+This document details the changes between this version, bash-4.2-release,
+and the previous version, bash-4.2-rc2.
+
+1. Changes to Bash
+
+a. Fixed a bug that caused some variables to be clobbered by a longjmp,
+ resulting in stack corruption.
+
+------------------------------------------------------------------------------
+This document details the changes between this version, bash-4.2-rc2,
+and the previous version, bash-4.2-rc1.
+
+1. Changes to Bash
+
+a. Changes to bash_directory_completion_hook so that it's assigned to the
+ readline rl_directory_rewrite_hook variable, which modifies the directory
+ name passed to opendir without modifying the directory name the user
+ typed.
+
+b. Fixed bug in select builtin that caused it to not terminate correctly if
+ the read timed out due to $TMOUT.
+
+c. Fixed a problem that resulted in non-repeatable sequences of random
+ numbers when RANDOM=0.
+
+------------------------------------------------------------------------------
+This document details the changes between this version, bash-4.2-rc1,
+and the previous version, bash-4.2-beta.
+
+1. Changes to Bash
+
+a. Fixed a bug that caused some redirection errors to leak file descriptors.
+
+b. Fixed a bug that caused unary `+' and `-' arithmetic operators to have a
+ higher precedence than unary `!' and `~'.
+
+c. Fixed a bug that caused simple commands in a pipeline to affect the exit
+ status ($?) seen by subsequent pipeline commands.
+
+d. A number of cygwin-specific changes to avoid the use of text-mode files
+ and file access, and to make sure that \r is handled correctly.
+
+e. Fixed a bug that caused the read builtin to not return failure if an
+ attempt is made to assign to a readonly variable.
+
+f. Fixed a bug that caused some builtin usage messages to not be translated.
+
+g. Fixed a bug that caused the getopts builtin to not return failure if an
+ attempt is made to assign to a readonly variable. Now it returns 2.
+
+h. Fixed the cd and pwd builtins to return failure if PWD is readonly and
+ cannot be assigned to.
+
+i. Added code to check the return value of access(2) on Solaris systems,
+ since it returns success for executable tests (e.g., `test -x') when
+ run by root, even if the file permissions don't allow execution.
+
+2. Changes to Readline
+
+a. Fixed a bug that caused directory names in words to be completed to not
+ be dequoted correctly.
+
+3. New Features in Bash
+
+4. New Features in Readline
+
+------------------------------------------------------------------------------
+This document details the changes between this version, bash-4.2-beta,
+and the previous version, bash-4.2-alpha.
+
+1. Changes to Bash
+
+a. Fixed a bug that caused the \W prompt string escape to not add a closing
+ NULL.
+
+b. Fixed a bug that caused partially-quoted words that were not subject to
+ word splitting to retained quoted NULLs.
+
+c. Added considerable efficiency speedups when pattern matching in multibyte
+ locales by skipping multibyte character functions where possible.
+
+d. Added considerable speedups to variable expansion when in multibyte locales.
+
+e. Fixed a bug that caused the expansion of $* when there are no positional
+ parameters to cause the shell to dump core when used in a pattern
+ matching context.
+
+f. Fixed a bug that caused variable expansions preceding regular builtins to
+ not change the shell environment during their execution.
+
+2. Changes to Readline
+
+a. Fixed a bug that made an explicit argument of 0 to yank-last-arg behave
+ as if it were a negative argument.
+
+------------------------------------------------------------------------------
+This document details the changes between this version, bash-4.2-alpha,
+and the previous version, bash-4.1-release.
+
+1. Changes to Bash
+
+a. Fixed a bug in the parser when processing alias expansions containing
+ quoted newlines.
+
+b. Fixed a memory leak in associative array expansion.
+
+c. Fixed a bug that caused quoted here-strings to be requoted when printed.
+
+d. Fixed a bug in arithmetic expansion that caused the index in an array
+ expansion to be evaluated twice under certain circumstances.
+
+e. Fixed several bugs with the expansion and display of variables that have
+ been given attributes but not values and are technically unset.
+
+f. Fixed a bug that caused core dumps when using filename completion that
+ expands to a filename containing a globbing character.
+
+g. Fixed a bug that caused assignment statements preceding a special builtin
+ when running in Posix mode to not persist after the builtin completed
+ when the special builtin was executed in a shell function without any
+ local variables.
+
+h. Fixed a bug that caused a command to remain in the hash table even after
+ `hash command' did not find anything if there was already an existing
+ hashed pathname.
+
+i. Fixed several bugs caused by executing unsafe functions from a signal
+ handler in the cases where a signal handler is executed immediately
+ rather than setting a flag for later execution.
+
+j. Fixed a bug that caused some internal flag variables to be set
+ incorrectly if `read -t' timed out.
+
+k. Fixed a Posix compatibility issue by making sure that a backslash escaping
+ a `}' within a double-quoted ${...} parameter expansion is removed as part
+ of the parameter expansion.
+
+l. Fixed a bug that caused execution of a trap to overwrite PIPESTATUS.
+
+m. Fixed a bug that caused here documents to not be displayed correctly
+ when attached to commands inside compound commands.
+
+n. Fixed a bug that caused the printf builtin to use the wrong precision
+ when using the `*' modifier.
+
+o. Fixed a bug that caused an arriving SIGCHLD to interrupt output functions
+ like those invoked by echo or printf.
+
+p. Changed to use a more robust mechanism than eaccess(2) when test is
+ checking filenames for execution permission.
+
+q. Fixed a bug that caused spurious semicolons to be added into the command
+ history in certain cases.
+
+r. Fixed a bug that caused the shell to free non-allocated memory when
+ unsetting element 0 of an associative array after it was assigned
+ implicitly.
+
+s. Fixed a bug that could cause the shell to dump core if using the `v'
+ vi editing command on a multi-line command.
+
+t. Fixed a bug that left FIFOs opened by process substitutions open long
+ enough to potentially cause file descriptor exhaustion when running a
+ shell function or shell builtin.
+
+u. Fixed a bug that caused the history expansion functions to not recognize
+ process substitution or extended glob patterns as single words.
+
+v. Fixed a bug that caused restricted shells to set a restricted command's
+ exit status incorrectly.
+
+w. Fixed a bug that caused bash to ignore the wrong set of filenames when
+ completing a command using the `complete-filename' readline command.
+
+x. Fixed a bug that caused a -PID argument following a -s sig or -n sig to
+ not be interpreted as a signal specification.
+
+y. Changed posix-mode behavior of a parse error in a `.' script or `eval'
+ command to exit the shell under Posix-specified conditions. Previous
+ versions printed a warning.
+
+z. Fixed a bug in \W prompt expansion that resulted in incorrect expansion
+ in the event of overlapping strings.
+
+aa. Fixed a bug that caused the := parameter expansion operator to return the
+ wrong value as the result of the expansion.
+
+bb. When in Posix mode, a single quote is not treated specially in a
+ double-quoted ${...} expansion, unless the expansion operator is
+ # or % or the non-Posix `//', `^', and `,'. In particular, it does
+ not define a new quoting context. This is from Posix interpretation 221.
+
+cc. Fixed a bug that inadvertently allowed program names containing slashes
+ to be entered into the command hash table.
+
+dd. Fixed a bug that caused the select builtin to incorrectly compute the
+ display width of the arguments in the presence of multibyte characters.
+
+ee. Fixed a bug that caused bash to not change the xtrace file descriptor if
+ BASH_XTRACEFD was found in the shell environment at startup.
+
+ff. Fixed a memory leak in the pattern removal parameter expansion.
+
+gg. Fixed a bug that caused SIGINT to fail to interrupt a nested loop if the
+ loop was in a pipeline.
+
+hh. Fixed a problem in $(...) parsing that caused the parser to add an extra
+ space to a here-document delimiter if the first word contained a `/'.
