fix for heuristic to detect case statements when parsing $() command substitutions to find history expansion; fix for history not being saved if a SIGHUP arrives during $PROMPT_COMMAND execution; workaround for Cygwin bug that results in bash incorrectly calculating the system pipe size

2026-06-27 07:43:07 +02:00 · 2026-03-09 14:54:45 -04:00
parent d0b41c2c5f
commit 1f292e433e
16 changed files with 6183 additions and 366 deletions
@@ -11776,7 +11776,7 @@ lib/sh/strtrans.c
 builtins/read.def
 	- read_builtin: make sure i is >= 0 after a timeout longjmp before
 	  trying to terminate input_string
-	  From a report from Duncan Roe <duncan_roe@optusnet.com.au>
+	  From a report from Duncan Roe <bduncan_roe@optusnet.com.au>

 jobs.c,jobs.h
 	- wait_for_background_pids: now takes a new first argument, WFLAGS.
@@ -12755,5 +12755,34 @@ execute_cmd.c
 	  if the redirections complete without errors, and defer environment
 	  creation until after calling expand_assignment_statements()

+				    3/5
+				    ---
+subst.c
+	- skip_to_histexp: fix typo in change from 2/12 that resulted in
+	  incorrect precedence for tests
+	  Report and patch from Grisha Levit <grishalevit@gmail.com>

+				    3/6
+				    ---
+variables.c
+	- initialize_shell_variables: use enable_history_list instead of
+	  remember_on_history to determine whether to initialize the history
+	  variables for consistency, though they should have the same value
+	  at this point

+shell.c
+	- exit_shell: use enable_history_list instead of remember_on_history
+	  to determine whether or not to save the history
+
+sig.c
+	- termsig_handler: save the history if either remember_on_history or
+	  enable_history_list is set (though only the latter should be
+	  necessary)
+	  Fixes problem with SIGHUP during $PROMPT_COMMAND evaluation
+	  reported in https://savannah.gnu.org/bugs/index.php?68128
+
+				    3/9
+				    ---
+builtins/psize.c
+	- sigpipe: work around cygwin SIGPIPE delivery bug
+	  Report and fix from Duncan Roe <bduncan_roe@optusnet.com.au>
@@ -625,6 +625,8 @@ po/ja.gmo		f
 po/ja.po		f
 po/ka.gmo		f
 po/ka.po		f
+po/kk.gmo		f
+po/kk.po		f
 po/ko.gmo		f
 po/ko.po		f
 po/lt.gmo		f
@@ -1,6 +1,6 @@
 /* psize.c - Find pipe size. */

-/* Copyright (C) 1987, 1991, 2022 Free Software Foundation, Inc.
+/* Copyright (C) 1987, 1991, 2022, 2026 Free Software Foundation, Inc.

   This file is part of GNU Bash, the Bourne Again SHell.

@@ -50,7 +50,11 @@ int nw;
 sighandler
 sigpipe (int sig)
 {
+#if defined (__CYGWIN__)
+  fprintf (stderr, "%d\n", nw - 128);
+#else
  fprintf (stderr, "%d\n", nw);
+#endif
  exit (0);
 }

@@ -1927,34 +1927,36 @@ EEXXPPAANNSSIIOONN
       In each of the cases below, _w_o_r_d is subject to tilde expansion, parame-
       ter expansion, command substitution, and arithmetic expansion.

-       When not performing substring expansion, using the forms documented be-
-       low  (e.g.,  ::--),  bbaasshh  tests  for  a parameter that is unset or null.
-       Omitting the colon tests only for a parameter that is unset.
+       When performing the first four expansions documented below (::--, ::==, ::??,
+       and  ::++), including the colon, bbaasshh tests for a parameter that is unset
+       or null.  Omitting the colon tests only for a parameter that is unset.

       ${_p_a_r_a_m_e_t_e_r::--_w_o_r_d}
-              UUssee DDeeffaauulltt VVaalluueess.  If _p_a_r_a_m_e_t_e_r is unset or null,  the  expan-
-              sion  of _w_o_r_d is substituted.  Otherwise, the value of _p_a_r_a_m_e_t_e_r
-              is substituted.
+              UUssee DDeeffaauulltt VVaalluueess.  If _p_a_r_a_m_e_t_e_r is unset or null, or unset  if
+              the  colon is not present, the expansion of _w_o_r_d is substituted.
+              Otherwise, the value of _p_a_r_a_m_e_t_e_r is substituted.

       ${_p_a_r_a_m_e_t_e_r::==_w_o_r_d}
-              AAssssiiggnn DDeeffaauulltt VVaalluueess.  If _p_a_r_a_m_e_t_e_r is unset or null,  the  ex-
-              pansion  of  _w_o_r_d is assigned to _p_a_r_a_m_e_t_e_r, and the expansion is
-              the final value of _p_a_r_a_m_e_t_e_r.  Positional parameters and special
-              parameters may not be assigned in this way.
+              AAssssiiggnn DDeeffaauulltt VVaalluueess.  If _p_a_r_a_m_e_t_e_r is unset or null, or  unset
+              if  the  colon is not present, the expansion of _w_o_r_d is assigned
+              to _p_a_r_a_m_e_t_e_r, and the expansion is the final value of _p_a_r_a_m_e_t_e_r.
+              Positional parameters and special parameters may not be assigned
+              in this way.

