1 This is a terse description of the new features added to bash-3.1 since
2 the release of bash-3.0. As always, the manual page (doc/bash.1) is
3 the place to look for complete descriptions.
5 1. New Features in Bash
7 a. Bash now understands LC_TIME as a special variable so that time display
8 tracks the current locale.
10 b. BASH_ARGC, BASH_ARGV, BASH_SOURCE, and BASH_LINENO are no longer created
11 as `invisible' variables and may not be unset.
13 c. In POSIX mode, if `xpg_echo' option is enabled, the `echo' builtin doesn't
14 try to interpret any options at all, as POSIX requires.
16 d. The `bg' builtin now accepts multiple arguments, as POSIX seems to specify.
18 e. Fixed vi-mode word completion and glob expansion to perform tilde
21 f. The `**' mathematic exponentiation operator is now right-associative.
23 g. The `ulimit' builtin has new options: -i (max number of pending signals),
24 -q (max size of POSIX message queues), and -x (max number of file locks).
26 h. A bare `%' once again expands to the current job when used as a job
29 i. The `+=' assignment operator (append to the value of a string or array) is
30 now supported for assignment statements and arguments to builtin commands
31 that accept assignment statements.
33 j. BASH_COMMAND now preserves its value when a DEBUG trap is executed.
35 k. The `gnu_errfmt' option is enabled automatically if the shell is running
36 in an emacs terminal window.
38 l. New configuration option: --single-help-strings. Causes long help text
39 to be written as a single string; intended to ease translation.
41 m. The COMP_WORDBREAKS variable now causes the list of word break characters
42 to be emptied when the variable is unset.
44 n. An unquoted expansion of $* when $IFS is empty now causes the positional
45 parameters to be concatenated if the expansion doesn't undergo word
48 o. Bash now inherits $_ from the environment if it appears there at startup.
50 p. New shell option: nocasematch. If non-zero, shell pattern matching ignores
51 case when used by `case' and `[[' commands.
53 q. The `printf' builtin takes a new option: -v var. That causes the output
54 to be placed into var instead of on stdout.
56 r. By default, the shell no longer reports processes dying from SIGPIPE.
58 s. Bash now sets the extern variable `environ' to the export environment it
59 creates, so C library functions that call getenv() (and can't use the
60 shell-provided replacement) get current values of environment variables.
62 t. A new configuration option, `--enable-strict-posix-default', which will
63 build bash to be POSIX conforming by default.
65 u. If compiled for strict POSIX conformance, LINES and COLUMNS may now
66 override the true terminal size.
68 2. New Features in Readline
70 a. The key sequence sent by the keypad `delete' key is now automatically
73 b. A negative argument to menu-complete now cycles backward through the
76 c. A new bindable readline variable: bind-tty-special-chars. If non-zero,
77 readline will bind the terminal special characters to their readline
78 equivalents when it's called (on by default).
80 d. New bindable command: vi-rubout. Saves deleted text for possible
81 reinsertion, as with any vi-mode `text modification' command; `X' is bound
82 to this in vi command mode.
84 e. A new external application-controllable variable that allows the LINES
85 and COLUMNS environment variables to set the window size regardless of
86 what the kernel returns: rl_prefer_env_winsize
88 -------------------------------------------------------------------------------
89 This is a terse description of the new features added to bash-3.0 since
90 the release of bash-2.05b. As always, the manual page (doc/bash.1) is
91 the place to look for complete descriptions.
93 1. New Features in Bash
95 a. ANSI string expansion now implements the \x{hexdigits} escape.
97 b. There is a new loadable `strftime' builtin.
99 c. New variable, COMP_WORDBREAKS, which controls the readline completer's
100 idea of word break characters.
102 d. The `type' builtin no longer reports on aliases unless alias expansion
103 will actually be performed.
105 e. HISTCONTROL is now a colon-separated list of values, which permits
106 more extensibility and backwards compatibility.
108 f. HISTCONTROL may now include the `erasedups' option, which causes all lines
109 matching a line being added to be removed from the history list.
111 g. `configure' has a new `--enable-multibyte' argument that permits multibyte
112 character support to be disabled even on systems that support it.
114 h. New variables to support the bash debugger: BASH_ARGC, BASH_ARGV,
115 BASH_SOURCE, BASH_LINENO, BASH_SUBSHELL, BASH_EXECUTION_STRING,
118 i. FUNCNAME has been changed to support the debugger: it's now an array
121 j. for, case, select, arithmetic commands now keep line number information
124 k. There is a new `RETURN' trap executed when a function or sourced script
125 returns (not inherited child processes; inherited by command substitution
126 if function tracing is enabled and the debugger is active).
128 l. New invocation option: --debugger. Enables debugging and turns on new
129 `extdebug' shell option.
131 m. New `functrace' and `errtrace' options to `set -o' cause DEBUG and ERR
132 traps, respectively, to be inherited by shell functions. Equivalent to
133 `set -T' and `set -E' respectively. The `functrace' option also controls
134 whether or not the DEBUG trap is inherited by sourced scripts.
136 n. The DEBUG trap is run before binding the variable and running the action
137 list in a `for' command, binding the selection variable and running the
138 query in a `select' command, and before attempting a match in a `case'
141 o. New `--enable-debugger' option to `configure' to compile in the debugger
144 p. `declare -F' now prints out extra line number and source file information
145 if the `extdebug' option is set.
147 q. If `extdebug' is enabled, a non-zero return value from a DEBUG trap causes
148 the next command to be skipped, and a return value of 2 while in a
149 function or sourced script forces a `return'.