+
+ii. Fixed a bug that caused functions defined with the `function' reserved
+ word to require braces around the function body.
+
+jj. Fixed a bug that caused bash to dump core when a variable expansion being
+ used as an array subscript failed.
+
+kk. Fixed a bug that caused bash to dump core if the case-modification
+ expansions were used on a variable with a null value.
+
+ll. Fixed a bug that caused partially-quoted strings to be split incorrectly
+ if a variable with a null value was expanded within double quotes.
+
+mm. The pattern substitution word expansion has been sped up dramatically
+ when running in a locale with multibyte characters.
+
+nn. Fixed a bug that caused history -a to not write the correct lines to
+ the history file if all the new lines in the history list were added
+ since the last time the history file was read or written.
+
+oo. Fixed a bug that caused completion of a word with an unclosed `` command
+ substitution to set the prompt incorrectly.
+
+pp. Fixed a bug that caused extended globbing patterns in $HISTIGNORE or
+ $GLOBIGNORE to be incorrectly scanned.
+
+qq. Fixed a bug caused by closing file descriptors 3-20 on shell startup. The
+ shell now sets them to close-on-exec.
+
+rr. Fixed a bug that caused the exit status of `exec file' to be set incorrectly
+ if `file' was a directory.
+
+ss. Fixed a bug in the `.' builtin to make a non-interactive posix-mode shell
+ exit if the file argument to `.' is not found. Prefixing exec with
+ `command' makes the shell not exit. Posix requires this behavior.
+
+tt. Fixed a bug that caused `sh -c 'command exec; exit 1' to hang.
+
+uu. Fixed a bug in $(...) command substitution parsing that caused the shell
+ to treat backslash-newline incorrectly when parsing a comment.
+
+vv. Fixed bug that caused brace expansion sequence generation to misbehave
+ when supplied integers greater than 2**31 - 1.
+
+ww. Fixed a bug that caused failure to save file descriptors for redirections
+ to corrupt shell file descriptors.
+
+xx. Fixed a bug that caused bash-forward-shellword to not correctly handle
+ quoted strings.
+
+2. Changes to Readline
+
+a. Fixed a bug that caused the unconverted filename to be added to the list of
+ completions when the application specified filename conversion functions.
+
+b. Fixed a bug that caused the wrong filename to be passed to opendir when the
+ application has specified a filename dequoting function.
+
+c. Fixed a bug when repeating a character search in vi mode in the case where
+ there was no search to repeat.
+
+d. When show-all-if-ambiguous is set, the completion routines no longer insert
+ a common match prefix that is shorter than the text being completed.
+
+e. The full set of vi editing commands may now be used in callback mode.
+
+f. Fixed a bug that caused readline to not update its idea of the terminal
+ dimensions while running in `no-echo' mode.
+
+h. Fixed a bug that caused readline to dump core if an application called
+ rl_prep_terminal without setting rl_instream.
+
+i. Fixed a bug that caused meta-prefixed characters bound to incremental
+ search forward or backward to not be recognized if they were typed
+ subsequently.
+
+j. The incremental search code treats key sequences that map to the same
+ functions as (default) ^G, ^W, and ^Y as equivalent to those characters.
+
+k. Fixed a bug in menu-complete that caused it to misbehave with large
+ negative argument.
+
+l. Fixed a bug that caused vi-mode yank-last-arg to ring the bell when invoked
+ at the end of the line.
+
+3. New Features in Bash
+
+a. `exec -a foo' now sets $0 to `foo' in an executable shell script without a
+ leading #!.
+
+b. Subshells begun to execute command substitutions or run shell functions or
+ builtins in subshells do not reset trap strings until a new trap is
+ specified. This allows $(trap) to display the caller's traps and the
+ trap strings to persist until a new trap is set.
+
+c. `trap -p' will now show signals ignored at shell startup, though their
+ disposition still cannot be modified.
+
+d. $'...', echo, and printf understand \uXXXX and \UXXXXXXXX escape sequences.
+
+e. declare/typeset has a new `-g' option, which creates variables in the
+ global scope even when run in a shell function.
+
+f. test/[/[[ have a new -v variable unary operator, which returns success if
+ `variable' has been set.
+
+g. Posix parsing changes to allow `! time command' and multiple consecutive
+ instances of `!' (which toggle) and `time' (which have no cumulative
+ effect).
+
+h. Posix change to allow `time' as a command by itself to print the elapsed
+ user, system, and real times for the shell and its children.
+
+j. $((...)) is always parsed as an arithmetic expansion first, instead of as
+ a potential nested command substitution, as Posix requires.
+
+k. A new FUNCNEST variable to allow the user to control the maximum shell
+ function nesting (recursive execution) level.
+
+l. The mapfile builtin now supplies a third argument to the callback command:
+ the line about to be assigned to the supplied array index.
+
+m. The printf builtin has a new %(fmt)T specifier, which allows time values
+ to use strftime-like formatting.
+
+n. There is a new `compat41' shell option.
+
+o. The cd builtin has a new Posix-mandated `-e' option.
+
+p. Negative subscripts to indexed arrays, previously errors, now are treated
+ as offsets from the maximum assigned index + 1.
+
+q. Negative length specifications in the ${var:offset:length} expansion,
+ previously errors, are now treated as offsets from the end of the variable.
+
+r. Parsing change to allow `time -p --'.
+
+s. Posix-mode parsing change to not recognize `time' as a keyword if the
+ following token begins with a `-'. This means no more Posix-mode
+ `time -p'. Posix interpretation 267.
+
+t. There is a new `lastpipe' shell option that runs the last command of a
+ pipeline in the current shell context. The lastpipe option has no
+ effect if job control is enabled.
+
+u. History expansion no longer expands the `$!' variable expansion.
+
+v. Posix mode shells no longer exit if a variable assignment error occurs
+ with an assignment preceding a command that is not a special builtin.
+
+w. Non-interactive mode shells exit if -u is enabled and an attempt is made
+ to use an unset variable with the % or # expansions, the `//', `^', or
+ `,' expansions, or the parameter length expansion.
+
+x. Posix-mode shells use the argument passed to `.' as-is if a $PATH search
+ fails, effectively searching the current directory. Posix-2008 change.
+
+4. New Features in Readline
+
+a. The history library does not try to write the history filename in the
+ current directory if $HOME is unset. This closes a potential security
+ problem if the application does not specify a history filename.
+
+b. New bindable variable `completion-display-width' to set the number of
+ columns used when displaying completions.
+
+c. New bindable variable `completion-case-map' to cause case-insensitive
+ completion to treat `-' and `_' as identical.
+
+d. There are new bindable vi-mode command names to avoid readline's case-
+ insensitive matching not allowing them to be bound separately.
+
+e. New bindable variable `menu-complete-display-prefix' causes the menu
+ completion code to display the common prefix of the possible completions
+ before cycling through the list, instead of after.
+
+------------------------------------------------------------------------------
+This document details the changes between this version, bash-4.1-rc,
+and the previous version, bash-4.1-beta.
+
+1. Changes to Bash
+
+a. Fixed a bug that caused printf to not return a partial value when it
+ encountered an error while converting an integer argument.
+
+b. Fixed a bug that caused setting one of the compatNN options to not
+ turn off the others.
+
+c. The (undocumented) --wordexp option is no longer included by default.
+
+d. Fixed a bug in conditional command execution that caused it to not
+ correctly ignore the exit status under certain circumstances.
+
+e. Added a configure-time check for correctly-working asprintf/snprintf.
+
+f. Fixed some problems with line number calculation and display when sourcing
+ a file in an interactive shell.
+
+g. Fixed a bug that caused the shell to crash when using `declare -A foo=bar'.
+
+h. Fixed a bug that caused an off-by-one error when calculating the directories
+ to display with the PROMPT_DIRTRIM option.
