
+msgstr "八进制数"
+
+#: builtins/umask.def:231
+#, c-format
+msgid "`%c': invalid symbolic mode operator"
+msgstr ""
+
+#: builtins/umask.def:286
+#, c-format
+msgid "`%c': invalid symbolic mode character"
+msgstr ""
+
+#: error.c:90 error.c:321 error.c:323 error.c:325
+msgid " line "
+msgstr "行"
+
+#: error.c:165
+#, c-format
+msgid "last command: %s\n"
+msgstr "上一个命令: %s\n"
+
+#: error.c:173
+#, c-format
+msgid "Aborting..."
+msgstr "放弃..."
+
+#: error.c:406
+msgid "unknown command error"
+msgstr "未知的命令错误"
+
+#: error.c:407
+msgid "bad command type"
+msgstr "坏的命令类型"
+
+#: error.c:408
+msgid "bad connector"
+msgstr ""
+
+#: error.c:409
+msgid "bad jump"
+msgstr ""
+
+#: error.c:447
+#, c-format
+msgid "%s: unbound variable"
+msgstr "%s: 为绑定变量"
+
+#: eval.c:181
+#, c-format
+msgid "\atimed out waiting for input: auto-logout\n"
+msgstr ""
+
+#: execute_cmd.c:497
+#, c-format
+msgid "cannot redirect standard input from /dev/null: %s"
+msgstr "无法从 /dev/null 重定向标准输入: %s"
+
+#: execute_cmd.c:1162
+#, c-format
+msgid "TIMEFORMAT: `%c': invalid format character"
+msgstr "时间格式: `%c': 无效的格式字符"
+
+#: execute_cmd.c:2075
+msgid "pipe error"
+msgstr "管道错误"
+
+#: execute_cmd.c:4481
+#, c-format
+msgid "%s: restricted: cannot specify `/' in command names"
+msgstr "%s: 受限的: 无法在命令名中使用 `/'"
+
+#: execute_cmd.c:4572
+#, c-format
+msgid "%s: command not found"
+msgstr "%s: 未找到命令"
+
+#: execute_cmd.c:4827
+#, c-format
+msgid "%s: %s: bad interpreter"
+msgstr "%s: %s: 坏的解释器"
+
+#: execute_cmd.c:4976
+#, c-format
+msgid "cannot duplicate fd %d to fd %d"
+msgstr ""
+
+#: expr.c:241
+msgid "expression recursion level exceeded"
+msgstr "表达式递归层次越界"
+
+#: expr.c:265
+msgid "recursion stack underflow"
+msgstr ""
+
+#: expr.c:379
+msgid "syntax error in expression"
+msgstr "表达式中有语法错误"
+
+#: expr.c:419
+msgid "attempted assignment to non-variable"
+msgstr "尝试给非变量赋值"
+
+#: expr.c:440 expr.c:445 expr.c:756
+msgid "division by 0"
+msgstr "除0"
+
+#: expr.c:471
+msgid "bug: bad expassign token"
+msgstr ""
+
+#: expr.c:513
+msgid "`:' expected for conditional expression"
+msgstr "条件表达式期待 `:'"
+
+#: expr.c:781
+msgid "exponent less than 0"
+msgstr ""
+
+#: expr.c:826
+msgid "identifier expected after pre-increment or pre-decrement"
+msgstr ""
+
+#: expr.c:854
+msgid "missing `)'"
+msgstr "缺少 `)'"
+
+#: expr.c:897 expr.c:1176
+msgid "syntax error: operand expected"
+msgstr "语法错误: 期待操作数"
+
+#: expr.c:1178
+msgid "syntax error: invalid arithmetic operator"
+msgstr "语法错误: 无效的算术运算符"
+
+#: expr.c:1202
+#, c-format
+msgid "%s%s%s: %s (error token is \"%s\")"
+msgstr ""
+
+#: expr.c:1260
+msgid "invalid arithmetic base"
+msgstr ""
+
+#: expr.c:1280
+msgid "value too great for base"
+msgstr ""
+
+#: expr.c:1329
+#, c-format
+msgid "%s: expression error\n"
+msgstr "%s: 表达式错误\n"
+
+#: general.c:61
+msgid "getcwd: cannot access parent directories"
+msgstr "getcwd: 无法访问父目录"
+
+#: input.c:94 subst.c:4857
+#, c-format
+msgid "cannot reset nodelay mode for fd %d"
+msgstr ""
+
+#: input.c:258
+#, c-format
+msgid "cannot allocate new file descriptor for bash input from fd %d"
+msgstr ""
+
+#: input.c:266
+#, c-format
+msgid "save_bash_input: buffer already exists for new fd %d"
+msgstr ""
+
+#: jobs.c:466
+msgid "start_pipeline: pgrp pipe"
+msgstr ""
+
+#: jobs.c:887
+#, c-format
+msgid "forked pid %d appears in running job %d"
+msgstr "生成的进程号 %d 显示为运行中的任务 %d"
+
+#: jobs.c:1005
+#, c-format
+msgid "deleting stopped job %d with process group %ld"
+msgstr ""
+
+#: jobs.c:1110
+#, c-format
+msgid "add_process: process %5ld (%s) in the_pipeline"
+msgstr ""
+
+#: jobs.c:1113
+#, c-format
+msgid "add_process: pid %5ld (%s) marked as still alive"
+msgstr ""
+
+#: jobs.c:1401
+#, c-format
+msgid "describe_pid: %ld: no such pid"
+msgstr ""
+
+#: jobs.c:1416
+#, c-format
+msgid "Signal %d"
+msgstr "信号 %d"
+
+#: jobs.c:1430 jobs.c:1455
+msgid "Done"
+msgstr "完成"
+
+#: jobs.c:1435 siglist.c:123
+msgid "Stopped"
+msgstr "已停止"
+
+#: jobs.c:1439
+#, c-format
+msgid "Stopped(%s)"
+msgstr "已停止 (%s)"
+
+#: jobs.c:1443
+msgid "Running"
+msgstr "运行中"
+
+#: jobs.c:1457
+#, c-format
+msgid "Done(%d)"
+msgstr "完成 (%d)"
+
+#: jobs.c:1459
+#, c-format
+msgid "Exit %d"
+msgstr "退出 %d"
+
+#: jobs.c:1462
+msgid "Unknown status"
+msgstr "未知状态"
+
+#: jobs.c:1549
+#, c-format
+msgid "(core dumped) "
+msgstr ""
+
+#: jobs.c:1568
+#, c-format
+msgid " (wd: %s)"
+msgstr ""
+
+#: jobs.c:1776
+#, c-format
+msgid "child setpgid (%ld to %ld)"
+msgstr ""
+
+#: jobs.c:2104 nojobs.c:585
+#, c-format
+msgid "wait: pid %ld is not a child of this shell"
+msgstr ""
+
+#: jobs.c:2331
+#, c-format
+msgid "wait_for: No record of process %ld"
+msgstr ""
+
+#: jobs.c:2607
+#, c-format
+msgid "wait_for_job: job %d is stopped"
+msgstr ""
+
+#: jobs.c:2829
+#, c-format
+msgid "%s: job has terminated"
+msgstr "%s: 任务已经终止"
+
+#: jobs.c:2838
+#, c-format
+msgid "%s: job %d already in background"
+msgstr "%s: 任务 %d 已在后台"
+
+#: jobs.c:3059
+msgid "waitchld: turning on WNOHANG to avoid indefinite block"
+msgstr ""
+
+#: jobs.c:3508
+#, c-format
+msgid "%s: line %d: "
+msgstr "%s: 行 %d: "
+
+#: jobs.c:3522 nojobs.c:814
+#, c-format
+msgid " (core dumped)"
+msgstr ""
+
+#: jobs.c:3534 jobs.c:3547
+#, c-format
+msgid "(wd now: %s)\n"
+msgstr ""
+
+#: jobs.c:3579
+msgid "initialize_job_control: getpgrp failed"
+msgstr ""
+
+#: jobs.c:3639
+msgid "initialize_job_control: line discipline"
+msgstr ""
+
+#: jobs.c:3649
+msgid "initialize_job_control: setpgid"
+msgstr ""
+
+#: jobs.c:3677
+#, c-format
+msgid "cannot set terminal process group (%d)"
+msgstr ""
+
+#: jobs.c:3682
+msgid "no job control in this shell"
+msgstr "此 shell 中无任务控制"
+
+#: lib/malloc/malloc.c:296
+#, c-format
+msgid "malloc: failed assertion: %s\n"
+msgstr ""
+
+#: lib/malloc/malloc.c:312
+#, c-format
+msgid ""
+"\r\n"
+"malloc: %s:%d: assertion botched\r\n"
+msgstr ""
+
+#: lib/malloc/malloc.c:313
+msgid "unknown"
+msgstr "未知"
+
+#: lib/malloc/malloc.c:797
+msgid "malloc: block on free list clobbered"
+msgstr ""
+
+#: lib/malloc/malloc.c:874
+msgid "free: called with already freed block argument"
+msgstr "free: 用已经释放的块作为参数被调用"
+
+#: lib/malloc/malloc.c:877
+msgid "free: called with unallocated block argument"
+msgstr "free: 用未分配的块作为参数被调用"
+
+#: lib/malloc/malloc.c:896
+msgid "free: underflow detected; mh_nbytes out of range"
+msgstr ""
+
+#: lib/malloc/malloc.c:902
+msgid "free: start and end chunk sizes differ"
+msgstr ""
+
+#: lib/malloc/malloc.c:1001
+msgid "realloc: called with unallocated block argument"
+msgstr "realloc: 用未分配的块作为参数被调用"
+
+#: lib/malloc/malloc.c:1016
+msgid "realloc: underflow detected; mh_nbytes out of range"
+msgstr ""
+
+#: lib/malloc/malloc.c:1022
+msgid "realloc: start and end chunk sizes differ"
+msgstr ""
+
+#: lib/malloc/table.c:177
+#, c-format
+msgid "register_alloc: alloc table is full with FIND_ALLOC?\n"
+msgstr ""
+
+#: lib/malloc/table.c:184
+#, c-format
+msgid "register_alloc: %p already in table as allocated?\n"
+msgstr ""
+
+#: lib/malloc/table.c:220
+#, c-format
+msgid "register_free: %p already in table as free?\n"
+msgstr ""
+
+#: lib/sh/fmtulong.c:101
+msgid "invalid base"
+msgstr ""
+
+#: lib/sh/netopen.c:168
+#, c-format
+msgid "%s: host unknown"
+msgstr "%s: 未知主机"
+
+#: lib/sh/netopen.c:175
+#, c-format
+msgid "%s: invalid service"
+msgstr ""
+
+#: lib/sh/netopen.c:306
+#, c-format
+msgid "%s: bad network path specification"
+msgstr "%s: 坏的网络路径声明"
+
+#: lib/sh/netopen.c:346
+msgid "network operations not supported"
+msgstr "不支持网络操作"
+
+#: locale.c:192
+#, c-format
+msgid "setlocale: LC_ALL: cannot change locale (%s)"
+msgstr ""
+
+#: locale.c:194
+#, c-format
+msgid "setlocale: LC_ALL: cannot change locale (%s): %s"
+msgstr ""
+
+#: locale.c:247
+#, c-format
+msgid "setlocale: %s: cannot change locale (%s)"
+msgstr ""
+
+#: locale.c:249
+#, c-format
+msgid "setlocale: %s: cannot change locale (%s): %s"
+msgstr ""
+
+#: mailcheck.c:433
+#, fuzzy
+msgid "You have mail in $_"
+msgstr "您在 $_ 中有邮件"
+
+#: mailcheck.c:458
+msgid "You have new mail in $_"
+msgstr "您在 $_ 中有新邮件"
+
+#: mailcheck.c:474
+#, c-format
+msgid "The mail in %s has been read\n"
+msgstr "%s 中的邮件已被阅读\n"
+
+#: make_cmd.c:323
+msgid "syntax error: arithmetic expression required"
+msgstr ""
+
+#: make_cmd.c:325
+msgid "syntax error: `;' unexpected"
+msgstr "语法错误: 期待 `;'"
+
+#: make_cmd.c:326
+#, c-format
+msgid "syntax error: `((%s))'"
+msgstr "语法错误: `((%s))'"
+
+#: make_cmd.c:575
+#, c-format
+msgid "make_here_document: bad instruction type %d"
+msgstr ""
+
+#: make_cmd.c:659
+#, c-format
+msgid "here-document at line %d delimited by end-of-file (wanted `%s')"
+msgstr ""
+
+#: make_cmd.c:756
+#, c-format
+msgid "make_redirection: redirection instruction `%d' out of range"
+msgstr ""
+
+#: parse.y:3133 parse.y:3369
+#, c-format
+msgid "unexpected EOF while looking for matching `%c'"
+msgstr "寻找匹配的 `%c' 是遇到了未预期的文件结束符"
+
+#: parse.y:3951
+msgid "unexpected EOF while looking for `]]'"
+msgstr "寻找 `]]' 是遇到了未预期的文件结束符"
+
+#: parse.y:3956
+#, c-format
+msgid "syntax error in conditional expression: unexpected token `%s'"
+msgstr "条件表达式中有语法错误: 未预期的符号 `%s'"
+
+#: parse.y:3960
+msgid "syntax error in conditional expression"
+msgstr "条件表达式中有语法错误"
+
+#: parse.y:4038
+#, c-format
+msgid "unexpected token `%s', expected `)'"
+msgstr "未预期的符号 `%s' ，期待 `)'"
+
+#: parse.y:4042
+msgid "expected `)'"
+msgstr "期待 `)'"
+
+#: parse.y:4070
+#, c-format
+msgid "unexpected argument `%s' to conditional unary operator"
+msgstr "一元条件运算符使用了未预期的参数 `%s'"
+
+#: parse.y:4074
+msgid "unexpected argument to conditional unary operator"
+msgstr "一元条件运算符使用了未预期的参数"
+
+#: parse.y:4120
+#, c-format
+msgid "unexpected token `%s', conditional binary operator expected"
+msgstr "未预期的符号 `%s'，期待二元条件运算符"
+
+#: parse.y:4124
+msgid "conditional binary operator expected"
+msgstr "期待二元条件运算符"
+
+#: parse.y:4146
+#, c-format
+msgid "unexpected argument `%s' to conditional binary operator"
+msgstr "二元条件运算符使用了未预期的参数 `%s'"
+
+#: parse.y:4150
+msgid "unexpected argument to conditional binary operator"
+msgstr "二元条件运算符使用了未预期的参数"
+
+#: parse.y:4161
+#, c-format
+msgid "unexpected token `%c' in conditional command"
+msgstr "条件命令中有未预期的符号 `%c'"
+
+#: parse.y:4164
+#, c-format
+msgid "unexpected token `%s' in conditional command"
+msgstr "条件命令中有未预期的符号 `%s'"
+
+#: parse.y:4168
+#, c-format
+msgid "unexpected token %d in conditional command"
+msgstr "条件命令中有未预期的符号 %d"
+
+#: parse.y:5459
+#, c-format
+msgid "syntax error near unexpected token `%s'"
+msgstr "未预期的符号 `%s' 附近有语法错误"
+
+#: parse.y:5477
+#, c-format
+msgid "syntax error near `%s'"
+msgstr "`%s' 附近有语法错误"
+
+#: parse.y:5487
+msgid "syntax error: unexpected end of file"
+msgstr "语法错误: 未预期的文件结尾"
+
+#: parse.y:5487
+msgid "syntax error"
+msgstr "语法错误"
+
+#: parse.y:5549
+#, c-format
+msgid "Use \"%s\" to leave the shell.\n"
+msgstr "使用 \"%s\" 退出 shell 。\n"
+
+#: parse.y:5711
+msgid "unexpected EOF while looking for matching `)'"
+msgstr "寻找匹配的 `)' 时遇到了未预期的文件结束符"
+
+#: pcomplete.c:1030
+#, c-format
+msgid "completion: function `%s' not found"
+msgstr "补完: 未找到函数 `%s'"
+
+#: pcomplib.c:179
+#, c-format
+msgid "progcomp_insert: %s: NULL COMPSPEC"
+msgstr ""
+
+#: print_cmd.c:290
+#, c-format
+msgid "print_command: bad connector `%d'"
+msgstr ""
+
+#: print_cmd.c:363
+#, c-format
+msgid "xtrace_set: %d: invalid file descriptor"
+msgstr ""
+
+#: print_cmd.c:368
+msgid "xtrace_set: NULL file pointer"
+msgstr ""
+
+#: print_cmd.c:372
+#, c-format
+msgid "xtrace fd (%d) != fileno xtrace fp (%d)"
+msgstr ""
+
+#: print_cmd.c:1461
+#, c-format
+msgid "cprintf: `%c': invalid format character"
+msgstr ""
+
+#: redir.c:110
+msgid "file descriptor out of range"
+msgstr "文件描述符超出范围"
+
+#: redir.c:166
+#, c-format
+msgid "%s: ambiguous redirect"
+msgstr "%s: 模糊的重定向"
+
+#: redir.c:170
+#, c-format
+msgid "%s: cannot overwrite existing file"
+msgstr "%s: 无法覆盖已存在的文件"
+
+#: redir.c:175
+#, c-format
+msgid "%s: restricted: cannot redirect output"
+msgstr "%s: 受限的: 无法重定向输出"
+
+#: redir.c:180
+#, c-format
+msgid "cannot create temp file for here-document: %s"
+msgstr ""
+
+#: redir.c:184
+#, c-format
+msgid "%s: cannot assign fd to variable"
+msgstr ""
+
+#: redir.c:544
+msgid "/dev/(tcp|udp)/host/port not supported without networking"
+msgstr "没有网络时不支持 /dev/(tcp|udp)/host/port"
+
+#: redir.c:1101
+msgid "redirection error: cannot duplicate fd"
+msgstr ""
+
+#: shell.c:332
+msgid "could not find /tmp, please create!"
+msgstr "无法找到 /tmp ，请创建"
+
+#: shell.c:336
+msgid "/tmp must be a valid directory name"
+msgstr "/tmp 必须为有效的目录名"
+
+#: shell.c:884
+#, c-format
+msgid "%c%c: invalid option"
+msgstr "%c%c: 无效的选项"
+
+#: shell.c:1651
+msgid "I have no name!"