       ${_p_a_r_a_m_e_t_e_r::??_w_o_r_d}
-              DDiissppllaayy EErrrroorr iiff NNuullll oorr UUnnsseett.  If _p_a_r_a_m_e_t_e_r is null or  unset,
-              the shell writes the expansion of _w_o_r_d (or a message to that ef-
-              fect if _w_o_r_d is not present) to the standard error and, if it is
-              not  interactive,  exits with a non-zero status.  An interactive
-              shell does not exit, but does not execute the command associated
-              with the expansion.  Otherwise, the value of _p_a_r_a_m_e_t_e_r  is  sub-
-              stituted.
+              DDiissppllaayy EErrrroorr iiff NNuullll oorr UUnnsseett.  If _p_a_r_a_m_e_t_e_r is unset or  null,
+              or  unset  if the colon is not present, the shell writes the ex-
+              pansion of _w_o_r_d (or a message to that  effect  if  _w_o_r_d  is  not
+              present)  to  the  standard error and, if it is not interactive,
+              exits with a non-zero status.  An  interactive  shell  does  not
+              exit,  but  does not execute the command associated with the ex-
+              pansion.  Otherwise, the value of _p_a_r_a_m_e_t_e_r is substituted.

       ${_p_a_r_a_m_e_t_e_r::++_w_o_r_d}
-              UUssee  AAlltteerrnnaattee VVaalluuee.  If _p_a_r_a_m_e_t_e_r is null or unset, nothing is
-              substituted, otherwise the expansion  of  _w_o_r_d  is  substituted.
-              The value of _p_a_r_a_m_e_t_e_r is not used.
+              UUssee AAlltteerrnnaattee VVaalluuee.  If _p_a_r_a_m_e_t_e_r is unset or null, or unset if
+              the colon is not present, nothing is substituted, otherwise  the
+              expansion of _w_o_r_d is substituted.  The value of _p_a_r_a_m_e_t_e_r is not
+              used.

       ${_p_a_r_a_m_e_t_e_r::_o_f_f_s_e_t}
       ${_p_a_r_a_m_e_t_e_r::_o_f_f_s_e_t::_l_e_n_g_t_h}
@@ -7618,4 +7620,4 @@ BBUUGGSS

       Array variables may not (yet) be exported.

-GNU Bash 5.3                    2026 January 14                        _B_A_S_H(1)
+GNU Bash 5.3                     2026 March 3                          _B_A_S_H(1)
@@ -5,7 +5,7 @@
 .\"	Case Western Reserve University
 .\"	chet.ramey@case.edu
 .\"
-.\"	Last Change: Wed Jan 14 15:46:08 EST 2026
+.\"	Last Change: Tue Mar  3 10:52:34 EST 2026
 .\"
 .\" For bash_builtins, strip all but "SHELL BUILTIN COMMANDS" section
 .\" For rbash, strip all but "RESTRICTED SHELL" section
@@ -22,7 +22,7 @@
 .ds zX \" empty
 .if \n(zZ=1 .ig zZ
 .if \n(zY=1 .ig zY
-.TH BASH 1 "2026 January 14" "GNU Bash 5.3"
+.TH BASH 1 "2026 March 3" "GNU Bash 5.3"
 .\"
 .ie \n(.g \{\
 .ds ' \(aq
@@ -3725,8 +3725,9 @@ introduce indirection.
 In each of the cases below, \fIword\fP is subject to tilde expansion,
 parameter expansion, command substitution, and arithmetic expansion.
 .PP
-When not performing substring expansion, using the forms documented below
-(e.g., \fB:-\fP),
+When performing the first four expansions documented below
+(\fB:-\fP, \fB:=\fP, \fB:?\fP, and \fB:+\fP),
+including the colon,
 \fBbash\fP tests for a parameter that is unset or null.
 Omitting the colon tests only for a parameter that is unset.
 .PP
@@ -3734,7 +3735,9 @@ Omitting the colon tests only for a parameter that is unset.
 ${\fIparameter\fP\fB:\-\fP\fIword\fP}
 \fBUse Default Values\fP.  If
 .I parameter
-is unset or null, the expansion of
+is unset or null,
+or unset if the colon is not present,
+the expansion of
 .I word
 is substituted.
 Otherwise, the value of
@@ -3745,7 +3748,9 @@ ${\fIparameter\fP\fB:=\fP\fIword\fP}
 \fBAssign Default Values\fP.
 If
 .I parameter
-is unset or null, the expansion of
+is unset or null,
+or unset if the colon is not present,
+the expansion of
 .I word
 is assigned to
 .IR parameter ,
@@ -3758,7 +3763,9 @@ ${\fIparameter\fP\fB:?\fP\fIword\fP}
 \fBDisplay Error if Null or Unset\fP.
 If
 .I parameter
-is null or unset, the shell writes
+is unset or null,
+or unset if the colon is not present,
+the shell writes
 the expansion of \fIword\fP (or a message to that effect
 if
 .I word
@@ -3772,7 +3779,9 @@ ${\fIparameter\fP\fB:+\fP\fIword\fP}
 \fBUse Alternate Value\fP.
 If
 .I parameter
-is null or unset, nothing is substituted, otherwise the expansion of
+is unset or null,
+or unset if the colon is not present,
+nothing is substituted, otherwise the expansion of
 .I word
 is substituted.
 The value of \fIparameter\fP is not used.
@@ -1,9 +1,9 @@
 This is bash.info, produced by makeinfo version 7.2 from bashref.texi.

 This text is a brief description of the features that are present in the
-Bash shell (version 5.3, 27 February 2026).
+Bash shell (version 5.3, 3 March 2026).

-   This is Edition 5.3, last updated 27 February 2026, of ‘The GNU Bash
+   This is Edition 5.3, last updated 3 March 2026, of ‘The GNU Bash
 Reference Manual’, for ‘Bash’, Version 5.3.

   Copyright © 1988-2026 Free Software Foundation, Inc.
@@ -26,10 +26,10 @@ Bash Features
 *************

 This text is a brief description of the features that are present in the
-Bash shell (version 5.3, 27 February 2026).  The Bash home page is
+Bash shell (version 5.3, 3 March 2026).  The Bash home page is
 <http://www.gnu.org/software/bash/>.