+
+2. Changes to Readline
+
+a. Fixed a bug that caused applications using the callback interface to not
+ react to SIGINT (or other signals) until another character arrived.
+
+------------------------------------------------------------------------------
+This document details the changes between this version, bash-4.1-beta,
+and the previous version, bash-4.1-alpha.
+
+1. Changes to Bash
+
+a. Fixed a bug in mapfile that caused the shell to crash if it was passed the
+ name of an associative array.
+
+b. Fixed a bug that caused the shell to incorrectly split case patterns if
+ they contained characters in $IFS.
+
+c. Fixed a bug that caused the shell to set $? to the wrong value when using
+ a construct ending with a variable assignment with set -x enabled and PS4
+ containing a command substitution.
+
+d. Fixed a bug that caused the shell to read commands incorrectly if an
+ expansion error occurred under certain conditions in a user-specified
+ subshell.
+
+e. Fixed a bug that caused the shell to set $? incorrectly if a parse error
+ occurred in an evaluation context ("eval", trap command, dot script, etc.)
+
+f. Fixed a bug that caused the shell to attempt command substitution
+ completion within a single-quoted string.
+
+g. Fixed a bug that caused the shell to insert an extra single quote during
+ word completion.
+
+h. Fixed a bug that caused the shell to crash if invoked with the environment
+ variable EMACS having a null value.
+
+i. Fixed a bug that caused bash to incorrectly report the presence of new
+ mail in a `maildir' environment.
+
+j. Fixed a bug that caused the shell to not recognize a here-document ending
+ delimiter inside a command substitution.
+
+k. Fixed a bug that caused the shell to crash when a a dynamic array variable
+ was assigned a scalar value.
+
+2. Changes to Readline
+
+3. New Features in Bash
+
+a. The mapfile/readarray builtin no longer stores the commands it invokes via
+ callbacks in the history list.
+
+b. There is a new `compat40' shopt option.
+
+c. The < and > operators to [[ do string comparisons using the current locale
+ only if the compatibility level is greater than 40 (set to 41 by default).
+
+4. New Features in Readline
+
+------------------------------------------------------------------------------
+This document details the changes between this version, bash-4.1-alpha,
+and the previous version, bash-4.0-release.
+
+1. Changes to Bash
+
+a. Fixed bugs in the parser involving new parsing of the commands contained
+ in command substitution when the substitution is read.
+
+b. Fixed a bug that caused the shell to dump core when performing programmable
+ completion using a shell function.
+
+c. Fixed a bug in `mapfile' that caused it to invoke callbacks at the wrong
+ time.
+
+d. Fixed a bug that caused the shell to dump core when listing jobs in the
+ `exit' builtin.
+
+e. Fixed several bugs encountered when reading subscripts in associative
+ array assignments and expansions.
+
+f. Fixed a bug that under some circumstances caused an associative array to
+ be converted to an indexed array.
+
+g. Fixed a bug that caused syntax errors and SIGINT interrupts to not set
+ $? to a value > 128.
+
+h. Fixed a bug that caused the shell to remove FIFOs associated with process
+ substitution inside shell functions.
+
+i. Fixed a bug that caused terminal attributes to not be reset when the
+ `read' builtin timed out.
+
+j. Fixed a bug in brace expansion that caused unwanted zero padding of the
+ expanded terms.
+
+k. Fixed a bug that prevented the |& construct from working as intended when
+ used with a simple command with additional redirections.
+
+l. Fixed a bug with the case statment ;& terminator that caused the shell to
+ dereference a NULL pointer.
+
+m. Fixed a bug that caused assignment statements or redirections preceding
+ a simple command name to inhibit alias expansion.
+
+n. Fixed the behavior of `set -u' to conform to the latest Posix interpretation:
+ every expansion of an unset variable except $@ and $* will cause the
+ shell to exit.
+
+o. Fixed a bug that caused double-quoted expansions of $* inside word
+ expansions like ${x#$*} to not expand properly when $IFS is empty.
+
+p. Fixed a bug that caused traps to set $LINENO to the wrong value when they
+ execute.
+
+q. Fixed a bug that caused off-by-one errors when computing history lines in
+ the `fc' builtin.
+
+r. Fixed a bug that caused some terminating signals to not exit the shell
+ quickly enough, forcing the kernel to send the signal (e.g., SIGSEGV)
+ multiple times.
+
+s. Fixed a bug that caused the shell to attempt to add empty lines to the
+ history list when reading here documents.
+
+t. Made some internal changes that dramatically speeds up sequential indexed
+ array access.
+
+u. Fixed a bug that caused the shell to write past the end of a string when
+ completing a double-quoted string ending in a backslash.
+
+v. Fixed a bug that caused the shell to replace too many characters when a
+ pattern match was null in a ${foo//bar} expansion.
+
+w. Fixed bugs in the expansion of ** that caused duplicate directory names
+ and the contents of the current directory to be omitted.
+
+x. Fixed a bug that caused $? to not be set correctly when referencing an
+ unset variable with set -u and set -e enabled.
+
+y. Fixed a bug caused by executing an external program from the DEBUG trap
+ while a pipeline was running. The effect was to disturb the pipeline
+ state, occasionally causing it to hang.
+
+z. Fixed a bug that caused the ** glob expansion to dump core if it
+ encountered an unsearchable directory.
+
+aa. Fixed a bug that caused `command -v' and `command -V' to not honor the
+ path set by the -p option.
+
+bb. Fixed a bug that caused brace expansion to take place too soon in some
+ compound array assignments.
+
+cc. Fixed a bug that caused programmable completion functions' changes to
+ READLINE_POINT to not be reflected back to readline.
+
+dd. Fixed a bug that caused the shell to dump core if a trap was executed
+ during a shell assignment statement.
+
+ee. Fixed an off-by-one error when computing the number of positional
+ parameters for the ${@:0:n} expansion.
+
+ff. Fixed a problem with setting COMP_CWORD for programmable completion
+ functions that could leave it set to -1.
+
+gg. Fixed a bug that caused the ERR trap to be triggered in some cases where
+ `set -e' would not have caused the shell to exit.
+
+hh. Fixed a bug that caused changes made by `compopt' to not persist past the
+ completion function in which compopt was executed.
+
+ii. Fixed a bug that caused the list of hostname completions to not be cleared
+ when HOSTNAME was unset.
+
+jj. Fixed a bug that caused variable expansion in here documents to look in
+ any temporary environment.
+
+kk. Bash and readline can now convert file names between precomposed and
+ decomposed Unicode on Mac OS X ("keyboard" and file system forms,
+ respectively). This affects filename completion (using new
+ rl_filename_rewrite_hook), globbing, and readline redisplay.
+
+ll. The ERR and EXIT traps now see a non-zero value for $? when a parser
+ error after set -e has been enabled causes the shell to exit.
+
+mm. Fixed a bug that in brace expansion that caused zero-prefixed terms to
+ not contain the correct number of digits.
+
+nn. Fixed a bug that caused the shell to free non-allocated memory when
+ unsetting an associative array which had had a value implicitly assigned
+ to index "0".
+
+oo. Fixed a memory leak in the ${!prefix@} expansion.
+
+pp. Fixed a bug that caused printf to not correctly report all write errors.
+
+qq. Fixed a bug that caused single and double quotes to act as delimiters
+ when splitting a command line into words for programmable completion.
+
+rr. Fixed a bug that caused ** globbing that caused **/path/* to match every
+ directory, not just those matching `path'.
+
+ss. Fixed a bug that caused the shell to dump core when running `help' without
+ arguments if the terminal width was fewer than 7 characters.
+
+2. Changes to Readline
+
+a. The SIGWINCH signal handler now avoids calling the redisplay code if
+ one arrives while in the middle of redisplay.
+
+b. Changes to the timeout code to make sure that timeout values greater
+ than one second are handled better.
+
+c. Fixed a bug in the redisplay code that was triggered by a prompt
+ containing invisible characters exactly the width of the screen.
+
+d. Fixed a bug in the redisplay code encountered when running in horizontal
+ scroll mode.
+
+e. Fixed a bug that prevented menu completion from properly completing
+ filenames.
+
+f. Fixed a redisplay bug caused by a multibyte character causing a line to
+ wrap.
+
+g. Fixed a bug that caused key sequences of two characters to not be
+ recognized when a longer sequence identical in the first two characters
+ was bound.
+
+h. Fixed a bug that caused history expansion to be attempted on $'...'
+ single-quoted strings.
+
+i. Fixed a bug that caused incorrect redisplay when the prompt contained
+ multibyte characters in an `invisible' sequence bracketed by \[ and
+ \].
+
+j. Fixed a bug that caused history expansion to short-circuit after
+ encountering a multibyte character.
+
+3. New Features in Bash
+
+a. Here-documents within $(...) command substitutions may once more be
+ delimited by the closing right paren, instead of requiring a newline.
+
+b. Bash's file status checks (executable, readable, etc.) now take file
+ system ACLs into account on file systems that support them.
+
+c. Bash now passes environment variables with names that are not valid
+ shell variable names through into the environment passed to child
+ processes.
+
+d. The `execute-unix-command' readline function now attempts to clear and
+ reuse the current line rather than move to a new one after the command
+ executes.
+
+e. `printf -v' can now assign values to array indices.
+
+f. New `complete -E' and `compopt -E' options that work on the "empty"
+ completion: completion attempted on an empty command line.
+
+g. New complete/compgen/compopt -D option to define a `default' completion:
+ a completion to be invoked on command for which no completion has been
+ defined. If this function returns 124, programmable completion is
+ attempted again, allowing a user to dynamically build a set of completions
+ as completion is attempted by having the default completion function
+ install individual completion functions each time it is invoked.
+
+h. When displaying associative arrays, subscripts are now quoted.
+
+i. Changes to dabbrev-expand to make it more `emacs-like': no space appended
+ after matches, completions are not sorted, and most recent history entries
+ are presented first.
+
+j. The [[ and (( commands are now subject to the setting of `set -e' and the
+ ERR trap.
+
+k. The source/. builtin now removes NUL bytes from the file before attempting
+ to parse commands.
+
+l. There is a new configuration option (in config-top.h) that forces bash to
+ forward all history entries to syslog.
+
+m. A new variable $BASHOPTS to export shell options settable using `shopt' to
+ child processes.
+
+n. There is a new confgure option that forces the extglob option to be
+ enabled by default.
+
+o. New variable $BASH_XTRACEFD; when set to an integer bash will write xtrace
+ output to that file descriptor.
+
+p. If the optional left-hand-side of a redirection is of the form {var}, the
+ shell assigns the file descriptor used to $var or uses $var as the file
+ descriptor to move or close, depending on the redirection operator.
+
+q. The < and > operators to the [[ conditional command now do string
+ comparison according to the current locale.
+
+r. Programmable completion now uses the completion for `b' instead of `a'
+ when completion is attempted on a line like: a $(b c.
+
+s. Force extglob on temporarily when parsing the pattern argument to
+ the == and != operators to the [[ command, for compatibility.
+
+t. Changed the behavior of interrupting the wait builtin when a SIGCHLD is
+ received and a trap on SIGCHLD is set to be Posix-mode only.
+
+u. The read builtin has a new `-N nchars' option, which reads exactly NCHARS
+ characters, ignoring delimiters like newline.
+
+4. New Features in Readline
+
+a. New bindable function: menu-complete-backward.
+
+b. In the vi insertion keymap, C-n is now bound to menu-complete by default,
+ and C-p to menu-complete-backward.
+
+c. When in vi command mode, repeatedly hitting ESC now does nothing, even
+ when ESC introduces a bound key sequence. This is closer to how
+ historical vi behaves.
+
+d. New bindable function: skip-csi-sequence. Can be used as a default to
+ consume key sequences generated by keys like Home and End without having
+ to bind all keys.
+
+e. New application-settable function: rl_filename_rewrite_hook. Can be used
+ to rewite or modify filenames read from the file system before they are
+ compared to the word to be completed.
+
+f. New bindable variable: skip-completed-text, active when completing in the
+ middle of a word. If enabled, it means that characters in the completion
+ that match characters in the remainder of the word are "skipped" rather
+ than inserted into the line.
+
+g. The pre-readline-6.0 version of menu completion is available as
+ "old-menu-complete" for users who do not like the readline-6.0 version.
+
+h. New bindable variable: echo-control-characters. If enabled, and the
+ tty ECHOCTL bit is set, controls the echoing of characters corresponding
+ to keyboard-generated signals.
+
+i. New bindable variable: enable-meta-key. Controls whether or not readline
+ sends the smm/rmm sequences if the terminal indicates it has a meta key
+ that enables eight-bit characters.
+
+------------------------------------------------------------------------------
+This document details the changes between this version, bash-4.0-release,
+and the previous version, bash-4.0-rc1.
+
+1. Changes to Bash
+
+a. Changed the message printed when setlocale(3) fails to only include the
+ strerror error text if the call changes errno.
+
+b. Changed trap command execution to reset the line number before running a
+ trap (except DEBUG and RETURN traps).
+
+c. Fixed behavior of case-modifiying word expansions to not work on
+ individual words within a variable's value.
+
+d. Fixed a bug that caused mapfile to not be interruptible when run in an
+ interactive shell.
+
+e. Fixed a bug that caused mapfile to not run callbacks for the first line
+ read.
+
+f. Fixed a bug that caused mapfile to not honor EOF typed in an interactive
+ shell.
+
+g. Fixed the coprocess reaping code to not run straight from a signal handler.
+
+h. Fixed a bug that caused printf -b to ignore the first % conversion specifier
+ in the format string on 64-bit systems.
+
+i. Fixed a bug that caused incorrect word splitting when `:', `=', or `~'
+ appeared in $IFS.
+
+j. Fixed a bug that caused data corruption in the programmable completion code
+ when a shell function called from a completion aborted execution.
+
+k. Fixed a bug that caused the CPU usage reported by the `time' builtin to be
+ capped at 100%.
+
+l. Changed behavior of shell when -e option is in effect to reflect consensus
+ of Posix shell standardization working group.
+
+m. Fixed a bug introduced in bash-4.0-alpha that caused redirections to not
+ be displayed by `type' or `declare' when appearing in functions under
+ certain circumstances.
+
+2. Changes to Readline
+
+a. Fixed a bug that caused !(...) extended glob patterns to inhibit later
+ history expansion.
+
+b. Reworked the signal handling to avoid calling disallowed functions from a
+ signal handler.
+
+3. New Features in Bash
+
+a. `readarray' is now a synonym for `mapfile'.
+------------------------------------------------------------------------------
+This document details the changes between this version, bash-4.0-rc1,
+and the previous version, bash-4.0-beta2.
+
+1. Changes to Bash
+
+a. Fixed a bug that caused parsing errors when a $()-style command
+ substitution was follwed immediately by a quoted newline.
+
+b. Fixed a bug that caused extended shell globbing patterns beginning with
+ `*(' to not work when used with pattern substitution word expansions.
+
+------------------------------------------------------------------------------
+This document details the changes between this version, bash-4.0-beta2,
+and the previous version, bash-4.0-beta.
+
+1. Changes to Bash
+
+a. Fixed a bug that caused failed word expansions to set $? but not
+ PIPESTATUS.
+
+b. Changed filename completion to quote the tilde in a filename with a
+ leading tilde that exists in the current directory.
+
+c. Fixed a bug that caused a file descriptor leak when performing
+ redirections attached to a compound command.
+
+d. Fixed a bug that caused expansions of $@ and $* to not exit the shell if
+ the -u option was enabled and there were no posititional parameters.
+
+e. Fixed a bug that resulted in bash not terminating immediately if a
+ terminating signal was received while performing output.
+
+f. Fixed a bug that caused the shell to crash after creating 256 process
+ substitutions during word completion.
+
+2. Changes to Readline
+
+a. Fixed a bug that caused redisplay errors when using prompts with invisible
+ characters and numeric arguments to a command in a multibyte locale.
+
+b. Fixed a bug that caused redisplay errors when using prompts with invisible
+ characters spanning more than two physical screen lines.
+
+------------------------------------------------------------------------------
+This document details the changes between this version, bash-4.0-beta,
+and the previous version, bash-4.0-alpha.
+
+1. Changes to Bash
+
+a. Fixed a typo that caused a variable to be used before initialization
+ while parsing Posix-style command substitutions.
+
+b. Fixed a bug that caused stray ^? when the expansion of a parameter used
+ as part of a pattern removal expansion is empty, but part of a non-
+ empty string.
+
+c. Fixed a bug that could cause strings not converted to numbers by strtol
+ to be treated as if the conversion had been successful.
+
+d. The `return' builtin now accepts no options and requires a `--' before
+ a negative return value, as Posix requires.
+
+e. Fixed a bug that caused local variables to be created with the empty
+ string for a value rather than no value.
+
+f. Changed behavior so the shell now acts as if it received an interrupt
+ when a pipeline is killed by SIGINT while executing a list.
+
+g. Fixed a bug that caused `declare var' and `typeset var' to initialize
+ `var' to the empty string.
+
+h. Changed `bind' builtin to print a warning but proceed if invoked when
+ line editing is not active.
+
+i. Fixed a bug that caused the shell to exit when the `errexit' option is
+ set and a command in a pipeline returns a non-zero exit status.
+
+j. Fixed a bug that caused the shell to not run the exit trap in a command
+ run with `bash -c' under some circumstances.
+
+k. Fixed a bug that caused parser errors to occasionally not set $? when
+ running commands with `eval'.
+
+l. Fixed a bug that caused stray control characters when evaluating compound
+ array assignments containing $'\x7f' escapes.
+
+m. Fixed a bug that caused redirections involving file descriptor 10 as the
+ target to behave incorrectly.
+
+n. Fixed a bug that could cause memory to be freed multiple times when
+ assigning to COMP_WORDBREAKS.
+
+o. Fixed a bug that could cause NULL pointer dereferences when COMP_WORDBREAKS
+ was unset.
+
+2. Changes to Readline
+
+3. New Features in Bash
+
+a. A value of 0 for the -t option to `read' now returns success if there is
+ input available to be read from the specified file descriptor.
+
+b. CDPATH and GLOBIGNORE are ignored when the shell is running in privileged
+ mode.
+
+c. New bindable readline functions shell-forward-word and shell-backward-word,
+ which move forward and backward words delimited by shell metacharacters
+ and honor shell quoting.
+
+d. New bindable readline functions shell-backward-kill-word and shell-kill-word
+ which kill words backward and forward, but use the same word boundaries
+ as shell-forward-word and shell-backward-word.
+
+4. New Features in Readline
+
+a. If the kernel supports it, readline displays special characters
+ corresponding to a keyboard-generated signal when the signal is received.
+
+------------------------------------------------------------------------------
+This document details the changes between this version, bash-4.0-alpha,
+and the previous version, bash-3.2-release.
+
+1. Changes to Bash
+
+a. Fixed several bugs in old-style `` command substitution parsing, including
+ comment parsing and quoted string handling.
+
+b. Fixed problems parsing arguments to the [[ command's =~ regular expression
+ matching operator: metacharacter and whitespace parsing.
+
+c. Fixed a bug that caused the shell to inappropriately reuse high-numbered
+ file descriptors it used internally.
+
+d. Fixed a bug in pattern replacement word expansions that caused a `/' as
+ the first character of an expanded pattern to be mistaken for a global
+ replacement specifier.
+
+e. Fixed several problems with the asprintf and snprintf replacement functions
+ that caused hangs and crashes.
+
+f. Fixed a bug in the calculation of the current and previous job that caused
+ it to refer to incorrect jobs.
+
+g. Fixed a bug in the check for the validity of a hashed command pathname that
+ caused unnecessary hash table deletions and additions.
+
+h. Fixed a bug that caused child processes to inherit the wrong value for $!.
+
+i. Fixed a bug that caused `.' to fail to read and execute commands from non-
+ regular files such as devices or named pipes.
+
+j. Fixed a bug in printf formatting for the %x and %X expansions that occurred
+ on some systems.
+
+k. Fixed a bug that caused the shell to crash when creating temporary files if
+ $TMPDIR named a non-writable directory.
+
+l. Fixed a bug that caused the shell to ignore $TMPDIR when creating temporary
+ files under some circumstances.
+
+m. Fixed a bug that caused named pipes created by process substitution to not
+ be cleaned up.
+
+n. Fixed a bug that caused HISTTIMEFORMAT to not be honored when it appeared
+ in the initial shell environment.
+
+o. Fixed several bugs in the expansion of $* and $@ (quoted and unquoted)
+ when IFS is null or contains non-whitespace characters; the same changes
+ apply to arrays subscripted with * or @.
+
+p. Fixed several problems with pattern substitution expansions on the
+ positional parameters and arrays subscripted with * or @ that occurred
+ when $IFS was set to the empty string.
+
+q. Made a change to the default locale initialization code that should
+ result in better behavior from the locale-aware library functions.
+
+r. Fixed a bug that caused compacting the jobs list to drop jobs.
+
+s. Fixed a bug that caused jumps back to the top-level processing loop from
+ a builtin command to leave the shell in an inconsistent state.
+
+t. Fixed a bug that caused characters that would be escaped internally to be
+ doubled when escaped with a backslash.
+
+u. Fixed the initialization of mailboxes to not cause maildirs to be read
+ (and stat(2) called for every message file) at shell startup.
+
+v. Fixed a bug that caused the shell to not display $PS2 when the read builtin
+ reads a line continued with a backslash.
+
+w. Fixed a bug that caused errors in word splitting when $IFS contained
+ characters used for internal quoting.
+
+x. Fixed bugs that caused problems with output from shell builtins not being
+ completely displayed on some systems.
+
+y. Fixed a bug that caused output to be lost when a redirection is acting on
+ the shell's output file descriptor.
+
+z. Fixed bugs caused by shell builtins not checking for all write errors.
+
+aa. Fixed a problem that caused the shell to dump core if expansions on the
+ pattern passed to the pattern removal word expansions resulted in expansion
+ errors.
+
+bb. Fixed a bug that caused bash to loop infinitely after creating and
+ waiting for 4096 jobs.
+
+cc. Fixed a bug that caused bash to lose the status of a background job under
+ certain circumstances.
+
+dd. Fixed a bug that caused bash to not look in the temporary environment
+ when performing variable lookup under certain circumstances.
+
+ee. Fixed a bug that caused bash to close file descriptors greater than 10
+ when they were used in redirections.
+
+ff. Fixed a problem that caused the shell to attempt to read from the standard
+ input when called as `bash -i script'.
+
+gg. Fixed a memory leak and variable initialization problems when the -v option
+ was supplied to `printf' that could cause incorrect results.
+
+hh. Fixed a bug that caused the `read' builtin to count bytes when the -n option
+ was supplied, rather than (possibly multibyte) characters.
+
+ii. Fixed a bug when displaying a function due to not converting the function
+ to an external form.
+
+jj. Changed job control initialization to ensure that the shell has a tty
+ as its controlling terminal before enabling job control.
+
+kk. Fixed a bug with the `test' builtin that caused it to misinterpret
+ arguments beginning with `-' but containing more than one character.
+
+ll. Fixed bug that could cause the shell to dump core in certain cases where
+ a command sets the SIGINT disposition to the default.
+
+mm. Fixed a bug in the pattern replacement (affecting both word expansion
+ and the `fc' builtin) that occurred when the pattern and replacement
+ strings were empty.
+
+nn. Fixed a bug that caused an arithmetic evaluation error to disable all
+ further evaluation.
+
+oo. Fixed a bug in pathname expansion that caused it to interpret backslashes
+ in the pathname as quoting characters.
+
+pp. Fixed a bug in the replacement getcwd() implementation that could cause
+ memory to be overwritten.
+
+qq. When in Posix mode, the `ulimit' builtin now uses a block size of 512 for
+ the `-c' and `-f' options.
+
+rr. Brace expansion now allows process substitutions to pass through unchanged.
+
+ss. Fixed a problem in the command name completion code to avoid quoting
+ escaped special characters twice when the command name begins with a tilde.
+
+tt. Fixed a problem in the printf builtin that resulted in single-byte
+ output for the "'" escape, even when using multibyte characters.
+
+uu. Fixed a bug that caused the failure exit status to be lost when redirections
+ attached to a compound command failed.
+
+vv. Fixed a bug that caused the internal random number generator to not be
+ re-seeded correctly when creating a subshell.
+
+ww. Fixed a bug that could cause the bash replacement getcwd to overwrite
+ memory.
+
+xx. Fixed a bug that caused the shell to not receive SIGINT if it was sent
+ while the shell was waiting for a command substitution to terminate, and
+ make sure the exit status is correct when it does.
+
+yy. Fixed a bug that resulted in the second and subsequent children spawned
+ by a shell begun to run a command substitution being placed into the
+ wrong process group.
+
+zz. Fixed a bug that caused the results of successful tilde expansion to be
+ subject to pathname expansion and word splitting.
+
+aaa. Fixed a bug that could cause the shell to hang if it encountered an
+ error that caused it to jump back to the top processing loop during a
+ command substitution or `eval' command.
+
+bbb. Fixed a bug that caused the `read' builtin to use the tty's attributes
+ instead of those of the file descriptor passed with the -u option when
+ processing the -n and -d options.
+
+ccc. Fixed a bug that caused incorrect expansion of ${array[@]:foo} if the
+ first character of $IFS was not whitespace.
+
+ddd. Fixed a bug that occurred when scanning for the ending delimiter of a
+ ${parameter/pat/sub} expansion.
+
+eee. Fixed a bug that caused the shell to inappropriately expand command
+ substitutions in words when expanding directory names for completion.
+
+fff. Fixed a bug that caused the `fc' builtin to look too far back in the
+ history list under certain circumstances.
+
+ggg. Fixed a bug that caused a shell running in Posix mode to search $PWD for
+ a file specified as an argument to source/. when the file was not found
+ in $PATH.
+
+hhh. Fixed a bug that caused the shell to modify the case of a command word
+ found via command completion when the shell was performing case-
+ insensitive completion.
+
+iii. Fixed a bug that caused the shell to search $PATH for an argument to
+ source/. even when it contained a `/'.
+
+jjj. Fixed a bug that caused brace expansion to misorder expansions when the
+ locale did not have a collating order like aAbBcC...zZ.
+
+kkk. Fixed a bug that did not allow `set +o history' to have any effect when
+ run in a startup file or from a sourced file.
+
+lll. Fixed a bug with the precedence of the ?: conditional arithmetic operator.
+
+mmm. Fixed a bug that caused side effects of temporary variable assignments
+ to persist in the shell environment.
+
+nnn. Fixed a bug that caused the terminal to be left in non-canonical mode
+ when using editing commands that invoke the an editor on the current
+ command line.
+
+ooo. Fixed a bug that caused globbing characters and characters in $IFS to not
+ be quoted appropriately when displaying assignment statements.
+
+ppp. Fixed a bug that caused the `-e' option to be inherited when sourcing a
+ file or evaluating a command with `eval' even if the return value of the
+ command was supposed to be ignored.
+
+qqq. Fixed a bug that caused the shell to attempt to created variables with
+ invalid names if such names appeared in the initial environment.
+
+rrr. Fixed a bug with quote removal in strings where the final character is a
+ backslash.
+
+sss. Fixed a bug that caused the effects of special variables to persist even
+ when the variables were unset as part of the shell reinitializing itself
+ to execute a shell script.
+
+ttt. Fixed a bug that caused the history to not be saved after `history -c' or
+ `history -d' was executed until a sufficient number of commands had been
+ saved to the history.
+
+uuu. Bash now parses command substitutions according to Posix rules: parsing
+ the command contained in $() to find the closing delimiter.
+
+vvv. Fixed a bug that caused traps on SIGCHLD set in a SIGCHLD handler to
+ not persist.
+
+www. Fixed a bug that didn't allow SIGCHLD to interrupt the `wait' builtin
+ as Posix specifies.
+
+xxx. Invalid numeric arguments to shell builtins no longer cause the shell to
+ short-circuit any executing compound command.
+
+yyy. Fixed a bug that caused the exit status to be lost when `break' was
+ used to short-circuit a loop's execution.
+
+zzz. Fixed a bug that caused stray ^? characters to be left in expansions of
+ "${array[*]}".
+
+aaaa. Bash now prints better error messages for here documents terminated by
+ EOF and for identifying the incorrect token in an invalid arithmetic
+ expression.
+
+bbbb. Fixed a bug in the variable length word expansion that caused it to
+ incorrectly calculate the number of multibyte characters.
+
+cccc. Fixed a race condition that could result in the top-level shell setting
+ the terminal's process group to an incorrect value if the process
+ group was changed by a child of a child of the shell.
+
+dddd. Fixed a bug that caused here documents belonging to commands within a
+ compound command to be displayed in a syntactially-incorrect form, which
+ prevented them from being re-read as input.
+
+eeee. The shell displays more warnings about failures to set the locale.
+
+ffff. Fixed a bug that caused the body of a here-document to not be saved to
+ the history list.
+
+gggg. Fixed a bug that caused configure to incorrectly conclude that FreeBSD
+ had /dev/fd available, resulting in problems with process substitution.
+
+2. Changes to Readline
+
+a. Fixed a number of redisplay errors in environments supporting multibyte
+ characters.
+
+b. Fixed bugs in vi command mode that caused motion commands to inappropriately
+ set the mark.
+
+c. When using the arrow keys in vi insertion mode, readline allows movement
+ beyond the current end of the line (unlike command mode).
+
+d. Fixed bugs that caused readline to loop when the terminal has been taken
+ away and reads return -1/EIO.
+
+e. Fixed bugs in redisplay occurring when displaying prompts containing
+ invisible characters.
+
+f. Fixed a bug that caused the completion append character to not be reset to
+ the default after an application-specified completion function changed it.
+
+g. Fixed a problem that caused incorrect positioning of the cursor while in
+ emacs editing mode when moving forward at the end of a line while using
+ a locale supporting multibyte characters.
+
+h. Fixed an off-by-one error that caused readline to drop every 511th
+ character of buffered input.
+
+i. Fixed a bug that resulted in SIGTERM not being caught or cleaned up.
+
+j. Fixed redisplay bugs caused by multiline prompts with invisible characters
+ or no characters following the final newline.
+
+k. Fixed redisplay bug caused by prompts consisting solely of invisible
+ characters.
+
+l. Fixed a bug in the code that buffers characters received very quickly in
+ succession which caused characters to be dropped.
+
+m. Fixed a bug that caused readline to reference uninitialized data structures
+ if it received a SIGWINCH before completing initialzation.
+
+n. Fixed a bug that caused the vi-mode `last command' to be set incorrectly
+ and therefore unrepeatable.
+
+o. Fixed a bug that caused readline to disable echoing when it was being used
+ with an output file descriptor that was not a terminal.
+
+p. Readline now blocks SIGINT while manipulating internal data structures
+ during redisplay.
+
+q. Fixed a bug in redisplay that caused readline to segfault when pasting a
+ very long line (over 130,000 characters).
+
+r. Fixed bugs in redisplay when using prompts with no visible printing
+ characters.
+
+3. New Features in Bash
+
+a. When using substring expansion on the positional parameters, a starting
+ index of 0 now causes $0 to be prefixed to the list.
+
+b. The `help' builtin now prints its columns with entries sorted vertically
+ rather than horizontally.
+
+c. There is a new variable, $BASHPID, which always returns the process id of
+ the current shell.
+
+d. There is a new `autocd' option that, when enabled, causes bash to attempt
+ to `cd' to a directory name that is supplied as the first word of a
+ simple command.
+
+e. There is a new `checkjobs' option that causes the shell to check for and
+ report any running or stopped jobs at exit.
+
+f. The programmable completion code exports a new COMP_TYPE variable, set to
+ a character describing the type of completion being attempted.
+
+g. The programmable completion code exports a new COMP_KEY variable, set to
+ the character that caused the completion to be invoked (e.g., TAB).
+
+h. If creation of a child process fails due to insufficient resources, bash
+ will try again several times before reporting failure.
+
+i. The programmable completion code now uses the same set of characters as
+ readline when breaking the command line into a list of words.
+
+j. The block multiplier for the ulimit -c and -f options is now 512 when in
+ Posix mode, as Posix specifies.
+
+k. Changed the behavior of the read builtin to save any partial input received
+ in the specified variable when the read builtin times out. This also
+ results in variables specified as arguments to read to be set to the empty
+ string when there is no input available. When the read builtin times out,
+ it returns an exit status greater than 128.
+
+l. The shell now has the notion of a `compatibility level', controlled by
+ new variables settable by `shopt'. Setting this variable currently
+ restores the bash-3.1 behavior when processing quoted strings on the rhs
+ of the `=~' operator to the `[[' command.
+
+m. The `ulimit' builtin now has new -b (socket buffer size) and -T (number
+ of threads) options.
+
+n. The -p option to `declare' now displays all variable values and attributes
+ (or function values and attributes if used with -f).
+
+o. There is a new `compopt' builtin that allows completion functions to modify
+ completion options for existing completions or the completion currently
+ being executed.
+
+p. The `read' builtin has a new -i option which inserts text into the reply
+ buffer when using readline.
+
+q. A new `-E' option to the complete builtin allows control of the default
+ behavior for completion on an empty line.
+
+r. There is now limited support for completing command name words containing
+ globbing characters.
+
+s. Changed format of internal help documentation for all builtins to roughly
+ follow man page format.
+
+t. The `help' builtin now has a new -d option, to display a short description,
+ and a -m option, to print help information in a man page-like format.
+
+u. There is a new `mapfile' builtin to populate an array with lines from a
+ given file.
+
+v. If a command is not found, the shell attempts to execute a shell function
+ named `command_not_found_handle', supplying the command words as the
+ function arguments.
+
+w. There is a new shell option: `globstar'. When enabled, the globbing code
+ treats `**' specially -- it matches all directories (and files within
+ them, when appropriate) recursively.
+
+x. There is a new shell option: `dirspell'. When enabled, the filename
+ completion code performs spelling correction on directory names during
+ completion.
+
+y. The `-t' option to the `read' builtin now supports fractional timeout
+ values.
+
+z. Brace expansion now allows zero-padding of expanded numeric values and
+ will add the proper number of zeroes to make sure all values contain the
+ same number of digits.
+
+aa. There is a new bash-specific bindable readline function: `dabbrev-expand'.
+ It uses menu completion on a set of words taken from the history list.
+
+bb. The command assigned to a key sequence with `bind -x' now sets two new
+ variables in the environment of the executed command: READLINE_LINE_BUFFER
+ and READLINE_POINT. The command can change the current readline line
+ and cursor position by modifying READLINE_LINE_BUFFER and READLINE_POINT,
+ respectively.
+
+cc. There is a new &>> redirection operator, which appends the standard output
+ and standard error to the named file.
+
+dd. The parser now understands `|&' as a synonym for `2>&1 |', which redirects
+ the standard error for a command through a pipe.
+
+ee. The new `;&' case statement action list terminator causes execution to
+ continue with the action associated with the next pattern in the
+ statement rather than terminating the command.
+
+ff. The new `;;&' case statement action list terminator causes the shell to
+ test the next set of patterns after completing execution of the current
+ action, rather than terminating the command.
+
+gg. The shell understands a new variable: PROMPT_DIRTRIM. When set to an
+ integer value greater than zero, prompt expansion of \w and \W will
+ retain only that number of trailing pathname components and replace
+ the intervening characters with `...'.
+
+hh. There are new case-modifying word expansions: uppercase (^[^]) and
+ lowercase (,[,]). They can work on either the first character or
+ array element, or globally. They accept an optional shell pattern
+ that determines which characters to modify. There is an optionally-
+ configured feature to include capitalization operators.
+
+ii. The shell provides associative array variables, with the appropriate
+ support to create, delete, assign values to, and expand them.
+
+jj. The `declare' builtin now has new -l (convert value to lowercase upon
+ assignment) and -u (convert value to uppercase upon assignment) options.
+ There is an optionally-configurable -c option to capitalize a value at
+ assignment.
+
+kk. There is a new `coproc' reserved word that specifies a coprocess: an
+ asynchronous command run with two pipes connected to the creating shell.
+ Coprocs can be named. The input and output file descriptors and the
+ PID of the coprocess are available to the calling shell in variables
+ with coproc-specific names.
+
+4. New Features in Readline
+
+a. A new variable, rl_sort_completion_matches; allows applications to inhibit
+ match list sorting (but beware: some things don't work right if
+ applications do this).
+
+b. A new variable, rl_completion_invoking_key; allows applications to discover
+ the key that invoked rl_complete or rl_menu_complete.
+
+c. The functions rl_block_sigint and rl_release_sigint are now public and
+ available to calling applications who want to protect critical sections
+ (like redisplay).
+
+d. The functions rl_save_state and rl_restore_state are now public and
+ available to calling applications; documented rest of readline's state
+ flag values.
+
+e. A new user-settable variable, `history-size', allows setting the maximum
+ number of entries in the history list.
+
+f. There is a new implementation of menu completion, with several improvements
+ over the old; the most notable improvement is a better `completions
+ browsing' mode.
+
+g. The menu completion code now uses the rl_menu_completion_entry_function
+ variable, allowing applications to provide their own menu completion
+ generators.
+
+h. There is support for replacing a prefix of a pathname with a `...' when
+ displaying possible completions. This is controllable by setting the
+ `completion-prefix-display-length' variable. Matches with a common prefix
+ longer than this value have the common prefix replaced with `...'.
+
+i. There is a new `revert-all-at-newline' variable. If enabled, readline will
+ undo all outstanding changes to all history lines when `accept-line' is
+ executed.
+
+------------------------------------------------------------------------------
+This document details the changes between this version, bash-3.2-release,
+and the previous version, bash-3.2-beta.
+
+1. Changes to Bash
+
+a. Fixed a bug that caused the temporary environment passed to a command to
+ affect the shell's environment under certain circumstances.
+
+b. Fixed a bug in the printf builtin that caused the %q format specifier to
+ ignore empty string arguments.
+
+c. Improved multibyte character environment detection at configuration time.
+
+d. Fixed a bug in the read builtin that left spurious escape characters in the
+ input after processing backslashes when assigning to an array variable.
+
+2. Changes to Readline
+
+a. Fixed a redisplay bug that occurred in multibyte-capable locales when the
+ prompt was one character longer than the screen width.
+------------------------------------------------------------------------------
+This document details the changes between this version, bash-3.2-beta,
+and the previous version, bash-3.2-alpha.
+
+1. Changes to Bash
+
+a. Changed the lexical analyzer to treat locale-specific blank characters as
+ white space.
+
+b. Fixed a bug in command printing to avoid confusion between redirections and
+ process substitution.
+
+c. Fixed problems with cross-compiling originating from inherited environment
+ variables.
+
+d. Added write error reporting to printf builtin.
+
+e. Fixed a bug in the variable expansion code that could cause a core dump in
+ a multi-byte locale.
+
+f. Fixed a bug that caused substring expansion of a null string to return
+ incorrect results.
+
+g. BASH_COMMAND now retains its previous value while executing commands as the
+ result of a trap, as the documentation states.
+
+2. Changes to Readline
+
+a. Fixed a bug with prompt redisplay in a multi-byte locale to avoid redrawing
+ the prompt and input line multiple times.
+
+b. Fixed history expansion to not be confused by here-string redirection.
+
+c. Readline no longer treats read errors by converting them to newlines, as
+ it does with EOF. This caused partial lines to be returned from readline().
+
+------------------------------------------------------------------------------
+This document details the changes between this version, bash-3.2-alpha,
+and the previous version, bash-3.1-release.
+
+1. Changes to Bash
+
+a. Fixed a source bug that caused the minimal configuration to not compile.
+
+b. Fixed memory leaks in error handling for the `read' builtin.
+
+c. Changed the [[ and (( compound commands to set PIPESTATUS with their exit
+ status.
+
+d. Fixed some parsing problems with compound array assignments.
+
+e. Added additional configuration changes for: NetBSD (incomplete multibyte
+ character support)
+
+f. Fixed two bugs with local array variable creation when shadowing a variable
+ of the same name from a previous context.
+
+g. Fixed the `read' builtin to restore the correct set of completion functions
+ if a timeout occurs.
+
+h. Added code to defer the initialization of HISTSIZE (and its stifling of the
+ history list) until the history file is loaded, allowing a startup file to
+ override the default value.
+
+i. Tightened up the arithmetic expression parsing to produce better error
+ messages when presented with invalid operators.
+
+j. Fixed the cross-compilation support to build the signal list at shell
+ invocation rather than compile time if cross-compiling.
+
+k. Fixed multibyte support for non-gcc compilers (or compilers that do not
+ allow automatic array variable sizing based on a non-constant value).
+
+l. Several fixes to the code that manages the list of terminated jobs and
+ their exit statuses, and the list of active and recently-terminated jobs
+ to avoid pid aliasing/wraparound and allocation errors.
+
+m. Fixed a problem that allowed scripts to die due to SIGINT while waiting
+ for children, even when started in the background or otherwise ignoring
+ SIGINT.
+
+n. Fixed a bug that caused shells invoked as -/bin/bash from not being
+ recognized as login shells.
+
+o. Fixed a problem that caused shells in the background to give the terminal
+ to a process group other than the foreground shell process group.
+
+p. Fixed a problem with extracting the `varname' in ${#varname}.
+
+q. Fixed the code that handles SIGQUIT to not exit immediately -- thereby
+ calling functions that may not be called in a signal handler context --
+ but set a flag and exit afterward (like SIGINT).
+
+r. Changed the brace expansion code to skip over braces that don't begin a
+ valid matched brace expansion construct.
+
+s. Fixed `typeset' and `declare' to not require that their shell function
+ operands to be valid shell identifiers.
+
+t. Changed `test' to use access(2) with a temporary uid/euid swap when testing
+ file attributes and running setuid, and access(2) in most other cases.
+
+u. Changed completion code to not attempt command name completion on a line
+ consisting solely of whitespace when no_empty_command_completion is set.
+
+v. The `hash' builtin now prints nothing in posix mode when the hash table is
+ empty, and prints a message to that effect to stdout instead of stderr
+ when not in posix mode.
+
+w. Fixed a bug in the extended pattern matching code that caused it to fail to
+ match periods with certain patterns.
+
+x. Fixed a bug that caused the shell to dump core when performing filename
+ generation in directories with thousands of files.
+
+y. Returned to the original Bourne shell rules for parsing ``: no recursive
+ parsing of embedded quoted strings or ${...} constructs.
+
+z. The inheritence of the DEBUG, RETURN, and ERR traps is now dependent only
+ on the settings of the `functrace' and `errtrace' shell options, rather
+ than whether or not the shell is in debugging mode.
+
+aa. Fixed a problem with $HOME being converted to ~ in the expansion of
+ members of the DIRSTACK array.
+
+bb. Fixed a problem with quoted arguments to arithmetic expansions in certain
+ constructs.
+
+cc. The command word completion code now no longer returns matching directories
+ while searching $PATH.
+
+dd. Fixed a bug with zero-padding and precision handling in snprintf()
+ replacement.
+
+ee. Fixed a bug that caused the command substitution code not to take embedded
+ shell comments into account.
+
+ff. Fixed a bug that caused $((...);(...)) to be misinterpreted as an
+ arithmetic substitution.
+
+gg. Fixed a bug in the prompt expansion code that inappropriately added a
+ \001 before a \002 under certain circumstances.
+
+hh. Fixed a bug that caused `unset LANG' to not properly reset the locale
+ (previous versions would set the locale back to what it was when bash
+ was started rather than the system's "native" locale).
+
+ii. Fixed a bug that could cause file descriptors > 10 to not be closed even
+ when closed explicitly by a script.
+
+jj. Fixed a bug that caused single quotes to be stripped from ANSI-C quoting
+ inside double-quoted command substitutions.
+
+kk. Fixed a bug that could cause core dumps when `return' was executed as the
+ last element of a pipeline inside a shell function.
+
+ll. Fixed a bug that caused DEBUG trap strings to overwrite commands stored in
+ the jobs list.
+
+2. Changes to Readline
+
+a. Fixed a problem that caused segmentation faults when using readline in
+ callback mode and typing consecutive DEL characters on an empty line.
+
+b. Fixed several redisplay problems with multibyte characters, all having to
+ do with the different code paths and variable meanings between single-byte
+ and multibyte character redisplay.
+
+c. Fixed a problem with key sequence translation when presented with the
+ sequence \M-\C-x.
+
+d. Fixed a problem that prevented the `a' command in vi mode from being
+ undone and redone properly.
+
+e. Fixed a problem that prevented empty inserts in vi mode from being undone
+ properly.
+
+f. Fixed a problem that caused readline to initialize with an incorrect idea
+ of whether or not the terminal can autowrap.
+
+g. Fixed output of key bindings (like bash `bind -p') to honor the setting of
+ convert-meta and use \e where appropriate.
+
+h. Changed the default filename completion function to call the filename
+ dequoting function if the directory completion hook isn't set. This means
+ that any directory completion hooks need to dequote the directory name,
+ since application-specific hooks need to know how the word was quoted,
+ even if no other changes are made.
+
+i. Fixed a bug with creating the prompt for a non-interactive search string
+ when there are non-printing characters in the primary prompt.
+
+j. Fixed a bug that caused prompts with invisible characters to be redrawn
+ multiple times in a multibyte locale.
+
+k. Fixed a bug that could cause the key sequence scanning code to return the
+ wrong function.
+
+l. Fixed a problem with the callback interface that caused it to fail when
+ using multi-character keyboard macros.
+
+m. Fixed a bug that could cause a core dump when an edited history entry was
+ re-executed under certain conditions.
+
+n. