1 This document details the changes between this version, bash-5.2-release, and
2 the previous version, bash-5.2-rc4.
8 a. When replacing a history entry, make sure the existing entry has a non-NULL
9 timestamp before copying it; it may have been added by the application, not
12 3. New Features in Bash
14 4. New Features in Readline
16 ------------------------------------------------------------------------------
17 This document details the changes between this version, bash-5.2-rc4, and
18 the previous version, bash-5.2-rc3.
22 a. Changed how the compatibility mode enabling of extglob works in conjunction
23 with parsing conditional commands.
25 b. Fixed a problem with aliases containing command substitutions.
27 2. Changes to Readline
29 3. New Features in Bash
31 4. New Features in Readline
33 ------------------------------------------------------------------------------
34 This document details the changes between this version, bash-5.2-rc3, and
35 the previous version, bash-5.2-rc2.
39 a. Added a compatibility mode feature that causes the parser to parse command
40 substitutions as if extglob were enabled. If it is enabled before execution,
41 parse at execution will succeed. If not, the subsequent execution parse will
44 b. Fixed an issue with handling a `return' executed in a trap action if the
45 trap is executed while running in a shell function.
47 2. Changes to Readline
49 3. New Features in Bash
51 4. New Features in Readline
53 a. Readline now checks for changes to locale settings (LC_ALL/LC_CTYPE/LANG)
54 each time it is called, and modifies the appropriate locale-specific display
55 and key binding variables when the locale changes.
57 ------------------------------------------------------------------------------
58 This document details the changes between this version, bash-5.2-rc2, and
59 the previous version, bash-5.2-rc1.
63 a. Fixed a bug that could disable history saving after a compound array
64 assignment in an interactive shell.
66 b. Fixed a bug that could cause incorrect error messages when running a DEBUG
67 trap during a conditional or arithmetic command.
69 c. Fixed a bug that caused test to print an error message when given ! ! arg
72 d. Fixed a bug that resulted in incorrect error messages when completing a
73 backquoted command substitution.
75 e. Changed command substitution parsing to reproduce the original text more
76 closely when reconsituting the command string from the parsed command.
78 f. Fixed a bug that could cause an EXIT trap to use the wrong variable context
79 when the errexit option is set.
81 g. Fixed a bug that could cause the parser to incorrectly delimit a token when
82 an alias expansion ended with a multibyte character.
84 2. Changes to Readline
86 3. New Features in Bash
88 a. Since there is no `declare -' equivalent of `local -', make sure to use
89 `local -' in the output of `local -p'.
91 b. Null anchored matches in pattern substitution now process `&' in the
92 replacement string, like sed.
94 4. New Features in Readline
96 ------------------------------------------------------------------------------
97 This document details the changes between this version, bash-5.2-rc1, and
98 the previous version, bash-5.2-beta.
102 a. Changes to `wait -p' and how it sets the variable name in the presence of
103 valid and invalid PID arguments.
105 b. Fixed a bug that caused compgen to dump core if the completion engine was
108 c. Fixed a memory leak in the variable name programmable completion code.
110 d. Here-documents and here-strings use tempfiles if the shell compatibility
111 level is 50 or lower.
113 e. Non-interactive shells exit on a syntax error encountered while parsing a
114 command substitution.
116 f. Fixed a bug with inherited parser state while parsing a command substitution.
118 g. Fixed a bug that caused the shell not to check for terminating signals
119 after executing the command_string supplied with `-c' and before executing
122 h. Changes to avoid a make race condition while generating builtins.c.
124 i. Make it explicit that BASH_REMATCH is always a global variable, and that
125 local copies are (currently) ignored.
127 j. Fixed a bug that caused an ambiguous redirection (>&word) to be printed
128 incorrectly (>&word) if no file descriptor was supplied.
130 2. Changes to Readline
132 a. Fixed a bug that caused rl_eof_found to be set prematurely while reading a
133 multi-character key sequence in callback mode.
135 3. New Features in Bash
137 a. In posix mode, the `printf' builtin checks for the `L' length modifier and
138 uses long double for floating point conversion specifiers if it's present,
141 b. The `globbing' completion code now takes the `globstar' option into account.
143 c. `suspend -f' now forces the shell to suspend even if job control is not
146 4. New Features in Readline
148 ------------------------------------------------------------------------------
149 This document details the changes between this version, bash-5.2-beta, and
150 the previous version, bash-5.2-alpha.
154 a. Fixed a problem with command-oriented history and multi-line commands that
155 caused embedded blank lines to be run together.
157 b. Changed the way `&' is quoted when performing pattern substitution and
158 `patsub_replacement' is enabled.
160 c. Fixed some integer overflows when expanding strings or reading the output
161 of command substitution larger than 2GB.
163 d. `wait -p' without the `-n' option now does something useful if there are no
166 e. Fixed an issue with read timeouts in posix mode.
