+This document details the changes between this version, bash-4.0-beta,
+and the previous version, bash-4.0-alpha.
+
+1. Changes to Bash
+
+a. Fixed a typo that caused a variable to be used before initialization
+ while parsing Posix-style command substitutions.
+
+b. Fixed a bug that caused stray ^? when the expansion of a parameter used
+ as part of a pattern removal expansion is empty, but part of a non-
+ empty string.
+
+c. Fixed a bug that could cause strings not converted to numbers by strtol
+ to be treated as if the conversion had been successful.
+
+d. The `return' builtin now accepts no options and requires a `--' before
+ a negative return value, as Posix requires.
+
+e. Fixed a bug that caused local variables to be created with the empty
+ string for a value rather than no value.
+
+f. Changed behavior so the shell now acts as if it received an interrupt
+ when a pipeline is killed by SIGINT while executing a list.
+
+g. Fixed a bug that caused `declare var' and `typeset var' to initialize
+ `var' to the empty string.
+
+h. Changed `bind' builtin to print a warning but proceed if invoked when
+ line editing is not active.
+
+i. Fixed a bug that caused the shell to exit when the `errexit' option is
+ set and a command in a pipeline returns a non-zero exit status.
+
+j. Fixed a bug that caused the shell to not run the exit trap in a command
+ run with `bash -c' under some circumstances.
+
+k. Fixed a bug that caused parser errors to occasionally not set $? when
+ running commands with `eval'.
+
+l. Fixed a bug that caused stray control characters when evaluating compound
+ array assignments containing $'\x7f' escapes.
+
+m. Fixed a bug that caused redirections involving file descriptor 10 as the
+ target to behave incorrectly.
+
+n. Fixed a bug that could cause memory to be freed multiple times when
+ assigning to COMP_WORDBREAKS.
+
+2. Changes to Readline
+
+3. New Features in Bash
+
+a. 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.
+
+b. CDPATH and GLOBIGNORE are ignored when the shell is running in privileged
+ mode.
+
+c. 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.
+
+d. 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.
+
+4. New Features in Readline
+
+a. If the kernel supports it, readline displays special characters
+ corresponding to a keyboard-generated signal when the signal is received.
+
+------------------------------------------------------------------------------
This document details the changes between this version, bash-4.0-alpha,
and the previous version, bash-3.2-release.
+This document details the changes between this version, bash-4.0-beta,
+and the previous version, bash-4.0-alpha.
+
+1. Changes to Bash
+
+a. Fixed a typo that caused a variable to be used before initialization
+ while parsing Posix-style command substitutions.
+
+b. Fixed a bug that caused stray ^? when the expansion of a parameter used
+ as part of a pattern removal expansion is empty, but part of a non-
+ empty string.
+
+c. Fixed a bug that could cause strings not converted to numbers by strtol
+ to be treated as if the conversion had been successful.
+
+d. The `return' builtin now accepts no options and requires a `--' before
+ a negative return value, as Posix requires.
+
+e. Fixed a bug that caused local variables to be created with the empty
+ string for a value rather than no value.
+
+f. Changed behavior so the shell now acts as if it received an interrupt
+ when a pipeline is killed by SIGINT while executing a list.
+
+g. Fixed a bug that caused `declare var' and `typeset var' to initialize
+ `var' to the empty string.
+
+h. Changed `bind' builtin to print a warning but proceed if invoked when
+ line editing is not active.
+
+i. Fixed a bug that caused the shell to exit when the `errexit' option is
+ set and a command in a pipeline returns a non-zero exit status.
+
+j. Fixed a bug that caused the shell to not run the exit trap in a command
+ run with `bash -c' under some circumstances.
+
+k. Fixed a bug that caused parser errors to occasionally not set $? when
+ running commands with `eval'.
+
+l. Fixed a bug that caused stray control characters when evaluating compound
+ array assignments containing $'\x7f' escapes.
+
+m. Fixed a bug that caused redirections involving file descriptor 10 as the
+ target to behave incorrectly.
+
+2. Changes to Readline
+
+3. New Features in Bash
+
+a. 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.
+
+b. CDPATH and GLOBIGNORE are ignored when the shell is running in privileged
+ mode.
+
+c. 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.
+
+d. 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.
+
+4. New Features in Readline
+
+a. If the kernel supports it, readline displays special characters
+ corresponding to a keyboard-generated signal when the signal is received.
+
+------------------------------------------------------------------------------
This document details the changes between this version, bash-4.0-alpha,
and the previous version, bash-3.2-release.
apply to arrays subscripted with * or @.
p. Fixed several problems with pattern substitution expansions on the
- positional parameters and arrays subscripted with * or @.
+ positional parameters and arrays subscripted with * or @ that occurred
+ when $IFS was set to the empty string.
q. Made a change to the default locale initialization code that should
result in better behavior from the locale-aware library functions.
r. Fixed a bug that caused compacting the jobs list to drop jobs.
-s. Fixed a bug that caused jumps back to the top-level processing loop from a
- builtin command to leave the shell in an inconsistent state.
+s. Fixed a bug that caused jumps back to the top-level processing loop from
+ a builtin command to leave the shell in an inconsistent state.
t. Fixed a bug that caused characters that would be escaped internally to be
doubled when escaped with a backslash.
-u. Fixed the initialization of mailboxes to not cause maildirs to be read (and
- stat(2) called for every message file) at shell startup.
+u. Fixed the initialization of mailboxes to not cause maildirs to be read
+ (and stat(2) called for every message file) at shell startup.
v. Fixed a bug that caused the shell to not display $PS2 when the read builtin
reads a line continued with a backslash.
ll. Fixed bug that could cause the shell to dump core in certain cases where
a command sets the SIGINT disposition to the default.
-mm. Fixed a bug in the pattern replacement word expansion that occurred when
- the pattern and replacement strings were empty.
+mm. Fixed a bug in the pattern replacement (affecting both word expansion
+ and the `fc' builtin) that occurred when the pattern and replacement
+ strings were empty.
nn. Fixed a bug that caused an arithmetic evaluation error to disable all
further evaluation.
ffff. Fixed a bug that caused the body of a here-document to not be saved to
the history list.
+gggg. Fixed a bug that caused configure to incorrectly conclude that FreeBSD
+ had /dev/fd available, resulting in problems with process substitution.
+
2. Changes to Readline
a. Fixed a number of redisplay errors in environments supporting multibyte
f. Fixed a bug that caused the completion append character to not be reset to
the default after an application-specified completion function changed it.
-g. Fixed a problem that caused incorrect positioning of the cursor in emacs
- mode when at the end of a line in a locale supporting multibyte characters.
+g. Fixed a problem that caused incorrect positioning of the cursor while in
+ emacs editing mode when moving forward at the end of a line while using
+ a locale supporting multibyte characters.
h. Fixed an off-by-one error that caused readline to drop every 511th
character of buffered input.
p. Readline now blocks SIGINT while manipulating internal data structures
during redisplay.
+q. Fixed a bug in redisplay that caused readline to segfault when pasting a
+ very long line (over 130,000 characters).
+
+r. Fixed bugs in redisplay when using prompts with no visible printing
+ characters.
+
3. New Features in Bash
a. When using substring expansion on the positional parameters, a starting
a file descriptor must be > fdbase if fdbase >= SHELL_FD_BASE. A
value of -1 for fdbase means to just use SHELL_FD_BASE. Fixes bug
with 0<&10 reported by Clark Jian Wang <dearvoid@gmail.com>
+
+ 11/5
+ ----
+unwind_prot.c
+ - new function: have_unwind_protects(); returns 1 if unwind_protect_list
+ is not empty
+
+unwind_prot.h
+ - extern declaration for have_unwind_protects
+
+builtins/evalstring.c
+ - in parse_and_execute_cleanup, make sure that we don't call
+ run_unwind_frame and expect it to decrement parse_and_execute_level
+ if there's no unwind_protect_list, since there's a while loop in
+ throw_to_top_level that calls parse_and_execute_cleanup as long as
+ parse_and_execute_level is non-zero
+
+ 11/9
+ ----
+variables.c
+ - fix the assign function for COMP_WORDBREAKS to allocate new memory
+ to store as the variable's value, to avoid freeing memory twice
+ if the variable is unset after rl_completer_word_break_characters
+ is freed and reallocated. Fix from Mike Stroyan <mike@stroyan.net
+
+[bash-4.0-beta frozen]
a file descriptor must be > fdbase if fdbase >= SHELL_FD_BASE. A
value of -1 for fdbase means to just use SHELL_FD_BASE. Fixes bug
with 0<&10 reported by Clark Jian Wang <dearvoid@gmail.com>
+
+ 11/5
+ ----
+unwind_prot.c
+ - new function: have_unwind_protects(); returns 1 if unwind_protect_list
+ is not empty
+
+unwind_prot.h
+ - extern declaration for have_unwind_protects
+
+builtins/evalstring.c
+ - in parse_and_execute_cleanup, make sure that we don't call
+ run_unwind_frame and expect it to decrement parse_and_execute_level
+ if there's no unwind_protect_list, since there's a while loop in
+ throw_to_top_level that calls parse_and_execute_cleanup as long as
+ parse_and_execute_level is non-zero
+
+ 11/9
+ ----
+variables.c
+ - fix the assign function for COMP_WORDBREAKS to allocate new memory
+ to store as the variable's value, to avoid freeing memory twice
+ if the variable is unset after rl_completer_word_break_characters
+ is freed and reallocated. Fix from Mike Stroyan <mike@stroyan.net>
+
+[bash-4.0-beta frozen]
PID of the coprocess are available to the calling shell in variables
with coproc-specific names.
+ll. 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.
+
+mm. CDPATH and GLOBIGNORE are ignored when the shell is running in privileged
+ mode.
+
+nn. 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.
+
+oo. 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.
+
2. New Features in Readline
a. A new variable, rl_sort_completion_matches; allows applications to inhibit
undo all outstanding changes to all history lines when `accept-line' is
executed.
+j. If the kernel supports it, readline displays special characters
+ corresponding to a keyboard-generated signal when the signal is received.
+
-------------------------------------------------------------------------------
This is a terse description of the new features added to bash-3.2 since
the release of bash-3.1. As always, the manual page (doc/bash.1) is
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.
--- /dev/null
+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.
+
+2. New Features in Readline
+
+a. A new variable, rl_sort_completion_matches; allows applications to inhibit
+ match list sorting (but beware: some things don't work right if
+ applications do this).
+
+b. A new variable, rl_completion_invoking_key; allows applications to discover
+ the key that invoked rl_complete or rl_menu_complete.
+
+c. The functions rl_block_sigint and rl_release_sigint are now public and
+ available to calling applications who want to protect critical sections
+ (like redisplay).
+
+d. The functions rl_save_state and rl_restore_state are now public and
+ available to calling applications; documented rest of readline's state
+ flag values.
+
+e. A new user-settable variable, `history-size', allows setting the maximum
+ number of entries in the history list.
+
+f. There is a new implementation of menu completion, with several improvements
+ over the old; the most notable improvement is a better `completions
+ browsing' mode.
+
+g. The menu completion code now uses the rl_menu_completion_entry_function
+ variable, allowing applications to provide their own menu completion
+ generators.
+
+h. There is support for replacing a prefix of a pathname with a `...' when
+ displaying possible completions. This is controllable by setting the
+ `completion-prefix-display-length' variable. Matches with a common prefix
+ longer than this value have the common prefix replaced with `...'.
+
+i. There is a new `revert-all-at-newline' variable. If enabled, readline will
+ undo all outstanding changes to all history lines when `accept-line' is
+ executed.
+
+j. If the kernel supports it, readline displays special characters
+ corresponding to a keyboard-generated signal when the signal is received.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-3.2 since
+the release of bash-3.1. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. Changed the parameter pattern replacement functions to not anchor the
+ pattern at the beginning of the string if doing global replacement - that
+ combination doesn't make any sense.
+
+b. When running in `word expansion only' mode (--wordexp option), inhibit
+ process substitution.
+
+c. Loadable builtins now work on MacOS X 10.[34].
+
+d. Shells running in posix mode no longer set $HOME, as POSIX requires.
+
+e. The code that checks for binary files being executed as shell scripts now
+ checks only for NUL rather than any non-printing character.
+
+f. Quoting the string argument to the [[ command's =~ operator now forces
+ string matching, as with the other pattern-matching operators.
+
+2. New Features in Readline
+
+a. Calling applications can now set the keyboard timeout to 0, allowing
+ poll-like behavior.
+
+b. The value of SYS_INPUTRC (configurable at compilation time) is now used as
+ the default last-ditch startup file.
+
+c. The history file reading functions now allow windows-like \r\n line
+ terminators.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-3.1 since
+the release of bash-3.0. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. Bash now understands LC_TIME as a special variable so that time display
+ tracks the current locale.
+
+b. BASH_ARGC, BASH_ARGV, BASH_SOURCE, and BASH_LINENO are no longer created
+ as `invisible' variables and may not be unset.
+
+c. In POSIX mode, if `xpg_echo' option is enabled, the `echo' builtin doesn't
+ try to interpret any options at all, as POSIX requires.
+
+d. The `bg' builtin now accepts multiple arguments, as POSIX seems to specify.
+
+e. Fixed vi-mode word completion and glob expansion to perform tilde
+ expansion.
+
+f. The `**' mathematic exponentiation operator is now right-associative.
+
+g. The `ulimit' builtin has new options: -i (max number of pending signals),
+ -q (max size of POSIX message queues), and -x (max number of file locks).
+
+h. A bare `%' once again expands to the current job when used as a job
+ specifier.
+
+i. The `+=' assignment operator (append to the value of a string or array) is
+ now supported for assignment statements and arguments to builtin commands
+ that accept assignment statements.
+
+j. BASH_COMMAND now preserves its value when a DEBUG trap is executed.
+
+k. The `gnu_errfmt' option is enabled automatically if the shell is running
+ in an emacs terminal window.
+
+l. New configuration option: --single-help-strings. Causes long help text
+ to be written as a single string; intended to ease translation.
+
+m. The COMP_WORDBREAKS variable now causes the list of word break characters
+ to be emptied when the variable is unset.
+
+n. An unquoted expansion of $* when $IFS is empty now causes the positional
+ parameters to be concatenated if the expansion doesn't undergo word
+ splitting.
+
+o. Bash now inherits $_ from the environment if it appears there at startup.
+
+p. New shell option: nocasematch. If non-zero, shell pattern matching ignores
+ case when used by `case' and `[[' commands.
+
+q. The `printf' builtin takes a new option: -v var. That causes the output
+ to be placed into var instead of on stdout.
+
+r. By default, the shell no longer reports processes dying from SIGPIPE.
+
+s. Bash now sets the extern variable `environ' to the export environment it
+ creates, so C library functions that call getenv() (and can't use the
+ shell-provided replacement) get current values of environment variables.
+
+t. A new configuration option, `--enable-strict-posix-default', which will
+ build bash to be POSIX conforming by default.
+
+u. If compiled for strict POSIX conformance, LINES and COLUMNS may now
+ override the true terminal size.
+
+2. New Features in Readline
+
+a. The key sequence sent by the keypad `delete' key is now automatically
+ bound to delete-char.
+
+b. A negative argument to menu-complete now cycles backward through the
+ completion list.
+
+c. A new bindable readline variable: bind-tty-special-chars. If non-zero,
+ readline will bind the terminal special characters to their readline
+ equivalents when it's called (on by default).
+
+d. New bindable command: vi-rubout. Saves deleted text for possible
+ reinsertion, as with any vi-mode `text modification' command; `X' is bound
+ to this in vi command mode.
+
+e. A new external application-controllable variable that allows the LINES
+ and COLUMNS environment variables to set the window size regardless of
+ what the kernel returns: rl_prefer_env_winsize
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-3.0 since
+the release of bash-2.05b. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. ANSI string expansion now implements the \x{hexdigits} escape.
+
+b. There is a new loadable `strftime' builtin.
+
+c. New variable, COMP_WORDBREAKS, which controls the readline completer's
+ idea of word break characters.
+
+d. The `type' builtin no longer reports on aliases unless alias expansion
+ will actually be performed.
+
+e. HISTCONTROL is now a colon-separated list of values, which permits
+ more extensibility and backwards compatibility.
+
+f. HISTCONTROL may now include the `erasedups' option, which causes all lines
+ matching a line being added to be removed from the history list.
+
+g. `configure' has a new `--enable-multibyte' argument that permits multibyte
+ character support to be disabled even on systems that support it.
+
+h. New variables to support the bash debugger: BASH_ARGC, BASH_ARGV,
+ BASH_SOURCE, BASH_LINENO, BASH_SUBSHELL, BASH_EXECUTION_STRING,
+ BASH_COMMAND
+
+i. FUNCNAME has been changed to support the debugger: it's now an array
+ variable.
+
+j. for, case, select, arithmetic commands now keep line number information
+ for the debugger.
+
+k. There is a new `RETURN' trap executed when a function or sourced script
+ returns (not inherited child processes; inherited by command substitution
+ if function tracing is enabled and the debugger is active).
+
+l. New invocation option: --debugger. Enables debugging and turns on new
+ `extdebug' shell option.
+
+m. New `functrace' and `errtrace' options to `set -o' cause DEBUG and ERR
+ traps, respectively, to be inherited by shell functions. Equivalent to
+ `set -T' and `set -E' respectively. The `functrace' option also controls
+ whether or not the DEBUG trap is inherited by sourced scripts.
+
+n. The DEBUG trap is run before binding the variable and running the action
+ list in a `for' command, binding the selection variable and running the
+ query in a `select' command, and before attempting a match in a `case'
+ command.
+
+o. New `--enable-debugger' option to `configure' to compile in the debugger
+ support code.
+
+p. `declare -F' now prints out extra line number and source file information
+ if the `extdebug' option is set.
+
+q. If `extdebug' is enabled, a non-zero return value from a DEBUG trap causes
+ the next command to be skipped, and a return value of 2 while in a
+ function or sourced script forces a `return'.
+
+r. New `caller' builtin to provide a call stack for the bash debugger.
+
+s. The DEBUG trap is run just before the first command in a function body is
+ executed, for the debugger.
+
+t. `for', `select', and `case' command heads are printed when `set -x' is
+ enabled.
+
+u. There is a new {x..y} brace expansion, which is shorthand for {x.x+1,
+ x+2,...,y}. x and y can be integers or single characters; the sequence
+ may ascend or descend; the increment is always 1.
+
+v. New ksh93-like ${!array[@]} expansion, expands to all the keys (indices)
+ of array.
+
+w. New `force_fignore' shopt option; if enabled, suffixes specified by
+ FIGNORE cause words to be ignored when performing word completion even
+ if they're the only possibilities.
+
+x. New `gnu_errfmt' shopt option; if enabled, error messages follow the `gnu
+ style' (filename:lineno:message) format.
+
+y. New `-o bashdefault' option to complete and compgen; if set, causes the
+ whole set of bash completions to be performed if the compspec doesn't
+ result in a match.
+
+z. New `-o plusdirs' option to complete and compgen; if set, causes directory
+ name completion to be performed and the results added to the rest of the
+ possible completions.
+
+aa. `kill' is available as a builtin even when the shell is built without
+ job control.
+
+bb. New HISTTIMEFORMAT variable; value is a format string to pass to
+ strftime(3). If set and not null, the `history' builtin prints out
+ timestamp information according to the specified format when displaying
+ history entries. If set, bash tells the history library to write out
+ timestamp information when the history file is written.
+
+cc. The [[ ... ]] command has a new binary `=~' operator that performs
+ extended regular expression (egrep-like) matching.
+
+dd. `configure' has a new `--enable-cond-regexp' option (enabled by default)
+ to enable the =~ operator and regexp matching in [[ ... ]].
+
+ee. Subexpressions matched by the =~ operator are placed in the new
+ BASH_REMATCH array variable.
+
+ff. New `failglob' option that causes an expansion error when pathname
+ expansion fails to produce a match.
+
+gg. New `set -o pipefail' option that causes a pipeline to return a failure
+ status if any of the processes in the pipeline fail, not just the last
+ one.
+
+hh. printf builtin understands two new escape sequences: \" and \?.
+
+ii. `echo -e' understands two new escape sequences: \" and \?.
+
+jj. The GNU `gettext' package and libintl have been integrated; the shell's
+ messages can be translated into different languages.
+
+kk. The `\W' prompt expansion now abbreviates $HOME as `~', like `\w'.
+
+ll. The error message printed when bash cannot open a shell script supplied
+ as argument 1 now includes the name of the shell, to better identify
+ the error as coming from bash.
+
+mm. The parameter pattern removal and substitution expansions are now much
+ faster and more efficient when using multibyte characters.
+
+nn. The `jobs', `kill', and `wait' builtins now accept job control notation
+ even if job control is not enabled.
+
+oo. The historical behavior of `trap' that allows a missing `action' argument
+ to cause each specified signal's handling to be reset to its default is
+ now only supported when `trap' is given a single non-option argument.
+
+2. New Features in Readline
+
+a. History expansion has a new `a' modifier equivalent to the `g' modifier
+ for compatibility with the BSD csh.
+
+b. History expansion has a new `G' modifier equivalent to the BSD csh `g'
+ modifier, which performs a substitution once per word.
+
+c. All non-incremental search operations may now undo the operation of
+ replacing the current line with the history line.
+
+d. The text inserted by an `a' command in vi mode can be reinserted with
+ `.'.
+
+e. New bindable variable, `show-all-if-unmodified'. If set, the readline
+ completer will list possible completions immediately if there is more
+ than one completion and partial completion cannot be performed.
+
+f. There is a new application-callable `free_history_entry()' function.
+
+g. History list entries now contain timestamp information; the history file
+ functions know how to read and write timestamp information associated
+ with each entry.
+
+h. Four new key binding functions have been added:
+
+ rl_bind_key_if_unbound()
+ rl_bind_key_if_unbound_in_map()
+ rl_bind_keyseq_if_unbound()
+ rl_bind_keyseq_if_unbound_in_map()
+
+i. New application variable, rl_completion_quote_character, set to any
+ quote character readline finds before it calls the application completion
+ function.
+
+j. New application variable, rl_completion_suppress_quote, settable by an
+ application completion function. If set to non-zero, readline does not
+ attempt to append a closing quote to a completed word.
+
+k. New application variable, rl_completion_found_quote, set to a non-zero
+ value if readline determines that the word to be completed is quoted.
+ Set before readline calls any application completion function.
+
+l. New function hook, rl_completion_word_break_hook, called when readline
+ needs to break a line into words when completion is attempted. Allows
+ the word break characters to vary based on position in the line.
+
+m. New bindable command: unix-filename-rubout. Does the same thing as
+ unix-word-rubout, but adds `/' to the set of word delimiters.
+
+n. When listing completions, directories have a `/' appended if the
+ `mark-directories' option has been enabled.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-2.05b since
+the release of bash-2.05a. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. If set, TMOUT is the default timeout for the `read' builtin.
+
+b. `type' has two new options: `-f' suppresses shell function lookup, and
+ `-P' forces a $PATH search.
+
+c. New code to handle multibyte characters.
+
+d. `select' was changed to be more ksh-compatible, in that the menu is
+ reprinted each time through the loop only if REPLY is set to NULL.
+ The previous behavior is available as a compile-time option.
+
+e. `complete -d' and `complete -o dirnames' now force a slash to be
+ appended to names which are symlinks to directories.
+
+f. There is now a bindable edit-and-execute-command readline command,
+ like the vi-mode `v' command, bound to C-xC-e in emacs mode.
+
+g. Added support for ksh93-like [:word:] character class in pattern matching.
+
+h. The $'...' quoting construct now expands \cX to Control-X.
+
+i. A new \D{...} prompt expansion; passes the `...' to strftime and inserts
+ the result into the expanded prompt.
+
+j. The shell now performs arithmetic in the largest integer size the
+ machine supports (intmax_t), instead of long.
+
+k. If a numeric argument is supplied to one of the bash globbing completion
+ functions, a `*' is appended to the word before expansion is attempted.
+
+l. The bash globbing completion functions now allow completions to be listed
+ with double tabs or if `show-all-if-ambiguous' is set.
+
+m. New `-o nospace' option for `complete' and `compgen' builtins; suppresses
+ readline's appending a space to the completed word.
+
+n. 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).
+
+p. There is a new configuration option `--enable-mem-scramble', controls
+ bash malloc behavior of writing garbage characters into memory at
+ allocation and free time.
+
+q. The `complete' and `compgen' builtins now have a new `-s/-A service'
+ option to complete on names from /etc/services.
+
+r. `read' has a new `-u fd' option to read from a specified file descriptor.
+
+s. Fix the completion code so that expansion errors in a directory name
+ don't cause a longjmp back to the command loop.
+
+t. Fixed word completion inside command substitution to work a little more
+ intuitively.
+
+u. The `printf' %q format specifier now uses $'...' quoting to print the
+ argument if it contains non-printing characters.
+
+v. The `declare' and `typeset' builtins have a new `-t' option. When applied
+ to functions, it causes the DEBUG trap to be inherited by the named
+ function. Currently has no effect on variables.
+
+w. The DEBUG trap is now run *before* simple commands, ((...)) commands,
+ [[...]] conditional commands, and for ((...)) loops.
+
+x. 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.
+
+y. 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. Code
+ from Gary Vaughan.
+
+z. New [n]<&word- and [n]>&word- redirections from ksh93 -- move fds (dup
+ and close).
+
+aa. There is a new `-l' invocation option, equivalent to `--login'.
+
+bb. The `hash' builtin has a new `-l' option to list contents in a reusable
+ format, and a `-d' option to remove a name from the hash table.
+
+cc. There is now support for placing the long help text into separate files
+ installed into ${datadir}/bash. Not enabled by default; can be turned
+ on with `--enable-separate-helpfiles' option to configure.
+
+dd. All builtins that take operands accept a `--' pseudo-option, except
+ `echo'.
+
+ee. The `echo' builtin now accepts \0xxx (zero to three octal digits following
+ the `0') in addition to \xxx (one to three octal digits) for SUSv3/XPG6/
+ POSIX.1-2001 compliance.
+
+
+2. New Features in Readline
+
+a. Support for key `subsequences': allows, e.g., ESC and ESC-a to both
+ be bound to readline functions. Now the arrow keys may be used in vi
+ insert mode.
+
+b. When listing completions, and the number of lines displayed is more than
+ the screen length, readline uses an internal pager to display the results.
+ This is controlled by the `page-completions' variable (default on).
+
+c. New code to handle editing and displaying multibyte characters.
+
+d. The behavior introduced in bash-2.05a of deciding whether or not to
+ append a slash to a completed name that is a symlink to a directory has
+ been made optional, controlled by the `mark-symlinked-directories'
+ variable (default is the 2.05a behavior).
+
+e. The `insert-comment' command now acts as a toggle if given a numeric
+ argument: if the first characters on the line don't specify a
+ comment, insert one; if they do, delete the comment text
+
+f. New application-settable completion variable:
+ rl_completion_mark_symlink_dirs, allows an application's completion
+ function to temporarily override the user's preference for appending
+ slashes to names which are symlinks to directories.
+
+g. New function available to application completion functions:
+ rl_completion_mode, to tell how the completion function was invoked
+ and decide which argument to supply to rl_complete_internal (to list
+ completions, etc.).
+
+h. Readline now has an overwrite mode, toggled by the `overwrite-mode'
+ bindable command, which could be bound to `Insert'.
+
+i. New application-settable completion variable:
+ rl_completion_suppress_append, inhibits appending of
+ rl_completion_append_character to completed words.
+
+j. New key bindings when reading an incremental search string: ^W yanks
+ the currently-matched word out of the current line into the search
+ string; ^Y yanks the rest of the current line into the search string,
+ DEL or ^H deletes characters from the search string.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-2.05a since
+the release of bash-2.05. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. Added support for DESTDIR installation root prefix, so you can do a
+ `make install DESTDIR=bash-root' and do easier binary packaging.
+
+b. Added support for builtin printf "'" flag character as per latest POSIX
+ drafts.
+
+c. Support for POSIX.2 printf(1) length specifiers `j', `t', and `z' (from
+ ISO C99).
+
+d. New autoconf macro, RL_LIB_READLINE_VERSION, for use by other applications
+ (bash doesn't use very much of what it returns).
+
+e. `set [-+]o nolog' is recognized as required by the latest POSIX drafts,
+ but ignored.
+
+f. New read-only `shopt' option: login_shell. Set to non-zero value if the
+ shell is a login shell.
+
+g. New `\A' prompt string escape sequence; expands to time in 24 HH:MM format.
+
+h. New `-A group/-g' option to complete and compgen; does group name
+ completion.
+
+i. New `-t' option to `hash' to list hash values for each filename argument.
+
+j. New [-+]O invocation option to set and unset `shopt' options at startup.
+
+k. configure's `--with-installed-readline' option now takes an optional
+ `=PATH' suffix to set the root of the tree where readline is installed
+ to PATH.
+
+l. The ksh-like `ERR' trap has been added. The `ERR' trap will be run
+ whenever the shell would have exited if the -e option were enabled.
+ It is not inherited by shell functions.