+msgstr "没有名字！"
+
+#: shell.c:1793
+#, c-format
+msgid "GNU bash, version %s-(%s)\n"
+msgstr "GNU bash，版本 %s-(%s)\n"
+
+#: shell.c:1794
+#, c-format
+msgid ""
+"Usage:\t%s [GNU long option] [option] ...\n"
+"\t%s [GNU long option] [option] script-file ...\n"
+msgstr ""
+
+#: shell.c:1796
+msgid "GNU long options:\n"
+msgstr "GNU 常选项:\n"
+
+#: shell.c:1800
+msgid "Shell options:\n"
+msgstr "Shell 选项:\n"
+
+#: shell.c:1801
+msgid "\t-irsD or -c command or -O shopt_option\t\t(invocation only)\n"
+msgstr ""
+
+#: shell.c:1816
+#, c-format
+msgid "\t-%s or -o option\n"
+msgstr ""
+
+#: shell.c:1822
+#, c-format
+msgid "Type `%s -c \"help set\"' for more information about shell options.\n"
+msgstr ""
+
+#: shell.c:1823
+#, c-format
+msgid "Type `%s -c help' for more information about shell builtin commands.\n"
+msgstr ""
+
+#: shell.c:1824
+#, c-format
+msgid "Use the `bashbug' command to report bugs.\n"
+msgstr ""
+
+#: sig.c:626
+#, c-format
+msgid "sigprocmask: %d: invalid operation"
+msgstr ""
+
+#: siglist.c:48
+msgid "Bogus signal"
+msgstr ""
+
+#: siglist.c:51
+msgid "Hangup"
+msgstr ""
+
+#: siglist.c:55
+msgid "Interrupt"
+msgstr "中断"
+
+#: siglist.c:59
+msgid "Quit"
+msgstr "退出"
+
+#: siglist.c:63
+msgid "Illegal instruction"
+msgstr "非法的指令"
+
+#: siglist.c:67
+msgid "BPT trace/trap"
+msgstr ""
+
+#: siglist.c:75
+msgid "ABORT instruction"
+msgstr ""
+
+#: siglist.c:79
+msgid "EMT instruction"
+msgstr ""
+
+#: siglist.c:83
+msgid "Floating point exception"
+msgstr "浮点数异常"
+
+#: siglist.c:87
+msgid "Killed"
+msgstr "已杀死"
+
+#: siglist.c:91
+msgid "Bus error"
+msgstr "总线错误"
+
+#: siglist.c:95
+msgid "Segmentation fault"
+msgstr "段错误"
+
+#: siglist.c:99
+msgid "Bad system call"
+msgstr "坏的系统调用"
+
+#: siglist.c:103
+msgid "Broken pipe"
+msgstr "破裂的管道"
+
+#: siglist.c:107
+msgid "Alarm clock"
+msgstr "闹钟"
+
+#: siglist.c:111
+msgid "Terminated"
+msgstr "已终止"
+
+#: siglist.c:115
+msgid "Urgent IO condition"
+msgstr ""
+
+#: siglist.c:119
+msgid "Stopped (signal)"
+msgstr "已停止(信号)"
+
+#: siglist.c:127
+msgid "Continue"
+msgstr "继续"
+
+#: siglist.c:135
+msgid "Child death or stop"
+msgstr "子进程已死或者停止"
+
+#: siglist.c:139
+msgid "Stopped (tty input)"
+msgstr "已停止 (tty 输入)"
+
+#: siglist.c:143
+msgid "Stopped (tty output)"
+msgstr "已停止 (tty 输出)"
+
+#: siglist.c:147
+msgid "I/O ready"
+msgstr "输入输出准备完毕"
+
+#: siglist.c:151
+msgid "CPU limit"
+msgstr ""
+
+#: siglist.c:155
+msgid "File limit"
+msgstr ""
+
+#: siglist.c:159
+msgid "Alarm (virtual)"
+msgstr ""
+
+#: siglist.c:163
+msgid "Alarm (profile)"
+msgstr ""
+
+#: siglist.c:167
+msgid "Window changed"
+msgstr ""
+
+#: siglist.c:171
+msgid "Record lock"
+msgstr ""
+
+#: siglist.c:175
+msgid "User signal 1"
+msgstr ""
+
+#: siglist.c:179
+msgid "User signal 2"
+msgstr ""
+
+#: siglist.c:183
+msgid "HFT input data pending"
+msgstr ""
+
+#: siglist.c:187
+msgid "power failure imminent"
+msgstr ""
+
+#: siglist.c:191
+msgid "system crash imminent"
+msgstr ""
+
+#: siglist.c:195
+msgid "migrate process to another CPU"
+msgstr ""
+
+#: siglist.c:199
+msgid "programming error"
+msgstr ""
+
+#: siglist.c:203
+msgid "HFT monitor mode granted"
+msgstr ""
+
+#: siglist.c:207
+msgid "HFT monitor mode retracted"
+msgstr ""
+
+#: siglist.c:211
+msgid "HFT sound sequence has completed"
+msgstr ""
+
+#: siglist.c:215
+msgid "Information request"
+msgstr ""
+
+#: siglist.c:223
+msgid "Unknown Signal #"
+msgstr ""
+
+#: siglist.c:225
+#, c-format
+msgid "Unknown Signal #%d"
+msgstr ""
+
+#: subst.c:1333 subst.c:1454
+#, c-format
+msgid "bad substitution: no closing `%s' in %s"
+msgstr ""
+
+#: subst.c:2735
+#, c-format
+msgid "%s: cannot assign list to array member"
+msgstr ""
+
+#: subst.c:4754 subst.c:4770
+msgid "cannot make pipe for process substitution"
+msgstr ""
+
+#: subst.c:4802
+msgid "cannot make child for process substitution"
+msgstr ""
+
+#: subst.c:4847
+#, c-format
+msgid "cannot open named pipe %s for reading"
+msgstr ""
+
+#: subst.c:4849
+#, c-format
+msgid "cannot open named pipe %s for writing"
+msgstr ""
+
+#: subst.c:4867
+#, c-format
+msgid "cannot duplicate named pipe %s as fd %d"
+msgstr ""
+
+#: subst.c:5063
+msgid "cannot make pipe for command substitution"
+msgstr ""
+
+#: subst.c:5097
+msgid "cannot make child for command substitution"
+msgstr ""
+
+#: subst.c:5114
+msgid "command_substitute: cannot duplicate pipe as fd 1"
+msgstr ""
+
+#: subst.c:5617
+#, c-format
+msgid "%s: parameter null or not set"
+msgstr ""
+
+#: subst.c:5907
+#, c-format
+msgid "%s: substring expression < 0"
+msgstr ""
+
+#: subst.c:6965
+#, c-format
+msgid "%s: bad substitution"
+msgstr ""
+
+#: subst.c:7045
+#, c-format
+msgid "$%s: cannot assign in this way"
+msgstr ""
+
+#: subst.c:7374
+msgid "future versions of the shell will force evaluation as an arithmetic substitution"
+msgstr ""
+
+#: subst.c:7839
+#, c-format
+msgid "bad substitution: no closing \"`\" in %s"
+msgstr ""
+
+#: subst.c:8720
+#, c-format
+msgid "no match: %s"
+msgstr ""
+
+#: test.c:146
+msgid "argument expected"
+msgstr ""
+
+#: test.c:155
+#, c-format
+msgid "%s: integer expression expected"
+msgstr ""
+
+#: test.c:263
+msgid "`)' expected"
+msgstr ""
+
+#: test.c:265
+#, c-format
+msgid "`)' expected, found %s"
+msgstr ""
+
+#: test.c:280 test.c:693 test.c:696
+#, c-format
+msgid "%s: unary operator expected"
+msgstr ""
+
+#: test.c:449 test.c:736
+#, c-format
+msgid "%s: binary operator expected"
+msgstr ""
+
+#: test.c:811
+msgid "missing `]'"
+msgstr ""
+
+#: trap.c:203
+msgid "invalid signal number"
+msgstr ""
+
+#: trap.c:327
+#, c-format
+msgid "run_pending_traps: bad value in trap_list[%d]: %p"
+msgstr ""
+
+#: trap.c:331
+#, c-format
+msgid "run_pending_traps: signal handler is SIG_DFL, resending %d (%s) to myself"
+msgstr ""
+
+#: trap.c:380
+#, c-format
+msgid "trap_handler: bad signal %d"
+msgstr ""
+
+#: variables.c:363
+#, c-format
+msgid "error importing function definition for `%s'"
+msgstr ""
+
+#: variables.c:748
+#, c-format
+msgid "shell level (%d) too high, resetting to 1"
+msgstr ""
+
+#: variables.c:1915
+msgid "make_local_variable: no function context at current scope"
+msgstr ""
+
+#: variables.c:3159
+msgid "all_local_variables: no function context at current scope"
+msgstr ""
+
+#: variables.c:3376
+#, c-format
+msgid "%s has null exportstr"
+msgstr ""
+
+#: variables.c:3381 variables.c:3390
+#, c-format
+msgid "invalid character %d in exportstr for %s"
+msgstr ""
+
+#: variables.c:3396
+#, c-format
+msgid "no `=' in exportstr for %s"
+msgstr ""
+
+#: variables.c:3835
+msgid "pop_var_context: head of shell_variables not a function context"
+msgstr ""
+
+#: variables.c:3848
+msgid "pop_var_context: no global_variables context"
+msgstr ""
+
+#: variables.c:3922
+msgid "pop_scope: head of shell_variables not a temporary environment scope"
+msgstr ""
+
+#: variables.c:4678
+#, c-format
+msgid "%s: %s: cannot open as FILE"
+msgstr ""
+
+#: variables.c:4683
+#, c-format
+msgid "%s: %s: invalid value for trace file descriptor"
+msgstr ""
+
+#: version.c:46
+msgid "Copyright (C) 2009 Free Software Foundation, Inc."
+msgstr ""
+
+#: version.c:47
+msgid "License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>\n"
+msgstr ""
+
+#: version.c:86 version2.c:83
+#, c-format
+msgid "GNU bash, version %s (%s)\n"
+msgstr ""
+
+#: version.c:91 version2.c:88
+#, c-format
+msgid "This is free software; you are free to change and redistribute it.\n"
+msgstr ""
+
+#: version.c:92 version2.c:89
+#, c-format
+msgid "There is NO WARRANTY, to the extent permitted by law.\n"
+msgstr ""
+
+#: version2.c:86
+#, c-format
+msgid "Copyright (C) 2009 Free Software Foundation, Inc.\n"
+msgstr ""
+
+#: version2.c:87
+#, c-format
+msgid "License GPLv2+: GNU GPL version 2 or later <http://gnu.org/licenses/gpl.html>\n"
+msgstr ""
+
+#: xmalloc.c:91
+#, c-format
+msgid "%s: cannot allocate %lu bytes (%lu bytes allocated)"
+msgstr ""
+
+#: xmalloc.c:93
+#, c-format
+msgid "%s: cannot allocate %lu bytes"
+msgstr ""
+
+#: xmalloc.c:163
+#, c-format
+msgid "%s: %s:%d: cannot allocate %lu bytes (%lu bytes allocated)"
+msgstr ""
+
+#: xmalloc.c:165
+#, c-format
+msgid "%s: %s:%d: cannot allocate %lu bytes"
+msgstr ""
+
+#: builtins.c:43
+msgid "alias [-p] [name[=value] ... ]"
+msgstr ""
+
+#: builtins.c:47
+msgid "unalias [-a] name [name ...]"
+msgstr ""
+
+#: builtins.c:51
+msgid "bind [-lpvsPVS] [-m keymap] [-f filename] [-q name] [-u name] [-r keyseq] [-x keyseq:shell-command] [keyseq:readline-function or readline-command]"
+msgstr ""
+
+#: builtins.c:54
+msgid "break [n]"
+msgstr ""
+
+#: builtins.c:56
+msgid "continue [n]"
+msgstr ""
+
+#: builtins.c:58
+msgid "builtin [shell-builtin [arg ...]]"
+msgstr ""
+
+#: builtins.c:61
+msgid "caller [expr]"
+msgstr ""
+
+#: builtins.c:64
+msgid "cd [-L|-P] [dir]"
+msgstr ""
+
+#: builtins.c:66
+msgid "pwd [-LP]"
+msgstr ""
+
+#: builtins.c:68
+msgid ":"
+msgstr ""
+
+#: builtins.c:70
+msgid "true"
+msgstr ""
+
+#: builtins.c:72
+msgid "false"
+msgstr ""
+
+#: builtins.c:74
+msgid "command [-pVv] command [arg ...]"
+msgstr ""
+
+#: builtins.c:76
+msgid "declare [-aAfFilrtux] [-p] [name[=value] ...]"
+msgstr ""
+
+#: builtins.c:78
+msgid "typeset [-aAfFilrtux] [-p] name[=value] ..."
+msgstr ""
+
+#: builtins.c:80
+msgid "local [option] name[=value] ..."
+msgstr ""
+
+#: builtins.c:83
+msgid "echo [-neE] [arg ...]"
+msgstr ""
+
+#: builtins.c:87
+msgid "echo [-n] [arg ...]"
+msgstr ""
+
+#: builtins.c:90
+msgid "enable [-a] [-dnps] [-f filename] [name ...]"
+msgstr ""
+
+#: builtins.c:92
+msgid "eval [arg ...]"
+msgstr ""
+
+#: builtins.c:94
+msgid "getopts optstring name [arg]"
+msgstr ""
+
+#: builtins.c:96
+msgid "exec [-cl] [-a name] [command [arguments ...]] [redirection ...]"
+msgstr ""
+
+#: builtins.c:98
+msgid "exit [n]"
+msgstr ""
+
+#: builtins.c:100
+msgid "logout [n]"
+msgstr ""
+
+#: builtins.c:103
+msgid "fc [-e ename] [-lnr] [first] [last] or fc -s [pat=rep] [command]"
+msgstr ""
+
+#: builtins.c:107
+msgid "fg [job_spec]"
+msgstr ""
+
+#: builtins.c:111
+msgid "bg [job_spec ...]"
+msgstr ""
+
+#: builtins.c:114
+msgid "hash [-lr] [-p pathname] [-dt] [name ...]"
+msgstr ""
+
+#: builtins.c:117
+msgid "help [-dms] [pattern ...]"
+msgstr ""
+
+#: builtins.c:121
+msgid "history [-c] [-d offset] [n] or history -anrw [filename] or history -ps arg [arg...]"
+msgstr ""
+
+#: builtins.c:125
+msgid "jobs [-lnprs] [jobspec ...] or jobs -x command [args]"
+msgstr ""
+
+#: builtins.c:129
+msgid "disown [-h] [-ar] [jobspec ...]"
+msgstr ""
+
+#: builtins.c:132
+msgid "kill [-s sigspec | -n signum | -sigspec] pid | jobspec ... or kill -l [sigspec]"
+msgstr ""
+
+#: builtins.c:134
+msgid "let arg [arg ...]"
+msgstr ""
+
+#: builtins.c:136
+msgid "read [-ers] [-a array] [-d delim] [-i text] [-n nchars] [-N nchars] [-p prompt] [-t timeout] [-u fd] [name ...]"
+msgstr ""
+
+#: builtins.c:138
+msgid "return [n]"
+msgstr ""
+
+#: builtins.c:140
+msgid "set [--abefhkmnptuvxBCHP] [-o option-name] [arg ...]"
+msgstr ""
+
+#: builtins.c:142
+msgid "unset [-f] [-v] [name ...]"
+msgstr ""
+
+#: builtins.c:144
+msgid "export [-fn] [name[=value] ...] or export -p"
+msgstr ""
+
+#: builtins.c:146
+msgid "readonly [-af] [name[=value] ...] or readonly -p"
+msgstr ""
+
+#: builtins.c:148
+msgid "shift [n]"
+msgstr ""
+
+#: builtins.c:150
+msgid "source filename [arguments]"
+msgstr ""
+
+#: builtins.c:152
+msgid ". filename [arguments]"
+msgstr ""
+
+#: builtins.c:155
+msgid "suspend [-f]"
+msgstr ""
+
+#: builtins.c:158
+msgid "test [expr]"
+msgstr ""
+
+#: builtins.c:160
+msgid "[ arg... ]"
+msgstr ""
+
+#: builtins.c:162
+msgid "times"
+msgstr ""
+
+#: builtins.c:164
+msgid "trap [-lp] [[arg] signal_spec ...]"
+msgstr ""
+
+#: builtins.c:166
+msgid "type [-afptP] name [name ...]"
+msgstr ""
+
+#: builtins.c:169
+msgid "ulimit [-SHacdefilmnpqrstuvx] [limit]"
+msgstr ""
+
+#: builtins.c:172
+msgid "umask [-p] [-S] [mode]"
+msgstr ""
+
+#: builtins.c:175
+msgid "wait [id]"
+msgstr ""
+
+#: builtins.c:179
+msgid "wait [pid]"
+msgstr ""
+
+#: builtins.c:182
+msgid "for NAME [in WORDS ... ] ; do COMMANDS; done"
+msgstr ""
+
+#: builtins.c:184
+msgid "for (( exp1; exp2; exp3 )); do COMMANDS; done"
+msgstr ""
+
+#: builtins.c:186
+msgid "select NAME [in WORDS ... ;] do COMMANDS; done"
+msgstr ""
+
+#: builtins.c:188
+msgid "time [-p] pipeline"
+msgstr ""
+
+#: builtins.c:190
+msgid "case WORD in [PATTERN [| PATTERN]...) COMMANDS ;;]... esac"
+msgstr ""
+
+#: builtins.c:192
+msgid "if COMMANDS; then COMMANDS; [ elif COMMANDS; then COMMANDS; ]... [ else COMMANDS; ] fi"
+msgstr ""
+
+#: builtins.c:194
+msgid "while COMMANDS; do COMMANDS; done"
+msgstr ""
+
+#: builtins.c:196
+msgid "until COMMANDS; do COMMANDS; done"
+msgstr ""
+
+#: builtins.c:198
+msgid "coproc [NAME] command [redirections]"
+msgstr ""
+
+#: builtins.c:200
+msgid "function name { COMMANDS ; } or name () { COMMANDS ; }"
+msgstr ""
+
+#: builtins.c:202
+msgid "{ COMMANDS ; }"
+msgstr ""
+
+#: builtins.c:204
+msgid "job_spec [&]"
+msgstr ""
+
+#: builtins.c:206
+msgid "(( expression ))"
+msgstr ""
+
+#: builtins.c:208
+msgid "[[ expression ]]"
+msgstr ""
+
+#: builtins.c:210
+msgid "variables - Names and meanings of some shell variables"
+msgstr ""
+
+#: builtins.c:213
+msgid "pushd [-n] [+N | -N | dir]"
+msgstr ""
+
+#: builtins.c:217
+msgid "popd [-n] [+N | -N]"
+msgstr ""
+
+#: builtins.c:221
+msgid "dirs [-clpv] [+N] [-N]"
+msgstr ""
+
+#: builtins.c:224
+msgid "shopt [-pqsu] [-o] [optname ...]"
+msgstr ""
+
+#: builtins.c:226
+msgid "printf [-v var] format [arguments]"
+msgstr ""
+
+#: builtins.c:229
+msgid "complete [-abcdefgjksuv] [-pr] [-DE] [-o option] [-A action] [-G globpat] [-W wordlist] [-F function] [-C command] [-X filterpat] [-P prefix] [-S suffix] [name ...]"
+msgstr ""
+
+#: builtins.c:233
+msgid "compgen [-abcdefgjksuv] [-o option] [-A action] [-G globpat] [-W wordlist] [-F function] [-C command] [-X filterpat] [-P prefix] [-S suffix] [word]"
+msgstr ""
+
+#: builtins.c:237
+msgid "compopt [-o|+o option] [-DE] [name ...]"
+msgstr ""
+
+#: builtins.c:240
+msgid "mapfile [-n count] [-O origin] [-s count] [-t] [-u fd] [-C callback] [-c quantum] [array]"
+msgstr ""
+
+#: builtins.c:242
+msgid "readarray [-n count] [-O origin] [-s count] [-t] [-u fd] [-C callback] [-c quantum] [array]"
+msgstr ""
+
+#: builtins.c:254
+msgid ""
+"Define or display aliases.\n"
+" \n"
+" Without arguments, `alias' prints the list of aliases in the reusable\n"
+" form `alias NAME=VALUE' on standard output.\n"
+" \n"
+" Otherwise, an alias is defined for each NAME whose VALUE is given.\n"
+" A trailing space in VALUE causes the next word to be checked for\n"
+" alias substitution when the alias is expanded.\n"
+" \n"
+" Options:\n"
+" -p\tPrint all defined aliases in a reusable format\n"
+" \n"
+" Exit Status:\n"
+" alias returns true unless a NAME is supplied for which no alias has been\n"
+" defined."
+msgstr ""
+
+#: builtins.c:276
+msgid ""
+"Remove each NAME from the list of defined aliases.\n"
+" \n"
+" Options:\n"
+" -a\tremove all alias definitions.\n"
+" \n"
+" Return success unless a NAME is not an existing alias."
+msgstr ""
+
+#: builtins.c:289
+msgid ""
+"Set Readline key bindings and variables.\n"
+" \n"
+" Bind a key sequence to a Readline function or a macro, or set a\n"
+" Readline variable. The non-option argument syntax is equivalent to\n"
+" that found in ~/.inputrc, but must be passed as a single argument:\n"
+" e.g., bind '\"\\C-x\\C-r\": re-read-init-file'.\n"
+" \n"
+" Options:\n"
+" -m keymap Use KEYMAP as the keymap for the duration of this\n"
+" command. Acceptable keymap names are emacs,\n"
+" emacs-standard, emacs-meta, emacs-ctlx, vi, vi-move,\n"
+" vi-command, and vi-insert.\n"
+" -l List names of functions.\n"
+" -P List function names and bindings.\n"
+" -p List functions and bindings in a form that can be\n"
+" reused as input.\n"
+" -S List key sequences that invoke macros and their values\n"
+" -s List key sequences that invoke macros and their values\n"
+" in a form that can be reused as input.\n"
+" -V List variable names and values\n"
+" -v List variable names and values in a form that can\n"
+" be reused as input.\n"
+" -q function-name Query about which keys invoke the named function.\n"
+" -u function-name Unbind all keys which are bound to the named function.\n"
+" -r keyseq Remove the binding for KEYSEQ.\n"
+" -f filename Read key bindings from FILENAME.\n"
+" -x keyseq:shell-command\tCause SHELL-COMMAND to be executed when\n"
+" \t\t\t\tKEYSEQ is entered.\n"
+" \n"
+" Exit Status:\n"
+" bind returns 0 unless an unrecognized option is given or an error occurs."