168 f. Changed here-document processing to process $'...' and $"..." only when they
169 appear in the WORD portion of ${PARAM OP WORD} in the here-document body
170 and the body is being expanded.
172 g. Changed alias expansion in command substitution to be posix-conformant
173 (performed while initially parsing the command substitution) when in posix
176 h. Bash optimizes away more forks in subshells.
178 i. Here-document construction now performs quote removal on the here-document
179 delimiter only if it's marked as quoted, which prevents quote characters in
180 command substitutions from being removed.
182 j. Prompt string expansion now gives invisible characters in the expansion of
183 the \w, \W, and \s escape sequences a visible representation to avoid
184 problems with redisplay.
186 k. Fixed a problem with SIGINT during the execution of a command bound with
187 `bind -x' affecting the saved terminal settings.
189 l. Fixed an inconsistency with how $@ expands in a construct like ${@:+set}
190 or ${array[@]:+set} in the presence of null positional parameters or
193 2. Changes to Readline
195 a. Prevent some display problems when running a command as the result of a
196 trap or one bound using `bind -x' and the command generates output.
198 b. Fixed an issue with multi-line prompt strings that have one or more
199 invisible characters at the end of a physical line.
201 c. Fixed an issue that caused a history line's undo list to be cleared when
202 it should not have been.
204 3. New Features in Bash
206 a. There is a new bindable readline command name: `vi-edit-and-execute-command'.
208 4. New Features in Readline
210 a. Two new bindable string variables: active-region-start-color and
211 active-region-end-color. The first sets the color used to display the
212 active region; the second turns it off. If set, these are used in place
213 of terminal standout mode.
215 b. New readline state (RL_STATE_EOF) and application-visible variable
216 (rl_eof_found) to allow applications to detect when readline reads EOF
217 before calling the deprep-terminal hook.
219 c. There is a new configuration option: --with-shared-termcap-library, which
220 forces linking the shared readline library with the shared termcap (or
221 curses/ncurses/termlib) library so applications don't have to do it.
223 ------------------------------------------------------------------------------
224 This document details the changes between this version, bash-5.2-alpha, and
225 the previous version, bash-5.1-release.
229 a. Fixed a bug that assigned a value to the variable name supplied as an
230 argument to `wait -p' when there were no jobs.
232 b. Fixed a bug that resulted in performing incorrect word expansion on the
233 key/value pairs in a compound array assignment.
235 c. Fixed a bug that could put the child forked to run a command substitution
236 into the wrong process group.
238 d. Fixed a problem that could cause the lastpipe option to work incorrectly if
239 file descriptor 0 was closed.
241 e. Bash tries to suppress traps if a forked child receives a trapped signal
242 before it has a chance to reset its signal handlers.
244 f. Fixed several memory leaks in compound array assignments.
246 g. Fixed a problem with performing an assignment with `+=' to an array element
247 that was the value of a nameref.
249 h. Fixed a bug that could cause a nameref containing an array reference using
250 `@' or `*' not to expand to multiple words.
252 i. Fixed a bug where extended glob functions could match `.' or `..' when it
253 wasn't explicitly specified, even if dotglob was set.
255 j. Fixed a bug that caused non-interactive posix-mode shells not to exit on a
256 variable assignment error while assigning into the temporary environment.
258 k. Fixed a bug that caused parsing errors if an alias contained a compound
261 l. Fixed a couple of instances where bash checked syntax too aggressively when
262 trying to determine how to add a partial command to command-oriented
265 m. Fixed a parser problem that caused it not to allow reserved words to follow
266 the `((' and `[[' commands.
268 n. Fixed a bad offset calculation when using negative offsets to `history -d'.
270 o. Fixed an off-by-one error that caused a read past the end of a buffer when
271 reading a multibyte character from the output of a command substitution.
273 p. Fixed a problem with a failed `exec' command not setting $? to the right
274 value for an exit trap.
276 q. Fixed a problem that caused bash not to unlink FIFOs created as part of
277 expanding redirections for an external command.
279 r. Fixed a bug that could cause aliases not to be expanded in case statements.
281 s. Fixed a bug that could cause word completion to attempt programmable
282 completion for the target of a redirection, instead of filename completion.
284 t. Fixed a bug that could result in errors after rebinding a key sequence with
285 `bind -x' multiple times.
287 u. Fixed a problem that could result in not quoting the result when performing
288 command name completion with a glob pattern in the command name.
290 v. `mapfile' now uses fully-buffered reads in more cases, which should improve
291 bulk read performance.
293 w. Fixed a bug that caused `wait -n' to not reset its internal state when
294 interrupted by a signal, resulting in subsequent calls failing.
296 x. Fixed a bug with parsing numeric arguments to readline key sequences
297 installed with `bind -x'.