151 r. New `caller' builtin to provide a call stack for the bash debugger.
153 s. The DEBUG trap is run just before the first command in a function body is
154 executed, for the debugger.
156 t. `for', `select', and `case' command heads are printed when `set -x' is
159 u. There is a new {x..y} brace expansion, which is shorthand for {x.x+1,
160 x+2,...,y}. x and y can be integers or single characters; the sequence
161 may ascend or descend; the increment is always 1.
163 v. New ksh93-like ${!array[@]} expansion, expands to all the keys (indices)
166 w. New `force_fignore' shopt option; if enabled, suffixes specified by
167 FIGNORE cause words to be ignored when performing word completion even
168 if they're the only possibilities.
170 x. New `gnu_errfmt' shopt option; if enabled, error messages follow the `gnu
171 style' (filename:lineno:message) format.
173 y. New `-o bashdefault' option to complete and compgen; if set, causes the
174 whole set of bash completions to be performed if the compspec doesn't
177 z. New `-o plusdirs' option to complete and compgen; if set, causes directory
178 name completion to be performed and the results added to the rest of the
179 possible completions.
181 aa. `kill' is available as a builtin even when the shell is built without
184 bb. New HISTTIMEFORMAT variable; value is a format string to pass to
185 strftime(3). If set and not null, the `history' builtin prints out
186 timestamp information according to the specified format when displaying
187 history entries. If set, bash tells the history library to write out
188 timestamp information when the history file is written.
190 cc. The [[ ... ]] command has a new binary `=~' operator that performs
191 extended regular expression (egrep-like) matching.
193 dd. `configure' has a new `--enable-cond-regexp' option (enabled by default)
194 to enable the =~ operator and regexp matching in [[ ... ]].
196 ee. Subexpressions matched by the =~ operator are placed in the new
197 BASH_REMATCH array variable.
199 ff. New `failglob' option that causes an expansion error when pathname
200 expansion fails to produce a match.
202 gg. New `set -o pipefail' option that causes a pipeline to return a failure
203 status if any of the processes in the pipeline fail, not just the last
206 hh. printf builtin understands two new escape sequences: \" and \?.
208 ii. `echo -e' understands two new escape sequences: \" and \?.
210 jj. The GNU `gettext' package and libintl have been integrated; the shell's
211 messages can be translated into different languages.
213 kk. The `\W' prompt expansion now abbreviates $HOME as `~', like `\w'.
215 ll. The error message printed when bash cannot open a shell script supplied
216 as argument 1 now includes the name of the shell, to better identify
217 the error as coming from bash.
219 mm. The parameter pattern removal and substitution expansions are now much
220 faster and more efficient when using multibyte characters.
222 nn. The `jobs', `kill', and `wait' builtins now accept job control notation
223 even if job control is not enabled.
225 oo. The historical behavior of `trap' that allows a missing `action' argument
226 to cause each specified signal's handling to be reset to its default is
227 now only supported when `trap' is given a single non-option argument.
229 2. New Features in Readline
231 a. History expansion has a new `a' modifier equivalent to the `g' modifier
232 for compatibility with the BSD csh.
234 b. History expansion has a new `G' modifier equivalent to the BSD csh `g'
235 modifier, which performs a substitution once per word.
237 c. All non-incremental search operations may now undo the operation of
238 replacing the current line with the history line.
240 d. The text inserted by an `a' command in vi mode can be reinserted with
243 e. New bindable variable, `show-all-if-unmodified'. If set, the readline
244 completer will list possible completions immediately if there is more
245 than one completion and partial completion cannot be performed.
247 f. There is a new application-callable `free_history_entry()' function.
249 g. History list entries now contain timestamp information; the history file
250 functions know how to read and write timestamp information associated
253 h. Four new key binding functions have been added:
255 rl_bind_key_if_unbound()
256 rl_bind_key_if_unbound_in_map()
257 rl_bind_keyseq_if_unbound()
258 rl_bind_keyseq_if_unbound_in_map()
260 i. New application variable, rl_completion_quote_character, set to any
261 quote character readline finds before it calls the application completion
264 j. New application variable, rl_completion_suppress_quote, settable by an
265 application completion function. If set to non-zero, readline does not
266 attempt to append a closing quote to a completed word.
268 k. New application variable, rl_completion_found_quote, set to a non-zero
269 value if readline determines that the word to be completed is quoted.
270 Set before readline calls any application completion function.
272 l. New function hook, rl_completion_word_break_hook, called when readline
273 needs to break a line into words when completion is attempted. Allows
274 the word break characters to vary based on position in the line.
276 m. New bindable command: unix-filename-rubout. Does the same thing as
277 unix-word-rubout, but adds `/' to the set of word delimiters.
279 n. When listing completions, directories have a `/' appended if the
280 `mark-directories' option has been enabled.
282 -------------------------------------------------------------------------------
283 This is a terse description of the new features added to bash-2.05b since
284 the release of bash-2.05a. As always, the manual page (doc/bash.1) is
285 the place to look for complete descriptions.
287 1. New Features in Bash
289 a. If set, TMOUT is the default timeout for the `read' builtin.
291 b. `type' has two new options: `-f' suppresses shell function lookup, and
292 `-P' forces a $PATH search.
294 c. New code to handle multibyte characters.
296 d. `select' was changed to be more ksh-compatible, in that the menu is
297 reprinted each time through the loop only if REPLY is set to NULL.
298 The previous behavior is available as a compile-time option.
300 e. `complete -d' and `complete -o dirnames' now force a slash to be
301 appended to names which are symlinks to directories.
303 f. There is now a bindable edit-and-execute-command readline command,
304 like the vi-mode `v' command, bound to C-xC-e in emacs mode.
306 g. Added support for ksh93-like [:word:] character class in pattern matching.
308 h. The $'...' quoting construct now expands \cX to Control-X.
310 i. A new \D{...} prompt expansion; passes the `...' to strftime and inserts
311 the result into the expanded prompt.
313 j. The shell now performs arithmetic in the largest integer size the
314 machine supports (intmax_t), instead of long.
316 k. If a numeric argument is supplied to one of the bash globbing completion
317 functions, a `*' is appended to the word before expansion is attempted.
319 l. The bash globbing completion functions now allow completions to be listed
320 with double tabs or if `show-all-if-ambiguous' is set.
322 m. New `-o nospace' option for `complete' and `compgen' builtins; suppresses
323 readline's appending a space to the completed word.
325 n. New `here-string' redirection operator: <<< word.
327 o. When displaying variables, function attributes and definitions are shown
328 separately, allowing them to be re-used as input (attempting to re-use
329 the old output would result in syntax errors).
331 p. There is a new configuration option `--enable-mem-scramble', controls
332 bash malloc behavior of writing garbage characters into memory at
333 allocation and free time.
335 q. The `complete' and `compgen' builtins now have a new `-s/-A service'
336 option to complete on names from /etc/services.
338 r. `read' has a new `-u fd' option to read from a specified file descriptor.
340 s. Fix the completion code so that expansion errors in a directory name
341 don't cause a longjmp back to the command loop.
343 t. Fixed word completion inside command substitution to work a little more
346 u. The `printf' %q format specifier now uses $'...' quoting to print the
347 argument if it contains non-printing characters.
349 v. The `declare' and `typeset' builtins have a new `-t' option. When applied
350 to functions, it causes the DEBUG trap to be inherited by the named
351 function. Currently has no effect on variables.
353 w. The DEBUG trap is now run *before* simple commands, ((...)) commands,
354 [[...]] conditional commands, and for ((...)) loops.
356 x. The expansion of $LINENO inside a shell function is only relative to the
357 function start if the shell is interactive -- if the shell is running a
358 script, $LINENO expands to the line number in the script. This is as
361 y. The bash debugger in examples/bashdb has been modified to work with the
362 new DEBUG trap semantics, the command set has been made more gdb-like,
363 and the changes to $LINENO make debugging functions work better. Code
366 z. New [n]<&word- and [n]>&word- redirections from ksh93 -- move fds (dup
369 aa. There is a new `-l' invocation option, equivalent to `--login'.
371 bb. The `hash' builtin has a new `-l' option to list contents in a reusable
372 format, and a `-d' option to remove a name from the hash table.
374 cc. There is now support for placing the long help text into separate files
375 installed into ${datadir}/bash. Not enabled by default; can be turned
376 on with `--enable-separate-helpfiles' option to configure.
378 dd. All builtins that take operands accept a `--' pseudo-option, except
381 ee. The `echo' builtin now accepts \0xxx (zero to three octal digits following
382 the `0') in addition to \xxx (one to three octal digits) for SUSv3/XPG6/
383 POSIX.1-2001 compliance.
386 2. New Features in Readline
388 a. Support for key `subsequences': allows, e.g., ESC and ESC-a to both
389 be bound to readline functions. Now the arrow keys may be used in vi
392 b. When listing completions, and the number of lines displayed is more than
393 the screen length, readline uses an internal pager to display the results.
394 This is controlled by the `page-completions' variable (default on).
396 c. New code to handle editing and displaying multibyte characters.
398 d. The behavior introduced in bash-2.05a of deciding whether or not to
399 append a slash to a completed name that is a symlink to a directory has
400 been made optional, controlled by the `mark-symlinked-directories'
401 variable (default is the 2.05a behavior).
403 e. The `insert-comment' command now acts as a toggle if given a numeric
404 argument: if the first characters on the line don't specify a
405 comment, insert one; if they do, delete the comment text
407 f. New application-settable completion variable:
408 rl_completion_mark_symlink_dirs, allows an application's completion
409 function to temporarily override the user's preference for appending
410 slashes to names which are symlinks to directories.
412 g. New function available to application completion functions:
413 rl_completion_mode, to tell how the completion function was invoked
414 and decide which argument to supply to rl_complete_internal (to list
417 h. Readline now has an overwrite mode, toggled by the `overwrite-mode'
418 bindable command, which could be bound to `Insert'.
420 i. New application-settable completion variable:
421 rl_completion_suppress_append, inhibits appending of
422 rl_completion_append_character to completed words.
424 j. New key bindings when reading an incremental search string: ^W yanks
425 the currently-matched word out of the current line into the search
426 string; ^Y yanks the rest of the current line into the search string,
427 DEL or ^H deletes characters from the search string.
429 -------------------------------------------------------------------------------
430 This is a terse description of the new features added to bash-2.05a since
431 the release of bash-2.05. As always, the manual page (doc/bash.1) is
432 the place to look for complete descriptions.
434 1. New Features in Bash
436 a. Added support for DESTDIR installation root prefix, so you can do a
437 `make install DESTDIR=bash-root' and do easier binary packaging.
439 b. Added support for builtin printf "'" flag character as per latest POSIX
442 c. Support for POSIX.2 printf(1) length specifiers `j', `t', and `z' (from
445 d. New autoconf macro, RL_LIB_READLINE_VERSION, for use by other applications
446 (bash doesn't use very much of what it returns).
448 e. `set [-+]o nolog' is recognized as required by the latest POSIX drafts,
451 f. New read-only `shopt' option: login_shell. Set to non-zero value if the
452 shell is a login shell.
454 g. New `\A' prompt string escape sequence; expands to time in 24 HH:MM format.
456 h. New `-A group/-g' option to complete and compgen; does group name
459 i. New `-t' option to `hash' to list hash values for each filename argument.
461 j. New [-+]O invocation option to set and unset `shopt' options at startup.
463 k. configure's `--with-installed-readline' option now takes an optional
464 `=PATH' suffix to set the root of the tree where readline is installed
467 l. The ksh-like `ERR' trap has been added. The `ERR' trap will be run
468 whenever the shell would have exited if the -e option were enabled.
469 It is not inherited by shell functions.
471 m. `readonly', `export', and `declare' now print variables which have been
472 given attributes but not set by assigning a value as just a command and
473 a variable name (like `export foo') when listing, as the latest POSIX
476 n. `bashbug' now requires that the subject be changed from the default.
478 o. configure has a new `--enable-largefile' option, like other GNU utilities.
480 p. `for' loops now allow empty word lists after `in', like the latest POSIX
483 q. The builtin `ulimit' now takes two new non-numeric arguments: `hard',
484 meaning the current hard limit, and `soft', meaning the current soft
485 limit, in addition to `unlimited'
487 r. `ulimit' now prints the option letter associated with a particular
488 resource when printing more than one limit.
490 s. `ulimit' prints `hard' or `soft' when a value is not `unlimited' but is
491 one of RLIM_SAVED_MAX or RLIM_SAVED_CUR, respectively.
493 t. The `printf' builtin now handles the %a and %A conversions if they're
494 implemented by printf(3).
496 u. The `printf' builtin now handles the %F conversion (just about like %f).
498 v. The `printf' builtin now handles the %n conversion like printf(3). The
499 corresponding argument is the name of a shell variable to which the
502 2. New Features in Readline
504 a. Added extern declaration for rl_get_termcap to readline.h, making it a
505 public function (it was always there, just not in readline.h).
507 b. New #defines in readline.h: RL_READLINE_VERSION, currently 0x0402,
508 RL_VERSION_MAJOR, currently 4, and RL_VERSION_MINOR, currently 2.
510 c. New readline variable: rl_readline_version, mirrors RL_READLINE_VERSION.
512 d. New bindable boolean readline variable: match-hidden-files. Controls
513 completion of files beginning with a `.' (on Unix). Enabled by default.
515 e. The history expansion code now allows any character to terminate a
516 `:first-' modifier, like csh.
518 f. New bindable variable `history-preserve-point'. If set, the history
519 code attempts to place the user at the same location on each history
520 line retrived with previous-history or next-history.
522 -------------------------------------------------------------------------------
523 This is a terse description of the new features added to bash-2.05 since
524 the release of bash-2.04. As always, the manual page (doc/bash.1) is
525 the place to look for complete descriptions.
527 1. New Features in Bash
529 a. Added a new `--init-file' invocation argument as a synonym for `--rcfile',
530 per the new GNU coding standards.
532 b. The /dev/tcp and /dev/udp redirections now accept service names as well as
535 c. `complete' and `compgen' now take a `-o value' option, which controls some
536 of the aspects of that compspec. Valid values are:
538 default - perform bash default completion if programmable
539 completion produces no matches
540 dirnames - perform directory name completion if programmable
541 completion produces no matches
542 filenames - tell readline that the compspec produces filenames,
543 so it can do things like append slashes to
544 directory names and suppress trailing spaces
546 d. A new loadable builtin, realpath, which canonicalizes and expands symlinks
547 in pathname arguments.
549 e. When `set' is called without options, it prints function defintions in a
550 way that allows them to be reused as input. This affects `declare' and
551 `declare -p' as well. This only happens when the shell is not in POSIX
552 mode, since POSIX.2 forbids this behavior.
554 f. Bash-2.05 once again honors the current locale setting when processing
555 ranges within pattern matching bracket expressions (e.g., [A-Z]).
557 2. New Features in Readline
559 a. The blink timeout for paren matching is now settable by applications,
560 via the rl_set_paren_blink_timeout() function.
562 b. _rl_executing_macro has been renamed to rl_executing_macro, which means
563 it's now part of the public interface.
565 c. Readline has a new variable, rl_readline_state, which is a bitmap that
566 encapsulates the current state of the library; intended for use by
567 callbacks and hook functions.
569 d. New application-callable function rl_set_prompt(const char *prompt):
570 expands its prompt string argument and sets rl_prompt to the result.
572 e. New application-callable function rl_set_screen_size(int rows, int cols):
573 public method for applications to set readline's idea of the screen
576 f. New function, rl_get_screen_size (int *rows, int *columns), returns
577 readline's idea of the screen dimensions.
579 g. The timeout in rl_gather_tyi (readline keyboard input polling function)
580 is now settable via a function (rl_set_keyboard_input_timeout()).
582 h. Renamed the max_input_history variable to history_max_entries; the old
583 variable is maintained for backwards compatibility.
585 i. The list of characters that separate words for the history tokenizer is
586 now settable with a variable: history_word_delimiters. The default
589 -------------------------------------------------------------------------------
590 This is a terse description of the new features added to bash-2.04 since
591 the release of bash-2.03. As always, the manual page (doc/bash.1) is
592 the place to look for complete descriptions.
594 1. New Features in Bash
596 a. The history builtin has a `-d offset' option to delete the history entry
597 at position `offset'.
599 b. The prompt expansion code has two new escape sequences: \j, the number of
600 active jobs; and \l, the basename of the shell's tty device name.
602 c. The `bind' builtin has a new `-x' option to bind key sequences to shell
605 d. There is a new shell option, no_empty_command_completion, which, when
606 enabled, disables command completion when TAB is typed on an empty line.
608 e. The `help' builtin has a `-s' option to just print a builtin's usage
611 f. There are several new arithmetic operators: id++, id-- (variable
612 post-increment/decrement), ++id, --id (variable pre-increment/decrement),
613 expr1 , expr2 (comma operator).
615 g. There is a new ksh-93 style arithmetic for command:
616 for ((expr1 ; expr2; expr3 )); do list; done
618 h. The `read' builtin has a number of new options:
619 -t timeout only wait timeout seconds for input
620 -n nchars only read nchars from input instead of a full line
621 -d delim read until delim rather than newline
622 -s don't echo input chars as they are read
624 i. The redirection code now handles several filenames specially:
625 /dev/fd/N, /dev/stdin, /dev/stdout, and /dev/stderr, whether or
626 not they are present in the file system.
628 j. The redirection code now recognizes pathnames of the form
629 /dev/tcp/host/port and /dev/udp/host/port, and tries to open a socket
630 of the appropriate type to the specified port on the specified host.
632 k. The ksh-93 ${!prefix*} expansion, which expands to the names of all
633 shell variables with prefix PREFIX, has been implemented.
635 l. There is a new dynamic variable, FUNCNAME, which expands to the name of
636 a currently-executing function. Assignments to FUNCNAME have no effect.
638 m. The GROUPS variable is no longer readonly; assignments to it are silently
639 discarded. This means it can be unset.
641 n. A new programmable completion facility, with two new builtin commands:
642 complete and compgen.
644 o. configure has a new option, `--enable-progcomp', to compile in the
645 programmable completion features (enabled by default).
647 p. `shopt' has a new option, `progcomp', to enable and disable programmable
648 completion at runtime.
650 q. Unsetting HOSTFILE now clears the list of hostnames used for completion.
652 r. configure has a new option, `--enable-bash-malloc', replacing the old
653 `--with-gnu-malloc' (which is still present for backwards compatibility).
655 s. There is a new manual page describing rbash, the restricted shell.
657 t. `bashbug' has new `--help' and `--version' options.
659 u. `shopt' has a new `xpg_echo' option, which controls the behavior of
660 `echo' with respect to backslash-escaped characters at runtime.
662 v. If NON_INTERACTIVE_LOGIN_SHELLS is defined, all login shells read the
663 startup files, even if they are not interactive.
665 w. The LC_NUMERIC variable is now treated specially, and used to set the
666 LC_NUMERIC locale category for number formatting, e.g., when `printf'
667 displays floating-point numbers.
669 2. New features in Readline
671 a. Parentheses matching is now always compiled into readline, and enabled
672 or disabled when the value of the `blink-matching-paren' variable is
675 b. MS-DOS systems now use ~/_inputrc as the last-ditch inputrc filename.
677 c. MS-DOS systems now use ~/_history as the default history file.
679 d. history-search-{forward,backward} now leave the point at the end of the
680 line when the string to search for is empty, like
681 {reverse,forward}-search-history.
683 e. history-search-{forward,backward} now leave the last history line found
684 in the readline buffer if the second or subsequent search fails.
686 f. New function for use by applications: rl_on_new_line_with_prompt, used
687 when an application displays the prompt itself before calling readline().
689 g. New variable for use by applications: rl_already_prompted. An application
690 that displays the prompt itself before calling readline() must set this to
693 h. A new variable, rl_gnu_readline_p, always 1. The intent is that an
694 application can verify whether or not it is linked with the `real'
695 readline library or some substitute.
697 -------------------------------------------------------------------------------
698 This is a terse description of the new features added to bash-2.03 since
699 the release of bash-2.02. As always, the manual page (doc/bash.1) is
700 the place to look for complete descriptions.
702 1. New Features in Bash
704 a. New `shopt' option, `restricted_shell', indicating whether or not the
705 shell was started in restricted mode, for use in startup files.
707 b. Filename generation is now performed on the words between ( and ) in
708 array assignments (which it probably should have done all along).
710 c. OLDPWD is now auto-exported, as POSIX.2 seems to require.
712 d. ENV and BASH_ENV are read-only variables in a restricted shell.
714 e. A change was made to the startup file code so that any shell begun with
715 the `--login' option, even non-interactive shells, will source the login
718 2. New Features in Readline
720 a. Many changes to the signal handling:
721 o Readline now catches SIGQUIT and cleans up the tty before returning;
722 o A new variable, rl_catch_signals, is available to application writers
723 to indicate to readline whether or not it should install its own
724 signal handlers for SIGINT, SIGTERM, SIGQUIT, SIGALRM, SIGTSTP,
725 SIGTTIN, and SIGTTOU;
726 o A new variable, rl_catch_sigwinch, is available to application
727 writers to indicate to readline whether or not it should install its
728 own signal handler for SIGWINCH, which will chain to the calling
729 applications's SIGWINCH handler, if one is installed;
730 o There is a new function, rl_free_line_state, for application signal
731 handlers to call to free up the state associated with the current
732 line after receiving a signal;
733 o There is a new function, rl_cleanup_after_signal, to clean up the
734 display and terminal state after receiving a signal;
735 o There is a new function, rl_reset_after_signal, to reinitialize the
736 terminal and display state after an application signal handler
737 returns and readline continues
739 b. There is a new function, rl_resize_terminal, to reset readline's idea of
740 the screen size after a SIGWINCH.
742 c. New public functions: rl_save_prompt and rl_restore_prompt. These were
743 previously private functions with a `_' prefix.
745 d. New function hook: rl_pre_input_hook, called just before readline starts
746 reading input, after initialization.
748 e. New function hook: rl_display_matches_hook, called when readline would
749 display the list of completion matches. The new function
750 rl_display_match_list is what readline uses internally, and is available
751 for use by application functions called via this hook.
753 f. New bindable function, delete-char-or-list, like tcsh.
755 g. A new variable, rl_erase_empty_line, which, if set by an application using
756 readline, will cause readline to erase, prompt and all, lines on which the
757 only thing typed was a newline.
759 h. New bindable variable: `isearch-terminators'.
761 i. New bindable function: `forward-backward-delete-char' (unbound by default).
763 -------------------------------------------------------------------------------
764 This is a terse description of the new features added to bash-2.02 since
765 the release of bash-2.01.1. As always, the manual page (doc/bash.1) is
766 the place to look for complete descriptions.
768 1. New Features in Bash
770 a. A new version of malloc, based on the older GNU malloc, that has many
771 changes, is more page-based, is more conservative with memory usage,
772 and does not `orphan' large blocks when they are freed.
774 b. A new version of gmalloc, based on the old GLIBC malloc, with many
775 changes and range checking included by default.
777 c. A new implementation of fnmatch(3) that includes full POSIX.2 Basic
778 Regular Expression matching, including character classes, collating
779 symbols, equivalence classes, and support for case-insensitive pattern
782 d. ksh-88 egrep-style extended pattern matching ([@+*?!](patlist)) has been
783 implemented, controlled by a new `shopt' option, `extglob'.
785 e. There is a new ksh-like `[[' compound command, which implements
786 extended `test' functionality.
788 f. There is a new `printf' builtin, implemented according to the POSIX.2
791 g. There is a new feature for command substitution: $(< filename) now expands
792 to the contents of `filename', with any trailing newlines removed
793 (equivalent to $(cat filename)).
795 h. There are new tilde prefixes which expand to directories from the
798 i. There is a new `**' arithmetic operator to do exponentiation.
800 j. There are new configuration options to control how bash is linked:
801 `--enable-profiling', to allow bash to be profiled with gprof, and
802 `--enable-static-link', to allow bash to be linked statically.
804 k. There is a new configuration option, `--enable-cond-command', which
805 controls whether or not the `[[' command is included. It is on by
808 l. There is a new configuration option, `--enable-extended-glob', which
809 controls whether or not the ksh extended globbing feature is included.
810 It is enabled by default.
812 m. There is a new configuration #define in config.h.top that, when enabled,
813 will cause all login shells to source /etc/profile and one of the user-
814 specific login shell startup files, whether or not the shell is
817 n. There is a new invocation option, `--dump-po-strings', to dump
818 a shell script's translatable strings ($"...") in GNU `po' format.
820 o. There is a new `shopt' option, `nocaseglob', to enable case-insensitive
821 pattern matching when globbing filenames and using the `case' construct.
823 p. There is a new `shopt' option, `huponexit', which, when enabled, causes
824 the shell to send SIGHUP to all jobs when an interactive login shell
827 q. `bind' has a new `-u' option, which takes a readline function name as an
828 argument and unbinds all key sequences bound to that function in a
831 r. `disown' now has `-a' and `-r' options, to limit operation to all jobs
832 and running jobs, respectively.
834 s. The `shopt' `-p' option now causes output to be displayed in a reusable
837 t. `test' has a new `-N' option, which returns true if the filename argument
838 has been modified since it was last accessed.
840 u. `umask' now has a `-p' option to print output in a reusable format.
842 v. A new escape sequence, `\xNNN', has been added to the `echo -e' and $'...'
843 translation code. It expands to the character whose ascii code is NNN
846 w. The prompt string expansion code has a new `\r' escape sequence.
848 x. The shell may now be cross-compiled for the CYGWIN32 environment on
851 2. New Features in Readline
853 a. There is now an option for `iterative' yank-last-arg handline, so a user
854 can keep entering `M-.', yanking the last argument of successive history
857 b. New variable, `print-completions-horizontally', which causes completion
858 matches to be displayed across the screen (like `ls -x') rather than up
859 and down the screen (like `ls').
861 c. New variable, `completion-ignore-case', which causes filename completion
862 and matching to be performed case-insensitively.
864 d. There is a new bindable command, `magic-space', which causes history
865 expansion to be performed on the current readline buffer and a space to
866 be inserted into the result.
868 e. There is a new bindable command, `menu-complete', which enables tcsh-like
869 menu completion (successive executions of menu-complete insert a single
870 completion match, cycling through the list of possible completions).
872 f. There is a new bindable command, `paste-from-clipboard', for use on Win32
873 systems, to insert the text from the Win32 clipboard into the editing
876 g. The key sequence translation code now understands printf-style backslash
877 escape sequences, including \NNN octal escapes. These escape sequences
878 may be used in key sequence definitions or macro values.
880 h. An `$include' inputrc file parser directive has been added.
882 -------------------------------------------------------------------------------
883 This is a terse description of the new features added to bash-2.01 since
884 the release of bash-2.0. As always, the manual page (doc/bash.1) is the
885 place to look for complete descriptions.
887 1. New Features in Bash
889 a. There is a new builtin array variable: GROUPS, the set of groups to which
890 the user belongs. This is used by the test suite.
892 2. New Features in Readline
894 a. If a key sequence bound to `universal-argument' is read while reading a
895 numeric argument started with `universal-argument', it terminates the
896 argument but is otherwise ignored. This provides a way to insert multiple
897 instances of a digit string, and is how GNU emacs does it.
899 -------------------------------------------------------------------------------
900 This is a terse description of the new features added to bash-2.0 since
901 the release of bash-1.14.7. As always, the manual page (doc/bash.1) is
902 the place to look for complete descriptions.
904 1. New Features in Bash
906 a. There is a new invocation option, -D, that dumps translatable strings
909 b. The `long' invocation options must now be prefixed with `--'.
911 c. New long invocation options: --dump-strings, --help, --verbose
913 d. The `nolineediting' invocation option was renamed to `noediting'.
915 e. The `nobraceexpansion' and `quiet' long invocation options were removed.
917 f. The `--help' and `--version' long options now work as the GNU coding
920 g. If invoked as `sh', bash now enters posix mode after reading the
921 startup files, and reads and executes commands from the file named
922 by $ENV if interactive (as POSIX.2 specifies). A login shell invoked
923 as `sh' reads $ENV after /etc/profile and ~/.profile.
925 h. There is a new reserved word, `time', for timing pipelines, builtin
926 commands, and shell functions. It uses the value of the TIMEFORMAT
927 variable as a format string describing how to print the timing
930 i. The $'...' quoting syntax expands ANSI-C escapes in ... and leaves the
931 result single-quoted.
933 j. The $"..." quoting syntax performs locale-specific translation of ...
934 and leaves the result double-quoted.
936 k. LINENO now works correctly in functions.
938 l. New variables: DIRSTACK, PIPESTATUS, BASH_VERSINFO, HOSTNAME, SHELLOPTS,
939 MACHTYPE. The first three are array variables.
941 m. The BASH_VERSION and BASH_VERSINFO variables now include the shell's
942 `release status' (alpha[N], beta[N], release).
944 n. Some variables have been removed: MAIL_WARNING, notify, history_control,
945 command_oriented_history, glob_dot_filenames, allow_null_glob_expansion,
946 nolinks, hostname_completion_file, noclobber, no_exit_on_failed_exec, and
947 cdable_vars. Most of them are now implemented with the new `shopt'
948 builtin; others were already implemented by `set'.
950 o. Bash now uses some new variables: LC_ALL, LC_MESSAGES, LC_CTYPE,
951 LC_COLLATE, LANG, GLOBIGNORE, HISTIGNORE.
953 p. The shell now supports integer-indexed arrays of unlimited length,
954 with a new compound assignment syntax and changes to the appropriate
955 builtin commands (declare/typeset, read, readonly, etc.). The array
956 index may be an arithmetic expression.
958 q. ${!var}: indirect variable expansion, equivalent to eval \${$var}.
960 r. ${paramter:offset[:length]}: variable substring extraction.
962 s. ${parameter/pattern[/[/]string]}: variable pattern substitution.
964 t. The $[...] arithmetic expansion syntax is no longer supported, in
967 u. Aliases can now be expanded in shell scripts with a shell option
968 (shopt expand_aliases).
970 v. History and history expansion can now be used in scripts with
971 set -o history and set -H.
973 w. All builtins now return an exit status of 2 for incorrect usage.
975 x. Interactive shells resend SIGHUP to all running or stopped children
976 if (and only if) they exit due to a SIGHUP.
978 y. New prompting expansions: \a, \e, \H, \T, \@, \v, \V.
980 z. Variable expansion in prompt strings is now controllable via a shell
981 option (shopt promptvars).
983 aa. Bash now defaults to using command-oriented history.
985 bb. The history file ($HISTFILE) is now truncated to $HISTFILESIZE after
988 cc. The POSIX.2 conditional arithmetic evaluation syntax (expr ? expr : expr)
989 has been implemented.
991 dd. Each builtin now accepts `--' to signify the end of the options, except
992 as documented (echo, etc.).
994 ee. All builtins use -p to display values in a re-readable format where
995 appropriate, except as documented (echo, type, etc.).
997 ff. The `alias' builtin has a new -p option.
999 gg. Changes to the `bind' builtin:
1000 o has new options: -psPSVr.
1001 o the `-d' option was renamed to `-p'
1002 o the `-v' option now dumps variables; the old `-v' is now `-P'
1004 hh. The `bye' synonym for `exit' was removed.
1006 ii. The -L and -P options to `cd' and `pwd' have been documented.
1008 jj. The `cd' builtin now does spelling correction on the directory name
1009 by default. This is settable with a shell option (shopt cdspell).
1011 kk. The `declare' builtin has new options: -a, -F, -p.
1013 ll. The `dirs' builtin has new options: -c, -p, -v.
1015 mm. The new `disown' builtin removes jobs from the shell's jobs table
1016 or inhibits the resending of SIGHUP when the shell receives a
1019 nn. The `echo' builtin has a new escape character: \e.
1021 oo. The `enable' builtin can now load new builtins dynamically from shared
1022 objects on systems with the dlopen/dlsym interface. There are a number
1023 of examples in the examples/loadables directory. There are also
1024 new options: -d, -f, -s, -p.
1026 pp. The `-all' option to `enable' was removed in favor of `-a'.
1028 qq. The `exec' builtin has new options: -l, -c, -a.
1030 rr. The `hash' builtin has a new option: -p.
1032 ss. The `history' builtin has new options: -c, -p, -s.
1034 tt. The `jobs' builtin has new options: -r, -s.
1036 uu. The `kill' builtin has new options: -n signum, -l signame.
1038 vv. The `pushd' and `popd' builtins have a new option: -n.
1040 ww. The `read' builtin has new options: -p prompt, -e, -a.
1042 xx. The `readonly' builtin has a new -a option, and the -n option was removed.
1044 yy. Changes to the `set' builtin:
1045 o new options: -B, -o keyword, -o onecmd, -o history
1046 o options removed: -l, -d, -o nohash
1047 o options changed: +o, -h, -o hashall
1048 o now displays variables in a format that can be re-read as input
1050 zz. The new `shopt' builtin controls shell optional behavior previously
1051 done by setting and unsetting certain shell variables.
1053 aaa. The `test' builtin has new operators: -o option, s1 == s2, s1 < s2,
1054 and s1 > s2, where s1 and s2 are strings.
1056 bbb. There is a new trap, DEBUG, executed after every simple command.
1058 ccc. The `trap' builtin has a new -p option.
1060 ddd. The `ulimit' builtin has a new -l option on 4.4BSD-based systems.
1062 eee. The PS1, PS2, PATH, and IFS variables may now be unset.
1064 fff. The restricted shell mode has been expanded and is now documented.
1066 ggg. Security improvements:
1067 o functions are not imported from the environment if running setuid
1069 o no startup files are sourced if running setuid or with -p
1071 hhh. The documentation has been overhauled: the texinfo manual was
1072 expanded, and HTML versions of the man page and texinfo manual
1075 iii. Changes to Posix mode:
1076 o Command lookup now finds special builtins before shell functions.
1077 o Failure of a special builtin causes a non-interactive shell to
1078 exit. Failures are defined in the POSIX.2 specification.
1079 o If the `cd' builtin finds a directory to change to using $CDPATH,
1080 the value assigned to PWD when `cd' completes does not contain
1082 o A non-interactive shell exits if a variable assignment error
1083 occurs when no command name follows the assignment statements.
1084 o A non-interactive shell exits if the interation variable in a
1085 `for' statement or the selection variable in a `select' statement
1086 is read-only or another variable assignment error occurs.
1087 o The `<>' redirection operator now opens a file for both stdin and
1088 stdout by default, not just when in posix mode.
1089 o Assignment statements preceding special builtins now persist in
1090 the shell's environment when the builtin completes.
1092 Posix mode is now completely POSIX.2-compliant (modulo bugs). When
1093 invoked as sh, bash should be completely POSIX.2-compliant.
1095 jjj. The default value of PS1 is now "\s-\v\$ ".
1097 kkk. The ksh-like ((...)) arithmetic command syntax has been implemented.
1098 This is exactly equivalent to `let "..."'.
1100 lll. Integer constants have been extended to base 64.
1102 mmm. The `ulimit' builtin now sets both hard and soft limits and reports the
1103 soft limit by default.
1105 2. New Features in Readline
1107 a. New variables: enable-keypad, input-meta (new name for meta-flag),
1108 mark-directories, visible-stats (now documented), disable-completion,
1111 b. New bindable commands: kill-region, copy-region-as-kill,
1112 copy-backward-word, copy-forward-word, set-mark, exchange-point-and-mark,
1113 character-search, character-search-backward, insert-comment,
1114 glob-expand-word, glob-list-expansions, dump-variables, dump-macros.
1116 c. New emacs keybindings: delete-horizontal-space (M-\),
1117 insert-completions (M-*), possible-completions (M-=).
1119 d. The history-search-backward and history-search-forward commands were
1120 modified to be the same as previous-line and next-line if point is at
1121 the start of the line.
1123 e. More file types are available for the visible-stats mode.
1125 3. Changes of interest in the Bash implementation
1127 a. There is a new autoconf-based configuration mechanism.
1129 b. More things have been moved from Posix mode to standard shell behavior.
1131 c. The trace output (set -x) now inserts quotes where necessary so it can
1134 d. There is a compile-time option for a system-wide interactive shell
1135 startup file (disabled by default).
1137 e. The YACC grammar is smaller and tighter, and all 66 shift-reduce
1138 conflicts are gone. Several parsing bugs have been fixed.
1140 f. Builtin option parsing has been regularized (using internal_getopt()),
1141 with the exception of `echo', `type', and `set'.
1143 g. Builtins now return standard usage messages constructed from the
1144 `short doc' used by the help builtin.
1146 h. Completion now quotes using backslashes by default, but honors
1147 user-supplied quotes.
1149 i. The GNU libc malloc is available as a configure-time option.
1151 j. There are more internationalization features; bash uses gettext if
1152 it is available. The $"..." translation syntax uses the current
1155 k. There is better reporting of job termination when the shell is not
1158 l. The shell is somewhat more efficient: it uses a little less memory and
1159 makes fewer system calls.
1161 4. Changes of interest in the Readline implementation
1163 a. There is now support for readline `callback' functions.
1165 b. There is now support for user-supplied input, redisplay, and terminal
1166 preparation functions.
1168 c. Most of the shell-specific code in readline has been generalized or
1171 d. Most of the annoying redisplay bugs have been fixed, notably the problems
1172 with incremental search and excessive redrawing when special characters
1173 appear in the prompt string.
1175 e. There are new library functions and variables available to application
1176 writers, most having to do with completion and quoting.
1178 f. The NEWLINE character (^J) is now treated as a search terminator by the
1179 incremental search functions.