+msgstr ""
+
+#: builtins.c:326
+msgid ""
+"Exit for, while, or until loops.\n"
+" \n"
+" Exit a FOR, WHILE or UNTIL loop. If N is specified, break N enclosing\n"
+" loops.\n"
+" \n"
+" Exit Status:\n"
+" The exit status is 0 unless N is not greater than or equal to 1."
+msgstr ""
+
+#: builtins.c:338
+msgid ""
+"Resume for, while, or until loops.\n"
+" \n"
+" Resumes the next iteration of the enclosing FOR, WHILE or UNTIL loop.\n"
+" If N is specified, resumes the Nth enclosing loop.\n"
+" \n"
+" Exit Status:\n"
+" The exit status is 0 unless N is not greater than or equal to 1."
+msgstr ""
+
+#: builtins.c:350
+msgid ""
+"Execute shell builtins.\n"
+" \n"
+" Execute SHELL-BUILTIN with arguments ARGs without performing command\n"
+" lookup. This is useful when you wish to reimplement a shell builtin\n"
+" as a shell function, but need to execute the builtin within the function.\n"
+" \n"
+" Exit Status:\n"
+" Returns the exit status of SHELL-BUILTIN, or false if SHELL-BUILTIN is\n"
+" not a shell builtin.."
+msgstr ""
+
+#: builtins.c:365
+msgid ""
+"Return the context of the current subroutine call.\n"
+" \n"
+" Without EXPR, returns \"$line $filename\". With EXPR, returns\n"
+" \"$line $subroutine $filename\"; this extra information can be used to\n"
+" provide a stack trace.\n"
+" \n"
+" The value of EXPR indicates how many call frames to go back before the\n"
+" current one; the top frame is frame 0.\n"
+" \n"
+" Exit Status:\n"
+" Returns 0 unless the shell is not executing a shell function or EXPR\n"
+" is invalid."
+msgstr ""
+
+#: builtins.c:383
+msgid ""
+"Change the shell working directory.\n"
+" \n"
+" Change the current directory to DIR. The default DIR is the value of the\n"
+" HOME shell variable.\n"
+" \n"
+" The variable CDPATH defines the search path for the directory containing\n"
+" DIR. Alternative directory names in CDPATH are separated by a colon (:).\n"
+" A null directory name is the same as the current directory. If DIR begins\n"
+" with a slash (/), then CDPATH is not used.\n"
+" \n"
+" If the directory is not found, and the shell option `cdable_vars' is set,\n"
+" the word is assumed to be a variable name. If that variable has a value,\n"
+" its value is used for DIR.\n"
+" \n"
+" Options:\n"
+" -L\tforce symbolic links to be followed\n"
+" -P\tuse the physical directory structure without following symbolic\n"
+" \tlinks\n"
+" \n"
+" The default is to follow symbolic links, as if `-L' were specified.\n"
+" \n"
+" Exit Status:\n"
+" Returns 0 if the directory is changed; non-zero otherwise."
+msgstr ""
+
+#: builtins.c:411
+msgid ""
+"Print the name of the current working directory.\n"
+" \n"
+" Options:\n"
+" -L\tprint the value of $PWD if it names the current working\n"
+" \tdirectory\n"
+" -P\tprint the physical directory, without any symbolic links\n"
+" \n"
+" By default, `pwd' behaves as if `-L' were specified.\n"
+" \n"
+" Exit Status:\n"
+" Returns 0 unless an invalid option is given or the current directory\n"
+" cannot be read."
+msgstr ""
+
+#: builtins.c:428
+msgid ""
+"Null command.\n"
+" \n"
+" No effect; the command does nothing.\n"
+" \n"
+" Exit Status:\n"
+" Always succeeds."
+msgstr ""
+
+#: builtins.c:439
+msgid ""
+"Return a successful result.\n"
+" \n"
+" Exit Status:\n"
+" Always succeeds."
+msgstr ""
+
+#: builtins.c:448
+msgid ""
+"Return an unsuccessful result.\n"
+" \n"
+" Exit Status:\n"
+" Always fails."
+msgstr ""
+
+#: builtins.c:457
+msgid ""
+"Execute a simple command or display information about commands.\n"
+" \n"
+" Runs COMMAND with ARGS suppressing shell function lookup, or display\n"
+" information about the specified COMMANDs. Can be used to invoke commands\n"
+" on disk when a function with the same name exists.\n"
+" \n"
+" Options:\n"
+" -p\tuse a default value for PATH that is guaranteed to find all of\n"
+" \tthe standard utilities\n"
+" -v\tprint a description of COMMAND similar to the `type' builtin\n"
+" -V\tprint a more verbose description of each COMMAND\n"
+" \n"
+" Exit Status:\n"
+" Returns exit status of COMMAND, or failure if COMMAND is not found."
+msgstr ""
+
+#: builtins.c:476
+msgid ""
+"Set variable values and attributes.\n"
+" \n"
+" Declare variables and give them attributes. If no NAMEs are given,\n"
+" display the attributes and values of all variables.\n"
+" \n"
+" Options:\n"
+" -f\trestrict action or display to function names and definitions\n"
+" -F\trestrict display to function names only (plus line number and\n"
+" \tsource file when debugging)\n"
+" -p\tdisplay the attributes and value of each NAME\n"
+" \n"
+" Options which set attributes:\n"
+" -a\tto make NAMEs indexed arrays (if supported)\n"
+" -A\tto make NAMEs associative arrays (if supported)\n"
+" -i\tto make NAMEs have the `integer' attribute\n"
+" -l\tto convert NAMEs to lower case on assignment\n"
+" -r\tto make NAMEs readonly\n"
+" -t\tto make NAMEs have the `trace' attribute\n"
+" -u\tto convert NAMEs to upper case on assignment\n"
+" -x\tto make NAMEs export\n"
+" \n"
+" Using `+' instead of `-' turns off the given attribute.\n"
+" \n"
+" Variables with the integer attribute have arithmetic evaluation (see\n"
+" the `let' command) performed when the variable is assigned a value.\n"
+" \n"
+" When used in a function, `declare' makes NAMEs local, as with the `local'\n"
+" command.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless an invalid option is supplied or an error occurs."
+msgstr ""
+
+#: builtins.c:512
+msgid ""
+"Set variable values and attributes.\n"
+" \n"
+" Obsolete. See `help declare'."
+msgstr ""
+
+#: builtins.c:520
+msgid ""
+"Define local variables.\n"
+" \n"
+" Create a local variable called NAME, and give it VALUE. OPTION can\n"
+" be any option accepted by `declare'.\n"
+" \n"
+" Local variables can only be used within a function; they are visible\n"
+" only to the function where they are defined and its children.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless an invalid option is supplied, an error occurs,\n"
+" or the shell is not executing a function."
+msgstr ""
+
+#: builtins.c:537
+msgid ""
+"Write arguments to the standard output.\n"
+" \n"
+" Display the ARGs on the standard output followed by a newline.\n"
+" \n"
+" Options:\n"
+" -n\tdo not append a newline\n"
+" -e\tenable interpretation of the following backslash escapes\n"
+" -E\texplicitly suppress interpretation of backslash escapes\n"
+" \n"
+" `echo' interprets the following backslash-escaped characters:\n"
+" \\a\talert (bell)\n"
+" \\b\tbackspace\n"
+" \\c\tsuppress further output\n"
+" \\e\tescape character\n"
+" \\f\tform feed\n"
+" \\n\tnew line\n"
+" \\r\tcarriage return\n"
+" \\t\thorizontal tab\n"
+" \\v\tvertical tab\n"
+" \\\\\tbackslash\n"
+" \\0nnn\tthe character whose ASCII code is NNN (octal). NNN can be\n"
+" \t0 to 3 octal digits\n"
+" \\xHH\tthe eight-bit character whose value is HH (hexadecimal). HH\n"
+" \tcan be one or two hex digits\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless a write error occurs."
+msgstr ""
+
+#: builtins.c:571
+msgid ""
+"Write arguments to the standard output.\n"
+" \n"
+" Display the ARGs on the standard output followed by a newline.\n"
+" \n"
+" Options:\n"
+" -n\tdo not append a newline\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless a write error occurs."
+msgstr ""
+
+#: builtins.c:586
+msgid ""
+"Enable and disable shell builtins.\n"
+" \n"
+" Enables and disables builtin shell commands. Disabling allows you to\n"
+" execute a disk command which has the same name as a shell builtin\n"
+" without using a full pathname.\n"
+" \n"
+" Options:\n"
+" -a\tprint a list of builtins showing whether or not each is enabled\n"
+" -n\tdisable each NAME or display a list of disabled builtins\n"
+" -p\tprint the list of builtins in a reusable format\n"
+" -s\tprint only the names of Posix `special' builtins\n"
+" \n"
+" Options controlling dynamic loading:\n"
+" -f\tLoad builtin NAME from shared object FILENAME\n"
+" -d\tRemove a builtin loaded with -f\n"
+" \n"
+" Without options, each NAME is enabled.\n"
+" \n"
+" To use the `test' found in $PATH instead of the shell builtin\n"
+" version, type `enable -n test'.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless NAME is not a shell builtin or an error occurs."
+msgstr ""
+
+#: builtins.c:614
+msgid ""
+"Execute arguments as a shell command.\n"
+" \n"
+" Combine ARGs into a single string, use the result as input to the shell,\n"
+" and execute the resulting commands.\n"
+" \n"
+" Exit Status:\n"
+" Returns exit status of command or success if command is null."
+msgstr ""
+
+#: builtins.c:626
+msgid ""
+"Parse option arguments.\n"
+" \n"
+" Getopts is used by shell procedures to parse positional parameters\n"
+" as options.\n"
+" \n"
+" OPTSTRING contains the option letters to be recognized; if a letter\n"
+" is followed by a colon, the option is expected to have an argument,\n"
+" which should be separated from it by white space.\n"
+" \n"
+" Each time it is invoked, getopts will place the next option in the\n"
+" shell variable $name, initializing name if it does not exist, and\n"
+" the index of the next argument to be processed into the shell\n"
+" variable OPTIND. OPTIND is initialized to 1 each time the shell or\n"
+" a shell script is invoked. When an option requires an argument,\n"
+" getopts places that argument into the shell variable OPTARG.\n"
+" \n"
+" getopts reports errors in one of two ways. If the first character\n"
+" of OPTSTRING is a colon, getopts uses silent error reporting. In\n"
+" this mode, no error messages are printed. If an invalid option is\n"
+" seen, getopts places the option character found into OPTARG. If a\n"
+" required argument is not found, getopts places a ':' into NAME and\n"
+" sets OPTARG to the option character found. If getopts is not in\n"
+" silent mode, and an invalid option is seen, getopts places '?' into\n"
+" NAME and unsets OPTARG. If a required argument is not found, a '?'\n"
+" is placed in NAME, OPTARG is unset, and a diagnostic message is\n"
+" printed.\n"
+" \n"
+" If the shell variable OPTERR has the value 0, getopts disables the\n"
+" printing of error messages, even if the first character of\n"
+" OPTSTRING is not a colon. OPTERR has the value 1 by default.\n"
+" \n"
+" Getopts normally parses the positional parameters ($0 - $9), but if\n"
+" more arguments are given, they are parsed instead.\n"
+" \n"
+" Exit Status:\n"
+" Returns success if an option is found; fails if the end of options is\n"
+" encountered or an error occurs."
+msgstr ""
+
+#: builtins.c:668
+msgid ""
+"Replace the shell with the given command.\n"
+" \n"
+" Execute COMMAND, replacing this shell with the specified program.\n"
+" ARGUMENTS become the arguments to COMMAND. If COMMAND is not specified,\n"
+" any redirections take effect in the current shell.\n"
+" \n"
+" Options:\n"
+" -a name\tpass NAME as the zeroth argument to COMMAND\n"
+" -c\t\texecute COMMAND with an empty environment\n"
+" -l\t\tplace a dash in the zeroth argument to COMMAND\n"
+" \n"
+" If the command cannot be executed, a non-interactive shell exits, unless\n"
+" the shell option `execfail' is set.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless COMMAND is not found or a redirection error occurs."
+msgstr ""
+
+#: builtins.c:689
+msgid ""
+"Exit the shell.\n"
+" \n"
+" Exits the shell with a status of N. If N is omitted, the exit status\n"
+" is that of the last command executed."
+msgstr ""
+
+#: builtins.c:698
+msgid ""
+"Exit a login shell.\n"
+" \n"
+" Exits a login shell with exit status N. Returns an error if not executed\n"
+" in a login shell."
+msgstr ""
+
+#: builtins.c:708
+msgid ""
+"Display or execute commands from the history list.\n"
+" \n"
+" fc is used to list or edit and re-execute commands from the history list.\n"
+" FIRST and LAST can be numbers specifying the range, or FIRST can be a\n"
+" string, which means the most recent command beginning with that\n"
+" string.\n"
+" \n"
+" Options:\n"
+" -e ENAME\tselect which editor to use. Default is FCEDIT, then EDITOR,\n"
+" \t\tthen vi\n"
+" -l \tlist lines instead of editing\n"
+" -n\tomit line numbers when listing\n"
+" -r\treverse the order of the lines (newest listed first)\n"
+" \n"
+" With the `fc -s [pat=rep ...] [command]' format, COMMAND is\n"
+" re-executed after the substitution OLD=NEW is performed.\n"
+" \n"
+" A useful alias to use with this is r='fc -s', so that typing `r cc'\n"
+" runs the last command beginning with `cc' and typing `r' re-executes\n"
+" the last command.\n"
+" \n"
+" Exit Status:\n"
+" Returns success or status of executed command; non-zero if an error occurs."
+msgstr ""
+
+#: builtins.c:738
+msgid ""
+"Move job to the foreground.\n"
+" \n"
+" Place the job identified by JOB_SPEC in the foreground, making it the\n"
+" current job. If JOB_SPEC is not present, the shell's notion of the\n"
+" current job is used.\n"
+" \n"
+" Exit Status:\n"
+" Status of command placed in foreground, or failure if an error occurs."
+msgstr ""
+
+#: builtins.c:753
+msgid ""
+"Move jobs to the background.\n"
+" \n"
+" Place the jobs identified by each JOB_SPEC in the background, as if they\n"
+" had been started with `&'. If JOB_SPEC is not present, the shell's notion\n"
+" of the current job is used.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless job control is not enabled or an error occurs."
+msgstr ""
+
+#: builtins.c:767
+msgid ""
+"Remember or display program locations.\n"
+" \n"
+" Determine and remember the full pathname of each command NAME. If\n"
+" no arguments are given, information about remembered commands is displayed.\n"
+" \n"
+" Options:\n"
+" -d\t\tforget the remembered location of each NAME\n"
+" -l\t\tdisplay in a format that may be reused as input\n"
+" -p pathname\tuse PATHNAME is the full pathname of NAME\n"
+" -r\t\tforget all remembered locations\n"
+" -t\t\tprint the remembered location of each NAME, preceding\n"
+" \t\teach location with the corresponding NAME if multiple\n"
+" \t\tNAMEs are given\n"
+" Arguments:\n"
+" NAME\t\tEach NAME is searched for in $PATH and added to the list\n"
+" \t\tof remembered commands.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless NAME is not found or an invalid option is given."
+msgstr ""
+
+#: builtins.c:792
+msgid ""
+"Display information about builtin commands.\n"
+" \n"
+" Displays brief summaries of builtin commands. If PATTERN is\n"
+" specified, gives detailed help on all commands matching PATTERN,\n"
+" otherwise the list of help topics is printed.\n"
+" \n"
+" Options:\n"
+" -d\toutput short description for each topic\n"
+" -m\tdisplay usage in pseudo-manpage format\n"
+" -s\toutput only a short usage synopsis for each topic matching\n"
+" \tPATTERN\n"
+" \n"
+" Arguments:\n"
+" PATTERN\tPattern specifiying a help topic\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless PATTERN is not found or an invalid option is given."
+msgstr ""
+
+#: builtins.c:816
+msgid ""
+"Display or manipulate the history list.\n"
+" \n"
+" Display the history list with line numbers, prefixing each modified\n"
+" entry with a `*'. An argument of N lists only the last N entries.\n"
+" \n"
+" Options:\n"
+" -c\tclear the history list by deleting all of the entries\n"
+" -d offset\tdelete the history entry at offset OFFSET.\n"
+" \n"
+" -a\tappend history lines from this session to the history file\n"
+" -n\tread all history lines not already read from the history file\n"
+" -r\tread the history file and append the contents to the history\n"
+" \tlist\n"
+" -w\twrite the current history to the history file\n"
+" \tand append them to the history list\n"
+" \n"
+" -p\tperform history expansion on each ARG and display the result\n"
+" \twithout storing it in the history list\n"
+" -s\tappend the ARGs to the history list as a single entry\n"
+" \n"
+" If FILENAME is given, it is used as the history file. Otherwise,\n"
+" if $HISTFILE has a value, that is used, else ~/.bash_history.\n"
+" \n"
+" If the $HISTTIMEFORMAT variable is set and not null, its value is used\n"
+" as a format string for strftime(3) to print the time stamp associated\n"
+" with each displayed history entry. No time stamps are printed otherwise.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless an invalid option is given or an error occurs."
+msgstr ""
+
+#: builtins.c:852
+msgid ""
+"Display status of jobs.\n"
+" \n"
+" Lists the active jobs. JOBSPEC restricts output to that job.\n"
+" Without options, the status of all active jobs is displayed.\n"
+" \n"
+" Options:\n"
+" -l\tlists process IDs in addition to the normal information\n"
+" -n\tlist only processes that have changed status since the last\n"
+" \tnotification\n"
+" -p\tlists process IDs only\n"
+" -r\trestrict output to running jobs\n"
+" -s\trestrict output to stopped jobs\n"
+" \n"
+" If -x is supplied, COMMAND is run after all job specifications that\n"
+" appear in ARGS have been replaced with the process ID of that job's\n"
+" process group leader.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless an invalid option is given or an error occurs.\n"
+" If -x is used, returns the exit status of COMMAND."
+msgstr ""
+
+#: builtins.c:879
+msgid ""
+"Remove jobs from current shell.\n"
+" \n"
+" Removes each JOBSPEC argument from the table of active jobs. Without\n"
+" any JOBSPECs, the shell uses its notion of the current job.\n"
+" \n"
+" Options:\n"
+" -a\tremove all jobs if JOBSPEC is not supplied\n"
+" -h\tmark each JOBSPEC so that SIGHUP is not sent to the job if the\n"
+" \tshell receives a SIGHUP\n"
+" -r\tremove only running jobs\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless an invalid option or JOBSPEC is given."
+msgstr ""
+
+#: builtins.c:898
+msgid ""
+"Send a signal to a job.\n"
+" \n"
+" Send the processes identified by PID or JOBSPEC the signal named by\n"
+" SIGSPEC or SIGNUM. If neither SIGSPEC nor SIGNUM is present, then\n"
+" SIGTERM is assumed.\n"
+" \n"
+" Options:\n"
+" -s sig\tSIG is a signal name\n"
+" -n sig\tSIG is a signal number\n"
+" -l\tlist the signal names; if arguments follow `-l' they are\n"
+" \tassumed to be signal numbers for which names should be listed\n"
+" \n"
+" Kill is a shell builtin for two reasons: it allows job IDs to be used\n"
+" instead of process IDs, and allows processes to be killed if the limit\n"
+" on processes that you can create is reached.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless an invalid option is given or an error occurs."