299 y. Bash suppresses forking in several additional cases, including most uses
302 z. If there are multiple `!' tokens in a [[ command, toggle the invert state
303 instead of setting it unconditionally.
305 aa. Fixed a bug where running `fc' on an empty history list would cause the
308 bb. Word completion now checks whether or not a quote character closes a
309 quoted string begun on a previous line, so readline doesn't interpret the
310 quote as starting a new quoted string.
312 cc. Fixed a typo that translated \UNNNNNNNN characters that were not valid in
313 the current locale encoding as \uNNNNNNNN.
315 dd. Fixed an issue that could cause bash to print timing statistics for the
316 wrong command when `set -e' causes a command to fail.
318 ee. Bash now runs the exit trap in function context if a failed command in
319 the function causes the shell to exit.
321 ff. Some fixes to how subshells modify $SHLVL.
323 gg. Fixed a bug that caused `mapfile -t' not to remove the delimiter when the
324 delimiter is > 128 in the current encoding.
326 hh. Fixed a problem that could cause the shell to attempt to free unallocated
327 memory if an expansion error occurred.
329 ii. Fixed a bug in the bash malloc implementation of malloc_usable_size. Bash
330 did not use it, but it could cause problems with library functions that
333 jj. If the `exec' builtin fails, and the shell does not exit, it restores
334 trapped signals to their trapped state.
336 kk. Fixed a bug that could cause variable assignment arguments to `declare' to
337 expand variables using attributes that the call to declare was turning off.
339 ll. Fixed a bug with LINENO and arithmetic for commands.
341 mm. Fixed a posix-mode bug that caused tildes not to be expanded after an
342 unquoted colon on the right side of an assignment statement.
344 nn. Fixed a problem with `caller' and line numbers when executing an ERR trap.
346 oo. Fixed a problem that could make the value returned by ${a:=b} not be the
347 final value assigned to a (e.g., if `a' has an attribute that modifies
348 the value on assignment).
350 pp. Fixed a problem with saving multi-line here-documents to the history list
351 where the here-document delimiter does not appear on the first line.
353 qq. Fixed a bug with using += to assign to dynamic variables like RANDOM.
355 rr. Fixed a bug that caused `set -n' to modify $? if set after execution had
358 ss. Builtins like printf/read/wait now behave more consistently when assigning
359 arbitrary keys to associative arrays (like `]'. when appropriately quoted).
361 tt. Fixed a problem with here-document collection printing the wrong prompt
362 when parsing a compound list in an interactive shell.
364 uu. Fixed a problem with quoting shell expansion characters (like `$') when
365 they appear in a tab-completed word along with characters that do need
366 quoting (e.g.. $HOME/VirtualBox VMs).
368 2. Changes to Readline
370 a. Fixed a problem with cleaning up active marks when using callback mode.
372 b. Fixed a problem with arithmetic comparison operators checking the version.
374 c. Fixed a problem that could cause readline not to build on systems without
375 POSIX signal functions.
377 d. Fixed a bug that could cause readline to crash if the application removed
378 the callback line handler before readline read all typeahead.
380 e. Added additional checks for read errors in the middle of readline commands.
382 f. Fixed a redisplay problem that occurred when switching from the digit-
383 argument prompt `(arg: N)' back to the regular prompt and the regular
384 prompt contained invisible characters.
386 g. Fixed a problem with restoring the prompt when aborting an incremental
389 h. Fix a problem with characters > 128 not being displayed correctly in certain
390 single-byte encodings.
392 i. Fixed a problem with unix-filename-rubout that caused it to delete too much
393 when applied to a pathname consisting only of one or more slashes.
395 j. Fixed a display problem that caused the prompt to be wrapped incorrectly if
396 the screen changed dimensions during a call to readline() and the prompt
397 became longer than the screen width.
399 k. Fixed a problem that caused the \r output by turning off bracketed paste
400 to overwrite the line if terminal echo was disabled.
402 l. Fixed a bug that could cause colored-completion-prefix to not display if
403 completion-prefix-display-length was set.
405 m. Fixed a problem with line wrapping prompts when a group of invisible
406 characters runs to the right edge of the screen and the prompt extends
407 longer then the screen width.
409 n. Fixed a couple problems that could cause rl_end to be set incorrectly by
412 3. New Features in Bash
414 a. The bash malloc returns memory that is aligned on 16-byte boundaries.
416 b. There is a new internal timer framework used for read builtin timeouts.
418 c. Rewrote the command substitution parsing code to call the parser recursively
419 and rebuild the command string from the parsed command. This allows better
420 syntax checking and catches errors much earlier. Along with this, if
421 command substitution parsing completes with here-documents remaining to be
422 read, the shell prints a warning message and reads the here-document bodies
423 from the current input stream.