-   This is Edition 5.3, last updated 27 February 2026, of ‘The GNU Bash
+   This is Edition 5.3, last updated 3 March 2026, of ‘The GNU Bash
 Reference Manual’, for ‘Bash’, Version 5.3.

   Bash contains features that appear in other popular shells, and some
@@ -1896,16 +1896,17 @@ introduce indirection.
   In each of the cases below, WORD is subject to tilde expansion,
 parameter expansion, command substitution, and arithmetic expansion.

-   When not performing substring expansion, using the forms described
-below (e.g., ‘:−’), Bash tests for a parameter that is unset or null.
-Omitting the colon results in a test only for a parameter that is unset.
-Put another way, if the colon is included, the operator tests for both
-PARAMETER's existence and that its value is not null; if the colon is
-omitted, the operator tests only for existence.
+   When performing the first four expansions documented below (‘:-’,
+‘:=’, ‘:?’, and ‘:+’), including the colon, Bash tests for a parameter
+that is unset or null.  Omitting the colon results in a test only for a
+parameter that is unset.  Put another way, if the colon is included, the
+operator tests for both PARAMETER's existence and that its value is not
+null; if the colon is omitted, the operator tests only for existence.

 ‘${PARAMETER:−WORD}’
-     If PARAMETER is unset or null, the expansion of WORD is
-     substituted.  Otherwise, the value of PARAMETER is substituted.
+     If PARAMETER is unset or null, or unset if the colon is not
+     present, the expansion of WORD is substituted.  Otherwise, the
+     value of PARAMETER is substituted.

          $ v=123
          $ echo ${v-unset}
@@ -1922,10 +1923,11 @@ omitted, the operator tests only for existence.
          unset-or-null

 ‘${PARAMETER:=WORD}’
-     If PARAMETER is unset or null, the expansion of WORD is assigned to
-     PARAMETER, and the result of the expansion is the final value of
-     PARAMETER.  Positional parameters and special parameters may not be
-     assigned in this way.
+     If PARAMETER is unset or null, or unset if the colon is not
+     present, the expansion of WORD is assigned to PARAMETER, and the
+     result of the expansion is the final value of PARAMETER.
+     Positional parameters and special parameters may not be assigned in
+     this way.

          $ unset var
          $ : ${var=DEFAULT}
@@ -1945,12 +1947,13 @@ omitted, the operator tests only for existence.
          DEFAULT

 ‘${PARAMETER:?WORD}’
-     If PARAMETER is null or unset, the shell writes the expansion of
-     WORD (or a message to that effect if WORD is not present) to the
-     standard error and, if it is not interactive, exits with a non-zero
-     status.  An interactive shell does not exit, but does not execute
-     the command associated with the expansion.  Otherwise, the value of
-     PARAMETER is substituted.
+     If PARAMETER is unset or null, or unset if the colon is not
+     present, the shell writes the expansion of WORD (or a message to
+     that effect if WORD is not present) to the standard error and, if
+     it is not interactive, exits with a non-zero status.  An
+     interactive shell does not exit, but does not execute the command
+     associated with the expansion.  Otherwise, the value of PARAMETER
+     is substituted.

          $ var=
          $ : ${var:?var is unset or null}
@@ -1967,9 +1970,9 @@ omitted, the operator tests only for existence.
          123

 ‘${PARAMETER:+WORD}’
-     If PARAMETER is null or unset, nothing is substituted, otherwise
-     the expansion of WORD is substituted.  The value of PARAMETER is
-     not used.
+     If PARAMETER is unset or null, or unset if the colon is not
+     present, nothing is substituted, otherwise the expansion of WORD is
+     substituted.  The value of PARAMETER is not used.

          $ var=123
          $ echo ${var:+var is set and not null}
@@ -7163,7 +7166,7 @@ shell variables may also be referenced by name without using the
 parameter expansion syntax.  This means you can use X, where X is a
 shell variable name, in an arithmetic expression, and the shell will
 evaluate its value as an expression and use the result.  A shell
-variable that is null or unset evaluates to 0 when referenced by name in
+variable that is unset or null evaluates to 0 when referenced by name in
 an expression.

   The value of a variable is evaluated as an arithmetic expression when
@@ -13735,138 +13738,138 @@ D.5 Concept Index