+msgstr ""
+
+#: builtins.c:921
+msgid ""
+"Evaluate arithmetic expressions.\n"
+" \n"
+" Evaluate each ARG as an arithmetic expression. Evaluation is done in\n"
+" fixed-width integers with no check for overflow, though division by 0\n"
+" is trapped and flagged as an error. The following list of operators is\n"
+" grouped into levels of equal-precedence operators. The levels are listed\n"
+" in order of decreasing precedence.\n"
+" \n"
+" \tid++, id--\tvariable post-increment, post-decrement\n"
+" \t++id, --id\tvariable pre-increment, pre-decrement\n"
+" \t-, +\t\tunary minus, plus\n"
+" \t!, ~\t\tlogical and bitwise negation\n"
+" \t**\t\texponentiation\n"
+" \t*, /, %\t\tmultiplication, division, remainder\n"
+" \t+, -\t\taddition, subtraction\n"
+" \t<<, >>\t\tleft and right bitwise shifts\n"
+" \t<=, >=, <, >\tcomparison\n"
+" \t==, !=\t\tequality, inequality\n"
+" \t&\t\tbitwise AND\n"
+" \t^\t\tbitwise XOR\n"
+" \t|\t\tbitwise OR\n"
+" \t&&\t\tlogical AND\n"
+" \t||\t\tlogical OR\n"
+" \texpr ? expr : expr\n"
+" \t\t\tconditional operator\n"
+" \t=, *=, /=, %=,\n"
+" \t+=, -=, <<=, >>=,\n"
+" \t&=, ^=, |=\tassignment\n"
+" \n"
+" Shell variables are allowed as operands. The name of the variable\n"
+" is replaced by its value (coerced to a fixed-width integer) within\n"
+" an expression. The variable need not have its integer attribute\n"
+" turned on to be used in an expression.\n"
+" \n"
+" Operators are evaluated in order of precedence. Sub-expressions in\n"
+" parentheses are evaluated first and may override the precedence\n"
+" rules above.\n"
+" \n"
+" Exit Status:\n"
+" If the last ARG evaluates to 0, let returns 1; let returns 0 otherwise.."
+msgstr ""
+
+#: builtins.c:966
+msgid ""
+"Read a line from the standard input and split it into fields.\n"
+" \n"
+" Reads a single line from the standard input, or from file descriptor FD\n"
+" if the -u option is supplied. The line is split into fields as with word\n"
+" splitting, and the first word is assigned to the first NAME, the second\n"
+" word to the second NAME, and so on, with any leftover words assigned to\n"
+" the last NAME. Only the characters found in $IFS are recognized as word\n"
+" delimiters.\n"
+" \n"
+" If no NAMEs are supplied, the line read is stored in the REPLY variable.\n"
+" \n"
+" Options:\n"
+" -a array\tassign the words read to sequential indices of the array\n"
+" \t\tvariable ARRAY, starting at zero\n"
+" -d delim\tcontinue until the first character of DELIM is read, rather\n"
+" \t\tthan newline\n"
+" -e\t\tuse Readline to obtain the line in an interactive shell\n"
+" -i text\tUse TEXT as the initial text for Readline\n"
+" -n nchars\treturn after reading NCHARS characters rather than waiting\n"
+" \t\tfor a newline, but honor a delimiter if fewer than NCHARS\n"
+" \t\tcharacters are read before the delimiter\n"
+" -N nchars\treturn only after reading exactly NCHARS characters, unless\n"
+" \t\tEOF is encountered or read times out, ignoring any delimiter\n"
+" -p prompt\toutput the string PROMPT without a trailing newline before\n"
+" \t\tattempting to read\n"
+" -r\t\tdo not allow backslashes to escape any characters\n"
+" -s\t\tdo not echo input coming from a terminal\n"
+" -t timeout\ttime out and return failure if a complete line of input is\n"
+" \t\tnot read withint TIMEOUT seconds. The value of the TMOUT\n"
+" \t\tvariable is the default timeout. TIMEOUT may be a\n"
+" \t\tfractional number. If TIMEOUT is 0, read returns success only\n"
+" \t\tif input is available on the specified file descriptor. The\n"
+" \t\texit status is greater than 128 if the timeout is exceeded\n"
+" -u fd\t\tread from file descriptor FD instead of the standard input\n"
+" \n"
+" Exit Status:\n"
+" The return code is zero, unless end-of-file is encountered, read times out,\n"
+" or an invalid file descriptor is supplied as the argument to -u."
+msgstr ""
+
+#: builtins.c:1009
+msgid ""
+"Return from a shell function.\n"
+" \n"
+" Causes a function or sourced script to exit with the return value\n"
+" specified by N. If N is omitted, the return status is that of the\n"
+" last command executed within the function or script.\n"
+" \n"
+" Exit Status:\n"
+" Returns N, or failure if the shell is not executing a function or script."
+msgstr ""
+
+#: builtins.c:1022
+msgid ""
+"Set or unset values of shell options and positional parameters.\n"
+" \n"
+" Change the value of shell attributes and positional parameters, or\n"
+" display the names and values of shell variables.\n"
+" \n"
+" Options:\n"
+" -a Mark variables which are modified or created for export.\n"
+" -b Notify of job termination immediately.\n"
+" -e Exit immediately if a command exits with a non-zero status.\n"
+" -f Disable file name generation (globbing).\n"
+" -h Remember the location of commands as they are looked up.\n"
+" -k All assignment arguments are placed in the environment for a\n"
+" command, not just those that precede the command name.\n"
+" -m Job control is enabled.\n"
+" -n Read commands but do not execute them.\n"
+" -o option-name\n"
+" Set the variable corresponding to option-name:\n"
+" allexport same as -a\n"
+" braceexpand same as -B\n"
+" emacs use an emacs-style line editing interface\n"
+" errexit same as -e\n"
+" errtrace same as -E\n"
+" functrace same as -T\n"
+" hashall same as -h\n"
+" histexpand same as -H\n"
+" history enable command history\n"
+" ignoreeof the shell will not exit upon reading EOF\n"
+" interactive-comments\n"
+" allow comments to appear in interactive commands\n"
+" keyword same as -k\n"
+" monitor same as -m\n"
+" noclobber same as -C\n"
+" noexec same as -n\n"
+" noglob same as -f\n"
+" nolog currently accepted but ignored\n"
+" notify same as -b\n"
+" nounset same as -u\n"
+" onecmd same as -t\n"
+" physical same as -P\n"
+" pipefail the return value of a pipeline is the status of\n"
+" the last command to exit with a non-zero status,\n"
+" or zero if no command exited with a non-zero status\n"
+" posix change the behavior of bash where the default\n"
+" operation differs from the Posix standard to\n"
+" match the standard\n"
+" privileged same as -p\n"
+" verbose same as -v\n"
+" vi use a vi-style line editing interface\n"
+" xtrace same as -x\n"
+" -p Turned on whenever the real and effective user ids do not match.\n"
+" Disables processing of the $ENV file and importing of shell\n"
+" functions. Turning this option off causes the effective uid and\n"
+" gid to be set to the real uid and gid.\n"
+" -t Exit after reading and executing one command.\n"
+" -u Treat unset variables as an error when substituting.\n"
+" -v Print shell input lines as they are read.\n"
+" -x Print commands and their arguments as they are executed.\n"
+" -B the shell will perform brace expansion\n"
+" -C If set, disallow existing regular files to be overwritten\n"
+" by redirection of output.\n"
+" -E If set, the ERR trap is inherited by shell functions.\n"
+" -H Enable ! style history substitution. This flag is on\n"
+" by default when the shell is interactive.\n"
+" -P If set, do not follow symbolic links when executing commands\n"
+" such as cd which change the current directory.\n"
+" -T If set, the DEBUG trap is inherited by shell functions.\n"
+" - Assign any remaining arguments to the positional parameters.\n"
+" The -x and -v options are turned off.\n"
+" \n"
+" Using + rather than - causes these flags to be turned off. The\n"
+" flags can also be used upon invocation of the shell. The current\n"
+" set of flags may be found in $-. The remaining n ARGs are positional\n"
+" parameters and are assigned, in order, to $1, $2, .. $n. If no\n"
+" ARGs are given, all shell variables are printed.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless an invalid option is given."
+msgstr ""
+
+#: builtins.c:1104
+msgid ""
+"Unset values and attributes of shell variables and functions.\n"
+" \n"
+" For each NAME, remove the corresponding variable or function.\n"
+" \n"
+" Options:\n"
+" -f\ttreat each NAME as a shell function\n"
+" -v\ttreat each NAME as a shell variable\n"
+" \n"
+" Without options, unset first tries to unset a variable, and if that fails,\n"
+" tries to unset a function.\n"
+" \n"
+" Some variables cannot be unset; also see `readonly'.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless an invalid option is given or a NAME is read-only."
+msgstr ""
+
+#: builtins.c:1124
+msgid ""
+"Set export attribute for shell variables.\n"
+" \n"
+" Marks each NAME for automatic export to the environment of subsequently\n"
+" executed commands. If VALUE is supplied, assign VALUE before exporting.\n"
+" \n"
+" Options:\n"
+" -f\trefer to shell functions\n"
+" -n\tremove the export property from each NAME\n"
+" -p\tdisplay a list of all exported variables and functions\n"
+" \n"
+" An argument of `--' disables further option processing.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless an invalid option is given or NAME is invalid."
+msgstr ""
+
+#: builtins.c:1143
+msgid ""
+"Mark shell variables as unchangeable.\n"
+" \n"
+" Mark each NAME as read-only; the values of these NAMEs may not be\n"
+" changed by subsequent assignment. If VALUE is supplied, assign VALUE\n"
+" before marking as read-only.\n"
+" \n"
+" Options:\n"
+" -a\trefer to indexed array variables\n"
+" -A\trefer to associative array variables\n"
+" -f\trefer to shell functions\n"
+" -p\tdisplay a list of all readonly variables and functions\n"
+" \n"
+" An argument of `--' disables further option processing.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless an invalid option is given or NAME is invalid."
+msgstr ""
+
+#: builtins.c:1164
+msgid ""
+"Shift positional parameters.\n"
+" \n"
+" Rename the positional parameters $N+1,$N+2 ... to $1,$2 ... If N is\n"
+" not given, it is assumed to be 1.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless N is negative or greater than $#."
+msgstr ""
+
+#: builtins.c:1176 builtins.c:1191
+msgid ""
+"Execute commands from a file in the current shell.\n"
+" \n"
+" Read and execute commands from FILENAME in the current shell. The\n"
+" entries in $PATH are used to find the directory containing FILENAME.\n"
+" If any ARGUMENTS are supplied, they become the positional parameters\n"
+" when FILENAME is executed.\n"
+" \n"
+" Exit Status:\n"
+" Returns the status of the last command executed in FILENAME; fails if\n"
+" FILENAME cannot be read."
+msgstr ""
+
+#: builtins.c:1207
+msgid ""
+"Suspend shell execution.\n"
+" \n"
+" Suspend the execution of this shell until it receives a SIGCONT signal.\n"
+" Unless forced, login shells cannot be suspended.\n"
+" \n"
+" Options:\n"
+" -f\tforce the suspend, even if the shell is a login shell\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless job control is not enabled or an error occurs."
+msgstr ""
+
+#: builtins.c:1223
+msgid ""
+"Evaluate conditional expression.\n"
+" \n"
+" Exits with a status of 0 (true) or 1 (false) depending on\n"
+" the evaluation of EXPR. Expressions may be unary or binary. Unary\n"
+" expressions are often used to examine the status of a file. There\n"
+" are string operators as well, and numeric comparison operators.\n"
+" \n"
+" File operators:\n"
+" \n"
+" -a FILE True if file exists.\n"
+" -b FILE True if file is block special.\n"
+" -c FILE True if file is character special.\n"
+" -d FILE True if file is a directory.\n"
+" -e FILE True if file exists.\n"
+" -f FILE True if file exists and is a regular file.\n"
+" -g FILE True if file is set-group-id.\n"
+" -h FILE True if file is a symbolic link.\n"
+" -L FILE True if file is a symbolic link.\n"
+" -k FILE True if file has its `sticky' bit set.\n"
+" -p FILE True if file is a named pipe.\n"
+" -r FILE True if file is readable by you.\n"
+" -s FILE True if file exists and is not empty.\n"
+" -S FILE True if file is a socket.\n"
+" -t FD True if FD is opened on a terminal.\n"
+" -u FILE True if the file is set-user-id.\n"
+" -w FILE True if the file is writable by you.\n"
+" -x FILE True if the file is executable by you.\n"
+" -O FILE True if the file is effectively owned by you.\n"
+" -G FILE True if the file is effectively owned by your group.\n"
+" -N FILE True if the file has been modified since it was last read.\n"
+" \n"
+" FILE1 -nt FILE2 True if file1 is newer than file2 (according to\n"
+" modification date).\n"
+" \n"
+" FILE1 -ot FILE2 True if file1 is older than file2.\n"
+" \n"
+" FILE1 -ef FILE2 True if file1 is a hard link to file2.\n"
+" \n"
+" String operators:\n"
+" \n"
+" -z STRING True if string is empty.\n"
+" \n"
+" -n STRING\n"
+" STRING True if string is not empty.\n"
+" \n"
+" STRING1 = STRING2\n"
+" True if the strings are equal.\n"
+" STRING1 != STRING2\n"
+" True if the strings are not equal.\n"
+" STRING1 < STRING2\n"
+" True if STRING1 sorts before STRING2 lexicographically.\n"
+" STRING1 > STRING2\n"
+" True if STRING1 sorts after STRING2 lexicographically.\n"
+" \n"
+" Other operators:\n"
+" \n"
+" -o OPTION True if the shell option OPTION is enabled.\n"
+" ! EXPR True if expr is false.\n"
+" EXPR1 -a EXPR2 True if both expr1 AND expr2 are true.\n"
+" EXPR1 -o EXPR2 True if either expr1 OR expr2 is true.\n"
+" \n"
+" arg1 OP arg2 Arithmetic tests. OP is one of -eq, -ne,\n"
+" -lt, -le, -gt, or -ge.\n"
+" \n"
+" Arithmetic binary operators return true if ARG1 is equal, not-equal,\n"
+" less-than, less-than-or-equal, greater-than, or greater-than-or-equal\n"
+" than ARG2.\n"
+" \n"
+" Exit Status:\n"
+" Returns success if EXPR evaluates to true; fails if EXPR evaluates to\n"
+" false or an invalid argument is given."
+msgstr ""
+
+#: builtins.c:1299
+msgid ""
+"Evaluate conditional expression.\n"
+" \n"
+" This is a synonym for the \"test\" builtin, but the last argument must\n"
+" be a literal `]', to match the opening `['."
+msgstr ""
+
+#: builtins.c:1308
+msgid ""
+"Display process times.\n"
+" \n"
+" Prints the accumulated user and system times for the shell and all of its\n"
+" child processes.\n"
+" \n"
+" Exit Status:\n"
+" Always succeeds."
+msgstr ""
+
+#: builtins.c:1320
+msgid ""
+"Trap signals and other events.\n"
+" \n"
+" Defines and activates handlers to be run when the shell receives signals\n"
+" or other conditions.\n"
+" \n"
+" ARG is a command to be read and executed when the shell receives the\n"
+" signal(s) SIGNAL_SPEC. If ARG is absent (and a single SIGNAL_SPEC\n"
+" is supplied) or `-', each specified signal is reset to its original\n"
+" value. If ARG is the null string each SIGNAL_SPEC is ignored by the\n"
+" shell and by the commands it invokes.\n"
+" \n"
+" If a SIGNAL_SPEC is EXIT (0) ARG is executed on exit from the shell. If\n"
+" a SIGNAL_SPEC is DEBUG, ARG is executed before every simple command.\n"
+" \n"
+" If no arguments are supplied, trap prints the list of commands associated\n"
+" with each signal.\n"
+" \n"
+" Options:\n"
+" -l\tprint a list of signal names and their corresponding numbers\n"
+" -p\tdisplay the trap commands associated with each SIGNAL_SPEC\n"
+" \n"
+" Each SIGNAL_SPEC is either a signal name in <signal.h> or a signal number.\n"
+" Signal names are case insensitive and the SIG prefix is optional. A\n"
+" signal may be sent to the shell with \"kill -signal $$\".\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless a SIGSPEC is invalid or an invalid option is given."
+msgstr ""
+
+#: builtins.c:1352
+msgid ""
+"Display information about command type.\n"
+" \n"
+" For each NAME, indicate how it would be interpreted if used as a\n"
+" command name.\n"
+" \n"
+" Options:\n"
+" -a\tdisplay all locations containing an executable named NAME;\n"
+" \tincludes aliases, builtins, and functions, if and only if\n"
+" \tthe `-p' option is not also used\n"
+" -f\tsuppress shell function lookup\n"
+" -P\tforce a PATH search for each NAME, even if it is an alias,\n"
+" \tbuiltin, or function, and returns the name of the disk file\n"
+" \tthat would be executed\n"
+" -p\treturns either the name of the disk file that would be executed,\n"
+" \tor nothing if `type -t NAME' would not return `file'.\n"
+" -t\toutput a single word which is one of `alias', `keyword',\n"
+" \t`function', `builtin', `file' or `', if NAME is an alias, shell\n"
+" \treserved word, shell function, shell builtin, disk file, or not\n"
+" \tfound, respectively\n"
+" \n"
+" Arguments:\n"
+" NAME\tCommand name to be interpreted.\n"
+" \n"
+" Exit Status:\n"
+" Returns success if all of the NAMEs are found; fails if any are not found."
+msgstr ""
+
+#: builtins.c:1383
+msgid ""
+"Modify shell resource limits.\n"
+" \n"
+" Provides control over the resources available to the shell and processes\n"
+" it creates, on systems that allow such control.\n"
+" \n"
+" Options:\n"
+" -S\tuse the `soft' resource limit\n"
+" -H\tuse the `hard' resource limit\n"
+" -a\tall current limits are reported\n"
+" -b\tthe socket buffer size\n"
+" -c\tthe maximum size of core files created\n"
+" -d\tthe maximum size of a process's data segment\n"
+" -e\tthe maximum scheduling priority (`nice')\n"
+" -f\tthe maximum size of files written by the shell and its children\n"
+" -i\tthe maximum number of pending signals\n"
+" -l\tthe maximum size a process may lock into memory\n"
+" -m\tthe maximum resident set size\n"
+" -n\tthe maximum number of open file descriptors\n"
+" -p\tthe pipe buffer size\n"
+" -q\tthe maximum number of bytes in POSIX message queues\n"
+" -r\tthe maximum real-time scheduling priority\n"
+" -s\tthe maximum stack size\n"
+" -t\tthe maximum amount of cpu time in seconds\n"
+" -u\tthe maximum number of user processes\n"
+" -v\tthe size of virtual memory\n"
+" -x\tthe maximum number of file locks\n"
+" \n"
+" If LIMIT is given, it is the new value of the specified resource; the\n"
+" special LIMIT values `soft', `hard', and `unlimited' stand for the\n"
+" current soft limit, the current hard limit, and no limit, respectively.\n"
+" Otherwise, the current value of the specified resource is printed. If\n"
+" no option is given, then -f is assumed.\n"
+" \n"
+" Values are in 1024-byte increments, except for -t, which is in seconds,\n"
+" -p, which is in increments of 512 bytes, and -u, which is an unscaled\n"
+" number of processes.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless an invalid option is supplied or an error occurs."
+msgstr ""
+
+#: builtins.c:1428
+msgid ""
+"Display or set file mode mask.\n"
+" \n"
+" Sets the user file-creation mask to MODE. If MODE is omitted, prints\n"
+" the current value of the mask.\n"
+" \n"
+" If MODE begins with a digit, it is interpreted as an octal number;\n"
+" otherwise it is a symbolic mode string like that accepted by chmod(1).\n"
+" \n"
+" Options:\n"
+" -p\tif MODE is omitted, output in a form that may be reused as input\n"
+" -S\tmakes the output symbolic; otherwise an octal number is output\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless MODE is invalid or an invalid option is given."
+msgstr ""
+
+#: builtins.c:1448
+msgid ""
+"Wait for job completion and return exit status.\n"
+" \n"
+" Waits for the process identified by ID, which may be a process ID or a\n"
+" job specification, and reports its termination status. If ID is not\n"
+" given, waits for all currently active child processes, and the return\n"
+" status is zero. If ID is a a job specification, waits for all processes\n"
+" in the job's pipeline.\n"
+" \n"
+" Exit Status:\n"
+" Returns the status of ID; fails if ID is invalid or an invalid option is\n"
+" given."
+msgstr ""
+
+#: builtins.c:1466
+msgid ""
+"Wait for process completion and return exit status.\n"
+" \n"
+" Waits for the specified process and reports its termination status. If\n"
+" PID is not given, all currently active child processes are waited for,\n"
+" and the return code is zero. PID must be a process ID.\n"
+" \n"
+" Exit Status:\n"
+" Returns the status of ID; fails if ID is invalid or an invalid option is\n"
+" given."
+msgstr ""
+
+#: builtins.c:1481
+msgid ""
+"Execute commands for each member in a list.\n"
+" \n"
+" The `for' loop executes a sequence of commands for each member in a\n"
+" list of items. If `in WORDS ...;' is not present, then `in \"$@\"' is\n"
+" assumed. For each element in WORDS, NAME is set to that element, and\n"
+" the COMMANDS are executed.\n"
+" \n"
+" Exit Status:\n"
+" Returns the status of the last command executed."
+msgstr ""
+
+#: builtins.c:1495
+msgid ""
+"Arithmetic for loop.\n"
+" \n"
+" Equivalent to\n"
+" \t(( EXP1 ))\n"
+" \twhile (( EXP2 )); do\n"
+" \t\tCOMMANDS\n"
+" \t\t(( EXP3 ))\n"
+" \tdone\n"
+" EXP1, EXP2, and EXP3 are arithmetic expressions. If any expression is\n"
+" omitted, it behaves as if it evaluates to 1.\n"
+" \n"
+" Exit Status:\n"
+" Returns the status of the last command executed."
+msgstr ""
+
+#: builtins.c:1513
+msgid ""
+"Select words from a list and execute commands.\n"
+" \n"
+" The WORDS are expanded, generating a list of words. The\n"
+" set of expanded words is printed on the standard error, each\n"
+" preceded by a number. If `in WORDS' is not present, `in \"$@\"'\n"
+" is assumed. The PS3 prompt is then displayed and a line read\n"
+" from the standard input. If the line consists of the number\n"
+" corresponding to one of the displayed words, then NAME is set\n"
+" to that word. If the line is empty, WORDS and the prompt are\n"
+" redisplayed. If EOF is read, the command completes. Any other\n"
+" value read causes NAME to be set to null. The line read is saved\n"
+" in the variable REPLY. COMMANDS are executed after each selection\n"
+" until a break command is executed.\n"
+" \n"
+" Exit Status:\n"
+" Returns the status of the last command executed."
+msgstr ""
+
+#: builtins.c:1534
+msgid ""
+"Report time consumed by pipeline's execution.\n"
+" \n"
+" Execute PIPELINE and print a summary of the real time, user CPU time,\n"
+" and system CPU time spent executing PIPELINE when it terminates.\n"
+" \n"
+" Options:\n"
+" -p\tprint the timing summary in the portable Posix format\n"
+" \n"
+" The value of the TIMEFORMAT variable is used as the output format.\n"
+" \n"
+" Exit Status:\n"
+" The return status is the return status of PIPELINE."
+msgstr ""
+
+#: builtins.c:1551
+msgid ""
+"Execute commands based on pattern matching.\n"
+" \n"
+" Selectively execute COMMANDS based upon WORD matching PATTERN. The\n"
+" `|' is used to separate multiple patterns.\n"
+" \n"
+" Exit Status:\n"
+" Returns the status of the last command executed."
+msgstr ""
+
+#: builtins.c:1563
+msgid ""
+"Execute commands based on conditional.\n"
+" \n"
+" The `if COMMANDS' list is executed. If its exit status is zero, then the\n"
+" `then COMMANDS' list is executed. Otherwise, each `elif COMMANDS' list is\n"
+" executed in turn, and if its exit status is zero, the corresponding\n"
+" `then COMMANDS' list is executed and the if command completes. Otherwise,\n"
+" the `else COMMANDS' list is executed, if present. The exit status of the\n"
+" entire construct is the exit status of the last command executed, or zero\n"
+" if no condition tested true.\n"
+" \n"
+" Exit Status:\n"
+" Returns the status of the last command executed."
+msgstr ""
+
+#: builtins.c:1580
+msgid ""
+"Execute commands as long as a test succeeds.\n"
+" \n"
+" Expand and execute COMMANDS as long as the final command in the\n"
+" `while' COMMANDS has an exit status of zero.\n"
+" \n"
+" Exit Status:\n"
+" Returns the status of the last command executed."
+msgstr ""
+
+#: builtins.c:1592
+msgid ""
+"Execute commands as long as a test does not succeed.\n"
+" \n"
+" Expand and execute COMMANDS as long as the final command in the\n"
+" `until' COMMANDS has an exit status which is not zero.\n"
+" \n"
+" Exit Status:\n"
+" Returns the status of the last command executed."
+msgstr ""
+
+#: builtins.c:1604
+msgid ""
+"Create a coprocess named NAME.\n"
+" \n"
+" Execute COMMAND asynchronously, with the standard output and standard\n"
+" input of the command connected via a pipe to file descriptors assigned\n"
+" to indices 0 and 1 of an array variable NAME in the executing shell.\n"
+" The default NAME is \"COPROC\".\n"
+" \n"
+" Exit Status:\n"
+" Returns the exit status of COMMAND."
+msgstr ""
+
+#: builtins.c:1618
+msgid ""
+"Define shell function.\n"
+" \n"
+" Create a shell function named NAME. When invoked as a simple command,\n"
+" NAME runs COMMANDs in the calling shell's context. When NAME is invoked,\n"
+" the arguments are passed to the function as $1...$n, and the function's\n"
+" name is in $FUNCNAME.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless NAME is readonly."
+msgstr ""
+
+#: builtins.c:1632
+msgid ""
+"Group commands as a unit.\n"
+" \n"
+" Run a set of commands in a group. This is one way to redirect an\n"
+" entire set of commands.\n"
+" \n"
+" Exit Status:\n"
+" Returns the status of the last command executed."
+msgstr ""
+
+#: builtins.c:1644
+msgid ""
+"Resume job in foreground.\n"
+" \n"
+" Equivalent to the JOB_SPEC argument to the `fg' command. Resume a\n"
+" stopped or background job. JOB_SPEC can specify either a job name\n"
+" or a job number. Following JOB_SPEC with a `&' places the job in\n"
+" the background, as if the job specification had been supplied as an\n"
+" argument to `bg'.\n"
+" \n"
+" Exit Status:\n"
+" Returns the status of the resumed job."
+msgstr ""
+
+#: builtins.c:1659
+msgid ""
+"Evaluate arithmetic expression.\n"
+" \n"
+" The EXPRESSION is evaluated according to the rules for arithmetic\n"
+" evaluation. Equivalent to \"let EXPRESSION\".\n"
+" \n"
+" Exit Status:\n"
+" Returns 1 if EXPRESSION evaluates to 0; returns 0 otherwise."
+msgstr ""
+
+#: builtins.c:1671
+msgid ""
+"Execute conditional command.\n"
+" \n"
+" Returns a status of 0 or 1 depending on the evaluation of the conditional\n"
+" expression EXPRESSION. Expressions are composed of the same primaries used\n"
+" by the `test' builtin, and may be combined using the following operators:\n"
+" \n"
+" ( EXPRESSION )\tReturns the value of EXPRESSION\n"
+" ! EXPRESSION\t\tTrue if EXPRESSION is false; else false\n"
+" EXPR1 && EXPR2\tTrue if both EXPR1 and EXPR2 are true; else false\n"
+" EXPR1 || EXPR2\tTrue if either EXPR1 or EXPR2 is true; else false\n"
+" \n"
+" When the `==' and `!=' operators are used, the string to the right of\n"
+" the operator is used as a pattern and pattern matching is performed.\n"
+" When the `=~' operator is used, the string to the right of the operator\n"
+" is matched as a regular expression.\n"
+" \n"
+" The && and || operators do not evaluate EXPR2 if EXPR1 is sufficient to\n"
+" determine the expression's value.\n"
+" \n"
+" Exit Status:\n"
+" 0 or 1 depending on value of EXPRESSION."
+msgstr ""
+
+#: builtins.c:1697
+msgid ""
+"Common shell variable names and usage.\n"
+" \n"
+" BASH_VERSION\tVersion information for this Bash.\n"
+" CDPATH\tA colon-separated list of directories to search\n"
+" \t\tfor directories given as arguments to `cd'.\n"
+" GLOBIGNORE\tA colon-separated list of patterns describing filenames to\n"
+" \t\tbe ignored by pathname expansion.\n"
+" HISTFILE\tThe name of the file where your command history is stored.\n"
+" HISTFILESIZE\tThe maximum number of lines this file can contain.\n"
+" HISTSIZE\tThe maximum number of history lines that a running\n"
+" \t\tshell can access.\n"
+" HOME\tThe complete pathname to your login directory.\n"
+" HOSTNAME\tThe name of the current host.\n"
+" HOSTTYPE\tThe type of CPU this version of Bash is running under.\n"
+" IGNOREEOF\tControls the action of the shell on receipt of an EOF\n"
+" \t\tcharacter as the sole input. If set, then the value\n"
+" \t\tof it is the number of EOF characters that can be seen\n"
+" \t\tin a row on an empty line before the shell will exit\n"
+" \t\t(default 10). When unset, EOF signifies the end of input.\n"
+" MACHTYPE\tA string describing the current system Bash is running on.\n"
+" MAILCHECK\tHow often, in seconds, Bash checks for new mail.\n"
+" MAILPATH\tA colon-separated list of filenames which Bash checks\n"
+" \t\tfor new mail.\n"
+" OSTYPE\tThe version of Unix this version of Bash is running on.\n"
+" PATH\tA colon-separated list of directories to search when\n"
+" \t\tlooking for commands.\n"
+" PROMPT_COMMAND\tA command to be executed before the printing of each\n"
+" \t\tprimary prompt.\n"
+" PS1\t\tThe primary prompt string.\n"
+" PS2\t\tThe secondary prompt string.\n"
+" PWD\t\tThe full pathname of the current directory.\n"
+" SHELLOPTS\tA colon-separated list of enabled shell options.\n"
+" TERM\tThe name of the current terminal type.\n"
+" TIMEFORMAT\tThe output format for timing statistics displayed by the\n"
+" \t\t`time' reserved word.\n"
+" auto_resume\tNon-null means a command word appearing on a line by\n"
+" \t\titself is first looked for in the list of currently\n"
+" \t\tstopped jobs. If found there, that job is foregrounded.\n"
+" \t\tA value of `exact' means that the command word must\n"
+" \t\texactly match a command in the list of stopped jobs. A\n"
+" \t\tvalue of `substring' means that the command word must\n"
+" \t\tmatch a substring of the job. Any other value means that\n"
+" \t\tthe command must be a prefix of a stopped job.\n"
+" histchars\tCharacters controlling history expansion and quick\n"
+" \t\tsubstitution. The first character is the history\n"
+" \t\tsubstitution character, usually `!'. The second is\n"
+" \t\tthe `quick substitution' character, usually `^'. The\n"
+" \t\tthird is the `history comment' character, usually `#'.\n"
+" HISTIGNORE\tA colon-separated list of patterns used to decide which\n"
+" \t\tcommands should be saved on the history list.\n"
+msgstr ""
+
+#: builtins.c:1754
+msgid ""
+"Add directories to stack.\n"
+" \n"
+" Adds a directory to the top of the directory stack, or rotates\n"
+" the stack, making the new top of the stack the current working\n"
+" directory. With no arguments, exchanges the top two directories.\n"
+" \n"
+" Options:\n"
+" -n\tSuppresses the normal change of directory when adding\n"
+" \tdirectories to the stack, so only the stack is manipulated.\n"
+" \n"
+" Arguments:\n"
+" +N\tRotates the stack so that the Nth directory (counting\n"
+" \tfrom the left of the list shown by `dirs', starting with\n"
+" \tzero) is at the top.\n"
+" \n"
+" -N\tRotates the stack so that the Nth directory (counting\n"
+" \tfrom the right of the list shown by `dirs', starting with\n"
+" \tzero) is at the top.\n"
+" \n"
+" dir\tAdds DIR to the directory stack at the top, making it the\n"
+" \tnew current working directory.\n"
+" \n"
+" The `dirs' builtin displays the directory stack.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless an invalid argument is supplied or the directory\n"
+" change fails."
+msgstr ""
+
+#: builtins.c:1788
+msgid ""
+"Remove directories from stack.\n"
+" \n"
+" Removes entries from the directory stack. With no arguments, removes\n"
+" the top directory from the stack, and changes to the new top directory.\n"
+" \n"
+" Options:\n"
+" -n\tSuppresses the normal change of directory when removing\n"
+" \tdirectories from the stack, so only the stack is manipulated.\n"
+" \n"
+" Arguments:\n"
+" +N\tRemoves the Nth entry counting from the left of the list\n"
+" \tshown by `dirs', starting with zero. For example: `popd +0'\n"
+" \tremoves the first directory, `popd +1' the second.\n"
+" \n"
+" -N\tRemoves the Nth entry counting from the right of the list\n"
+" \tshown by `dirs', starting with zero. For example: `popd -0'\n"
+" \tremoves the last directory, `popd -1' the next to last.\n"
+" \n"
+" The `dirs' builtin displays the directory stack.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless an invalid argument is supplied or the directory\n"
+" change fails."
+msgstr ""
+
+#: builtins.c:1818
+msgid ""
+"Display directory stack.\n"
+" \n"
+" Display the list of currently remembered directories. Directories\n"
+" find their way onto the list with the `pushd' command; you can get\n"
+" back up through the list with the `popd' command.\n"
+" \n"
+" Options:\n"
+" -c\tclear the directory stack by deleting all of the elements\n"
+" -l\tdo not print tilde-prefixed versions of directories relative\n"
+" \tto your home directory\n"
+" -p\tprint the directory stack with one entry per line\n"
+" -v\tprint the directory stack with one entry per line prefixed\n"
+" \twith its position in the stack\n"
+" \n"
+" Arguments:\n"
+" +N\tDisplays the Nth entry counting from the left of the list shown by\n"
+" \tdirs when invoked without options, starting with zero.\n"
+" \n"
+" -N\tDisplays the Nth entry counting from the right of the list shown by\n"
+" \tdirs when invoked without options, starting with zero.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless an invalid option is supplied or an error occurs."
+msgstr ""
+
+#: builtins.c:1847
+msgid ""
+"Set and unset shell options.\n"
+" \n"
+" Change the setting of each shell option OPTNAME. Without any option\n"
+" arguments, list all shell options with an indication of whether or not each\n"
+" is set.\n"
+" \n"
+" Options:\n"
+" -o\trestrict OPTNAMEs to those defined for use with `set -o'\n"
+" -p\tprint each shell option with an indication of its status\n"
+" -q\tsuppress output\n"
+" -s\tenable (set) each OPTNAME\n"
+" -u\tdisable (unset) each OPTNAME\n"
+" \n"
+" Exit Status:\n"
+" Returns success if OPTNAME is enabled; fails if an invalid option is\n"
+" given or OPTNAME is disabled."
+msgstr ""
+
+#: builtins.c:1868
+msgid ""
+"Formats and prints ARGUMENTS under control of the FORMAT.\n"
+" \n"
+" Options:\n"
+" -v var\tassign the output to shell variable VAR rather than\n"
+" \t\tdisplay it on the standard output\n"
+" \n"
+" FORMAT is a character string which contains three types of objects: plain\n"
+" characters, which are simply copied to standard output; character escape\n"
+" sequences, which are converted and copied to the standard output; and\n"
+" format specifications, each of which causes printing of the next successive\n"
+" argument.\n"
+" \n"
+" In addition to the standard format specifications described in printf(1)\n"
+" and printf(3), printf interprets:\n"
+" \n"
+" %b\texpand backslash escape sequences in the corresponding argument\n"
+" %q\tquote the argument in a way that can be reused as shell input\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless an invalid option is given or a write or assignment\n"
+" error occurs."
+msgstr ""
+
+#: builtins.c:1895
+msgid ""
+"Specify how arguments are to be completed by Readline.\n"
+" \n"
+" For each NAME, specify how arguments are to be completed. If no options\n"
+" are supplied, existing completion specifications are printed in a way that\n"
+" allows them to be reused as input.\n"
+" \n"
+" Options:\n"
+" -p\tprint existing completion specifications in a reusable format\n"
+" -r\tremove a completion specification for each NAME, or, if no\n"
+" \tNAMEs are supplied, all completion specifications\n"
+" -D\tapply the completions and actions as the default for commands\n"
+" \twithout any specific completion defined\n"
+" -E\tapply the completions and actions to \"empty\" commands --\n"
+" \tcompletion attempted on a blank line\n"
+" \n"
+" When completion is attempted, the actions are applied in the order the\n"
+" uppercase-letter options are listed above. The -D option takes\n"
+" precedence over -E.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless an invalid option is supplied or an error occurs."
+msgstr ""
+
+#: builtins.c:1923
+msgid ""
+"Display possible completions depending on the options.\n"
+" \n"
+" Intended to be used from within a shell function generating possible\n"
+" completions. If the optional WORD argument is supplied, matches against\n"
+" WORD are generated.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless an invalid option is supplied or an error occurs."
+msgstr ""
+
+#: builtins.c:1938
+msgid ""
+"Modify or display completion options.\n"
+" \n"
+" Modify the completion options for each NAME, or, if no NAMEs are supplied,\n"
+" the completion currently begin executed. If no OPTIONs are givenm, print\n"
+" the completion options for each NAME or the current completion specification.\n"
+" \n"
+" Options:\n"
+" \t-o option\tSet completion option OPTION for each NAME\n"
+" \t-D\t\tChange options for the \"default\" command completion\n"
+" \t-E\t\tChange options for the \"empty\" command completion\n"
+" \n"
+" Using `+o' instead of `-o' turns off the specified option.\n"
+" \n"
+" Arguments:\n"
+" \n"
+" Each NAME refers to a command for which a completion specification must\n"
+" have previously been defined using the `complete' builtin. If no NAMEs\n"
+" are supplied, compopt must be called by a function currently generating\n"
+" completions, and the options for that currently-executing completion\n"
+" generator are modified.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless an invalid option is supplied or NAME does not\n"
+" have a completion specification defined."
+msgstr ""
+
+#: builtins.c:1968
+msgid ""
+"Read lines from the standard input into an indexed array variable.\n"
+" \n"
+" Read lines from the standard input into the indexed array variable ARRAY, or\n"
+" from file descriptor FD if the -u option is supplied. The variable MAPFILE\n"
+" is the default ARRAY.\n"
+" \n"
+" Options:\n"
+" -n count\tCopy at most COUNT lines. If COUNT is 0, all lines are copied.\n"
+" -O origin\tBegin assigning to ARRAY at index ORIGIN. The default index is 0.\n"
+" -s count \tDiscard the first COUNT lines read.\n"
+" -t\t\tRemove a trailing newline from each line read.\n"
+" -u fd\t\tRead lines from file descriptor FD instead of the standard input.\n"
+" -C callback\tEvaluate CALLBACK each time QUANTUM lines are read.\n"
+" -c quantum\tSpecify the number of lines read between each call to CALLBACK.\n"
+" \n"
+" Arguments:\n"
+" ARRAY\t\tArray variable name to use for file data.\n"
+" \n"
+" If -C is supplied without -c, the default quantum is 5000. When\n"
+" CALLBACK is evaluated, it is supplied the index of the next array\n"
+" element to be assigned as an additional argument.\n"
+" \n"
+" If not supplied with an explicit origin, mapfile will clear ARRAY before\n"
+" assigning to it.\n"
+" \n"
+" Exit Status:\n"
+" Returns success unless an invalid option is given or ARRAY is readonly or\n"
+" not an indexed array."
+msgstr ""
+
+#: builtins.c:2001
+msgid ""
+"Read lines from a file into an array variable.\n"
+" \n"
+" A synonym for `mapfile'."
+msgstr ""
make_command_string_internal (command)
COMMAND *command;
{
- char s[3], *op;
+ char s[3];
if (command == 0)
cprintf ("");
print_redirection (redirect)
REDIRECT *redirect;
{
- int kill_leading, redirector, redir_fd;
+ int redirector, redir_fd;
WORD_DESC *redirectee, *redir_word;
- kill_leading = 0;
redirectee = redirect->redirectee.filename;
redir_fd = redirect->redirectee.dest;
else if (redirector != 0)
cprintf ("%d", redirector);
#if 0
+ /* Don't need to check whether or not to requote, since original quotes
+ are still intact. The only thing that has happened is that $'...'
+ has been replaced with 'expanded ...'. */
if (ansic_shouldquote (redirect->redirectee.filename->word))
{
char *x;
int posixly_correct = 0; /* Non-zero means posix.2 superset. */
#endif
-
/* Some long-winded argument names. These are obviously new. */
#define Int 1
#define Charp 2
char **subshell_argv;
char **subshell_envp;
+char *exec_argv0;
+
#if defined (BUFFERED_INPUT)
/* The file descriptor from which the shell is reading input. */
int default_buffered_input = -1;
}
free (dollar_vars[0]);
- dollar_vars[0] = savestring (script_name);
+ dollar_vars[0] = exec_argv0 ? savestring (exec_argv0) : savestring (script_name);
+ if (exec_argv0)
+ {
+ free (exec_argv0);
+ exec_argv0 = (char *)NULL;
+ }
#if defined (ARRAY_VARS)
GET_ARRAY_FROM_VAR ("FUNCNAME", funcname_v, funcname_a);
initialize_flags ();
/* Initialize the shell options. Don't import the shell options
- from the environment variable $SHELLOPTS if we are running in
- privileged or restricted mode or if the shell is running setuid. */
+ from the environment variables $SHELLOPTS or $BASHOPTS if we are
+ running in privileged or restricted mode or if the shell is running
+ setuid. */
#if defined (RESTRICTED_SHELL)
initialize_shell_options (privileged_mode||restricted||running_setuid);
initialize_bashopts (privileged_mode||restricted||running_setuid);
--- /dev/null
+/* shell.c -- GNU's idea of the POSIX shell specification. */
+
+/* Copyright (C) 1987-2009 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 <http://www.gnu.org/licenses/>.
+*/
+
+/*
+ Birthdate:
+ Sunday, January 10th, 1988.
+ Initial author: Brian Fox
+*/
+#define INSTALL_DEBUG_MODE
+
+#include "config.h"
+
+#include "bashtypes.h"
+#if !defined (_MINIX) && defined (HAVE_SYS_FILE_H)
+# include <sys/file.h>
+#endif
+#include "posixstat.h"
+#include "posixtime.h"
+#include "bashansi.h"
+#include <stdio.h>
+#include <signal.h>
+#include <errno.h>
+#include "filecntl.h"
+#include <pwd.h>
+
+#if defined (HAVE_UNISTD_H)
+# include <unistd.h>
+#endif
+
+#include "bashintl.h"
+
+#define NEED_SH_SETLINEBUF_DECL /* used in externs.h */
+
+#include "shell.h"
+#include "flags.h"
+#include "trap.h"
+#include "mailcheck.h"
+#include "builtins.h"
+#include "builtins/common.h"
+
+#if defined (JOB_CONTROL)
+#include "jobs.h"
+#endif /* JOB_CONTROL */
+
+#include "input.h"
+#include "execute_cmd.h"
+#include "findcmd.h"
+
+#if defined (USING_BASH_MALLOC) && defined (DEBUG) && !defined (DISABLE_MALLOC_WRAPPERS)
+# include <malloc/shmalloc.h>
+#endif
+
+#if defined (HISTORY)
+# include "bashhist.h"
+# include <readline/history.h>
+#endif
+
+#if defined (READLINE)
+# include "bashline.h"
+#endif
+
+#include <tilde/tilde.h>
+#include <glob/strmatch.h>
+
+#if defined (__OPENNT)
+# include <opennt/opennt.h>
+#endif
+
+#if !defined (HAVE_GETPW_DECLS)
+extern struct passwd *getpwuid ();
+#endif /* !HAVE_GETPW_DECLS */
+
+#if !defined (errno)
+extern int errno;
+#endif
+
+#if defined (NO_MAIN_ENV_ARG)
+extern char **environ; /* used if no third argument to main() */
+#endif
+
+extern char *dist_version, *release_status;
+extern int patch_level, build_version;
+extern int shell_level;
+extern int subshell_environment;
+extern int last_command_exit_value;
+extern int line_number;
+extern int expand_aliases;
+extern int array_needs_making;
+extern int gnu_error_format;
+extern char *primary_prompt, *secondary_prompt;
+extern char *this_command_name;
+
+/* Non-zero means that this shell has already been run; i.e. you should
+ call shell_reinitialize () if you need to start afresh. */
+int shell_initialized = 0;
+
+COMMAND *global_command = (COMMAND *)NULL;
+
+/* Information about the current user. */
+struct user_info current_user =
+{
+ (uid_t)-1, (uid_t)-1, (gid_t)-1, (gid_t)-1,
+ (char *)NULL, (char *)NULL, (char *)NULL
+};
+
+/* The current host's name. */
+char *current_host_name = (char *)NULL;
+
+/* Non-zero means that this shell is a login shell.
+ Specifically:
+ 0 = not login shell.
+ 1 = login shell from getty (or equivalent fake out)
+ -1 = login shell from "--login" (or -l) flag.
+ -2 = both from getty, and from flag.
+ */
+int login_shell = 0;
+
+/* Non-zero means that at this moment, the shell is interactive. In
+ general, this means that the shell is at this moment reading input
+ from the keyboard. */
+int interactive = 0;
+
+/* Non-zero means that the shell was started as an interactive shell. */
+int interactive_shell = 0;
+
+/* Non-zero means to send a SIGHUP to all jobs when an interactive login
+ shell exits. */
+int hup_on_exit = 0;
+
+/* Non-zero means to list status of running and stopped jobs at shell exit */
+int check_jobs_at_exit = 0;
+
+/* Non-zero means to change to a directory name supplied as a command name */
+int autocd = 0;
+
+/* Tells what state the shell was in when it started:
+ 0 = non-interactive shell script
+ 1 = interactive
+ 2 = -c command
+ 3 = wordexp evaluation
+ This is a superset of the information provided by interactive_shell.
+*/
+int startup_state = 0;
+
+/* Special debugging helper. */
+int debugging_login_shell = 0;
+
+/* The environment that the shell passes to other commands. */
+char **shell_environment;
+
+/* Non-zero when we are executing a top-level command. */
+int executing = 0;
+
+/* The number of commands executed so far. */
+int current_command_number = 1;
+
+/* Non-zero is the recursion depth for commands. */
+int indirection_level = 0;
+
+/* The name of this shell, as taken from argv[0]. */
+char *shell_name = (char *)NULL;
+
+/* time in seconds when the shell was started */
+time_t shell_start_time;
+
+/* Are we running in an emacs shell window? */
+int running_under_emacs;
+
+/* Do we have /dev/fd? */
+#ifdef HAVE_DEV_FD
+int have_devfd = HAVE_DEV_FD;
+#else
+int have_devfd = 0;
+#endif
+
+/* The name of the .(shell)rc file. */
+static char *bashrc_file = "~/.bashrc";
+
+/* Non-zero means to act more like the Bourne shell on startup. */
+static int act_like_sh;
+
+/* Non-zero if this shell is being run by `su'. */
+static int su_shell;
+
+/* Non-zero if we have already expanded and sourced $ENV. */
+static int sourced_env;
+
+/* Is this shell running setuid? */
+static int running_setuid;
+
+/* Values for the long-winded argument names. */
+static int debugging; /* Do debugging things. */
+static int no_rc; /* Don't execute ~/.bashrc */
+static int no_profile; /* Don't execute .profile */
+static int do_version; /* Display interesting version info. */
+static int make_login_shell; /* Make this shell be a `-bash' shell. */
+static int want_initial_help; /* --help option */
+
+int debugging_mode = 0; /* In debugging mode with --debugger */
+int no_line_editing = 0; /* Don't do fancy line editing. */
+int dump_translatable_strings; /* Dump strings in $"...", don't execute. */
+int dump_po_strings; /* Dump strings in $"..." in po format */
+int wordexp_only = 0; /* Do word expansion only */
+int protected_mode = 0; /* No command substitution with --wordexp */
+
+#if defined (STRICT_POSIX)
+int posixly_correct = 1; /* Non-zero means posix.2 superset. */
+#else
+int posixly_correct = 0; /* Non-zero means posix.2 superset. */
+#endif
+
+/* Some long-winded argument names. These are obviously new. */
+#define Int 1
+#define Charp 2
+static const struct {
+ const char *name;
+ int type;
+ int *int_value;
+ char **char_value;
+} long_args[] = {
+ { "debug", Int, &debugging, (char **)0x0 },
+#if defined (DEBUGGER)
+ { "debugger", Int, &debugging_mode, (char **)0x0 },
+#endif
+ { "dump-po-strings", Int, &dump_po_strings, (char **)0x0 },
+ { "dump-strings", Int, &dump_translatable_strings, (char **)0x0 },
+ { "help", Int, &want_initial_help, (char **)0x0 },
+ { "init-file", Charp, (int *)0x0, &bashrc_file },
+ { "login", Int, &make_login_shell, (char **)0x0 },
+ { "noediting", Int, &no_line_editing, (char **)0x0 },
+ { "noprofile", Int, &no_profile, (char **)0x0 },
+ { "norc", Int, &no_rc, (char **)0x0 },
+ { "posix", Int, &posixly_correct, (char **)0x0 },
+ { "protected", Int, &protected_mode, (char **)0x0 },
+ { "rcfile", Charp, (int *)0x0, &bashrc_file },
+#if defined (RESTRICTED_SHELL)
+ { "restricted", Int, &restricted, (char **)0x0 },
+#endif
+ { "verbose", Int, &echo_input_at_read, (char **)0x0 },
+ { "version", Int, &do_version, (char **)0x0 },
+#if defined (WORDEXP_OPTION)
+ { "wordexp", Int, &wordexp_only, (char **)0x0 },
+#endif
+ { (char *)0x0, Int, (int *)0x0, (char **)0x0 }
+};
+
+/* These are extern so execute_simple_command can set them, and then
+ longjmp back to main to execute a shell script, instead of calling
+ main () again and resulting in indefinite, possibly fatal, stack
+ growth. */
+procenv_t subshell_top_level;
+int subshell_argc;
+char **subshell_argv;
+char **subshell_envp;
+
+char *exec_argv0;
+
+#if defined (BUFFERED_INPUT)
+/* The file descriptor from which the shell is reading input. */
+int default_buffered_input = -1;
+#endif
+
+/* The following two variables are not static so they can show up in $-. */
+int read_from_stdin; /* -s flag supplied */
+int want_pending_command; /* -c flag supplied */
+
+/* This variable is not static so it can be bound to $BASH_EXECUTION_STRING */
+char *command_execution_string; /* argument to -c option */
+
+int malloc_trace_at_exit = 0;
+
+static int shell_reinitialized = 0;
+
+static FILE *default_input;
+
+static STRING_INT_ALIST *shopt_alist;
+static int shopt_ind = 0, shopt_len = 0;
+
+static int parse_long_options __P((char **, int, int));
+static int parse_shell_options __P((char **, int, int));
+static int bind_args __P((char **, int, int, int));
+
+static void start_debugger __P((void));
+
+static void add_shopt_to_alist __P((char *, int));
+static void run_shopt_alist __P((void));
+
+static void execute_env_file __P((char *));
+static void run_startup_files __P((void));
+static int open_shell_script __P((char *));
+static void set_bash_input __P((void));
+static int run_one_command __P((char *));
+#if defined (WORDEXP_OPTION)
+static int run_wordexp __P((char *));
+#endif
+
+static int uidget __P((void));
+
+static void init_interactive __P((void));
+static void init_noninteractive __P((void));
+static void init_interactive_script __P((void));
+
+static void set_shell_name __P((char *));
+static void shell_initialize __P((void));
+static void shell_reinitialize __P((void));
+
+static void show_shell_usage __P((FILE *, int));
+
+#ifdef __CYGWIN__
+static void
+_cygwin32_check_tmp ()
+{
+ struct stat sb;
+
+ if (stat ("/tmp", &sb) < 0)
+ internal_warning (_("could not find /tmp, please create!"));
+ else
+ {
+ if (S_ISDIR (sb.st_mode) == 0)
+ internal_warning (_("/tmp must be a valid directory name"));
+ }
+}
+#endif /* __CYGWIN__ */
+
+#if defined (NO_MAIN_ENV_ARG)
+/* systems without third argument to main() */
+int
+main (argc, argv)
+ int argc;
+ char **argv;
+#else /* !NO_MAIN_ENV_ARG */
+int
+main (argc, argv, env)
+ int argc;
+ char **argv, **env;
+#endif /* !NO_MAIN_ENV_ARG */
+{
+ register int i;
+ int code, old_errexit_flag;
+#if defined (RESTRICTED_SHELL)
+ int saverst;
+#endif
+ volatile int locally_skip_execution;
+ volatile int arg_index, top_level_arg_index;
+#ifdef __OPENNT
+ char **env;
+
+ env = environ;
+#endif /* __OPENNT */
+
+ USE_VAR(argc);
+ USE_VAR(argv);
+ USE_VAR(env);
+ USE_VAR(code);
+ USE_VAR(old_errexit_flag);
+#if defined (RESTRICTED_SHELL)
+ USE_VAR(saverst);
+#endif
+
+ /* Catch early SIGINTs. */
+ code = setjmp (top_level);
+ if (code)
+ exit (2);
+
+ xtrace_init ();
+
+#if defined (USING_BASH_MALLOC) && defined (DEBUG) && !defined (DISABLE_MALLOC_WRAPPERS)
+# if 1
+ malloc_set_register (1);
+# endif
+#endif
+
+ check_dev_tty ();
+
+#ifdef __CYGWIN__
+ _cygwin32_check_tmp ();
+#endif /* __CYGWIN__ */
+
+ /* Wait forever if we are debugging a login shell. */
+ while (debugging_login_shell) sleep (3);
+
+ set_default_locale ();
+
+ running_setuid = uidget ();
+
+ if (getenv ("POSIXLY_CORRECT") || getenv ("POSIX_PEDANTIC"))
+ posixly_correct = 1;
+
+#if defined (USE_GNU_MALLOC_LIBRARY)
+ mcheck (programming_error, (void (*) ())0);
+#endif /* USE_GNU_MALLOC_LIBRARY */
+
+ if (setjmp (subshell_top_level))
+ {
+ argc = subshell_argc;
+ argv = subshell_argv;
+ env = subshell_envp;
+ sourced_env = 0;
+ }
+
+ shell_reinitialized = 0;
+
+ /* Initialize `local' variables for all `invocations' of main (). */
+ arg_index = 1;
+ if (arg_index > argc)
+ arg_index = argc;
+ command_execution_string = (char *)NULL;
+ want_pending_command = locally_skip_execution = read_from_stdin = 0;
+ default_input = stdin;
+#if defined (BUFFERED_INPUT)
+ default_buffered_input = -1;
+#endif
+
+ /* Fix for the `infinite process creation' bug when running shell scripts
+ from startup files on System V. */
+ login_shell = make_login_shell = 0;
+
+ /* If this shell has already been run, then reinitialize it to a
+ vanilla state. */
+ if (shell_initialized || shell_name)
+ {
+ /* Make sure that we do not infinitely recurse as a login shell. */
+ if (*shell_name == '-')
+ shell_name++;
+
+ shell_reinitialize ();
+ if (setjmp (top_level))
+ exit (2);
+ }
+
+ shell_environment = env;
+ set_shell_name (argv[0]);
+ shell_start_time = NOW; /* NOW now defined in general.h */
+
+ /* Parse argument flags from the input line. */
+
+ /* Find full word arguments first. */
+ arg_index = parse_long_options (argv, arg_index, argc);
+
+ if (want_initial_help)
+ {
+ show_shell_usage (stdout, 1);
+ exit (EXECUTION_SUCCESS);
+ }
+
+ if (do_version)
+ {
+ show_shell_version (1);
+ exit (EXECUTION_SUCCESS);
+ }
+
+ /* All done with full word options; do standard shell option parsing.*/
+ this_command_name = shell_name; /* for error reporting */
+ arg_index = parse_shell_options (argv, arg_index, argc);
+
+ /* If user supplied the "--login" (or -l) flag, then set and invert
+ LOGIN_SHELL. */
+ if (make_login_shell)
+ {
+ login_shell++;
+ login_shell = -login_shell;
+ }
+
+ set_login_shell ("login_shell", login_shell != 0);
+
+ if (dump_po_strings)
+ dump_translatable_strings = 1;
+
+ if (dump_translatable_strings)
+ read_but_dont_execute = 1;
+
+ if (running_setuid && privileged_mode == 0)
+ disable_priv_mode ();
+
+ /* Need to get the argument to a -c option processed in the
+ above loop. The next arg is a command to execute, and the
+ following args are $0...$n respectively. */
+ if (want_pending_command)
+ {
+ command_execution_string = argv[arg_index];
+ if (command_execution_string == 0)
+ {
+ report_error (_("%s: option requires an argument"), "-c");
+ exit (EX_BADUSAGE);
+ }
+ arg_index++;
+ }
+ this_command_name = (char *)NULL;
+
+ cmd_init(); /* initialize the command object caches */
+
+ /* First, let the outside world know about our interactive status.
+ A shell is interactive if the `-i' flag was given, or if all of
+ the following conditions are met:
+ no -c command
+ no arguments remaining or the -s flag given
+ standard input is a terminal
+ standard error is a terminal
+ Refer to Posix.2, the description of the `sh' utility. */
+
+ if (forced_interactive || /* -i flag */
+ (!command_execution_string && /* No -c command and ... */
+ wordexp_only == 0 && /* No --wordexp and ... */
+ ((arg_index == argc) || /* no remaining args or... */
+ read_from_stdin) && /* -s flag with args, and */
+ isatty (fileno (stdin)) && /* Input is a terminal and */
+ isatty (fileno (stderr)))) /* error output is a terminal. */
+ init_interactive ();
+ else
+ init_noninteractive ();
+
+#define CLOSE_FDS_AT_LOGIN
+#if defined (CLOSE_FDS_AT_LOGIN)
+ /*
+ * Some systems have the bad habit of starting login shells with lots of open
+ * file descriptors. For instance, most systems that have picked up the
+ * pre-4.0 Sun YP code leave a file descriptor open each time you call one
+ * of the getpw* functions, and it's set to be open across execs. That
+ * means one for login, one for xterm, one for shelltool, etc.
+ */
+ if (login_shell && interactive_shell)
+ {
+ for (i = 3; i < 20; i++)
+ close (i);
+ }
+#endif /* CLOSE_FDS_AT_LOGIN */
+
+ /* If we're in a strict Posix.2 mode, turn on interactive comments,
+ alias expansion in non-interactive shells, and other Posix.2 things. */
+ if (posixly_correct)
+ {
+ bind_variable ("POSIXLY_CORRECT", "y", 0);
+ sv_strict_posix ("POSIXLY_CORRECT");
+ }
+
+ /* Now we run the shopt_alist and process the options. */
+ if (shopt_alist)
+ run_shopt_alist ();
+
+ /* From here on in, the shell must be a normal functioning shell.
+ Variables from the environment are expected to be set, etc. */
+ shell_initialize ();
+
+ set_default_lang ();
+ set_default_locale_vars ();
+
+ /*
+ * M-x term -> TERM=eterm EMACS=22.1 (term:0.96) (eterm)
+ * M-x shell -> TERM=dumb EMACS=t (no line editing)
+ * M-x terminal -> TERM=emacs-em7955 EMACS= (line editing)
+ */
+ if (interactive_shell)
+ {
+ char *term, *emacs;
+
+ term = get_string_value ("TERM");
+ emacs = get_string_value ("EMACS");
+
+ /* Not sure any emacs terminal emulator sets TERM=emacs any more */
+ no_line_editing |= term && (STREQ (term, "emacs"));
+ no_line_editing |= emacs && emacs[0] == 't' && emacs[1] == '\0' && STREQ (term, "dumb");
+
+ /* running_under_emacs == 2 for `eterm' */
+ running_under_emacs = (emacs != 0) || (term && STREQN (term, "emacs", 5));
+ running_under_emacs += term && STREQN (term, "eterm", 5) && emacs && strstr (emacs, "term");
+
+ if (running_under_emacs)
+ gnu_error_format = 1;
+ }
+
+ top_level_arg_index = arg_index;
+ old_errexit_flag = exit_immediately_on_error;
+
+ /* Give this shell a place to longjmp to before executing the
+ startup files. This allows users to press C-c to abort the
+ lengthy startup. */
+ code = setjmp (top_level);
+ if (code)
+ {
+ if (code == EXITPROG || code == ERREXIT)
+ exit_shell (last_command_exit_value);
+ else
+ {
+#if defined (JOB_CONTROL)
+ /* Reset job control, since run_startup_files turned it off. */
+ set_job_control (interactive_shell);
+#endif
+ /* Reset value of `set -e', since it's turned off before running
+ the startup files. */
+ exit_immediately_on_error += old_errexit_flag;
+ locally_skip_execution++;
+ }
+ }
+
+ arg_index = top_level_arg_index;
+
+ /* Execute the start-up scripts. */
+
+ if (interactive_shell == 0)
+ {
+ unbind_variable ("PS1");
+ unbind_variable ("PS2");
+ interactive = 0;
+#if 0
+ /* This has already been done by init_noninteractive */
+ expand_aliases = posixly_correct;
+#endif
+ }
+ else
+ {
+ change_flag ('i', FLAG_ON);
+ interactive = 1;
+ }
+
+#if defined (RESTRICTED_SHELL)
+ /* Set restricted_shell based on whether the basename of $0 indicates that
+ the shell should be restricted or if the `-r' option was supplied at
+ startup. */
+ restricted_shell = shell_is_restricted (shell_name);
+
+ /* If the `-r' option is supplied at invocation, make sure that the shell
+ is not in restricted mode when running the startup files. */
+ saverst = restricted;
+ restricted = 0;
+#endif
+
+ /* The startup files are run with `set -e' temporarily disabled. */
+ if (locally_skip_execution == 0 && running_setuid == 0)
+ {
+ old_errexit_flag = exit_immediately_on_error;
+ exit_immediately_on_error = 0;
+
+ run_startup_files ();
+ exit_immediately_on_error += old_errexit_flag;
+ }
+
+ /* If we are invoked as `sh', turn on Posix mode. */
+ if (act_like_sh)
+ {
+ bind_variable ("POSIXLY_CORRECT", "y", 0);
+ sv_strict_posix ("POSIXLY_CORRECT");
+ }
+
+#if defined (RESTRICTED_SHELL)
+ /* Turn on the restrictions after executing the startup files. This
+ means that `bash -r' or `set -r' invoked from a startup file will
+ turn on the restrictions after the startup files are executed. */
+ restricted = saverst || restricted;
+ if (shell_reinitialized == 0)
+ maybe_make_restricted (shell_name);
+#endif /* RESTRICTED_SHELL */
+
+#if defined (WORDEXP_OPTION)
+ if (wordexp_only)
+ {
+ startup_state = 3;
+ last_command_exit_value = run_wordexp (argv[arg_index]);
+ exit_shell (last_command_exit_value);
+ }
+#endif
+
+ if (command_execution_string)
+ {
+ arg_index = bind_args (argv, arg_index, argc, 0);
+ startup_state = 2;
+
+ if (debugging_mode)
+ start_debugger ();
+
+#if defined (ONESHOT)
+ executing = 1;
+ run_one_command (command_execution_string);
+ exit_shell (last_command_exit_value);
+#else /* ONESHOT */
+ with_input_from_string (command_execution_string, "-c");
+ goto read_and_execute;
+#endif /* !ONESHOT */
+ }
+
+ /* Get possible input filename and set up default_buffered_input or
+ default_input as appropriate. */
+ if (arg_index != argc && read_from_stdin == 0)
+ {
+ open_shell_script (argv[arg_index]);
+ arg_index++;
+ }
+ else if (interactive == 0)
+ /* In this mode, bash is reading a script from stdin, which is a
+ pipe or redirected file. */
+#if defined (BUFFERED_INPUT)
+ default_buffered_input = fileno (stdin); /* == 0 */
+#else
+ setbuf (default_input, (char *)NULL);
+#endif /* !BUFFERED_INPUT */
+
+ set_bash_input ();
+
+ /* Bind remaining args to $1 ... $n */
+ arg_index = bind_args (argv, arg_index, argc, 1);
+
+ if (debugging_mode && locally_skip_execution == 0 && running_setuid == 0)
+ start_debugger ();
+
+ /* Do the things that should be done only for interactive shells. */
+ if (interactive_shell)
+ {
+ /* Set up for checking for presence of mail. */
+ reset_mail_timer ();
+ init_mail_dates ();
+
+#if defined (HISTORY)
+ /* Initialize the interactive history stuff. */
+ bash_initialize_history ();
+ /* Don't load the history from the history file if we've already
+ saved some lines in this session (e.g., by putting `history -s xx'
+ into one of the startup files). */
+ if (shell_initialized == 0 && history_lines_this_session == 0)
+ load_history ();
+#endif /* HISTORY */
+
+ /* Initialize terminal state for interactive shells after the
+ .bash_profile and .bashrc are interpreted. */
+ get_tty_state ();
+ }
+
+#if !defined (ONESHOT)
+ read_and_execute:
+#endif /* !ONESHOT */
+
+ shell_initialized = 1;
+
+ /* Read commands until exit condition. */
+ reader_loop ();
+ exit_shell (last_command_exit_value);
+}
+
+static int
+parse_long_options (argv, arg_start, arg_end)
+ char **argv;
+ int arg_start, arg_end;
+{
+ int arg_index, longarg, i;
+ char *arg_string;
+
+ arg_index = arg_start;
+ while ((arg_index != arg_end) && (arg_string = argv[arg_index]) &&
+ (*arg_string == '-'))
+ {
+ longarg = 0;
+
+ /* Make --login equivalent to -login. */
+ if (arg_string[1] == '-' && arg_string[2])
+ {
+ longarg = 1;
+ arg_string++;
+ }
+
+ for (i = 0; long_args[i].name; i++)
+ {
+ if (STREQ (arg_string + 1, long_args[i].name))
+ {
+ if (long_args[i].type == Int)
+ *long_args[i].int_value = 1;
+ else if (argv[++arg_index] == 0)
+ {
+ report_error (_("%s: option requires an argument"), long_args[i].name);
+ exit (EX_BADUSAGE);
+ }
+ else
+ *long_args[i].char_value = argv[arg_index];
+
+ break;
+ }
+ }
+ if (long_args[i].name == 0)
+ {
+ if (longarg)
+ {
+ report_error (_("%s: invalid option"), argv[arg_index]);
+ show_shell_usage (stderr, 0);
+ exit (EX_BADUSAGE);
+ }
+ break; /* No such argument. Maybe flag arg. */
+ }
+
+ arg_index++;
+ }
+
+ return (arg_index);
+}
+
+static int
+parse_shell_options (argv, arg_start, arg_end)
+ char **argv;
+ int arg_start, arg_end;
+{
+ int arg_index;
+ int arg_character, on_or_off, next_arg, i;
+ char *o_option, *arg_string;
+
+ arg_index = arg_start;
+ while (arg_index != arg_end && (arg_string = argv[arg_index]) &&
+ (*arg_string == '-' || *arg_string == '+'))
+ {
+ /* There are flag arguments, so parse them. */
+ next_arg = arg_index + 1;
+
+ /* A single `-' signals the end of options. From the 4.3 BSD sh.
+ An option `--' means the same thing; this is the standard
+ getopt(3) meaning. */
+ if (arg_string[0] == '-' &&
+ (arg_string[1] == '\0' ||
+ (arg_string[1] == '-' && arg_string[2] == '\0')))
+ return (next_arg);
+
+ i = 1;
+ on_or_off = arg_string[0];
+ while (arg_character = arg_string[i++])
+ {
+ switch (arg_character)
+ {
+ case 'c':
+ want_pending_command = 1;
+ break;
+
+ case 'l':
+ make_login_shell = 1;
+ break;
+
+ case 's':
+ read_from_stdin = 1;
+ break;
+
+ case 'o':
+ o_option = argv[next_arg];
+ if (o_option == 0)
+ {
+ list_minus_o_opts (-1, (on_or_off == '-') ? 0 : 1);
+ break;
+ }
+ if (set_minus_o_option (on_or_off, o_option) != EXECUTION_SUCCESS)
+ exit (EX_BADUSAGE);
+ next_arg++;
+ break;
+
+ case 'O':
+ /* Since some of these can be overridden by the normal
+ interactive/non-interactive shell initialization or
+ initializing posix mode, we save the options and process
+ them after initialization. */
+ o_option = argv[next_arg];
+ if (o_option == 0)
+ {
+ shopt_listopt (o_option, (on_or_off == '-') ? 0 : 1);
+ break;
+ }
+ add_shopt_to_alist (o_option, on_or_off);
+ next_arg++;
+ break;
+
+ case 'D':
+ dump_translatable_strings = 1;
+ break;
+
+ default:
+ if (change_flag (arg_character, on_or_off) == FLAG_ERROR)
+ {
+ report_error (_("%c%c: invalid option"), on_or_off, arg_character);
+ show_shell_usage (stderr, 0);
+ exit (EX_BADUSAGE);
+ }
+ }
+ }
+ /* Can't do just a simple increment anymore -- what about
+ "bash -abouo emacs ignoreeof -hP"? */
+ arg_index = next_arg;
+ }
+
+ return (arg_index);
+}
+
+/* Exit the shell with status S. */
+void
+exit_shell (s)
+ int s;
+{
+ fflush (stdout); /* XXX */
+ fflush (stderr);
+
+ /* Do trap[0] if defined. Allow it to override the exit status
+ passed to us. */
+ if (signal_is_trapped (0))
+ s = run_exit_trap ();
+
+#if defined (PROCESS_SUBSTITUTION)
+ unlink_fifo_list ();
+#endif /* PROCESS_SUBSTITUTION */
+
+#if defined (HISTORY)
+ if (interactive_shell)
+ maybe_save_shell_history ();
+#endif /* HISTORY */
+
+#if defined (COPROCESS_SUPPORT)
+ coproc_flush ();
+#endif
+
+#if defined (JOB_CONTROL)
+ /* If the user has run `shopt -s huponexit', hangup all jobs when we exit
+ an interactive login shell. ksh does this unconditionally. */
+ if (interactive_shell && login_shell && hup_on_exit)
+ hangup_all_jobs ();
+
+ /* If this shell is interactive, terminate all stopped jobs and
+ restore the original terminal process group. Don't do this if we're
+ in a subshell and calling exit_shell after, for example, a failed
+ word expansion. */
+ if (subshell_environment == 0)
+ end_job_control ();
+#endif /* JOB_CONTROL */
+
+ /* Always return the exit status of the last command to our parent. */
+ sh_exit (s);
+}
+
+/* A wrapper for exit that (optionally) can do other things, like malloc
+ statistics tracing. */
+void
+sh_exit (s)
+ int s;
+{
+#if defined (MALLOC_DEBUG) && defined (USING_BASH_MALLOC)
+ if (malloc_trace_at_exit)
+ trace_malloc_stats (get_name_for_error (), (char *)NULL);
+#endif
+
+ exit (s);
+}
+
+/* Source the bash startup files. If POSIXLY_CORRECT is non-zero, we obey
+ the Posix.2 startup file rules: $ENV is expanded, and if the file it
+ names exists, that file is sourced. The Posix.2 rules are in effect
+ for interactive shells only. (section 4.56.5.3) */
+
+/* Execute ~/.bashrc for most shells. Never execute it if
+ ACT_LIKE_SH is set, or if NO_RC is set.
+
+ If the executable file "/usr/gnu/src/bash/foo" contains:
+
+ #!/usr/gnu/bin/bash
+ echo hello
+
+ then:
+
+ COMMAND EXECUTE BASHRC
+ --------------------------------
+ bash -c foo NO
+ bash foo NO
+ foo NO
+ rsh machine ls YES (for rsh, which calls `bash -c')
+ rsh machine foo YES (for shell started by rsh) NO (for foo!)
+ echo ls | bash NO
+ login NO
+ bash YES
+*/
+
+static void
+execute_env_file (env_file)
+ char *env_file;
+{
+ char *fn;
+
+ if (env_file && *env_file)
+ {
+ fn = expand_string_unsplit_to_string (env_file, Q_DOUBLE_QUOTES);
+ if (fn && *fn)
+ maybe_execute_file (fn, 1);
+ FREE (fn);
+ }
+}
+
+static void
+run_startup_files ()
+{
+#if defined (JOB_CONTROL)
+ int old_job_control;
+#endif
+ int sourced_login, run_by_ssh;
+
+ /* get the rshd/sshd case out of the way first. */
+ if (interactive_shell == 0 && no_rc == 0 && login_shell == 0 &&
+ act_like_sh == 0 && command_execution_string)
+ {
+#ifdef SSH_SOURCE_BASHRC
+ run_by_ssh = (find_variable ("SSH_CLIENT") != (SHELL_VAR *)0) ||
+ (find_variable ("SSH2_CLIENT") != (SHELL_VAR *)0);
+#else
+ run_by_ssh = 0;
+#endif
+
+ /* If we were run by sshd or we think we were run by rshd, execute
+ ~/.bashrc if we are a top-level shell. */
+ if ((run_by_ssh || isnetconn (fileno (stdin))) && shell_level < 2)
+ {
+#ifdef SYS_BASHRC
+# if defined (__OPENNT)
+ maybe_execute_file (_prefixInstallPath(SYS_BASHRC, NULL, 0), 1);
+# else
+ maybe_execute_file (SYS_BASHRC, 1);
+# endif
+#endif
+ maybe_execute_file (bashrc_file, 1);
+ return;
+ }
+ }
+
+#if defined (JOB_CONTROL)
+ /* Startup files should be run without job control enabled. */
+ old_job_control = interactive_shell ? set_job_control (0) : 0;
+#endif
+
+ sourced_login = 0;
+
+ /* A shell begun with the --login (or -l) flag that is not in posix mode
+ runs the login shell startup files, no matter whether or not it is
+ interactive. If NON_INTERACTIVE_LOGIN_SHELLS is defined, run the
+ startup files if argv[0][0] == '-' as well. */
+#if defined (NON_INTERACTIVE_LOGIN_SHELLS)
+ if (login_shell && posixly_correct == 0)
+#else
+ if (login_shell < 0 && posixly_correct == 0)
+#endif
+ {
+ /* We don't execute .bashrc for login shells. */
+ no_rc++;
+
+ /* Execute /etc/profile and one of the personal login shell
+ initialization files. */
+ if (no_profile == 0)
+ {
+ maybe_execute_file (SYS_PROFILE, 1);
+
+ if (act_like_sh) /* sh */
+ maybe_execute_file ("~/.profile", 1);
+ else if ((maybe_execute_file ("~/.bash_profile", 1) == 0) &&
+ (maybe_execute_file ("~/.bash_login", 1) == 0)) /* bash */
+ maybe_execute_file ("~/.profile", 1);
+ }
+
+ sourced_login = 1;
+ }
+
+ /* A non-interactive shell not named `sh' and not in posix mode reads and
+ executes commands from $BASH_ENV. If `su' starts a shell with `-c cmd'
+ and `-su' as the name of the shell, we want to read the startup files.
+ No other non-interactive shells read any startup files. */
+ if (interactive_shell == 0 && !(su_shell && login_shell))
+ {
+ if (posixly_correct == 0 && act_like_sh == 0 && privileged_mode == 0 &&
+ sourced_env++ == 0)
+ execute_env_file (get_string_value ("BASH_ENV"));
+ return;
+ }
+
+ /* Interactive shell or `-su' shell. */
+ if (posixly_correct == 0) /* bash, sh */
+ {
+ if (login_shell && sourced_login++ == 0)
+ {
+ /* We don't execute .bashrc for login shells. */
+ no_rc++;
+
+ /* Execute /etc/profile and one of the personal login shell
+ initialization files. */
+ if (no_profile == 0)
+ {
+ maybe_execute_file (SYS_PROFILE, 1);
+
+ if (act_like_sh) /* sh */
+ maybe_execute_file ("~/.profile", 1);
+ else if ((maybe_execute_file ("~/.bash_profile", 1) == 0) &&
+ (maybe_execute_file ("~/.bash_login", 1) == 0)) /* bash */
+ maybe_execute_file ("~/.profile", 1);
+ }
+ }
+
+ /* bash */
+ if (act_like_sh == 0 && no_rc == 0)
+ {
+#ifdef SYS_BASHRC
+# if defined (__OPENNT)
+ maybe_execute_file (_prefixInstallPath(SYS_BASHRC, NULL, 0), 1);
+# else
+ maybe_execute_file (SYS_BASHRC, 1);
+# endif
+#endif
+ maybe_execute_file (bashrc_file, 1);
+ }
+ /* sh */
+ else if (act_like_sh && privileged_mode == 0 && sourced_env++ == 0)
+ execute_env_file (get_string_value ("ENV"));
+ }
+ else /* bash --posix, sh --posix */
+ {
+ /* bash and sh */
+ if (interactive_shell && privileged_mode == 0 && sourced_env++ == 0)
+ execute_env_file (get_string_value ("ENV"));
+ }
+
+#if defined (JOB_CONTROL)
+ set_job_control (old_job_control);
+#endif
+}
+
+#if defined (RESTRICTED_SHELL)
+/* Return 1 if the shell should be a restricted one based on NAME or the
+ value of `restricted'. Don't actually do anything, just return a
+ boolean value. */
+int
+shell_is_restricted (name)
+ char *name;
+{
+ char *temp;
+
+ if (restricted)
+ return 1;
+ temp = base_pathname (name);
+ if (*temp == '-')
+ temp++;
+ return (STREQ (temp, RESTRICTED_SHELL_NAME));
+}
+
+/* Perhaps make this shell a `restricted' one, based on NAME. If the
+ basename of NAME is "rbash", then this shell is restricted. The
+ name of the restricted shell is a configurable option, see config.h.
+ In a restricted shell, PATH, SHELL, ENV, and BASH_ENV are read-only
+ and non-unsettable.