+
+m. `readonly', `export', and `declare' now print variables which have been
+ given attributes but not set by assigning a value as just a command and
+ a variable name (like `export foo') when listing, as the latest POSIX
+ drafts require.
+
+n. `bashbug' now requires that the subject be changed from the default.
+
+o. configure has a new `--enable-largefile' option, like other GNU utilities.
+
+p. `for' loops now allow empty word lists after `in', like the latest POSIX
+ drafts require.
+
+q. The builtin `ulimit' now takes two new non-numeric arguments: `hard',
+ meaning the current hard limit, and `soft', meaning the current soft
+ limit, in addition to `unlimited'
+
+r. `ulimit' now prints the option letter associated with a particular
+ resource when printing more than one limit.
+
+s. `ulimit' prints `hard' or `soft' when a value is not `unlimited' but is
+ one of RLIM_SAVED_MAX or RLIM_SAVED_CUR, respectively.
+
+t. The `printf' builtin now handles the %a and %A conversions if they're
+ implemented by printf(3).
+
+u. The `printf' builtin now handles the %F conversion (just about like %f).
+
+v. The `printf' builtin now handles the %n conversion like printf(3). The
+ corresponding argument is the name of a shell variable to which the
+ value is assigned.
+
+2. New Features in Readline
+
+a. Added extern declaration for rl_get_termcap to readline.h, making it a
+ public function (it was always there, just not in readline.h).
+
+b. New #defines in readline.h: RL_READLINE_VERSION, currently 0x0402,
+ RL_VERSION_MAJOR, currently 4, and RL_VERSION_MINOR, currently 2.
+
+c. New readline variable: rl_readline_version, mirrors RL_READLINE_VERSION.
+
+d. New bindable boolean readline variable: match-hidden-files. Controls
+ completion of files beginning with a `.' (on Unix). Enabled by default.
+
+e. The history expansion code now allows any character to terminate a
+ `:first-' modifier, like csh.
+
+f. New bindable variable `history-preserve-point'. If set, the history
+ code attempts to place the user at the same location on each history
+ line retrived with previous-history or next-history.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-2.05 since
+the release of bash-2.04. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. Added a new `--init-file' invocation argument as a synonym for `--rcfile',
+ per the new GNU coding standards.
+
+b. The /dev/tcp and /dev/udp redirections now accept service names as well as
+ port numbers.
+
+c. `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
+
+d. A new loadable builtin, realpath, which canonicalizes and expands symlinks
+ in pathname arguments.
+
+e. 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.
+
+f. Bash-2.05 once again honors the current locale setting when processing
+ ranges within pattern matching bracket expressions (e.g., [A-Z]).
+
+2. New Features in Readline
+
+a. The blink timeout for paren matching is now settable by applications,
+ via the rl_set_paren_blink_timeout() function.
+
+b. _rl_executing_macro has been renamed to rl_executing_macro, which means
+ it's now part of the public interface.
+
+c. Readline has a new variable, rl_readline_state, which is a bitmap that
+ encapsulates the current state of the library; intended for use by
+ callbacks and hook functions.
+
+d. New application-callable function rl_set_prompt(const char *prompt):
+ expands its prompt string argument and sets rl_prompt to the result.
+
+e. New application-callable function rl_set_screen_size(int rows, int cols):
+ public method for applications to set readline's idea of the screen
+ dimensions.
+
+f. New function, rl_get_screen_size (int *rows, int *columns), returns
+ readline's idea of the screen dimensions.
+
+g. The timeout in rl_gather_tyi (readline keyboard input polling function)
+ is now settable via a function (rl_set_keyboard_input_timeout()).
+
+h. Renamed the max_input_history variable to history_max_entries; the old
+ variable is maintained for backwards compatibility.
+
+i. The list of characters that separate words for the history tokenizer is
+ now settable with a variable: history_word_delimiters. The default
+ value is as before.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-2.04 since
+the release of bash-2.03. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. The history builtin has a `-d offset' option to delete the history entry
+ at position `offset'.
+
+b. The prompt expansion code has two new escape sequences: \j, the number of
+ active jobs; and \l, the basename of the shell's tty device name.
+
+c. The `bind' builtin has a new `-x' option to bind key sequences to shell
+ commands.
+
+d. There is a new shell option, no_empty_command_completion, which, when
+ enabled, disables command completion when TAB is typed on an empty line.
+
+e. The `help' builtin has a `-s' option to just print a builtin's usage
+ synopsis.
+
+f. There are several new arithmetic operators: id++, id-- (variable
+ post-increment/decrement), ++id, --id (variable pre-increment/decrement),
+ expr1 , expr2 (comma operator).
+
+g. There is a new ksh-93 style arithmetic for command:
+ for ((expr1 ; expr2; expr3 )); do list; done
+
+h. The `read' builtin has a number of new options:
+ -t timeout only wait timeout seconds for input
+ -n nchars only read nchars from input instead of a full line
+ -d delim read until delim rather than newline
+ -s don't echo input chars as they are read
+
+i. The redirection code now handles several filenames specially:
+ /dev/fd/N, /dev/stdin, /dev/stdout, and /dev/stderr, whether or
+ not they are present in the file system.
+
+j. The redirection code now recognizes pathnames of the form
+ /dev/tcp/host/port and /dev/udp/host/port, and tries to open a socket
+ of the appropriate type to the specified port on the specified host.
+
+k. The ksh-93 ${!prefix*} expansion, which expands to the names of all
+ shell variables with prefix PREFIX, has been implemented.
+
+l. There is a new dynamic variable, FUNCNAME, which expands to the name of
+ a currently-executing function. Assignments to FUNCNAME have no effect.
+
+m. The GROUPS variable is no longer readonly; assignments to it are silently
+ discarded. This means it can be unset.
+
+n. A new programmable completion facility, with two new builtin commands:
+ complete and compgen.
+
+o. configure has a new option, `--enable-progcomp', to compile in the
+ programmable completion features (enabled by default).
+
+p. `shopt' has a new option, `progcomp', to enable and disable programmable
+ completion at runtime.
+
+q. Unsetting HOSTFILE now clears the list of hostnames used for completion.
+
+r. configure has a new option, `--enable-bash-malloc', replacing the old
+ `--with-gnu-malloc' (which is still present for backwards compatibility).
+
+s. There is a new manual page describing rbash, the restricted shell.
+
+t. `bashbug' has new `--help' and `--version' options.
+
+u. `shopt' has a new `xpg_echo' option, which controls the behavior of
+ `echo' with respect to backslash-escaped characters at runtime.
+
+v. If NON_INTERACTIVE_LOGIN_SHELLS is defined, all login shells read the
+ startup files, even if they are not interactive.
+
+w. The LC_NUMERIC variable is now treated specially, and used to set the
+ LC_NUMERIC locale category for number formatting, e.g., when `printf'
+ displays floating-point numbers.
+
+2. New features in Readline
+
+a. Parentheses matching is now always compiled into readline, and enabled
+ or disabled when the value of the `blink-matching-paren' variable is
+ changed.
+
+b. MS-DOS systems now use ~/_inputrc as the last-ditch inputrc filename.
+
+c. MS-DOS systems now use ~/_history as the default history file.
+
+d. history-search-{forward,backward} now leave the point at the end of the
+ line when the string to search for is empty, like
+ {reverse,forward}-search-history.
+
+e. history-search-{forward,backward} now leave the last history line found
+ in the readline buffer if the second or subsequent search fails.
+
+f. New function for use by applications: rl_on_new_line_with_prompt, used
+ when an application displays the prompt itself before calling readline().
+
+g. New variable for use by applications: rl_already_prompted. An application
+ that displays the prompt itself before calling readline() must set this to
+ a non-zero value.
+
+h. A new variable, rl_gnu_readline_p, always 1. The intent is that an
+ application can verify whether or not it is linked with the `real'
+ readline library or some substitute.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-2.03 since
+the release of bash-2.02. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. New `shopt' option, `restricted_shell', indicating whether or not the
+ shell was started in restricted mode, for use in startup files.
+
+b. Filename generation is now performed on the words between ( and ) in
+ array assignments (which it probably should have done all along).
+
+c. OLDPWD is now auto-exported, as POSIX.2 seems to require.
+
+d. ENV and BASH_ENV are read-only variables in a restricted shell.
+
+e. A change was made to the startup file code so that any shell begun with
+ the `--login' option, even non-interactive shells, will source the login
+ shell startup files.
+
+2. New Features in Readline
+
+a. Many changes to the signal handling:
+ o Readline now catches SIGQUIT and cleans up the tty before returning;
+ o A new variable, rl_catch_signals, is available to application writers
+ to indicate to readline whether or not it should install its own
+ signal handlers for SIGINT, SIGTERM, SIGQUIT, SIGALRM, SIGTSTP,
+ SIGTTIN, and SIGTTOU;
+ o A new variable, rl_catch_sigwinch, is available to application
+ writers to indicate to readline whether or not it should install its
+ own signal handler for SIGWINCH, which will chain to the calling
+ applications's SIGWINCH handler, if one is installed;
+ o There is a new function, rl_free_line_state, for application signal
+ handlers to call to free up the state associated with the current
+ line after receiving a signal;
+ o There is a new function, rl_cleanup_after_signal, to clean up the
+ display and terminal state after receiving a signal;
+ o There is a new function, rl_reset_after_signal, to reinitialize the
+ terminal and display state after an application signal handler
+ returns and readline continues
+
+b. There is a new function, rl_resize_terminal, to reset readline's idea of
+ the screen size after a SIGWINCH.
+
+c. New public functions: rl_save_prompt and rl_restore_prompt. These were
+ previously private functions with a `_' prefix.
+
+d. New function hook: rl_pre_input_hook, called just before readline starts
+ reading input, after initialization.
+
+e. New function hook: rl_display_matches_hook, called when readline would
+ display the list of completion matches. The new function
+ rl_display_match_list is what readline uses internally, and is available
+ for use by application functions called via this hook.
+
+f. New bindable function, delete-char-or-list, like tcsh.
+
+g. A new variable, rl_erase_empty_line, which, if set by an application using
+ readline, will cause readline to erase, prompt and all, lines on which the
+ only thing typed was a newline.
+
+h. New bindable variable: `isearch-terminators'.
+
+i. New bindable function: `forward-backward-delete-char' (unbound by default).
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-2.02 since
+the release of bash-2.01.1. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. A new version of malloc, based on the older GNU malloc, that has many
+ changes, is more page-based, is more conservative with memory usage,
+ and does not `orphan' large blocks when they are freed.
+
+b. A new version of gmalloc, based on the old GLIBC malloc, with many
+ changes and range checking included by default.
+
+c. A new implementation of fnmatch(3) that includes full POSIX.2 Basic
+ Regular Expression matching, including character classes, collating
+ symbols, equivalence classes, and support for case-insensitive pattern
+ matching.
+
+d. ksh-88 egrep-style extended pattern matching ([@+*?!](patlist)) has been
+ implemented, controlled by a new `shopt' option, `extglob'.
+
+e. There is a new ksh-like `[[' compound command, which implements
+ extended `test' functionality.
+
+f. There is a new `printf' builtin, implemented according to the POSIX.2
+ specification.
+
+g. There is a new feature for command substitution: $(< filename) now expands
+ to the contents of `filename', with any trailing newlines removed
+ (equivalent to $(cat filename)).
+
+h. There are new tilde prefixes which expand to directories from the
+ directory stack.
+
+i. There is a new `**' arithmetic operator to do exponentiation.
+
+j. There are new configuration options to control how bash is linked:
+ `--enable-profiling', to allow bash to be profiled with gprof, and
+ `--enable-static-link', to allow bash to be linked statically.
+
+k. There is a new configuration option, `--enable-cond-command', which
+ controls whether or not the `[[' command is included. It is on by
+ default.
+
+l. There is a new configuration option, `--enable-extended-glob', which
+ controls whether or not the ksh extended globbing feature is included.
+ It is enabled by default.
+
+m. There is a new configuration #define in config.h.top that, when enabled,
+ will cause all login shells to source /etc/profile and one of the user-
+ specific login shell startup files, whether or not the shell is
+ interactive.
+
+n. There is a new invocation option, `--dump-po-strings', to dump
+ a shell script's translatable strings ($"...") in GNU `po' format.
+
+o. There is a new `shopt' option, `nocaseglob', to enable case-insensitive
+ pattern matching when globbing filenames and using the `case' construct.
+
+p. There is a new `shopt' option, `huponexit', which, when enabled, causes
+ the shell to send SIGHUP to all jobs when an interactive login shell
+ exits.
+
+q. `bind' has a new `-u' option, which takes a readline function name as an
+ argument and unbinds all key sequences bound to that function in a
+ specified keymap.
+
+r. `disown' now has `-a' and `-r' options, to limit operation to all jobs
+ and running jobs, respectively.
+
+s. The `shopt' `-p' option now causes output to be displayed in a reusable
+ format.
+
+t. `test' has a new `-N' option, which returns true if the filename argument
+ has been modified since it was last accessed.
+
+u. `umask' now has a `-p' option to print output in a reusable format.
+
+v. A new escape sequence, `\xNNN', has been added to the `echo -e' and $'...'
+ translation code. It expands to the character whose ascii code is NNN
+ in hexadecimal.
+
+w. The prompt string expansion code has a new `\r' escape sequence.
+
+x. The shell may now be cross-compiled for the CYGWIN32 environment on
+ a Unix machine.
+
+2. New Features in Readline
+
+a. There is now an option for `iterative' yank-last-arg handline, so a user
+ can keep entering `M-.', yanking the last argument of successive history
+ lines.
+
+b. New variable, `print-completions-horizontally', which causes completion
+ matches to be displayed across the screen (like `ls -x') rather than up
+ and down the screen (like `ls').
+
+c. New variable, `completion-ignore-case', which causes filename completion
+ and matching to be performed case-insensitively.
+
+d. There is a new bindable command, `magic-space', which causes history
+ expansion to be performed on the current readline buffer and a space to
+ be inserted into the result.
+
+e. There is a new bindable command, `menu-complete', which enables tcsh-like
+ menu completion (successive executions of menu-complete insert a single
+ completion match, cycling through the list of possible completions).
+
+f. There is a new bindable command, `paste-from-clipboard', for use on Win32
+ systems, to insert the text from the Win32 clipboard into the editing
+ buffer.
+
+g. The key sequence translation code now understands printf-style backslash
+ escape sequences, including \NNN octal escapes. These escape sequences
+ may be used in key sequence definitions or macro values.
+
+h. An `$include' inputrc file parser directive has been added.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-2.01 since
+the release of bash-2.0. As always, the manual page (doc/bash.1) is the
+place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. There is a new builtin array variable: GROUPS, the set of groups to which
+ the user belongs. This is used by the test suite.
+
+2. New Features in Readline
+
+a. If a key sequence bound to `universal-argument' is read while reading a
+ numeric argument started with `universal-argument', it terminates the
+ argument but is otherwise ignored. This provides a way to insert multiple
+ instances of a digit string, and is how GNU emacs does it.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-2.0 since
+the release of bash-1.14.7. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. There is a new invocation option, -D, that dumps translatable strings
+ in a script.
+
+b. The `long' invocation options must now be prefixed with `--'.
+
+c. New long invocation options: --dump-strings, --help, --verbose
+
+d. The `nolineediting' invocation option was renamed to `noediting'.
+
+e. The `nobraceexpansion' and `quiet' long invocation options were removed.
+
+f. The `--help' and `--version' long options now work as the GNU coding
+ standards specify.
+
+g. If invoked as `sh', bash now enters posix mode after reading the
+ startup files, and reads and executes commands from the file named
+ by $ENV if interactive (as POSIX.2 specifies). A login shell invoked
+ as `sh' reads $ENV after /etc/profile and ~/.profile.
+
+h. There is a new reserved word, `time', for timing pipelines, builtin
+ commands, and shell functions. It uses the value of the TIMEFORMAT
+ variable as a format string describing how to print the timing
+ statistics.
+
+i. The $'...' quoting syntax expands ANSI-C escapes in ... and leaves the
+ result single-quoted.
+
+j. The $"..." quoting syntax performs locale-specific translation of ...
+ and leaves the result double-quoted.
+
+k. LINENO now works correctly in functions.
+
+l. New variables: DIRSTACK, PIPESTATUS, BASH_VERSINFO, HOSTNAME, SHELLOPTS,
+ MACHTYPE. The first three are array variables.
+
+m. The BASH_VERSION and BASH_VERSINFO variables now include the shell's
+ `release status' (alpha[N], beta[N], release).
+
+n. 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'.
+
+o. Bash now uses some new variables: LC_ALL, LC_MESSAGES, LC_CTYPE,
+ LC_COLLATE, LANG, GLOBIGNORE, HISTIGNORE.
+
+p. The shell now supports integer-indexed arrays of unlimited length,
+ with a new compound assignment syntax and changes to the appropriate
+ builtin commands (declare/typeset, read, readonly, etc.). The array
+ index may be an arithmetic expression.
+
+q. ${!var}: indirect variable expansion, equivalent to eval \${$var}.
+
+r. ${paramter:offset[:length]}: variable substring extraction.
+
+s. ${parameter/pattern[/[/]string]}: variable pattern substitution.
+
+t. The $[...] arithmetic expansion syntax is no longer supported, in
+ favor of $((...)).
+
+u. Aliases can now be expanded in shell scripts with a shell option
+ (shopt expand_aliases).
+
+v. History and history expansion can now be used in scripts with
+ set -o history and set -H.
+
+w. All builtins now return an exit status of 2 for incorrect usage.
+
+x. Interactive shells resend SIGHUP to all running or stopped children
+ if (and only if) they exit due to a SIGHUP.
+
+y. New prompting expansions: \a, \e, \H, \T, \@, \v, \V.
+
+z. Variable expansion in prompt strings is now controllable via a shell
+ option (shopt promptvars).
+
+aa. Bash now defaults to using command-oriented history.
+
+bb. The history file ($HISTFILE) is now truncated to $HISTFILESIZE after
+ being written.
+
+cc. The POSIX.2 conditional arithmetic evaluation syntax (expr ? expr : expr)
+ has been implemented.
+
+dd. Each builtin now accepts `--' to signify the end of the options, except
+ as documented (echo, etc.).
+
+ee. All builtins use -p to display values in a re-readable format where
+ appropriate, except as documented (echo, type, etc.).
+
+ff. The `alias' builtin has a new -p option.
+
+gg. Changes to the `bind' builtin:
+ o has new options: -psPSVr.
+ o the `-d' option was renamed to `-p'
+ o the `-v' option now dumps variables; the old `-v' is now `-P'
+
+hh. The `bye' synonym for `exit' was removed.
+
+ii. The -L and -P options to `cd' and `pwd' have been documented.
+
+jj. The `cd' builtin now does spelling correction on the directory name
+ by default. This is settable with a shell option (shopt cdspell).
+
+kk. The `declare' builtin has new options: -a, -F, -p.
+
+ll. The `dirs' builtin has new options: -c, -p, -v.
+
+mm. The new `disown' builtin removes jobs from the shell's jobs table
+ or inhibits the resending of SIGHUP when the shell receives a
+ SIGHUP.
+
+nn. The `echo' builtin has a new escape character: \e.
+
+oo. The `enable' builtin can now load new builtins dynamically from shared
+ objects on systems with the dlopen/dlsym interface. There are a number
+ of examples in the examples/loadables directory. There are also
+ new options: -d, -f, -s, -p.
+
+pp. The `-all' option to `enable' was removed in favor of `-a'.
+
+qq. The `exec' builtin has new options: -l, -c, -a.
+
+rr. The `hash' builtin has a new option: -p.
+
+ss. The `history' builtin has new options: -c, -p, -s.
+
+tt. The `jobs' builtin has new options: -r, -s.
+
+uu. The `kill' builtin has new options: -n signum, -l signame.
+
+vv. The `pushd' and `popd' builtins have a new option: -n.
+
+ww. The `read' builtin has new options: -p prompt, -e, -a.
+
+xx. The `readonly' builtin has a new -a option, and the -n option was removed.
+
+yy. Changes to the `set' builtin:
+ o new options: -B, -o keyword, -o onecmd, -o history
+ o options removed: -l, -d, -o nohash
+ o options changed: +o, -h, -o hashall
+ o now displays variables in a format that can be re-read as input
+
+zz. The new `shopt' builtin controls shell optional behavior previously
+ done by setting and unsetting certain shell variables.
+
+aaa. The `test' builtin has new operators: -o option, s1 == s2, s1 < s2,
+ and s1 > s2, where s1 and s2 are strings.
+
+bbb. There is a new trap, DEBUG, executed after every simple command.
+
+ccc. The `trap' builtin has a new -p option.
+
+ddd. The `ulimit' builtin has a new -l option on 4.4BSD-based systems.
+
+eee. The PS1, PS2, PATH, and IFS variables may now be unset.
+
+fff. The restricted shell mode has been expanded and is now documented.
+
+ggg. Security improvements:
+ o functions are not imported from the environment if running setuid
+ or with -p
+ o no startup files are sourced if running setuid or with -p
+
+hhh. The documentation has been overhauled: the texinfo manual was
+ expanded, and HTML versions of the man page and texinfo manual
+ are included.
+
+iii. Changes to Posix mode:
+ o Command lookup now finds special builtins before shell functions.
+ o Failure of a special builtin causes a non-interactive shell to
+ exit. Failures are defined in the POSIX.2 specification.
+ o If the `cd' builtin finds a directory to change to using $CDPATH,
+ the value assigned to PWD when `cd' completes does not contain
+ any symbolic links.
+ o A non-interactive shell exits if a variable assignment error
+ occurs when no command name follows the assignment statements.
+ o A non-interactive shell exits if the interation variable in a
+ `for' statement or the selection variable in a `select' statement
+ is read-only or another variable assignment error occurs.
+ o The `<>' redirection operator now opens a file for both stdin and
+ stdout by default, not just when in posix mode.
+ o Assignment statements preceding special builtins now persist in
+ the shell's environment when the builtin completes.
+
+ Posix mode is now completely POSIX.2-compliant (modulo bugs). When
+ invoked as sh, bash should be completely POSIX.2-compliant.
+
+jjj. The default value of PS1 is now "\s-\v\$ ".
+
+kkk. The ksh-like ((...)) arithmetic command syntax has been implemented.
+ This is exactly equivalent to `let "..."'.
+
+lll. Integer constants have been extended to base 64.
+
+mmm. The `ulimit' builtin now sets both hard and soft limits and reports the
+ soft limit by default.
+
+2. New Features in Readline
+
+a. New variables: enable-keypad, input-meta (new name for meta-flag),
+ mark-directories, visible-stats (now documented), disable-completion,
+ comment-begin.
+
+b. New bindable commands: kill-region, copy-region-as-kill,
+ copy-backward-word, copy-forward-word, set-mark, exchange-point-and-mark,
+ character-search, character-search-backward, insert-comment,
+ glob-expand-word, glob-list-expansions, dump-variables, dump-macros.
+
+c. New emacs keybindings: delete-horizontal-space (M-\),
+ insert-completions (M-*), possible-completions (M-=).
+
+d. The history-search-backward and history-search-forward commands were
+ modified to be the same as previous-line and next-line if point is at
+ the start of the line.
+
+e. More file types are available for the visible-stats mode.
+
+3. Changes of interest in the Bash implementation
+
+a. There is a new autoconf-based configuration mechanism.
+
+b. More things have been moved from Posix mode to standard shell behavior.
+
+c. The trace output (set -x) now inserts quotes where necessary so it can
+ be reused as input.
+
+d. There is a compile-time option for a system-wide interactive shell
+ startup file (disabled by default).
+
+e. The YACC grammar is smaller and tighter, and all 66 shift-reduce
+ conflicts are gone. Several parsing bugs have been fixed.
+
+f. Builtin option parsing has been regularized (using internal_getopt()),
+ with the exception of `echo', `type', and `set'.
+
+g. Builtins now return standard usage messages constructed from the
+ `short doc' used by the help builtin.
+
+h. Completion now quotes using backslashes by default, but honors
+ user-supplied quotes.
+
+i. The GNU libc malloc is available as a configure-time option.
+
+j. There are more internationalization features; bash uses gettext if
+ it is available. The $"..." translation syntax uses the current
+ locale and gettext.
+
+k. There is better reporting of job termination when the shell is not
+ interactive.
+
+l. The shell is somewhat more efficient: it uses a little less memory and
+ makes fewer system calls.
+
+4. Changes of interest in the Readline implementation
+
+a. There is now support for readline `callback' functions.
+
+b. There is now support for user-supplied input, redisplay, and terminal
+ preparation functions.
+
+c. Most of the shell-specific code in readline has been generalized or
+ removed.
+
+d. Most of the annoying redisplay bugs have been fixed, notably the problems
+ with incremental search and excessive redrawing when special characters
+ appear in the prompt string.
+
+e. There are new library functions and variables available to application
+ writers, most having to do with completion and quoting.
+
+f. The NEWLINE character (^J) is now treated as a search terminator by the
+ incremental search functions.
--- /dev/null
+This is a terse description of the new features added to bash-4.0 since
+the release of bash-3.2. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. When using substring expansion on the positional parameters, a starting
+ index of 0 now causes $0 to be prefixed to the list.
+
+b. The `help' builtin now prints its columns with entries sorted vertically
+ rather than horizontally.
+
+c. There is a new variable, $BASHPID, which always returns the process id of
+ the current shell.
+
+d. 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.
+
+e. There is a new `checkjobs' option that causes the shell to check for and
+ report any running or stopped jobs at exit.
+
+f. The programmable completion code exports a new COMP_TYPE variable, set to
+ a character describing the type of completion being attempted.
+
+g. The programmable completion code exports a new COMP_KEY variable, set to
+ the character that caused the completion to be invoked (e.g., TAB).
+
+h. If creation of a child process fails due to insufficient resources, bash
+ will try again several times before reporting failure.
+
+i. The programmable completion code now uses the same set of characters as
+ readline when breaking the command line into a list of words.
+
+j. The block multiplier for the ulimit -c and -f options is now 512 when in
+ Posix mode, as Posix specifies.
+
+k. 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.
+
+l. 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.
+
+m. The `ulimit' builtin now has new -b (socket buffer size) and -T (number
+ of threads) options.
+
+n. The -p option to `declare' now displays all variable values and attributes
+ (or function values and attributes if used with -f).
+
+o. There is a new `compopt' builtin that allows completion functions to modify
+ completion options for existing completions or the completion currently
+ being executed.
+
+p. The `read' builtin has a new -i option which inserts text into the reply
+ buffer when using readline.
+
+q. A new `-E' option to the complete builtin allows control of the default
+ behavior for completion on an empty line.
+
+r. There is now limited support for completing command name words containing
+ globbing characters.
+
+s. Changed format of internal help documentation for all builtins to roughly
+ follow man page format.
+
+t. 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.
+
+u. There is a new `mapfile' builtin to populate an array with lines from a
+ given file.
+
+v. 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.
+
+w. 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.
+
+x. There is a new shell option: `dirspell'. When enabled, the filename
+ completion code performs spelling correction on directory names during
+ completion.
+
+y. The `-t' option to the `read' builtin now supports fractional timeout
+ values.
+
+z. 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.
+
+aa. 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.
+
+bb. 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.
+
+cc. There is a new >>& redirection operator, which appends the standard output
+ and standard error to the named file.
+
+dd. The parser now understands `|&' as a synonym for `2>&1 |', which redirects
+ the standard error for a command through a pipe.
+
+ee. 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.
+
+ff. 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.
+
+gg. 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 `...'.
+
+hh. 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.
+
+ii. The shell provides associative array variables, with the appropriate
+ support to create, delete, assign values to, and expand them.
+
+jj. 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.
+
+kk. 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.
+
+2. New Features in Readline
+
+a. A new variable, rl_sort_completion_matches; allows applications to inhibit
+ match list sorting (but beware: some things don't work right if
+ applications do this).
+
+b. A new variable, rl_completion_invoking_key; allows applications to discover
+ the key that invoked rl_complete or rl_menu_complete.
+
+c. The functions rl_block_sigint and rl_release_sigint are now public and
+ available to calling applications who want to protect critical sections
+ (like redisplay).
+
+d. The functions rl_save_state and rl_restore_state are now public and
+ available to calling applications; documented rest of readline's state
+ flag values.
+
+e. A new user-settable variable, `history-size', allows setting the maximum
+ number of entries in the history list.
+
+f. There is a new implementation of menu completion, with several improvements
+ over the old; the most notable improvement is a better `completions
+ browsing' mode.
+
+g. The menu completion code now uses the rl_menu_completion_entry_function
+ variable, allowing applications to provide their own menu completion
+ generators.
+
+h. There is support for replacing a prefix of a pathname with a `...' when
+ displaying possible completions. This is controllable by setting the
+ `completion-prefix-display-length' variable. Matches with a common prefix
+ longer than this value have the common prefix replaced with `...'.
+
+i. There is a new `revert-all-at-newline' variable. If enabled, readline will
+ undo all outstanding changes to all history lines when `accept-line' is
+ executed.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-3.2 since
+the release of bash-3.1. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. Changed the parameter pattern replacement functions to not anchor the
+ pattern at the beginning of the string if doing global replacement - that
+ combination doesn't make any sense.