 Tag Table:
-Node: Top901
-Node: Introduction2842
-Node: What is Bash?3055
-Node: What is a shell?4188
-Node: Definitions6798
-Node: Basic Shell Features10125
-Node: Shell Syntax11349
-Node: Shell Operation12376
-Node: Quoting13667
-Node: Escape Character15005
-Node: Single Quotes15540
-Node: Double Quotes15889
-Node: ANSI-C Quoting17234
-Node: Locale Translation18628
-Node: Creating Internationalized Scripts20031
-Node: Comments24229
-Node: Shell Commands24996
-Node: Reserved Words25935
-Node: Simple Commands27078
-Node: Pipelines27740
-Node: Lists30996
-Node: Compound Commands32945
-Node: Looping Constructs33954
-Node: Conditional Constructs36503
-Node: Command Grouping51640
-Node: Coprocesses53132
-Node: GNU Parallel55818
-Node: Shell Functions56736
-Node: Shell Parameters65184
-Node: Positional Parameters70085
-Node: Special Parameters71175
-Node: Shell Expansions74636
-Node: Brace Expansion76825
-Node: Tilde Expansion80161
-Node: Shell Parameter Expansion83116
-Node: Command Substitution103763
-Node: Arithmetic Expansion107614
-Node: Process Substitution108790
-Node: Word Splitting109898
-Node: Filename Expansion112342
-Node: Pattern Matching115566
-Node: Quote Removal121332
-Node: Redirections121636
-Node: Executing Commands131892
-Node: Simple Command Expansion132559
-Node: Command Search and Execution134667
-Node: Command Execution Environment137111
-Node: Environment140637
-Node: Exit Status142540
-Node: Signals144599
-Node: Shell Scripts149547
-Node: Shell Builtin Commands152845
-Node: Bourne Shell Builtins155186
-Node: Bash Builtins181905
-Node: Modifying Shell Behavior219641
-Node: The Set Builtin219983
-Node: The Shopt Builtin231977
-Node: Special Builtins249030
-Node: Shell Variables250019
-Node: Bourne Shell Variables250453
-Node: Bash Variables252961
-Node: Bash Features292245
-Node: Invoking Bash293259
-Node: Bash Startup Files299843
-Node: Interactive Shells305085
-Node: What is an Interactive Shell?305493
-Node: Is this Shell Interactive?306155
-Node: Interactive Shell Behavior306979
-Node: Bash Conditional Expressions310740
-Node: Shell Arithmetic316157
-Node: Aliases319484
-Node: Arrays322618
-Node: The Directory Stack330321
-Node: Directory Stack Builtins331118
-Node: Controlling the Prompt335563
-Node: The Restricted Shell338447
-Node: Bash POSIX Mode341540
-Node: Shell Compatibility Mode361356
-Node: Job Control370363
-Node: Job Control Basics370820
-Node: Job Control Builtins377188
-Node: Job Control Variables383976
-Node: Command Line Editing385207
-Node: Introduction and Notation386910
-Node: Readline Interaction389262
-Node: Readline Bare Essentials390450
-Node: Readline Movement Commands392258
-Node: Readline Killing Commands393254
-Node: Readline Arguments395277
-Node: Searching396367
-Node: Readline Init File398610
-Node: Readline Init File Syntax399913
-Node: Conditional Init Constructs426864
-Node: Sample Init File431249
-Node: Bindable Readline Commands434369
-Node: Commands For Moving435907
-Node: Commands For History438371
-Node: Commands For Text443762
-Node: Commands For Killing447887
-Node: Numeric Arguments450675
-Node: Commands For Completion451827
-Node: Keyboard Macros457523
-Node: Miscellaneous Commands458224
-Node: Readline vi Mode465767
-Node: Programmable Completion466744
-Node: Programmable Completion Builtins476480
-Node: A Programmable Completion Example488217
-Node: Using History Interactively493562
-Node: Bash History Facilities494243
-Node: Bash History Builtins497978
-Node: History Interaction505573
-Node: Event Designators510523
-Node: Word Designators512101
-Node: Modifiers514493
-Node: Installing Bash516430
-Node: Basic Installation517546
-Node: Compilers and Options521422
-Node: Compiling For Multiple Architectures522172
-Node: Installation Names523925
-Node: Specifying the System Type526159
-Node: Sharing Defaults526905
-Node: Operation Controls527619
-Node: Optional Features528638
-Node: Reporting Bugs541361
-Node: Major Differences From The Bourne Shell542718
-Node: GNU Free Documentation License564145
-Node: Indexes589322
-Node: Builtin Index589773
-Node: Reserved Word Index596871
-Node: Variable Index599316
-Node: Function Index616729
-Node: Concept Index630862
+Node: Top893
+Node: Introduction2826
+Node: What is Bash?3039
+Node: What is a shell?4172
+Node: Definitions6782
+Node: Basic Shell Features10109
+Node: Shell Syntax11333
+Node: Shell Operation12360
+Node: Quoting13651
+Node: Escape Character14989
+Node: Single Quotes15524
+Node: Double Quotes15873
+Node: ANSI-C Quoting17218
+Node: Locale Translation18612
+Node: Creating Internationalized Scripts20015
+Node: Comments24213
+Node: Shell Commands24980
+Node: Reserved Words25919
+Node: Simple Commands27062
+Node: Pipelines27724
+Node: Lists30980
+Node: Compound Commands32929
+Node: Looping Constructs33938
+Node: Conditional Constructs36487
+Node: Command Grouping51624
+Node: Coprocesses53116
+Node: GNU Parallel55802
+Node: Shell Functions56720
+Node: Shell Parameters65168
+Node: Positional Parameters70069
+Node: Special Parameters71159
+Node: Shell Expansions74620
+Node: Brace Expansion76809
+Node: Tilde Expansion80145
+Node: Shell Parameter Expansion83100
+Node: Command Substitution103948
+Node: Arithmetic Expansion107799
+Node: Process Substitution108975
+Node: Word Splitting110083
+Node: Filename Expansion112527
+Node: Pattern Matching115751
+Node: Quote Removal121517
+Node: Redirections121821
+Node: Executing Commands132077
+Node: Simple Command Expansion132744
+Node: Command Search and Execution134852
+Node: Command Execution Environment137296
+Node: Environment140822
+Node: Exit Status142725
+Node: Signals144784
+Node: Shell Scripts149732
+Node: Shell Builtin Commands153030
+Node: Bourne Shell Builtins155371
+Node: Bash Builtins182090
+Node: Modifying Shell Behavior219826
+Node: The Set Builtin220168
+Node: The Shopt Builtin232162
+Node: Special Builtins249215
+Node: Shell Variables250204
+Node: Bourne Shell Variables250638
+Node: Bash Variables253146
+Node: Bash Features292430
+Node: Invoking Bash293444
+Node: Bash Startup Files300028
+Node: Interactive Shells305270
+Node: What is an Interactive Shell?305678
+Node: Is this Shell Interactive?306340
+Node: Interactive Shell Behavior307164
+Node: Bash Conditional Expressions310925
+Node: Shell Arithmetic316342
+Node: Aliases319669
+Node: Arrays322803
+Node: The Directory Stack330506
+Node: Directory Stack Builtins331303
+Node: Controlling the Prompt335748
+Node: The Restricted Shell338632
+Node: Bash POSIX Mode341725
+Node: Shell Compatibility Mode361541
+Node: Job Control370548
+Node: Job Control Basics371005
+Node: Job Control Builtins377373
+Node: Job Control Variables384161
+Node: Command Line Editing385392
+Node: Introduction and Notation387095
+Node: Readline Interaction389447
+Node: Readline Bare Essentials390635
+Node: Readline Movement Commands392443
+Node: Readline Killing Commands393439
+Node: Readline Arguments395462
+Node: Searching396552
+Node: Readline Init File398795
+Node: Readline Init File Syntax400098
+Node: Conditional Init Constructs427049
+Node: Sample Init File431434
+Node: Bindable Readline Commands434554
+Node: Commands For Moving436092
+Node: Commands For History438556
+Node: Commands For Text443947
+Node: Commands For Killing448072
+Node: Numeric Arguments450860
+Node: Commands For Completion452012
+Node: Keyboard Macros457708
+Node: Miscellaneous Commands458409
+Node: Readline vi Mode465952
+Node: Programmable Completion466929
+Node: Programmable Completion Builtins476665
+Node: A Programmable Completion Example488402
+Node: Using History Interactively493747
+Node: Bash History Facilities494428
+Node: Bash History Builtins498163
+Node: History Interaction505758
+Node: Event Designators510708
+Node: Word Designators512286
+Node: Modifiers514678
+Node: Installing Bash516615
+Node: Basic Installation517731
+Node: Compilers and Options521607
+Node: Compiling For Multiple Architectures522357
+Node: Installation Names524110
+Node: Specifying the System Type526344
+Node: Sharing Defaults527090
+Node: Operation Controls527804
+Node: Optional Features528823
+Node: Reporting Bugs541546
+Node: Major Differences From The Bourne Shell542903
+Node: GNU Free Documentation License564330
+Node: Indexes589507
+Node: Builtin Index589958
+Node: Reserved Word Index597056
+Node: Variable Index599501
+Node: Function Index616914
+Node: Concept Index631047