+ Do this also if `restricted' is already set to 1; maybe the shell was
+ started with -r. */
+int
+maybe_make_restricted (name)
+ char *name;
+{
+ char *temp;
+
+ temp = base_pathname (name);
+ if (*temp == '-')
+ temp++;
+ if (restricted || (STREQ (temp, RESTRICTED_SHELL_NAME)))
+ {
+ set_var_read_only ("PATH");
+ set_var_read_only ("SHELL");
+ set_var_read_only ("ENV");
+ set_var_read_only ("BASH_ENV");
+ restricted = 1;
+ }
+ return (restricted);
+}
+#endif /* RESTRICTED_SHELL */
+
+/* Fetch the current set of uids and gids and return 1 if we're running
+ setuid or setgid. */
+static int
+uidget ()
+{
+ uid_t u;
+
+ u = getuid ();
+ if (current_user.uid != u)
+ {
+ FREE (current_user.user_name);
+ FREE (current_user.shell);
+ FREE (current_user.home_dir);
+ current_user.user_name = current_user.shell = current_user.home_dir = (char *)NULL;
+ }
+ current_user.uid = u;
+ current_user.gid = getgid ();
+ current_user.euid = geteuid ();
+ current_user.egid = getegid ();
+
+ /* See whether or not we are running setuid or setgid. */
+ return (current_user.uid != current_user.euid) ||
+ (current_user.gid != current_user.egid);
+}
+
+void
+disable_priv_mode ()
+{
+ setuid (current_user.uid);
+ setgid (current_user.gid);
+ current_user.euid = current_user.uid;
+ current_user.egid = current_user.gid;
+}
+
+#if defined (WORDEXP_OPTION)
+static int
+run_wordexp (words)
+ char *words;
+{
+ int code, nw, nb;
+ WORD_LIST *wl, *tl, *result;
+
+ code = setjmp (top_level);
+
+ if (code != NOT_JUMPED)
+ {
+ switch (code)
+ {
+ /* Some kind of throw to top_level has occured. */
+ case FORCE_EOF:
+ return last_command_exit_value = 127;
+ case ERREXIT:
+ case EXITPROG:
+ return last_command_exit_value;
+ case DISCARD:
+ return last_command_exit_value = 1;
+ default:
+ command_error ("run_wordexp", CMDERR_BADJUMP, code, 0);
+ }
+ }
+
+ /* Run it through the parser to get a list of words and expand them */
+ if (words && *words)
+ {
+ with_input_from_string (words, "--wordexp");
+ if (parse_command () != 0)
+ return (126);
+ if (global_command == 0)
+ {
+ printf ("0\n0\n");
+ return (0);
+ }
+ if (global_command->type != cm_simple)
+ return (126);
+ wl = global_command->value.Simple->words;
+ if (protected_mode)
+ for (tl = wl; tl; tl = tl->next)
+ tl->word->flags |= W_NOCOMSUB|W_NOPROCSUB;
+ result = wl ? expand_words_no_vars (wl) : (WORD_LIST *)0;
+ }
+ else
+ result = (WORD_LIST *)0;
+
+ last_command_exit_value = 0;
+
+ if (result == 0)
+ {
+ printf ("0\n0\n");
+ return (0);
+ }
+
+ /* Count up the number of words and bytes, and print them. Don't count
+ the trailing NUL byte. */
+ for (nw = nb = 0, wl = result; wl; wl = wl->next)
+ {
+ nw++;
+ nb += strlen (wl->word->word);
+ }
+ printf ("%u\n%u\n", nw, nb);
+ /* Print each word on a separate line. This will have to be changed when
+ the interface to glibc is completed. */
+ for (wl = result; wl; wl = wl->next)
+ printf ("%s\n", wl->word->word);
+
+ return (0);
+}
+#endif
+
+#if defined (ONESHOT)
+/* Run one command, given as the argument to the -c option. Tell
+ parse_and_execute not to fork for a simple command. */
+static int
+run_one_command (command)
+ char *command;
+{
+ int code;
+
+ code = setjmp (top_level);
+
+ if (code != NOT_JUMPED)
+ {
+#if defined (PROCESS_SUBSTITUTION)
+ unlink_fifo_list ();
+#endif /* PROCESS_SUBSTITUTION */
+ switch (code)
+ {
+ /* Some kind of throw to top_level has occured. */
+ case FORCE_EOF:
+ return last_command_exit_value = 127;
+ case ERREXIT:
+ case EXITPROG:
+ return last_command_exit_value;
+ case DISCARD:
+ return last_command_exit_value = 1;
+ default:
+ command_error ("run_one_command", CMDERR_BADJUMP, code, 0);
+ }
+ }
+ return (parse_and_execute (savestring (command), "-c", SEVAL_NOHIST));
+}
+#endif /* ONESHOT */
+
+static int
+bind_args (argv, arg_start, arg_end, start_index)
+ char **argv;
+ int arg_start, arg_end, start_index;
+{
+ register int i;
+ WORD_LIST *args;
+
+ for (i = arg_start, args = (WORD_LIST *)NULL; i < arg_end; i++)
+ args = make_word_list (make_word (argv[i]), args);
+ if (args)
+ {
+ args = REVERSE_LIST (args, WORD_LIST *);
+ if (start_index == 0) /* bind to $0...$n for sh -c command */
+ {
+ /* Posix.2 4.56.3 says that the first argument after sh -c command
+ becomes $0, and the rest of the arguments become $1...$n */
+ shell_name = savestring (args->word->word);
+ FREE (dollar_vars[0]);
+ dollar_vars[0] = savestring (args->word->word);
+ remember_args (args->next, 1);
+ push_args (args->next); /* BASH_ARGV and BASH_ARGC */
+ }
+ else /* bind to $1...$n for shell script */
+ {
+ remember_args (args, 1);
+ push_args (args); /* BASH_ARGV and BASH_ARGC */
+ }
+
+ dispose_words (args);
+ }
+
+ return (i);
+}
+
+void
+unbind_args ()
+{
+ remember_args ((WORD_LIST *)NULL, 1);
+ pop_args (); /* Reset BASH_ARGV and BASH_ARGC */
+}
+
+static void
+start_debugger ()
+{
+#if defined (DEBUGGER) && defined (DEBUGGER_START_FILE)
+ int old_errexit;
+
+ old_errexit = exit_immediately_on_error;
+ exit_immediately_on_error = 0;
+
+ maybe_execute_file (DEBUGGER_START_FILE, 1);
+ function_trace_mode = 1;
+
+ exit_immediately_on_error += old_errexit;
+#endif
+}
+
+static int
+open_shell_script (script_name)
+ char *script_name;
+{
+ int fd, e, fd_is_tty;
+ char *filename, *path_filename, *t;
+ char sample[80];
+ int sample_len;
+ struct stat sb;
+#if defined (ARRAY_VARS)
+ SHELL_VAR *funcname_v, *bash_source_v, *bash_lineno_v;
+ ARRAY *funcname_a, *bash_source_a, *bash_lineno_a;
+#endif
+
+ filename = savestring (script_name);
+
+ fd = open (filename, O_RDONLY);
+ if ((fd < 0) && (errno == ENOENT) && (absolute_program (filename) == 0))
+ {
+ e = errno;
+ /* If it's not in the current directory, try looking through PATH
+ for it. */
+ path_filename = find_path_file (script_name);
+ if (path_filename)
+ {
+ free (filename);
+ filename = path_filename;
+ fd = open (filename, O_RDONLY);
+ }
+ else
+ errno = e;
+ }
+
+ if (fd < 0)
+ {
+ e = errno;
+ file_error (filename);
+ exit ((e == ENOENT) ? EX_NOTFOUND : EX_NOINPUT);
+ }
+
+ free (dollar_vars[0]);
+ dollar_vars[0] = exec_argv0 ? savestring (exec_argv0) : savestring (script_name);
+ if (exec_argv[0])
+ {
+ free (exec_argv0);
+ exec_argv0 = (char *)NULL;
+ }
+
+#if defined (ARRAY_VARS)
+ GET_ARRAY_FROM_VAR ("FUNCNAME", funcname_v, funcname_a);
+ GET_ARRAY_FROM_VAR ("BASH_SOURCE", bash_source_v, bash_source_a);
+ GET_ARRAY_FROM_VAR ("BASH_LINENO", bash_lineno_v, bash_lineno_a);
+
+ array_push (bash_source_a, filename);
+ if (bash_lineno_a)
+ {
+ t = itos (executing_line_number ());
+ array_push (bash_lineno_a, t);
+ free (t);
+ }
+ array_push (funcname_a, "main");
+#endif
+
+#ifdef HAVE_DEV_FD
+ fd_is_tty = isatty (fd);
+#else
+ fd_is_tty = 0;
+#endif
+
+ /* Only do this with non-tty file descriptors we can seek on. */
+ if (fd_is_tty == 0 && (lseek (fd, 0L, 1) != -1))
+ {
+ /* Check to see if the `file' in `bash file' is a binary file
+ according to the same tests done by execute_simple_command (),
+ and report an error and exit if it is. */
+ sample_len = read (fd, sample, sizeof (sample));
+ if (sample_len < 0)
+ {
+ e = errno;
+ if ((fstat (fd, &sb) == 0) && S_ISDIR (sb.st_mode))
+ internal_error (_("%s: is a directory"), filename);
+ else
+ {
+ errno = e;
+ file_error (filename);
+ }
+ exit (EX_NOEXEC);
+ }
+ else if (sample_len > 0 && (check_binary_file (sample, sample_len)))
+ {
+ internal_error (_("%s: cannot execute binary file"), filename);
+ exit (EX_BINARY_FILE);
+ }
+ /* Now rewind the file back to the beginning. */
+ lseek (fd, 0L, 0);
+ }
+
+ /* Open the script. But try to move the file descriptor to a randomly
+ large one, in the hopes that any descriptors used by the script will
+ not match with ours. */
+ fd = move_to_high_fd (fd, 1, -1);
+
+#if defined (__CYGWIN__) && defined (O_TEXT)
+ setmode (fd, O_TEXT);
+#endif
+
+#if defined (BUFFERED_INPUT)
+ default_buffered_input = fd;
+ SET_CLOSE_ON_EXEC (default_buffered_input);
+#else /* !BUFFERED_INPUT */
+ default_input = fdopen (fd, "r");
+
+ if (default_input == 0)
+ {
+ file_error (filename);
+ exit (EX_NOTFOUND);
+ }
+
+ SET_CLOSE_ON_EXEC (fd);
+ if (fileno (default_input) != fd)
+ SET_CLOSE_ON_EXEC (fileno (default_input));
+#endif /* !BUFFERED_INPUT */
+
+ /* Just about the only way for this code to be executed is if something
+ like `bash -i /dev/stdin' is executed. */
+ if (interactive_shell && fd_is_tty)
+ {
+ dup2 (fd, 0);
+ close (fd);
+ fd = 0;
+#if defined (BUFFERED_INPUT)
+ default_buffered_input = 0;
+#else
+ fclose (default_input);
+ default_input = stdin;
+#endif
+ }
+ else if (forced_interactive && fd_is_tty == 0)
+ /* But if a script is called with something like `bash -i scriptname',
+ we need to do a non-interactive setup here, since we didn't do it
+ before. */
+ init_interactive_script ();
+
+ free (filename);
+ return (fd);
+}
+
+/* Initialize the input routines for the parser. */
+static void
+set_bash_input ()
+{
+ /* Make sure the fd from which we are reading input is not in
+ no-delay mode. */
+#if defined (BUFFERED_INPUT)
+ if (interactive == 0)
+ sh_unset_nodelay_mode (default_buffered_input);
+ else
+#endif /* !BUFFERED_INPUT */
+ sh_unset_nodelay_mode (fileno (stdin));
+
+ /* with_input_from_stdin really means `with_input_from_readline' */
+ if (interactive && no_line_editing == 0)
+ with_input_from_stdin ();
+#if defined (BUFFERED_INPUT)
+ else if (interactive == 0)
+ with_input_from_buffered_stream (default_buffered_input, dollar_vars[0]);
+#endif /* BUFFERED_INPUT */
+ else
+ with_input_from_stream (default_input, dollar_vars[0]);
+}
+
+/* Close the current shell script input source and forget about it. This is
+ extern so execute_cmd.c:initialize_subshell() can call it. If CHECK_ZERO
+ is non-zero, we close default_buffered_input even if it's the standard
+ input (fd 0). */
+void
+unset_bash_input (check_zero)
+ int check_zero;
+{
+#if defined (BUFFERED_INPUT)
+ if ((check_zero && default_buffered_input >= 0) ||
+ (check_zero == 0 && default_buffered_input > 0))
+ {
+ close_buffered_fd (default_buffered_input);
+ default_buffered_input = bash_input.location.buffered_fd = -1;
+ bash_input.type = st_none; /* XXX */
+ }
+#else /* !BUFFERED_INPUT */
+ if (default_input)
+ {
+ fclose (default_input);
+ default_input = (FILE *)NULL;
+ }
+#endif /* !BUFFERED_INPUT */
+}
+
+
+#if !defined (PROGRAM)
+# define PROGRAM "bash"
+#endif
+
+static void
+set_shell_name (argv0)
+ char *argv0;
+{
+ /* Here's a hack. If the name of this shell is "sh", then don't do
+ any startup files; just try to be more like /bin/sh. */
+ shell_name = argv0 ? base_pathname (argv0) : PROGRAM;
+
+ if (argv0 && *argv0 == '-')
+ {
+ if (*shell_name == '-')
+ shell_name++;
+ login_shell++;
+ }
+
+ if (shell_name[0] == 's' && shell_name[1] == 'h' && shell_name[2] == '\0')
+ act_like_sh++;
+ if (shell_name[0] == 's' && shell_name[1] == 'u' && shell_name[2] == '\0')
+ su_shell++;
+
+ shell_name = argv0 ? argv0 : PROGRAM;
+ FREE (dollar_vars[0]);
+ dollar_vars[0] = savestring (shell_name);
+
+ /* A program may start an interactive shell with
+ "execl ("/bin/bash", "-", NULL)".
+ If so, default the name of this shell to our name. */
+ if (!shell_name || !*shell_name || (shell_name[0] == '-' && !shell_name[1]))
+ shell_name = PROGRAM;
+}
+
+static void
+init_interactive ()
+{
+ expand_aliases = interactive_shell = startup_state = 1;
+ interactive = 1;
+}
+
+static void
+init_noninteractive ()
+{
+#if defined (HISTORY)
+ bash_history_reinit (0);
+#endif /* HISTORY */
+ interactive_shell = startup_state = interactive = 0;
+ expand_aliases = posixly_correct; /* XXX - was 0 not posixly_correct */
+ no_line_editing = 1;
+#if defined (JOB_CONTROL)
+ set_job_control (0);
+#endif /* JOB_CONTROL */
+}
+
+static void
+init_interactive_script ()
+{
+ init_noninteractive ();
+ expand_aliases = interactive_shell = startup_state = 1;
+}
+
+void
+get_current_user_info ()
+{
+ struct passwd *entry;
+
+ /* Don't fetch this more than once. */
+ if (current_user.user_name == 0)
+ {
+ entry = getpwuid (current_user.uid);
+ if (entry)
+ {
+ current_user.user_name = savestring (entry->pw_name);
+ current_user.shell = (entry->pw_shell && entry->pw_shell[0])
+ ? savestring (entry->pw_shell)
+ : savestring ("/bin/sh");
+ current_user.home_dir = savestring (entry->pw_dir);
+ }
+ else
+ {
+ current_user.user_name = _("I have no name!");
+ current_user.user_name = savestring (current_user.user_name);
+ current_user.shell = savestring ("/bin/sh");
+ current_user.home_dir = savestring ("/");
+ }
+ endpwent ();
+ }
+}
+
+/* Do whatever is necessary to initialize the shell.
+ Put new initializations in here. */
+static void
+shell_initialize ()
+{
+ char hostname[256];
+
+ /* Line buffer output for stderr and stdout. */
+ if (shell_initialized == 0)
+ {
+ sh_setlinebuf (stderr);
+ sh_setlinebuf (stdout);
+ }
+
+ /* Sort the array of shell builtins so that the binary search in
+ find_shell_builtin () works correctly. */
+ initialize_shell_builtins ();
+
+ /* Initialize the trap signal handlers before installing our own
+ signal handlers. traps.c:restore_original_signals () is responsible
+ for restoring the original default signal handlers. That function
+ is called when we make a new child. */
+ initialize_traps ();
+ initialize_signals (0);
+
+ /* It's highly unlikely that this will change. */
+ if (current_host_name == 0)
+ {
+ /* Initialize current_host_name. */
+ if (gethostname (hostname, 255) < 0)
+ current_host_name = "??host??";
+ else
+ current_host_name = savestring (hostname);
+ }
+
+ /* Initialize the stuff in current_user that comes from the password
+ file. We don't need to do this right away if the shell is not
+ interactive. */
+ if (interactive_shell)
+ get_current_user_info ();
+
+ /* Initialize our interface to the tilde expander. */
+ tilde_initialize ();
+
+ /* Initialize internal and environment variables. Don't import shell
+ functions from the environment if we are running in privileged or
+ restricted mode or if the shell is running setuid. */
+#if defined (RESTRICTED_SHELL)
+ initialize_shell_variables (shell_environment, privileged_mode||restricted||running_setuid);
+#else
+ initialize_shell_variables (shell_environment, privileged_mode||running_setuid);
+#endif
+
+ /* Initialize the data structures for storing and running jobs. */
+ initialize_job_control (0);
+
+ /* Initialize input streams to null. */
+ initialize_bash_input ();
+
+ initialize_flags ();
+
+ /* Initialize the shell options. Don't import the shell options
+ from the environment variables $SHELLOPTS or $BASHOPTS if we are
+ running in privileged or restricted mode or if the shell is running
+ setuid. */
+#if defined (RESTRICTED_SHELL)
+ initialize_shell_options (privileged_mode||restricted||running_setuid);
+ initialize_bashopts (privileged_mode||restricted||running_setuid);
+#else
+ initialize_shell_options (privileged_mode||running_setuid);
+ initialize_bashopts (privileged_mode||running_setuid);
+#endif
+}
+
+/* Function called by main () when it appears that the shell has already
+ had some initialization performed. This is supposed to reset the world
+ back to a pristine state, as if we had been exec'ed. */
+static void
+shell_reinitialize ()
+{
+ /* The default shell prompts. */
+ primary_prompt = PPROMPT;
+ secondary_prompt = SPROMPT;
+
+ /* Things that get 1. */
+ current_command_number = 1;
+
+ /* We have decided that the ~/.bashrc file should not be executed
+ for the invocation of each shell script. If the variable $ENV
+ (or $BASH_ENV) is set, its value is used as the name of a file
+ to source. */
+ no_rc = no_profile = 1;
+
+ /* Things that get 0. */
+ login_shell = make_login_shell = interactive = executing = 0;
+ debugging = do_version = line_number = last_command_exit_value = 0;
+ forced_interactive = interactive_shell = subshell_environment = 0;
+ expand_aliases = 0;
+
+#if defined (HISTORY)
+ bash_history_reinit (0);
+#endif /* HISTORY */
+
+#if defined (RESTRICTED_SHELL)
+ restricted = 0;
+#endif /* RESTRICTED_SHELL */
+
+ /* Ensure that the default startup file is used. (Except that we don't
+ execute this file for reinitialized shells). */
+ bashrc_file = "~/.bashrc";
+
+ /* Delete all variables and functions. They will be reinitialized when
+ the environment is parsed. */
+ delete_all_contexts (shell_variables);
+ delete_all_variables (shell_functions);
+
+ reinit_special_variables ();
+
+#if defined (READLINE)
+ bashline_reinitialize ();
+#endif
+
+ shell_reinitialized = 1;
+}
+
+static void
+show_shell_usage (fp, extra)
+ FILE *fp;
+ int extra;
+{
+ int i;
+ char *set_opts, *s, *t;
+
+ if (extra)
+ fprintf (fp, _("GNU bash, version %s-(%s)\n"), shell_version_string (), MACHTYPE);
+ fprintf (fp, _("Usage:\t%s [GNU long option] [option] ...\n\t%s [GNU long option] [option] script-file ...\n"),
+ shell_name, shell_name);
+ fputs (_("GNU long options:\n"), fp);
+ for (i = 0; long_args[i].name; i++)
+ fprintf (fp, "\t--%s\n", long_args[i].name);
+
+ fputs (_("Shell options:\n"), fp);
+ fputs (_("\t-irsD or -c command or -O shopt_option\t\t(invocation only)\n"), fp);
+
+ for (i = 0, set_opts = 0; shell_builtins[i].name; i++)
+ if (STREQ (shell_builtins[i].name, "set"))
+ set_opts = savestring (shell_builtins[i].short_doc);
+ if (set_opts)
+ {
+ s = strchr (set_opts, '[');
+ if (s == 0)
+ s = set_opts;
+ while (*++s == '-')
+ ;
+ t = strchr (s, ']');
+ if (t)
+ *t = '\0';
+ fprintf (fp, _("\t-%s or -o option\n"), s);
+ free (set_opts);
+ }
+
+ if (extra)
+ {
+ fprintf (fp, _("Type `%s -c \"help set\"' for more information about shell options.\n"), shell_name);
+ fprintf (fp, _("Type `%s -c help' for more information about shell builtin commands.\n"), shell_name);
+ fprintf (fp, _("Use the `bashbug' command to report bugs.\n"));
+ }
+}
+
+static void
+add_shopt_to_alist (opt, on_or_off)
+ char *opt;
+ int on_or_off;
+{
+ if (shopt_ind >= shopt_len)
+ {
+ shopt_len += 8;
+ shopt_alist = (STRING_INT_ALIST *)xrealloc (shopt_alist, shopt_len * sizeof (shopt_alist[0]));
+ }
+ shopt_alist[shopt_ind].word = opt;
+ shopt_alist[shopt_ind].token = on_or_off;
+ shopt_ind++;
+}
+
+static void
+run_shopt_alist ()
+{
+ register int i;
+
+ for (i = 0; i < shopt_ind; i++)
+ if (shopt_setopt (shopt_alist[i].word, (shopt_alist[i].token == '-')) != EXECUTION_SUCCESS)
+ exit (EX_BADUSAGE);
+ free (shopt_alist);
+ shopt_alist = 0;
+ shopt_ind = shopt_len = 0;
+}
if ((flags & SX_COMMAND) && string[i] == '$' && string[i+1] == LPAREN)
{
si = i + 2;
- t = extract_command_subst (string, &si, flags);
+ t = extract_command_subst (string, &si, flags|SX_NOALLOC);
i = si + 1;
continue;
}
const WORD_DESC *word;
int expand;
{
- int offset, tlen, appendop, assign_list, aflags, retval;
- char *name, *value;
+ int offset, appendop, assign_list, aflags, retval;
+ char *name, *value, *temp;
SHELL_VAR *entry;
#if defined (ARRAY_VARS)
char *t;
if (name[offset] == '=')
{
- char *temp;
-
if (name[offset - 1] == '+')
{
appendop = 1;
name[offset] = 0; /* might need this set later */
temp = name + offset + 1;
- tlen = STRLEN (temp);
#if defined (ARRAY_VARS)
if (expand && (word->flags & W_COMPASSIGN))
else if (array_p (var))
return (array ? array_num_elements (array) : 0);
else
- return (value_cell (var) ? 1 : 0);
+ return (var_isset (var) ? 1 : 0);
}
if (assoc_p (var))
#if defined (READLINE)
static int winsize_assignment; /* currently assigning to LINES or COLUMNS */
-static int winsize_assigned; /* assigned to LINES or COLUMNS */
#endif
/* Some forward declarations. */
{
if (legal_number (value_cell (v), &xd) == 0)
return;
- winsize_assignment = winsize_assigned = 1;
+ winsize_assignment = 1;
d = xd; /* truncate */
if (name[0] == 'L') /* LINES */
rl_set_screen_size (d, -1);
rv = get_random_number ();
last_random_value = rv;
-fprintf(stderr, "get_random: rv = %d\n", rv);
p = itos (rv);
FREE (value_cell (var));
projects / thirdparty / bash.git / commitdiff