+
+b. When running in `word expansion only' mode (--wordexp option), inhibit
+ process substitution.
+
+c. Loadable builtins now work on MacOS X 10.[34].
+
+d. Shells running in posix mode no longer set $HOME, as POSIX requires.
+
+e. The code that checks for binary files being executed as shell scripts now
+ checks only for NUL rather than any non-printing character.
+
+f. Quoting the string argument to the [[ command's =~ operator now forces
+ string matching, as with the other pattern-matching operators.
+
+2. New Features in Readline
+
+a. Calling applications can now set the keyboard timeout to 0, allowing
+ poll-like behavior.
+
+b. The value of SYS_INPUTRC (configurable at compilation time) is now used as
+ the default last-ditch startup file.
+
+c. The history file reading functions now allow windows-like \r\n line
+ terminators.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-3.1 since
+the release of bash-3.0. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. Bash now understands LC_TIME as a special variable so that time display
+ tracks the current locale.
+
+b. BASH_ARGC, BASH_ARGV, BASH_SOURCE, and BASH_LINENO are no longer created
+ as `invisible' variables and may not be unset.
+
+c. In POSIX mode, if `xpg_echo' option is enabled, the `echo' builtin doesn't
+ try to interpret any options at all, as POSIX requires.
+
+d. The `bg' builtin now accepts multiple arguments, as POSIX seems to specify.
+
+e. Fixed vi-mode word completion and glob expansion to perform tilde
+ expansion.
+
+f. The `**' mathematic exponentiation operator is now right-associative.
+
+g. The `ulimit' builtin has new options: -i (max number of pending signals),
+ -q (max size of POSIX message queues), and -x (max number of file locks).
+
+h. A bare `%' once again expands to the current job when used as a job
+ specifier.
+
+i. The `+=' assignment operator (append to the value of a string or array) is
+ now supported for assignment statements and arguments to builtin commands
+ that accept assignment statements.
+
+j. BASH_COMMAND now preserves its value when a DEBUG trap is executed.
+
+k. The `gnu_errfmt' option is enabled automatically if the shell is running
+ in an emacs terminal window.
+
+l. New configuration option: --single-help-strings. Causes long help text
+ to be written as a single string; intended to ease translation.
+
+m. The COMP_WORDBREAKS variable now causes the list of word break characters
+ to be emptied when the variable is unset.
+
+n. An unquoted expansion of $* when $IFS is empty now causes the positional
+ parameters to be concatenated if the expansion doesn't undergo word
+ splitting.
+
+o. Bash now inherits $_ from the environment if it appears there at startup.
+
+p. New shell option: nocasematch. If non-zero, shell pattern matching ignores
+ case when used by `case' and `[[' commands.
+
+q. The `printf' builtin takes a new option: -v var. That causes the output
+ to be placed into var instead of on stdout.
+
+r. By default, the shell no longer reports processes dying from SIGPIPE.
+
+s. Bash now sets the extern variable `environ' to the export environment it
+ creates, so C library functions that call getenv() (and can't use the
+ shell-provided replacement) get current values of environment variables.
+
+t. A new configuration option, `--enable-strict-posix-default', which will
+ build bash to be POSIX conforming by default.
+
+u. If compiled for strict POSIX conformance, LINES and COLUMNS may now
+ override the true terminal size.
+
+2. New Features in Readline
+
+a. The key sequence sent by the keypad `delete' key is now automatically
+ bound to delete-char.
+
+b. A negative argument to menu-complete now cycles backward through the
+ completion list.
+
+c. A new bindable readline variable: bind-tty-special-chars. If non-zero,
+ readline will bind the terminal special characters to their readline
+ equivalents when it's called (on by default).
+
+d. New bindable command: vi-rubout. Saves deleted text for possible
+ reinsertion, as with any vi-mode `text modification' command; `X' is bound
+ to this in vi command mode.
+
+e. A new external application-controllable variable that allows the LINES
+ and COLUMNS environment variables to set the window size regardless of
+ what the kernel returns: rl_prefer_env_winsize
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-3.0 since
+the release of bash-2.05b. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. ANSI string expansion now implements the \x{hexdigits} escape.
+
+b. There is a new loadable `strftime' builtin.
+
+c. New variable, COMP_WORDBREAKS, which controls the readline completer's
+ idea of word break characters.
+
+d. The `type' builtin no longer reports on aliases unless alias expansion
+ will actually be performed.
+
+e. HISTCONTROL is now a colon-separated list of values, which permits
+ more extensibility and backwards compatibility.
+
+f. HISTCONTROL may now include the `erasedups' option, which causes all lines
+ matching a line being added to be removed from the history list.
+
+g. `configure' has a new `--enable-multibyte' argument that permits multibyte
+ character support to be disabled even on systems that support it.
+
+h. New variables to support the bash debugger: BASH_ARGC, BASH_ARGV,
+ BASH_SOURCE, BASH_LINENO, BASH_SUBSHELL, BASH_EXECUTION_STRING,
+ BASH_COMMAND
+
+i. FUNCNAME has been changed to support the debugger: it's now an array
+ variable.
+
+j. for, case, select, arithmetic commands now keep line number information
+ for the debugger.
+
+k. There is a new `RETURN' trap executed when a function or sourced script
+ returns (not inherited child processes; inherited by command substitution
+ if function tracing is enabled and the debugger is active).
+
+l. New invocation option: --debugger. Enables debugging and turns on new
+ `extdebug' shell option.
+
+m. New `functrace' and `errtrace' options to `set -o' cause DEBUG and ERR
+ traps, respectively, to be inherited by shell functions. Equivalent to
+ `set -T' and `set -E' respectively. The `functrace' option also controls
+ whether or not the DEBUG trap is inherited by sourced scripts.
+
+n. The DEBUG trap is run before binding the variable and running the action
+ list in a `for' command, binding the selection variable and running the
+ query in a `select' command, and before attempting a match in a `case'
+ command.
+
+o. New `--enable-debugger' option to `configure' to compile in the debugger
+ support code.
+
+p. `declare -F' now prints out extra line number and source file information
+ if the `extdebug' option is set.
+
+q. If `extdebug' is enabled, a non-zero return value from a DEBUG trap causes
+ the next command to be skipped, and a return value of 2 while in a
+ function or sourced script forces a `return'.
+
+r. New `caller' builtin to provide a call stack for the bash debugger.
+
+s. The DEBUG trap is run just before the first command in a function body is
+ executed, for the debugger.
+
+t. `for', `select', and `case' command heads are printed when `set -x' is
+ enabled.
+
+u. There is a new {x..y} brace expansion, which is shorthand for {x.x+1,
+ x+2,...,y}. x and y can be integers or single characters; the sequence
+ may ascend or descend; the increment is always 1.
+
+v. New ksh93-like ${!array[@]} expansion, expands to all the keys (indices)
+ of array.
+
+w. New `force_fignore' shopt option; if enabled, suffixes specified by
+ FIGNORE cause words to be ignored when performing word completion even
+ if they're the only possibilities.
+
+x. New `gnu_errfmt' shopt option; if enabled, error messages follow the `gnu
+ style' (filename:lineno:message) format.
+
+y. New `-o bashdefault' option to complete and compgen; if set, causes the
+ whole set of bash completions to be performed if the compspec doesn't
+ result in a match.
+
+z. New `-o plusdirs' option to complete and compgen; if set, causes directory
+ name completion to be performed and the results added to the rest of the
+ possible completions.
+
+aa. `kill' is available as a builtin even when the shell is built without
+ job control.
+
+bb. New HISTTIMEFORMAT variable; value is a format string to pass to
+ strftime(3). If set and not null, the `history' builtin prints out
+ timestamp information according to the specified format when displaying
+ history entries. If set, bash tells the history library to write out
+ timestamp information when the history file is written.
+
+cc. The [[ ... ]] command has a new binary `=~' operator that performs
+ extended regular expression (egrep-like) matching.
+
+dd. `configure' has a new `--enable-cond-regexp' option (enabled by default)
+ to enable the =~ operator and regexp matching in [[ ... ]].
+
+ee. Subexpressions matched by the =~ operator are placed in the new
+ BASH_REMATCH array variable.
+
+ff. New `failglob' option that causes an expansion error when pathname
+ expansion fails to produce a match.
+
+gg. New `set -o pipefail' option that causes a pipeline to return a failure
+ status if any of the processes in the pipeline fail, not just the last
+ one.
+
+hh. printf builtin understands two new escape sequences: \" and \?.
+
+ii. `echo -e' understands two new escape sequences: \" and \?.
+
+jj. The GNU `gettext' package and libintl have been integrated; the shell's
+ messages can be translated into different languages.
+
+kk. The `\W' prompt expansion now abbreviates $HOME as `~', like `\w'.
+
+ll. The error message printed when bash cannot open a shell script supplied
+ as argument 1 now includes the name of the shell, to better identify
+ the error as coming from bash.
+
+mm. The parameter pattern removal and substitution expansions are now much
+ faster and more efficient when using multibyte characters.
+
+nn. The `jobs', `kill', and `wait' builtins now accept job control notation
+ even if job control is not enabled.
+
+oo. The historical behavior of `trap' that allows a missing `action' argument
+ to cause each specified signal's handling to be reset to its default is
+ now only supported when `trap' is given a single non-option argument.
+
+2. New Features in Readline
+
+a. History expansion has a new `a' modifier equivalent to the `g' modifier
+ for compatibility with the BSD csh.
+
+b. History expansion has a new `G' modifier equivalent to the BSD csh `g'
+ modifier, which performs a substitution once per word.
+
+c. All non-incremental search operations may now undo the operation of
+ replacing the current line with the history line.
+
+d. The text inserted by an `a' command in vi mode can be reinserted with
+ `.'.
+
+e. New bindable variable, `show-all-if-unmodified'. If set, the readline
+ completer will list possible completions immediately if there is more
+ than one completion and partial completion cannot be performed.
+
+f. There is a new application-callable `free_history_entry()' function.
+
+g. History list entries now contain timestamp information; the history file
+ functions know how to read and write timestamp information associated
+ with each entry.
+
+h. Four new key binding functions have been added:
+
+ rl_bind_key_if_unbound()
+ rl_bind_key_if_unbound_in_map()
+ rl_bind_keyseq_if_unbound()
+ rl_bind_keyseq_if_unbound_in_map()
+
+i. New application variable, rl_completion_quote_character, set to any
+ quote character readline finds before it calls the application completion
+ function.
+
+j. New application variable, rl_completion_suppress_quote, settable by an
+ application completion function. If set to non-zero, readline does not
+ attempt to append a closing quote to a completed word.
+
+k. New application variable, rl_completion_found_quote, set to a non-zero
+ value if readline determines that the word to be completed is quoted.
+ Set before readline calls any application completion function.
+
+l. New function hook, rl_completion_word_break_hook, called when readline
+ needs to break a line into words when completion is attempted. Allows
+ the word break characters to vary based on position in the line.
+
+m. New bindable command: unix-filename-rubout. Does the same thing as
+ unix-word-rubout, but adds `/' to the set of word delimiters.
+
+n. When listing completions, directories have a `/' appended if the
+ `mark-directories' option has been enabled.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-2.05b since
+the release of bash-2.05a. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. If set, TMOUT is the default timeout for the `read' builtin.
+
+b. `type' has two new options: `-f' suppresses shell function lookup, and
+ `-P' forces a $PATH search.
+
+c. New code to handle multibyte characters.
+
+d. `select' was changed to be more ksh-compatible, in that the menu is
+ reprinted each time through the loop only if REPLY is set to NULL.
+ The previous behavior is available as a compile-time option.
+
+e. `complete -d' and `complete -o dirnames' now force a slash to be
+ appended to names which are symlinks to directories.
+
+f. There is now a bindable edit-and-execute-command readline command,
+ like the vi-mode `v' command, bound to C-xC-e in emacs mode.
+
+g. Added support for ksh93-like [:word:] character class in pattern matching.
+
+h. The $'...' quoting construct now expands \cX to Control-X.
+
+i. A new \D{...} prompt expansion; passes the `...' to strftime and inserts
+ the result into the expanded prompt.
+
+j. The shell now performs arithmetic in the largest integer size the
+ machine supports (intmax_t), instead of long.
+
+k. If a numeric argument is supplied to one of the bash globbing completion
+ functions, a `*' is appended to the word before expansion is attempted.
+
+l. The bash globbing completion functions now allow completions to be listed
+ with double tabs or if `show-all-if-ambiguous' is set.
+
+m. New `-o nospace' option for `complete' and `compgen' builtins; suppresses
+ readline's appending a space to the completed word.
+
+n. 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).
+
+p. There is a new configuration option `--enable-mem-scramble', controls
+ bash malloc behavior of writing garbage characters into memory at
+ allocation and free time.
+
+q. The `complete' and `compgen' builtins now have a new `-s/-A service'
+ option to complete on names from /etc/services.
+
+r. `read' has a new `-u fd' option to read from a specified file descriptor.
+
+s. Fix the completion code so that expansion errors in a directory name
+ don't cause a longjmp back to the command loop.
+
+t. Fixed word completion inside command substitution to work a little more
+ intuitively.
+
+u. The `printf' %q format specifier now uses $'...' quoting to print the
+ argument if it contains non-printing characters.
+
+v. The `declare' and `typeset' builtins have a new `-t' option. When applied
+ to functions, it causes the DEBUG trap to be inherited by the named
+ function. Currently has no effect on variables.
+
+w. The DEBUG trap is now run *before* simple commands, ((...)) commands,
+ [[...]] conditional commands, and for ((...)) loops.
+
+x. 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.
+
+y. 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. Code
+ from Gary Vaughan.
+
+z. New [n]<&word- and [n]>&word- redirections from ksh93 -- move fds (dup
+ and close).
+
+aa. There is a new `-l' invocation option, equivalent to `--login'.
+
+bb. The `hash' builtin has a new `-l' option to list contents in a reusable
+ format, and a `-d' option to remove a name from the hash table.
+
+cc. There is now support for placing the long help text into separate files
+ installed into ${datadir}/bash. Not enabled by default; can be turned
+ on with `--enable-separate-helpfiles' option to configure.
+
+dd. All builtins that take operands accept a `--' pseudo-option, except
+ `echo'.
+
+ee. The `echo' builtin now accepts \0xxx (zero to three octal digits following
+ the `0') in addition to \xxx (one to three octal digits) for SUSv3/XPG6/
+ POSIX.1-2001 compliance.
+
+
+2. New Features in Readline
+
+a. Support for key `subsequences': allows, e.g., ESC and ESC-a to both
+ be bound to readline functions. Now the arrow keys may be used in vi
+ insert mode.
+
+b. When listing completions, and the number of lines displayed is more than
+ the screen length, readline uses an internal pager to display the results.
+ This is controlled by the `page-completions' variable (default on).
+
+c. New code to handle editing and displaying multibyte characters.
+
+d. The behavior introduced in bash-2.05a of deciding whether or not to
+ append a slash to a completed name that is a symlink to a directory has
+ been made optional, controlled by the `mark-symlinked-directories'
+ variable (default is the 2.05a behavior).
+
+e. The `insert-comment' command now acts as a toggle if given a numeric
+ argument: if the first characters on the line don't specify a
+ comment, insert one; if they do, delete the comment text
+
+f. New application-settable completion variable:
+ rl_completion_mark_symlink_dirs, allows an application's completion
+ function to temporarily override the user's preference for appending
+ slashes to names which are symlinks to directories.
+
+g. New function available to application completion functions:
+ rl_completion_mode, to tell how the completion function was invoked
+ and decide which argument to supply to rl_complete_internal (to list
+ completions, etc.).
+
+h. Readline now has an overwrite mode, toggled by the `overwrite-mode'
+ bindable command, which could be bound to `Insert'.
+
+i. New application-settable completion variable:
+ rl_completion_suppress_append, inhibits appending of
+ rl_completion_append_character to completed words.
+
+j. New key bindings when reading an incremental search string: ^W yanks
+ the currently-matched word out of the current line into the search
+ string; ^Y yanks the rest of the current line into the search string,
+ DEL or ^H deletes characters from the search string.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-2.05a since
+the release of bash-2.05. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. Added support for DESTDIR installation root prefix, so you can do a
+ `make install DESTDIR=bash-root' and do easier binary packaging.
+
+b. Added support for builtin printf "'" flag character as per latest POSIX
+ drafts.
+
+c. Support for POSIX.2 printf(1) length specifiers `j', `t', and `z' (from
+ ISO C99).
+
+d. New autoconf macro, RL_LIB_READLINE_VERSION, for use by other applications
+ (bash doesn't use very much of what it returns).
+
+e. `set [-+]o nolog' is recognized as required by the latest POSIX drafts,
+ but ignored.
+
+f. New read-only `shopt' option: login_shell. Set to non-zero value if the
+ shell is a login shell.
+
+g. New `\A' prompt string escape sequence; expands to time in 24 HH:MM format.
+
+h. New `-A group/-g' option to complete and compgen; does group name
+ completion.
+
+i. New `-t' option to `hash' to list hash values for each filename argument.
+
+j. New [-+]O invocation option to set and unset `shopt' options at startup.
+
+k. configure's `--with-installed-readline' option now takes an optional
+ `=PATH' suffix to set the root of the tree where readline is installed
+ to PATH.
+
+l. The ksh-like `ERR' trap has been added. The `ERR' trap will be run
+ whenever the shell would have exited if the -e option were enabled.
+ It is not inherited by shell functions.
+
+m. `readonly', `export', and `declare' now print variables which have been
+ given attributes but not set by assigning a value as just a command and
+ a variable name (like `export foo') when listing, as the latest POSIX
+ drafts require.
+
+n. `bashbug' now requires that the subject be changed from the default.
+
+o. configure has a new `--enable-largefile' option, like other GNU utilities.
+
+p. `for' loops now allow empty word lists after `in', like the latest POSIX
+ drafts require.
+
+q. The builtin `ulimit' now takes two new non-numeric arguments: `hard',
+ meaning the current hard limit, and `soft', meaning the current soft
+ limit, in addition to `unlimited'
+
+r. `ulimit' now prints the option letter associated with a particular
+ resource when printing more than one limit.
+
+s. `ulimit' prints `hard' or `soft' when a value is not `unlimited' but is
+ one of RLIM_SAVED_MAX or RLIM_SAVED_CUR, respectively.
+
+t. The `printf' builtin now handles the %a and %A conversions if they're
+ implemented by printf(3).
+
+u. The `printf' builtin now handles the %F conversion (just about like %f).
+
+v. The `printf' builtin now handles the %n conversion like printf(3). The
+ corresponding argument is the name of a shell variable to which the
+ value is assigned.
+
+2. New Features in Readline
+
+a. Added extern declaration for rl_get_termcap to readline.h, making it a
+ public function (it was always there, just not in readline.h).
+
+b. New #defines in readline.h: RL_READLINE_VERSION, currently 0x0402,
+ RL_VERSION_MAJOR, currently 4, and RL_VERSION_MINOR, currently 2.
+
+c. New readline variable: rl_readline_version, mirrors RL_READLINE_VERSION.
+
+d. New bindable boolean readline variable: match-hidden-files. Controls
+ completion of files beginning with a `.' (on Unix). Enabled by default.
+
+e. The history expansion code now allows any character to terminate a
+ `:first-' modifier, like csh.
+
+f. New bindable variable `history-preserve-point'. If set, the history
+ code attempts to place the user at the same location on each history
+ line retrived with previous-history or next-history.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-2.05 since
+the release of bash-2.04. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. Added a new `--init-file' invocation argument as a synonym for `--rcfile',
+ per the new GNU coding standards.
+
+b. The /dev/tcp and /dev/udp redirections now accept service names as well as
+ port numbers.
+
+c. `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
+
+d. A new loadable builtin, realpath, which canonicalizes and expands symlinks
+ in pathname arguments.
+
+e. 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.
+
+f. Bash-2.05 once again honors the current locale setting when processing
+ ranges within pattern matching bracket expressions (e.g., [A-Z]).
+
+2. New Features in Readline
+
+a. The blink timeout for paren matching is now settable by applications,
+ via the rl_set_paren_blink_timeout() function.
+
+b. _rl_executing_macro has been renamed to rl_executing_macro, which means
+ it's now part of the public interface.
+
+c. Readline has a new variable, rl_readline_state, which is a bitmap that
+ encapsulates the current state of the library; intended for use by
+ callbacks and hook functions.
+
+d. New application-callable function rl_set_prompt(const char *prompt):
+ expands its prompt string argument and sets rl_prompt to the result.
+
+e. New application-callable function rl_set_screen_size(int rows, int cols):
+ public method for applications to set readline's idea of the screen
+ dimensions.
+
+f. New function, rl_get_screen_size (int *rows, int *columns), returns
+ readline's idea of the screen dimensions.
+
+g. The timeout in rl_gather_tyi (readline keyboard input polling function)
+ is now settable via a function (rl_set_keyboard_input_timeout()).
+
+h. Renamed the max_input_history variable to history_max_entries; the old
+ variable is maintained for backwards compatibility.
+
+i. The list of characters that separate words for the history tokenizer is
+ now settable with a variable: history_word_delimiters. The default
+ value is as before.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-2.04 since
+the release of bash-2.03. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. The history builtin has a `-d offset' option to delete the history entry
+ at position `offset'.
+
+b. The prompt expansion code has two new escape sequences: \j, the number of
+ active jobs; and \l, the basename of the shell's tty device name.
+
+c. The `bind' builtin has a new `-x' option to bind key sequences to shell
+ commands.
+
+d. There is a new shell option, no_empty_command_completion, which, when
+ enabled, disables command completion when TAB is typed on an empty line.
+
+e. The `help' builtin has a `-s' option to just print a builtin's usage
+ synopsis.
+
+f. There are several new arithmetic operators: id++, id-- (variable
+ post-increment/decrement), ++id, --id (variable pre-increment/decrement),
+ expr1 , expr2 (comma operator).
+
+g. There is a new ksh-93 style arithmetic for command:
+ for ((expr1 ; expr2; expr3 )); do list; done
+
+h. The `read' builtin has a number of new options:
+ -t timeout only wait timeout seconds for input
+ -n nchars only read nchars from input instead of a full line
+ -d delim read until delim rather than newline
+ -s don't echo input chars as they are read
+
+i. The redirection code now handles several filenames specially:
+ /dev/fd/N, /dev/stdin, /dev/stdout, and /dev/stderr, whether or
+ not they are present in the file system.
+
+j. The redirection code now recognizes pathnames of the form
+ /dev/tcp/host/port and /dev/udp/host/port, and tries to open a socket
+ of the appropriate type to the specified port on the specified host.
+
+k. The ksh-93 ${!prefix*} expansion, which expands to the names of all
+ shell variables with prefix PREFIX, has been implemented.
+
+l. There is a new dynamic variable, FUNCNAME, which expands to the name of
+ a currently-executing function. Assignments to FUNCNAME have no effect.
+
+m. The GROUPS variable is no longer readonly; assignments to it are silently
+ discarded. This means it can be unset.
+
+n. A new programmable completion facility, with two new builtin commands:
+ complete and compgen.
+
+o. configure has a new option, `--enable-progcomp', to compile in the
+ programmable completion features (enabled by default).
+
+p. `shopt' has a new option, `progcomp', to enable and disable programmable
+ completion at runtime.
+
+q. Unsetting HOSTFILE now clears the list of hostnames used for completion.
+
+r. configure has a new option, `--enable-bash-malloc', replacing the old
+ `--with-gnu-malloc' (which is still present for backwards compatibility).
+
+s. There is a new manual page describing rbash, the restricted shell.
+
+t. `bashbug' has new `--help' and `--version' options.
+
+u. `shopt' has a new `xpg_echo' option, which controls the behavior of
+ `echo' with respect to backslash-escaped characters at runtime.
+
+v. If NON_INTERACTIVE_LOGIN_SHELLS is defined, all login shells read the
+ startup files, even if they are not interactive.
+
+w. The LC_NUMERIC variable is now treated specially, and used to set the
+ LC_NUMERIC locale category for number formatting, e.g., when `printf'
+ displays floating-point numbers.
+
+2. New features in Readline
+
+a. Parentheses matching is now always compiled into readline, and enabled
+ or disabled when the value of the `blink-matching-paren' variable is
+ changed.
+
+b. MS-DOS systems now use ~/_inputrc as the last-ditch inputrc filename.
+
+c. MS-DOS systems now use ~/_history as the default history file.
+
+d. history-search-{forward,backward} now leave the point at the end of the
+ line when the string to search for is empty, like
+ {reverse,forward}-search-history.
+
+e. history-search-{forward,backward} now leave the last history line found
+ in the readline buffer if the second or subsequent search fails.
+
+f. New function for use by applications: rl_on_new_line_with_prompt, used
+ when an application displays the prompt itself before calling readline().
+
+g. New variable for use by applications: rl_already_prompted. An application
+ that displays the prompt itself before calling readline() must set this to
+ a non-zero value.
+
+h. A new variable, rl_gnu_readline_p, always 1. The intent is that an
+ application can verify whether or not it is linked with the `real'
+ readline library or some substitute.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-2.03 since
+the release of bash-2.02. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. New `shopt' option, `restricted_shell', indicating whether or not the
+ shell was started in restricted mode, for use in startup files.
+
+b. Filename generation is now performed on the words between ( and ) in
+ array assignments (which it probably should have done all along).
+
+c. OLDPWD is now auto-exported, as POSIX.2 seems to require.
+
+d. ENV and BASH_ENV are read-only variables in a restricted shell.
+
+e. A change was made to the startup file code so that any shell begun with
+ the `--login' option, even non-interactive shells, will source the login
+ shell startup files.
+
+2. New Features in Readline
+
+a. Many changes to the signal handling:
+ o Readline now catches SIGQUIT and cleans up the tty before returning;
+ o A new variable, rl_catch_signals, is available to application writers
+ to indicate to readline whether or not it should install its own
+ signal handlers for SIGINT, SIGTERM, SIGQUIT, SIGALRM, SIGTSTP,
+ SIGTTIN, and SIGTTOU;
+ o A new variable, rl_catch_sigwinch, is available to application
+ writers to indicate to readline whether or not it should install its
+ own signal handler for SIGWINCH, which will chain to the calling
+ applications's SIGWINCH handler, if one is installed;
+ o There is a new function, rl_free_line_state, for application signal
+ handlers to call to free up the state associated with the current
+ line after receiving a signal;
+ o There is a new function, rl_cleanup_after_signal, to clean up the
+ display and terminal state after receiving a signal;
+ o There is a new function, rl_reset_after_signal, to reinitialize the
+ terminal and display state after an application signal handler
+ returns and readline continues
+
+b. There is a new function, rl_resize_terminal, to reset readline's idea of
+ the screen size after a SIGWINCH.
+
+c. New public functions: rl_save_prompt and rl_restore_prompt. These were
+ previously private functions with a `_' prefix.
+
+d. New function hook: rl_pre_input_hook, called just before readline starts
+ reading input, after initialization.
+
+e. New function hook: rl_display_matches_hook, called when readline would
+ display the list of completion matches. The new function
+ rl_display_match_list is what readline uses internally, and is available
+ for use by application functions called via this hook.
+
+f. New bindable function, delete-char-or-list, like tcsh.
+
+g. A new variable, rl_erase_empty_line, which, if set by an application using
+ readline, will cause readline to erase, prompt and all, lines on which the
+ only thing typed was a newline.
+
+h. New bindable variable: `isearch-terminators'.
+
+i. New bindable function: `forward-backward-delete-char' (unbound by default).
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-2.02 since
+the release of bash-2.01.1. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. A new version of malloc, based on the older GNU malloc, that has many
+ changes, is more page-based, is more conservative with memory usage,
+ and does not `orphan' large blocks when they are freed.
+
+b. A new version of gmalloc, based on the old GLIBC malloc, with many
+ changes and range checking included by default.
+
+c. A new implementation of fnmatch(3) that includes full POSIX.2 Basic
+ Regular Expression matching, including character classes, collating
+ symbols, equivalence classes, and support for case-insensitive pattern
+ matching.
+
+d. ksh-88 egrep-style extended pattern matching ([@+*?!](patlist)) has been
+ implemented, controlled by a new `shopt' option, `extglob'.
+
+e. There is a new ksh-like `[[' compound command, which implements
+ extended `test' functionality.
+
+f. There is a new `printf' builtin, implemented according to the POSIX.2
+ specification.
+
+g. There is a new feature for command substitution: $(< filename) now expands
+ to the contents of `filename', with any trailing newlines removed
+ (equivalent to $(cat filename)).
+
+h. There are new tilde prefixes which expand to directories from the
+ directory stack.
+
+i. There is a new `**' arithmetic operator to do exponentiation.
+
+j. There are new configuration options to control how bash is linked:
+ `--enable-profiling', to allow bash to be profiled with gprof, and
+ `--enable-static-link', to allow bash to be linked statically.
+
+k. There is a new configuration option, `--enable-cond-command', which
+ controls whether or not the `[[' command is included. It is on by
+ default.