 End Tag Table

@@ -2,9 +2,9 @@ This is bashref.info, produced by makeinfo version 7.2 from
 bashref.texi.

 This text is a brief description of the features that are present in the
-Bash shell (version 5.3, 27 February 2026).
+Bash shell (version 5.3, 3 March 2026).

-   This is Edition 5.3, last updated 27 February 2026, of ‘The GNU Bash
+   This is Edition 5.3, last updated 3 March 2026, of ‘The GNU Bash
 Reference Manual’, for ‘Bash’, Version 5.3.

   Copyright © 1988-2026 Free Software Foundation, Inc.
@@ -27,10 +27,10 @@ Bash Features
 *************

 This text is a brief description of the features that are present in the
-Bash shell (version 5.3, 27 February 2026).  The Bash home page is
+Bash shell (version 5.3, 3 March 2026).  The Bash home page is
 <http://www.gnu.org/software/bash/>.

-   This is Edition 5.3, last updated 27 February 2026, of ‘The GNU Bash
+   This is Edition 5.3, last updated 3 March 2026, of ‘The GNU Bash
 Reference Manual’, for ‘Bash’, Version 5.3.

   Bash contains features that appear in other popular shells, and some
@@ -1897,16 +1897,17 @@ introduce indirection.
   In each of the cases below, WORD is subject to tilde expansion,
 parameter expansion, command substitution, and arithmetic expansion.

-   When not performing substring expansion, using the forms described
-below (e.g., ‘:−’), Bash tests for a parameter that is unset or null.
-Omitting the colon results in a test only for a parameter that is unset.
-Put another way, if the colon is included, the operator tests for both
-PARAMETER's existence and that its value is not null; if the colon is
-omitted, the operator tests only for existence.
+   When performing the first four expansions documented below (‘:-’,
+‘:=’, ‘:?’, and ‘:+’), including the colon, Bash tests for a parameter
+that is unset or null.  Omitting the colon results in a test only for a
+parameter that is unset.  Put another way, if the colon is included, the
+operator tests for both PARAMETER's existence and that its value is not
+null; if the colon is omitted, the operator tests only for existence.

 ‘${PARAMETER:−WORD}’
-     If PARAMETER is unset or null, the expansion of WORD is
-     substituted.  Otherwise, the value of PARAMETER is substituted.
+     If PARAMETER is unset or null, or unset if the colon is not
+     present, the expansion of WORD is substituted.  Otherwise, the
+     value of PARAMETER is substituted.

          $ v=123
          $ echo ${v-unset}
@@ -1923,10 +1924,11 @@ omitted, the operator tests only for existence.
          unset-or-null

 ‘${PARAMETER:=WORD}’
-     If PARAMETER is unset or null, the expansion of WORD is assigned to
-     PARAMETER, and the result of the expansion is the final value of
-     PARAMETER.  Positional parameters and special parameters may not be
-     assigned in this way.
+     If PARAMETER is unset or null, or unset if the colon is not
+     present, the expansion of WORD is assigned to PARAMETER, and the
+     result of the expansion is the final value of PARAMETER.
+     Positional parameters and special parameters may not be assigned in
+     this way.

          $ unset var
          $ : ${var=DEFAULT}
@@ -1946,12 +1948,13 @@ omitted, the operator tests only for existence.
          DEFAULT

 ‘${PARAMETER:?WORD}’
-     If PARAMETER is null or unset, the shell writes the expansion of
-     WORD (or a message to that effect if WORD is not present) to the
-     standard error and, if it is not interactive, exits with a non-zero
-     status.  An interactive shell does not exit, but does not execute
-     the command associated with the expansion.  Otherwise, the value of
-     PARAMETER is substituted.
+     If PARAMETER is unset or null, or unset if the colon is not
+     present, the shell writes the expansion of WORD (or a message to
+     that effect if WORD is not present) to the standard error and, if
+     it is not interactive, exits with a non-zero status.  An
+     interactive shell does not exit, but does not execute the command
+     associated with the expansion.  Otherwise, the value of PARAMETER
+     is substituted.