425 d. The `ulimit' builtin now treats an operand remaining after all of the options
426 and arguments are parsed as an argument to the last command specified by
427 an option. This is for POSIX compatibility.
429 e. Here-document parsing now handles $'...' and $"..." quoting when reading the
432 f. The `shell-expand-line' and `history-and-alias-expand-line' bindable readline
433 commands now understand $'...' and $"..." quoting.
435 g. There is a new `spell-correct-word' bindable readline command to perform
436 spelling correction on the current word.
438 h. The `unset' builtin now attempts to treat arguments as array subscripts
439 without parsing or expanding the subscript, even when `assoc_expand_once'
442 i. There is a default value for $BASH_LOADABLES_PATH in config-top.h.
444 j. Associative array assignment and certain instances of referencing (e.g.,
445 `test -v') now allow `@' and `*' to be used as keys.
447 k. Bash attempts to expand indexed and associative array subscripts only
448 once when executing shell constructs and word expansions.
450 l. The `unset' builtin allows a subscript of `@' or `*' to unset a key with
451 that value for associative arrays instead of unsetting the entire array
452 (which you can still do with `unset arrayname'). For indexed arrays, it
453 removes all elements of the array without unsetting it (like `A=()').
455 m. Additional builtins (printf/test/read/wait) do a better job of not
456 parsing array subscripts if array_expand_once is set.
458 n. New READLINE_ARGUMENT variable set to numeric argument for readline commands
459 defined using `bind -x'.
461 o. The new `varredir_close' shell option causes bash to automatically close
462 file descriptors opened with {var}<fn and other styles of varassign
463 redirection unless they're arguments to the `exec' builtin.
465 p. The `$0' special parameter is now set to the name of the script when running
466 any (non-interactive) startup files such as $BASH_ENV.
468 q. The `enable' builtin tries to load a loadable builtin using the default
469 search path if `enable name' (without any options) attempts to enable a
470 non-existent builtin.
472 r. The `printf' builtin has a new format specifier: %Q. This acts like %q but
473 applies any specified precision to the original unquoted argument, then
474 quotes and outputs the result.
476 s. The new `noexpand_translations' option controls whether or not the translated
477 output of $"..." is single-quoted.
479 t. There is a new parameter transformation operator: @k. This is like @K, but
480 expands the result to separate words after word splitting.
482 u. There is an alternate array implementation, selectable at `configure' time,
483 that optimizes access speed over memory use (use the new configure
484 --enable-alt-array-implementation option).
486 v. If an [N]<&WORD- or [N]>&WORD- redirection has WORD expand to the empty
487 string, treat the redirection as [N]<&- or [N]>&- and close file descriptor
490 w. Invalid parameter transformation operators are now invalid word expansions,
491 and so cause fatal errors in non-interactive shells.
493 x. New shell option: patsub_replacement. When enabled, a `&' in the replacement
494 string of the pattern substitution expansion is replaced by the portion of
495 the string that matched the pattern. Backslash will escape the `&' and
496 insert a literal `&'.
498 y. `command -p' no longer looks in the hash table for the specified command.
500 z. The new `--enable-translatable-strings' option to `configure' allows $"..."
501 support to be compiled in or out.
503 aa. The new `globskipdots' shell option forces pathname expansion never to
504 return `.' or `..' unless explicitly matched. It is enabled by default.
506 bb. Array references using `@' and `*' that are the value of nameref variables
507 (declare -n ref='v[@]' ; echo $ref) no longer cause the shell to exit if
508 set -u is enabled and the array (v) is unset.
510 4. New Features in Readline
512 a. There is now an HS_HISTORY_VERSION containing the version number of the
513 history library for applications to use.
515 b. History expansion better understands multiple history expansions that may
516 contain strings that would ordinarily inhibit history expansion (e.g.,
519 c. There is a new framework for readline timeouts, including new public
520 functions to set timeouts and query how much time is remaining before a
521 timeout hits, and a hook function that can trigger when readline times
522 out. There is a new state value to indicate a timeout.
524 d. Automatically bind termcap key sequences for page-up and page-down to
525 history-search-backward and history-search-forward, respectively.
527 e. There is a new `fetch-history' bindable command that retrieves the history
528 entry corresponding to its numeric argument. Negative arguments count back
529 from the end of the history.
531 f. `vi-undo' is now a bindable command.
533 g. There is a new option: `enable-active-region'. This separates control of
534 the active region and bracketed-paste. It has the same default value as
535 bracketed-paste, and enabling bracketed paste enables the active region.
536 Users can now turn off the active region while leaving bracketed paste
539 h. rl_completer_word_break_characters is now `const char *' like
540 rl_basic_word_break_characters.
542 i. Readline looks in $LS_COLORS for a custom filename extension
543 (*.readline-colored-completion-prefix) and uses that as the default color
544 for the common prefix displayed when `colored-completion-prefix' is set.