+
+l. There is a new configuration option, `--enable-extended-glob', which
+ controls whether or not the ksh extended globbing feature is included.
+ It is enabled by default.
+
+m. There is a new configuration #define in config.h.top that, when enabled,
+ will cause all login shells to source /etc/profile and one of the user-
+ specific login shell startup files, whether or not the shell is
+ interactive.
+
+n. There is a new invocation option, `--dump-po-strings', to dump
+ a shell script's translatable strings ($"...") in GNU `po' format.
+
+o. There is a new `shopt' option, `nocaseglob', to enable case-insensitive
+ pattern matching when globbing filenames and using the `case' construct.
+
+p. There is a new `shopt' option, `huponexit', which, when enabled, causes
+ the shell to send SIGHUP to all jobs when an interactive login shell
+ exits.
+
+q. `bind' has a new `-u' option, which takes a readline function name as an
+ argument and unbinds all key sequences bound to that function in a
+ specified keymap.
+
+r. `disown' now has `-a' and `-r' options, to limit operation to all jobs
+ and running jobs, respectively.
+
+s. The `shopt' `-p' option now causes output to be displayed in a reusable
+ format.
+
+t. `test' has a new `-N' option, which returns true if the filename argument
+ has been modified since it was last accessed.
+
+u. `umask' now has a `-p' option to print output in a reusable format.
+
+v. A new escape sequence, `\xNNN', has been added to the `echo -e' and $'...'
+ translation code. It expands to the character whose ascii code is NNN
+ in hexadecimal.
+
+w. The prompt string expansion code has a new `\r' escape sequence.
+
+x. The shell may now be cross-compiled for the CYGWIN32 environment on
+ a Unix machine.
+
+2. New Features in Readline
+
+a. There is now an option for `iterative' yank-last-arg handline, so a user
+ can keep entering `M-.', yanking the last argument of successive history
+ lines.
+
+b. New variable, `print-completions-horizontally', which causes completion
+ matches to be displayed across the screen (like `ls -x') rather than up
+ and down the screen (like `ls').
+
+c. New variable, `completion-ignore-case', which causes filename completion
+ and matching to be performed case-insensitively.
+
+d. There is a new bindable command, `magic-space', which causes history
+ expansion to be performed on the current readline buffer and a space to
+ be inserted into the result.
+
+e. There is a new bindable command, `menu-complete', which enables tcsh-like
+ menu completion (successive executions of menu-complete insert a single
+ completion match, cycling through the list of possible completions).
+
+f. There is a new bindable command, `paste-from-clipboard', for use on Win32
+ systems, to insert the text from the Win32 clipboard into the editing
+ buffer.
+
+g. The key sequence translation code now understands printf-style backslash
+ escape sequences, including \NNN octal escapes. These escape sequences
+ may be used in key sequence definitions or macro values.
+
+h. An `$include' inputrc file parser directive has been added.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-2.01 since
+the release of bash-2.0. As always, the manual page (doc/bash.1) is the
+place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. There is a new builtin array variable: GROUPS, the set of groups to which
+ the user belongs. This is used by the test suite.
+
+2. New Features in Readline
+
+a. If a key sequence bound to `universal-argument' is read while reading a
+ numeric argument started with `universal-argument', it terminates the
+ argument but is otherwise ignored. This provides a way to insert multiple
+ instances of a digit string, and is how GNU emacs does it.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to bash-2.0 since
+the release of bash-1.14.7. As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1. New Features in Bash
+
+a. There is a new invocation option, -D, that dumps translatable strings
+ in a script.
+
+b. The `long' invocation options must now be prefixed with `--'.
+
+c. New long invocation options: --dump-strings, --help, --verbose
+
+d. The `nolineediting' invocation option was renamed to `noediting'.
+
+e. The `nobraceexpansion' and `quiet' long invocation options were removed.
+
+f. The `--help' and `--version' long options now work as the GNU coding
+ standards specify.
+
+g. If invoked as `sh', bash now enters posix mode after reading the
+ startup files, and reads and executes commands from the file named
+ by $ENV if interactive (as POSIX.2 specifies). A login shell invoked
+ as `sh' reads $ENV after /etc/profile and ~/.profile.
+
+h. There is a new reserved word, `time', for timing pipelines, builtin
+ commands, and shell functions. It uses the value of the TIMEFORMAT
+ variable as a format string describing how to print the timing
+ statistics.
+
+i. The $'...' quoting syntax expands ANSI-C escapes in ... and leaves the
+ result single-quoted.
+
+j. The $"..." quoting syntax performs locale-specific translation of ...
+ and leaves the result double-quoted.
+
+k. LINENO now works correctly in functions.
+
+l. New variables: DIRSTACK, PIPESTATUS, BASH_VERSINFO, HOSTNAME, SHELLOPTS,
+ MACHTYPE. The first three are array variables.
+
+m. The BASH_VERSION and BASH_VERSINFO variables now include the shell's
+ `release status' (alpha[N], beta[N], release).
+
+n. 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'.
+
+o. Bash now uses some new variables: LC_ALL, LC_MESSAGES, LC_CTYPE,
+ LC_COLLATE, LANG, GLOBIGNORE, HISTIGNORE.
+
+p. The shell now supports integer-indexed arrays of unlimited length,
+ with a new compound assignment syntax and changes to the appropriate
+ builtin commands (declare/typeset, read, readonly, etc.). The array
+ index may be an arithmetic expression.
+
+q. ${!var}: indirect variable expansion, equivalent to eval \${$var}.
+
+r. ${paramter:offset[:length]}: variable substring extraction.
+
+s. ${parameter/pattern[/[/]string]}: variable pattern substitution.
+
+t. The $[...] arithmetic expansion syntax is no longer supported, in
+ favor of $((...)).
+
+u. Aliases can now be expanded in shell scripts with a shell option
+ (shopt expand_aliases).
+
+v. History and history expansion can now be used in scripts with
+ set -o history and set -H.
+
+w. All builtins now return an exit status of 2 for incorrect usage.
+
+x. Interactive shells resend SIGHUP to all running or stopped children
+ if (and only if) they exit due to a SIGHUP.
+
+y. New prompting expansions: \a, \e, \H, \T, \@, \v, \V.
+
+z. Variable expansion in prompt strings is now controllable via a shell
+ option (shopt promptvars).
+
+aa. Bash now defaults to using command-oriented history.
+
+bb. The history file ($HISTFILE) is now truncated to $HISTFILESIZE after
+ being written.
+
+cc. The POSIX.2 conditional arithmetic evaluation syntax (expr ? expr : expr)
+ has been implemented.
+
+dd. Each builtin now accepts `--' to signify the end of the options, except
+ as documented (echo, etc.).
+
+ee. All builtins use -p to display values in a re-readable format where
+ appropriate, except as documented (echo, type, etc.).
+
+ff. The `alias' builtin has a new -p option.
+
+gg. Changes to the `bind' builtin:
+ o has new options: -psPSVr.
+ o the `-d' option was renamed to `-p'
+ o the `-v' option now dumps variables; the old `-v' is now `-P'
+
+hh. The `bye' synonym for `exit' was removed.
+
+ii. The -L and -P options to `cd' and `pwd' have been documented.
+
+jj. The `cd' builtin now does spelling correction on the directory name
+ by default. This is settable with a shell option (shopt cdspell).
+
+kk. The `declare' builtin has new options: -a, -F, -p.
+
+ll. The `dirs' builtin has new options: -c, -p, -v.
+
+mm. The new `disown' builtin removes jobs from the shell's jobs table
+ or inhibits the resending of SIGHUP when the shell receives a
+ SIGHUP.
+
+nn. The `echo' builtin has a new escape character: \e.
+
+oo. The `enable' builtin can now load new builtins dynamically from shared
+ objects on systems with the dlopen/dlsym interface. There are a number
+ of examples in the examples/loadables directory. There are also
+ new options: -d, -f, -s, -p.
+
+pp. The `-all' option to `enable' was removed in favor of `-a'.
+
+qq. The `exec' builtin has new options: -l, -c, -a.
+
+rr. The `hash' builtin has a new option: -p.
+
+ss. The `history' builtin has new options: -c, -p, -s.
+
+tt. The `jobs' builtin has new options: -r, -s.
+
+uu. The `kill' builtin has new options: -n signum, -l signame.
+
+vv. The `pushd' and `popd' builtins have a new option: -n.
+
+ww. The `read' builtin has new options: -p prompt, -e, -a.
+
+xx. The `readonly' builtin has a new -a option, and the -n option was removed.
+
+yy. Changes to the `set' builtin:
+ o new options: -B, -o keyword, -o onecmd, -o history
+ o options removed: -l, -d, -o nohash
+ o options changed: +o, -h, -o hashall
+ o now displays variables in a format that can be re-read as input
+
+zz. The new `shopt' builtin controls shell optional behavior previously
+ done by setting and unsetting certain shell variables.
+
+aaa. The `test' builtin has new operators: -o option, s1 == s2, s1 < s2,
+ and s1 > s2, where s1 and s2 are strings.
+
+bbb. There is a new trap, DEBUG, executed after every simple command.
+
+ccc. The `trap' builtin has a new -p option.
+
+ddd. The `ulimit' builtin has a new -l option on 4.4BSD-based systems.
+
+eee. The PS1, PS2, PATH, and IFS variables may now be unset.
+
+fff. The restricted shell mode has been expanded and is now documented.
+
+ggg. Security improvements:
+ o functions are not imported from the environment if running setuid
+ or with -p
+ o no startup files are sourced if running setuid or with -p
+
+hhh. The documentation has been overhauled: the texinfo manual was
+ expanded, and HTML versions of the man page and texinfo manual
+ are included.
+
+iii. Changes to Posix mode:
+ o Command lookup now finds special builtins before shell functions.
+ o Failure of a special builtin causes a non-interactive shell to
+ exit. Failures are defined in the POSIX.2 specification.
+ o If the `cd' builtin finds a directory to change to using $CDPATH,
+ the value assigned to PWD when `cd' completes does not contain
+ any symbolic links.
+ o A non-interactive shell exits if a variable assignment error
+ occurs when no command name follows the assignment statements.
+ o A non-interactive shell exits if the interation variable in a
+ `for' statement or the selection variable in a `select' statement
+ is read-only or another variable assignment error occurs.
+ o The `<>' redirection operator now opens a file for both stdin and
+ stdout by default, not just when in posix mode.
+ o Assignment statements preceding special builtins now persist in
+ the shell's environment when the builtin completes.
+
+ Posix mode is now completely POSIX.2-compliant (modulo bugs). When
+ invoked as sh, bash should be completely POSIX.2-compliant.
+
+jjj. The default value of PS1 is now "\s-\v\$ ".
+
+kkk. The ksh-like ((...)) arithmetic command syntax has been implemented.
+ This is exactly equivalent to `let "..."'.
+
+lll. Integer constants have been extended to base 64.
+
+mmm. The `ulimit' builtin now sets both hard and soft limits and reports the
+ soft limit by default.
+
+2. New Features in Readline
+
+a. New variables: enable-keypad, input-meta (new name for meta-flag),
+ mark-directories, visible-stats (now documented), disable-completion,
+ comment-begin.
+
+b. New bindable commands: kill-region, copy-region-as-kill,
+ copy-backward-word, copy-forward-word, set-mark, exchange-point-and-mark,
+ character-search, character-search-backward, insert-comment,
+ glob-expand-word, glob-list-expansions, dump-variables, dump-macros.
+
+c. New emacs keybindings: delete-horizontal-space (M-\),
+ insert-completions (M-*), possible-completions (M-=).
+
+d. The history-search-backward and history-search-forward commands were
+ modified to be the same as previous-line and next-line if point is at
+ the start of the line.
+
+e. More file types are available for the visible-stats mode.
+
+3. Changes of interest in the Bash implementation
+
+a. There is a new autoconf-based configuration mechanism.
+
+b. More things have been moved from Posix mode to standard shell behavior.
+
+c. The trace output (set -x) now inserts quotes where necessary so it can
+ be reused as input.
+
+d. There is a compile-time option for a system-wide interactive shell
+ startup file (disabled by default).
+
+e. The YACC grammar is smaller and tighter, and all 66 shift-reduce
+ conflicts are gone. Several parsing bugs have been fixed.
+
+f. Builtin option parsing has been regularized (using internal_getopt()),
+ with the exception of `echo', `type', and `set'.
+
+g. Builtins now return standard usage messages constructed from the
+ `short doc' used by the help builtin.
+
+h. Completion now quotes using backslashes by default, but honors
+ user-supplied quotes.
+
+i. The GNU libc malloc is available as a configure-time option.
+
+j. There are more internationalization features; bash uses gettext if
+ it is available. The $"..." translation syntax uses the current
+ locale and gettext.
+
+k. There is better reporting of job termination when the shell is not
+ interactive.
+
+l. The shell is somewhat more efficient: it uses a little less memory and
+ makes fewer system calls.
+
+4. Changes of interest in the Readline implementation
+
+a. There is now support for readline `callback' functions.
+
+b. There is now support for user-supplied input, redisplay, and terminal
+ preparation functions.
+
+c. Most of the shell-specific code in readline has been generalized or
+ removed.
+
+d. Most of the annoying redisplay bugs have been fixed, notably the problems
+ with incremental search and excessive redrawing when special characters
+ appear in the prompt string.
+
+e. There are new library functions and variables available to application
+ writers, most having to do with completion and quoting.
+
+f. The NEWLINE character (^J) is now treated as a search terminator by the
+ incremental search functions.
@%:@! /bin/sh
-@%:@ From configure.in for Bash 4.0, version 4.006.
+@%:@ From configure.in for Bash 4.0, version 4.007.
@%:@ Guess values for system-dependent variables and create Makefiles.
-@%:@ Generated by GNU Autoconf 2.62 for bash 4.0-alpha.
+@%:@ Generated by GNU Autoconf 2.62 for bash 4.0-beta.
@%:@
@%:@ Report bugs to <bug-bash@gnu.org>.
@%:@
# Identity of this package.
PACKAGE_NAME='bash'
PACKAGE_TARNAME='bash'
-PACKAGE_VERSION='4.0-alpha'
-PACKAGE_STRING='bash 4.0-alpha'
+PACKAGE_VERSION='4.0-beta'
+PACKAGE_STRING='bash 4.0-beta'
PACKAGE_BUGREPORT='bug-bash@gnu.org'
ac_unique_file="shell.h"
# Omit some internal or obsolete options to make the list less imposing.
# This message is too long to be a string in the A/UX 3.1 sh.
cat <<_ACEOF
-\`configure' configures bash 4.0-alpha to adapt to many kinds of systems.
+\`configure' configures bash 4.0-beta to adapt to many kinds of systems.
Usage: $0 [OPTION]... [VAR=VALUE]...
if test -n "$ac_init_help"; then
case $ac_init_help in
- short | recursive ) echo "Configuration of bash 4.0-alpha:";;
+ short | recursive ) echo "Configuration of bash 4.0-beta:";;
esac
cat <<\_ACEOF
test -n "$ac_init_help" && exit $ac_status
if $ac_init_version; then
cat <<\_ACEOF
-bash configure 4.0-alpha
+bash configure 4.0-beta
generated by GNU Autoconf 2.62
Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
This file contains any messages produced by compilers while
running configure, to aid debugging if configure makes a mistake.
-It was created by bash $as_me 4.0-alpha, which was
+It was created by bash $as_me 4.0-beta, which was
generated by GNU Autoconf 2.62. Invocation command line was
$ $0 $@
BASHVERS=4.0
-RELSTATUS=alpha
+RELSTATUS=beta
case "$RELSTATUS" in
alp*|bet*|dev*|rc*|maint*) DEBUG='-DDEBUG' MALLOC_DEBUG='-DMALLOC_DEBUG' ;;
# report actual input values of CONFIG_FILES etc. instead of their
# values after options handling.
ac_log="
-This file was extended by bash $as_me 4.0-alpha, which was
+This file was extended by bash $as_me 4.0-beta, which was
generated by GNU Autoconf 2.62. Invocation command line was
CONFIG_FILES = $CONFIG_FILES
_ACEOF
cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
ac_cs_version="\\
-bash config.status 4.0-alpha
+bash config.status 4.0-beta
configured by $0, generated by GNU Autoconf 2.62,
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],
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+ 'AC_CONFIG_LINKS' => 1,
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'sinclude' => 1,
- 'AM_CONDITIONAL' => 1,
+ 'm4_pattern_allow' => 1,
+ 'AM_PROG_CC_C_O' => 1,
'AC_CANONICAL_SYSTEM' => 1,
+ 'AM_CONDITIONAL' => 1,
'AC_CONFIG_HEADERS' => 1,
'AC_DEFINE_TRACE_LITERAL' => 1,
'm4_include' => 1,
-m4trace:configure.in:29: -1- AC_INIT([bash], [4.0-alpha], [bug-bash@gnu.org])
+m4trace:configure.in:29: -1- AC_INIT([bash], [4.0-beta], [bug-bash@gnu.org])
m4trace:configure.in:29: -1- m4_pattern_forbid([^_?A[CHUM]_])
m4trace:configure.in:29: -1- m4_pattern_forbid([_AC_])
m4trace:configure.in:29: -1- m4_pattern_forbid([^LIBOBJS$], [do not use LIBOBJS directly, use AC_LIBOBJ (see section `AC_LIBOBJ vs LIBOBJS'])
run_trap_cleanup (running_trap - 1);
unfreeze_jobs_list ();
}
- run_unwind_frame (PE_TAG);
+
+ if (have_unwind_protects ())
+ run_unwind_frame (PE_TAG);
+ else
+ parse_and_execute_level = 0; /* XXX */
}
static void
#! /bin/sh
-# From configure.in for Bash 4.0, version 4.006.
+# From configure.in for Bash 4.0, version 4.007.
# Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.62 for bash 4.0-alpha.
+# Generated by GNU Autoconf 2.62 for bash 4.0-beta.
#
# Report bugs to <bug-bash@gnu.org>.
#
# Identity of this package.
PACKAGE_NAME='bash'
PACKAGE_TARNAME='bash'
-PACKAGE_VERSION='4.0-alpha'
-PACKAGE_STRING='bash 4.0-alpha'
+PACKAGE_VERSION='4.0-beta'
+PACKAGE_STRING='bash 4.0-beta'
PACKAGE_BUGREPORT='bug-bash@gnu.org'
ac_unique_file="shell.h"
# Omit some internal or obsolete options to make the list less imposing.
# This message is too long to be a string in the A/UX 3.1 sh.
cat <<_ACEOF
-\`configure' configures bash 4.0-alpha to adapt to many kinds of systems.
+\`configure' configures bash 4.0-beta to adapt to many kinds of systems.
Usage: $0 [OPTION]... [VAR=VALUE]...
if test -n "$ac_init_help"; then
case $ac_init_help in
- short | recursive ) echo "Configuration of bash 4.0-alpha:";;
+ short | recursive ) echo "Configuration of bash 4.0-beta:";;
esac
cat <<\_ACEOF
test -n "$ac_init_help" && exit $ac_status
if $ac_init_version; then
cat <<\_ACEOF
-bash configure 4.0-alpha
+bash configure 4.0-beta
generated by GNU Autoconf 2.62
Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
This file contains any messages produced by compilers while
running configure, to aid debugging if configure makes a mistake.
-It was created by bash $as_me 4.0-alpha, which was
+It was created by bash $as_me 4.0-beta, which was
generated by GNU Autoconf 2.62. Invocation command line was
$ $0 $@
BASHVERS=4.0
-RELSTATUS=alpha
+RELSTATUS=beta
case "$RELSTATUS" in
alp*|bet*|dev*|rc*|maint*) DEBUG='-DDEBUG' MALLOC_DEBUG='-DMALLOC_DEBUG' ;;
# report actual input values of CONFIG_FILES etc. instead of their
# values after options handling.
ac_log="
-This file was extended by bash $as_me 4.0-alpha, which was
+This file was extended by bash $as_me 4.0-beta, which was
generated by GNU Autoconf 2.62. Invocation command line was
CONFIG_FILES = $CONFIG_FILES
_ACEOF
cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
ac_cs_version="\\
-bash config.status 4.0-alpha
+bash config.status 4.0-beta
configured by $0, generated by GNU Autoconf 2.62,
with options \\"`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`\\"
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
-AC_REVISION([for Bash 4.0, version 4.006])dnl
+AC_REVISION([for Bash 4.0, version 4.007])dnl
define(bashvers, 4.0)
-define(relstatus, alpha)
+define(relstatus, beta)
AC_INIT([bash], bashvers-relstatus, [bug-bash@gnu.org])
# Copyright (C) 1987-2008 Free Software Foundation, Inc.
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 2, or (at your option)
-# any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program; if not, write to the Free Software
-# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
-# 02111-1307, USA.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
-AC_REVISION([for Bash 4.0, version 4.003])dnl
+AC_REVISION([for Bash 4.0, version 4.006])dnl
define(bashvers, 4.0)
-define(relstatus, devel)
+define(relstatus, alpha)
AC_INIT([bash], bashvers-relstatus, [bug-bash@gnu.org])
AC_CHECK_FUNCS(getpwent getpwnam getpwuid)
AC_REPLACE_FUNCS(getcwd memset strcasecmp strerror strftime strnlen strpbrk strstr)
AC_REPLACE_FUNCS(strtod strtol strtoul strtoll strtoull strtoimax strtoumax)
+AC_REPLACE_FUNCS(fdprintf)
AC_CHECK_DECLS([confstr])
AC_CHECK_DECLS([printf])
LOCAL_DEFS=-DSHELL
dnl use this section to possibly define more cpp variables, specify local
-dnl libraries, and specify any additional local cc flags
+dnl libraries, and specify any additional local cc or ld flags
dnl
dnl this should really go away someday
sco3.2*) LOCAL_CFLAGS=-DMUST_UNBLOCK_CHLD ;;
sunos4*) LOCAL_CFLAGS=-DSunOS4 ;;
solaris2.5*) LOCAL_CFLAGS="-DSunOS5 -DSOLARIS" ;;
+solaris2.8*) LOCAL_CFLAGS=-DSOLARIS LOCAL_LDFLAGS='-z interpose' ;;
+solaris2.9*) LOCAL_CFLAGS=-DSOLARIS LOCAL_LDFLAGS='-z interpose' ;;
+solaris2.10*) LOCAL_CFLAGS=-DSOLARIS LOCAL_LDFLAGS='-z interpose' ;;
solaris2*) LOCAL_CFLAGS=-DSOLARIS ;;
lynxos*) LOCAL_CFLAGS=-DRECYCLES_PIDS ;;
linux*) LOCAL_LDFLAGS=-rdynamic # allow dynamic loading
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.
+
A short feature history dating from Bash-2.0:
Bash-3.2 contained the following new features:
--- /dev/null
+This is the Bash FAQ, version 3.37, for Bash version 4.0.
+
+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 4.0?
+B2) Are there any user-visible incompatibilities between bash-4.0,
+ bash-3.2, and bash-2.05b?
+
+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?
+
+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 4.0, first made available on XXX YYYYY, 2008.
+
+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 4.0:
+
+ftp://ftp.gnu.org/pub/gnu/bash/bash-4.0.tar.gz
+ftp://ftp.cwru.edu/pub/bash/bash-4.0.tar.gz
+
+Formatted versions of the documentation are available with the URLs:
+
+ftp://ftp.gnu.org/pub/gnu/bash/bash-doc-4.0.tar.gz
+ftp://ftp.cwru.edu/pub/bash/bash-doc-4.0.tar.gz
+
+Any patches for the current version are available with the URL:
+
+ftp://ftp.cwru.edu/pub/bash/bash-4.0-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-2.05b and bash-3.2 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-4.0, 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 4.0?
+
+Bash-4.0 is the fourth major release of bash. There are numerous new features,
+some experimental. Depending on community reception, the experimental
+features will evolve.
+
+Bash-4.0 contains the following new features (see the manual page for
+complete descriptions and the CHANGES and NEWS files in the bash-4.0
+distribution):
+
+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.
+
+A short feature history dating from Bash-2.0:
+
+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-4.0, bash-3.2,
+ and bash-2.05b?
+
+There are a few incompatibilities between version 4.0 and version 3.2.
+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
+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
+ 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,
+ 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
+
+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, 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
+
+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?
+
+New things in ksh-93 not in bash-4.0:
+ floating point arithmetic and variables
+ math library functions
+ ${!name[sub]} name of subscript for associative array
+ `.' is allowed in variable names to create a hierarchical namespace
+ more extensive compound assignment syntax
+ discipline functions
+ `sleep' and `getconf' builtins (bash has loadable versions)
+ typeset -n and `nameref' variables
+ KEYBD trap
+ variables: .sh.edchar, .sh.edmode, .sh.edcol, .sh.edtext, .sh.version,
+ .sh.name, .sh.subscript, .sh.value, .sh.match, HISTEDIT
+ backreferences in pattern matching (\N)
+ `&' operator in pattern lists for matching
+ print -f (bash uses printf)
+ `fc' has been renamed to `hist'
+ `.' can execute shell functions
+ exit statuses between 0 and 255
+ FPATH and PATH mixing
+ getopts -a
+ -I invocation option
+ printf %H, %P, %T, %Z modifiers, output base for %d
+ lexical scoping for local variables in `ksh' functions
+ no scoping for local variables in `POSIX' functions
+
+New things in ksh-93 present in bash-4.0:
+ 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'
+ `command', `builtin', `disown' builtins
+ new $'...' and $"..." quoting
+ FIGNORE (but bash uses GLOBIGNORE), HISTCMD
+ set -o notify/-C
+ changes to kill builtin
+ read -A (bash uses read -a)
+ read -t/-d
+ trap -p
+ exec -c/-a
+ `.' restores the positional parameters when it completes
+ POSIX.2 `test'
+ umask -S
+ unalias -a
+ command and arithmetic substitution performed on PS1, PS4, and ENV
+ command name completion
+ ENV processed only for interactive shells
+ set -o pipefail
+ The `+=' assignment operator
+
+Section D: Why does bash do some things differently than other Unix shells?
+
+D1) Why does bash run a different version of `command' than
+ `which command' says it will?
+
+On many systems, `which' is actually a csh script that assumes
+you're running csh. In tcsh, `which' and its cousin `where'
+are builtins. On other Unix systems, `which' is a perl script
+that uses the PATH environment variable. Many Linux distributions
+use GNU `which', which is a C program that can understand shell
+aliases.
+
+The csh script version reads the csh startup files from your
+home directory and uses those to determine which `command' will
+be invoked. Since bash doesn't use any of those startup files,
+there's a good chance that your bash environment differs from
+your csh environment. The bash `type' builtin does everything
+`which' does, and will report correct results for the running
+shell. If you're really wedded to the name `which', try adding
+the following function definition to your .bashrc:
+
+ which()
+ {
+ builtin type "$@"
+ }
+
+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.
+
+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-3.0)
+associative arrays
+co-processes, but with a new-style syntax that looks like function declaration
+
+H4) What's on the bash `wish list' for future versions?
+
+These are features that may or may not appear in a future version of bash.
+
+breaking some of the shell functionality into embeddable libraries
+a module system like zsh's, using dynamic loading like builtins
+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 2007. Never make predictions.
+
+This document is Copyright 1995-2006 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.
js.c_totforked++;
js.c_living++;
+itrace("make_child: `%s' --> %ld", command, pid);
/* Unblock SIGINT and SIGCHLD unless creating a pipeline, in which case
SIGCHLD remains blocked until all commands in the pipeline have been
created. */
or until loop, act as if the shell received SIGINT as
well, so the loop can be broken. This doesn't call the
SIGINT signal handler; maybe it should. */
- if (signal_is_trapped (SIGINT) == 0 && (loop_level || executing_list))
+ if (signal_is_trapped (SIGINT) == 0 && (loop_level || (shell_compatibility_level > 32 && executing_list)))
ADDINTERRUPT;
else
{
-BUILD_DIR=/usr/local/build/bash/bash-current
+BUILD_DIR=/usr/local/build/chet/bash/bash-current
THIS_SH=$BUILD_DIR/bash
PATH=$PATH:$BUILD_DIR
}
}
+int
+have_unwind_protects ()
+{
+ return (unwind_protect_list != 0);
+}
+
/* **************************************************************** */
/* */
/* The Actual Functions */
extern void remove_unwind_protect __P((void));
extern void run_unwind_protects __P((void));
extern void clear_unwind_protect_list __P((int));
+extern int have_unwind_protects __P((void));
extern void uwp_init __P((void));
/* Define for people who like their code to look a certain way. */
if (rl_completer_word_break_characters == 0 && bash_readline_initialized == 0)
enable_hostname_completion (perform_hostname_completion);
- var_setvalue (var, rl_completer_word_break_characters);
+ FREE (value_cell (var));
+ var_setvalue (var, savestring (rl_completer_word_break_characters));
return (var);
}
sv_globignore (name)
char *name;
{
- setup_glob_ignore (name);
+ if (privileged_mode == 0)
+ setup_glob_ignore (name);
}
#if defined (READLINE)
projects / thirdparty / bash.git / commitdiff