          $ var=
          $ : ${var:?var is unset or null}
@@ -1968,9 +1971,9 @@ omitted, the operator tests only for existence.
          123

 ‘${PARAMETER:+WORD}’
-     If PARAMETER is null or unset, nothing is substituted, otherwise
-     the expansion of WORD is substituted.  The value of PARAMETER is
-     not used.
+     If PARAMETER is unset or null, or unset if the colon is not
+     present, nothing is substituted, otherwise the expansion of WORD is
+     substituted.  The value of PARAMETER is not used.

          $ var=123
          $ echo ${var:+var is set and not null}
@@ -7164,7 +7167,7 @@ shell variables may also be referenced by name without using the
 parameter expansion syntax.  This means you can use X, where X is a
 shell variable name, in an arithmetic expression, and the shell will
 evaluate its value as an expression and use the result.  A shell
-variable that is null or unset evaluates to 0 when referenced by name in
+variable that is unset or null evaluates to 0 when referenced by name in
 an expression.

   The value of a variable is evaluated as an arithmetic expression when
@@ -13736,138 +13739,138 @@ D.5 Concept Index


 Tag Table:
-Node: Top904
-Node: Introduction2848
-Node: What is Bash?3064
-Node: What is a shell?4200
-Node: Definitions6813
-Node: Basic Shell Features10143
-Node: Shell Syntax11370
-Node: Shell Operation12400
-Node: Quoting13694
-Node: Escape Character15035
-Node: Single Quotes15573
-Node: Double Quotes15925
-Node: ANSI-C Quoting17273
-Node: Locale Translation18670
-Node: Creating Internationalized Scripts20076
-Node: Comments24277
-Node: Shell Commands25047
-Node: Reserved Words25989
-Node: Simple Commands27135
-Node: Pipelines27800
-Node: Lists31059
-Node: Compound Commands33011
-Node: Looping Constructs34023
-Node: Conditional Constructs36575
-Node: Command Grouping51715
-Node: Coprocesses53210
-Node: GNU Parallel55899
-Node: Shell Functions56820
-Node: Shell Parameters65271
-Node: Positional Parameters70175
-Node: Special Parameters71268
-Node: Shell Expansions74732
-Node: Brace Expansion76924
-Node: Tilde Expansion80263
-Node: Shell Parameter Expansion83221
-Node: Command Substitution103871
-Node: Arithmetic Expansion107725
-Node: Process Substitution108904
-Node: Word Splitting110015
-Node: Filename Expansion112462
-Node: Pattern Matching115689
-Node: Quote Removal121458
-Node: Redirections121765
-Node: Executing Commands132024
-Node: Simple Command Expansion132694
-Node: Command Search and Execution134805
-Node: Command Execution Environment137252
-Node: Environment140781
-Node: Exit Status142687
-Node: Signals144749
-Node: Shell Scripts149700
-Node: Shell Builtin Commands153001
-Node: Bourne Shell Builtins155345
-Node: Bash Builtins182067
-Node: Modifying Shell Behavior219806
-Node: The Set Builtin220151
-Node: The Shopt Builtin232148
-Node: Special Builtins249204
-Node: Shell Variables250196
-Node: Bourne Shell Variables250633
-Node: Bash Variables253144
-Node: Bash Features292431
-Node: Invoking Bash293448
-Node: Bash Startup Files300035
-Node: Interactive Shells305280
-Node: What is an Interactive Shell?305691
-Node: Is this Shell Interactive?306356
-Node: Interactive Shell Behavior307183
-Node: Bash Conditional Expressions310947
-Node: Shell Arithmetic316367
-Node: Aliases319697
-Node: Arrays322834
-Node: The Directory Stack330540
-Node: Directory Stack Builtins331340
-Node: Controlling the Prompt335788
-Node: The Restricted Shell338675
-Node: Bash POSIX Mode341771
-Node: Shell Compatibility Mode361590
-Node: Job Control370600
-Node: Job Control Basics371060
-Node: Job Control Builtins377431
-Node: Job Control Variables384222
-Node: Command Line Editing385456
-Node: Introduction and Notation387162
-Node: Readline Interaction389517
-Node: Readline Bare Essentials390708
-Node: Readline Movement Commands392519
-Node: Readline Killing Commands393518
-Node: Readline Arguments395544
-Node: Searching396637
-Node: Readline Init File398883
-Node: Readline Init File Syntax400189
-Node: Conditional Init Constructs427143
-Node: Sample Init File431531
-Node: Bindable Readline Commands434654
-Node: Commands For Moving436195
-Node: Commands For History438662
-Node: Commands For Text444056
-Node: Commands For Killing448184
-Node: Numeric Arguments450975
-Node: Commands For Completion452130
-Node: Keyboard Macros457829
-Node: Miscellaneous Commands458533
-Node: Readline vi Mode466079
-Node: Programmable Completion467059
-Node: Programmable Completion Builtins476798
-Node: A Programmable Completion Example488538
-Node: Using History Interactively493886
-Node: Bash History Facilities494570
-Node: Bash History Builtins498308
-Node: History Interaction505906
-Node: Event Designators510859
-Node: Word Designators512440
-Node: Modifiers514835
-Node: Installing Bash516775
-Node: Basic Installation517894
-Node: Compilers and Options521773
-Node: Compiling For Multiple Architectures522526
-Node: Installation Names524282
-Node: Specifying the System Type526519
-Node: Sharing Defaults527268
-Node: Operation Controls527985
-Node: Optional Features529007
-Node: Reporting Bugs541733
-Node: Major Differences From The Bourne Shell543093
-Node: GNU Free Documentation License564523
-Node: Indexes589703
-Node: Builtin Index590157
-Node: Reserved Word Index597258
-Node: Variable Index599706
-Node: Function Index617122
-Node: Concept Index631258
+Node: Top896
+Node: Introduction2832
+Node: What is Bash?3048
+Node: What is a shell?4184
+Node: Definitions6797
+Node: Basic Shell Features10127
+Node: Shell Syntax11354
+Node: Shell Operation12384
+Node: Quoting13678
+Node: Escape Character15019
+Node: Single Quotes15557
+Node: Double Quotes15909
+Node: ANSI-C Quoting17257
+Node: Locale Translation18654
+Node: Creating Internationalized Scripts20060
+Node: Comments24261
+Node: Shell Commands25031
+Node: Reserved Words25973
+Node: Simple Commands27119
+Node: Pipelines27784
+Node: Lists31043
+Node: Compound Commands32995
+Node: Looping Constructs34007
+Node: Conditional Constructs36559
+Node: Command Grouping51699
+Node: Coprocesses53194
+Node: GNU Parallel55883
+Node: Shell Functions56804
+Node: Shell Parameters65255
+Node: Positional Parameters70159
+Node: Special Parameters71252
+Node: Shell Expansions74716
+Node: Brace Expansion76908
+Node: Tilde Expansion80247
+Node: Shell Parameter Expansion83205
+Node: Command Substitution104056
+Node: Arithmetic Expansion107910
+Node: Process Substitution109089
+Node: Word Splitting110200
+Node: Filename Expansion112647
+Node: Pattern Matching115874
+Node: Quote Removal121643
+Node: Redirections121950
+Node: Executing Commands132209
+Node: Simple Command Expansion132879
+Node: Command Search and Execution134990
+Node: Command Execution Environment137437
+Node: Environment140966
+Node: Exit Status142872
+Node: Signals144934
+Node: Shell Scripts149885
+Node: Shell Builtin Commands153186
+Node: Bourne Shell Builtins155530
+Node: Bash Builtins182252
+Node: Modifying Shell Behavior219991
+Node: The Set Builtin220336
+Node: The Shopt Builtin232333
+Node: Special Builtins249389
+Node: Shell Variables250381
+Node: Bourne Shell Variables250818
+Node: Bash Variables253329
+Node: Bash Features292616
+Node: Invoking Bash293633
+Node: Bash Startup Files300220
+Node: Interactive Shells305465
+Node: What is an Interactive Shell?305876
+Node: Is this Shell Interactive?306541
+Node: Interactive Shell Behavior307368
+Node: Bash Conditional Expressions311132
+Node: Shell Arithmetic316552
+Node: Aliases319882
+Node: Arrays323019
+Node: The Directory Stack330725
+Node: Directory Stack Builtins331525
+Node: Controlling the Prompt335973
+Node: The Restricted Shell338860
+Node: Bash POSIX Mode341956
+Node: Shell Compatibility Mode361775
+Node: Job Control370785
+Node: Job Control Basics371245
+Node: Job Control Builtins377616
+Node: Job Control Variables384407
+Node: Command Line Editing385641
+Node: Introduction and Notation387347
+Node: Readline Interaction389702
+Node: Readline Bare Essentials390893
+Node: Readline Movement Commands392704
+Node: Readline Killing Commands393703
+Node: Readline Arguments395729
+Node: Searching396822
+Node: Readline Init File399068
+Node: Readline Init File Syntax400374
+Node: Conditional Init Constructs427328
+Node: Sample Init File431716
+Node: Bindable Readline Commands434839
+Node: Commands For Moving436380
+Node: Commands For History438847
+Node: Commands For Text444241
+Node: Commands For Killing448369
+Node: Numeric Arguments451160
+Node: Commands For Completion452315
+Node: Keyboard Macros458014
+Node: Miscellaneous Commands458718
+Node: Readline vi Mode466264
+Node: Programmable Completion467244
+Node: Programmable Completion Builtins476983
+Node: A Programmable Completion Example488723
+Node: Using History Interactively494071
+Node: Bash History Facilities494755
+Node: Bash History Builtins498493
+Node: History Interaction506091
+Node: Event Designators511044
+Node: Word Designators512625
+Node: Modifiers515020
+Node: Installing Bash516960
+Node: Basic Installation518079
+Node: Compilers and Options521958
+Node: Compiling For Multiple Architectures522711
+Node: Installation Names524467
+Node: Specifying the System Type526704
+Node: Sharing Defaults527453
+Node: Operation Controls528170
+Node: Optional Features529192
+Node: Reporting Bugs541918
+Node: Major Differences From The Bourne Shell543278
+Node: GNU Free Documentation License564708
+Node: Indexes589888
+Node: Builtin Index590342
+Node: Reserved Word Index597443
+Node: Variable Index599891
+Node: Function Index617307
+Node: Concept Index631443

 End Tag Table

@@ -2306,8 +2306,10 @@ introduce indirection.
 In each of the cases below, @var{word} is subject to tilde expansion,
 parameter expansion, command substitution, and arithmetic expansion.

-When not performing substring expansion, using the forms described
-below (e.g., @samp{:@minus{}}), Bash tests for a parameter that is unset or null.
+When performing the first four expansions documented below
+(@samp{:-}, @samp{:=}, @samp{:?}, and @samp{:+}),
+including the colon,
+Bash tests for a parameter that is unset or null.
 Omitting the colon results in a test only for a parameter that is unset.
 Put another way, if the colon is included,
 the operator tests for both @var{parameter}'s existence and that its value
@@ -2316,7 +2318,10 @@ is not null; if the colon is omitted, the operator tests only for existence.
@table @code

@item $@{@var{parameter}:@minus{}@var{word}@}
-If @var{parameter} is unset or null, the expansion of
+If @var{parameter}
+is unset or null,
+or unset if the colon is not present,
+the expansion of
@var{word} is substituted.
 Otherwise, the value of @var{parameter} is substituted.

@@ -2337,7 +2342,10 @@ unset-or-null
@end example

@item $@{@var{parameter}:=@var{word}@}
-If @var{parameter} is unset or null, the expansion of @var{word}
+If @var{parameter}
+is unset or null,
+or unset if the colon is not present,
+the expansion of @var{word}
 is assigned to @var{parameter},
 and the result of the expansion
 is the final value of @var{parameter}.
@@ -2365,7 +2373,9 @@ DEFAULT

@item $@{@var{parameter}:?@var{word}@}
 If @var{parameter}
-is null or unset, the shell writes
+is unset or null,
+or unset if the colon is not present,
+the shell writes
 the expansion of @var{word} (or a message
 to that effect if @var{word}
 is not present) to the standard error and, if it
@@ -2392,7 +2402,10 @@ $ echo $@{var:?var is unset or null@}

@item $@{@var{parameter}:+@var{word}@}
 If @var{parameter}
-is null or unset, nothing is substituted, otherwise the expansion of
+is unset or null,
+or unset if the colon is not present,
+nothing is substituted,
+otherwise the expansion of
@var{word} is substituted.
 The value of @var{parameter} is not used.

@@ -8569,7 +8582,7 @@ This means you can use @var{x},
 where @var{x} is a shell variable name, in an arithmetic expression,
 and the shell will evaluate its value as an expression and use the
 result.
-A shell variable that is null or unset evaluates to 0 when referenced
+A shell variable that is unset or null evaluates to 0 when referenced
 by name in an expression.

 The value of a variable is evaluated as an arithmetic expression
@@ -2,10 +2,10 @@
 Copyright (C) 1988-2026 Free Software Foundation, Inc.
@end ignore

-@set LASTCHANGE Fri Feb 27 12:23:35 EST 2026
+@set LASTCHANGE Tue Mar  3 10:46:54 EST 2026

@set EDITION 5.3
@set VERSION 5.3

-@set UPDATED 27 February 2026
-@set UPDATED-MONTH February 2026
+@set UPDATED 3 March 2026
+@set UPDATED-MONTH March 2026
@@ -1,2 +1,2 @@
 # Set of available languages.
-en@quot en@boldquot af ar bg ca cs da de el eo es et fi fr ga gl hr hu id it ja ka ko lt nb nl pl pt pt_BR ro ru sk sl sq sr sv tr uk vi zh_CN zh_TW
+en@quot en@boldquot af ar bg ca cs da de el eo es et fi fr ga gl hr hu id it ja ka kk ko lt nb nl pl pt pt_BR ro ru sk sl sq sr sv tr uk vi zh_CN zh_TW
@@ -1005,7 +1005,7 @@ exit_shell (int s)
 #endif /* PROCESS_SUBSTITUTION */

 #if defined (HISTORY)
-  if (remember_on_history)
+  if (enable_history_list)
    maybe_save_shell_history ();
 #endif /* HISTORY */

@@ -616,7 +616,7 @@ termsig_handler (int sig)
     an interactive shell is running in a terminal window that gets closed
     with the `close' button.  We can't test for RL_STATE_READCMD because
     readline no longer handles SIGTERM synchronously.  */
-  if (interactive_shell && interactive && (sig == SIGHUP || sig == SIGTERM) && remember_on_history)
+  if (interactive_shell && interactive && (sig == SIGHUP || sig == SIGTERM) && (remember_on_history || enable_history_list))
    maybe_save_shell_history ();
 #endif /* HISTORY */

@@ -2505,8 +2505,7 @@ skip_to_histexp (const char *string, int start, const char *delims, int flags)
 	  continue;
 	}
      else if (histexp_comsub && c == 'c' &&
-	      (i == 0) || shellbreak (string[i-1]) &&	/* incomplete reserved word eligibility test */
-	      (i <= slen - 4) &&
+	      (i == 0 || shellbreak (string[i-1])) &&	/* incomplete reserved word eligibility test */
 	      string[i+1] == 'a' && string[i+2] == 's' && string[i+3] == 'e' &&
 	      (shellblank (string[i+4]) || string[i+4] == '\0'))
 	{
@@ -2516,8 +2515,7 @@ skip_to_histexp (const char *string, int start, const char *delims, int flags)
 	  continue;
 	}
      else if (histexp_comsub && c == 'e' &&
-	      (i == 0) || shellbreak (string[i-1]) &&	/* incomplete reserved word eligibility test */
-	      (i <= slen - 4) &&
+	      (i == 0 || shellbreak (string[i-1])) &&	/* incomplete reserved word eligibility test */
 	      string[i+1] == 's' && string[i+2] == 'a' && string[i+3] == 'c' &&
 	      (shellbreak (string[i+4]) || string[i+4] == '\0'))
 	{
@@ -652,7 +652,7 @@ initialize_shell_variables (char **env, int privmode)
  /* Set history variables to defaults, and then do whatever we would
     do if the variable had just been set.  Do this only in the case
     that we are remembering commands on the history list. */
-  if (remember_on_history)
+  if (enable_history_list)
    {
      name = bash_default_histfile ();

@@ -677,7 +677,7 @@ initialize_shell_variables (char **env, int privmode)
    }

 #if defined (HISTORY)
-  if (interactive_shell && remember_on_history)
+  if (interactive_shell && enable_history_list)
    {
      sv_history_control ("HISTCONTROL");
      sv_histignore ("HISTIGNORE");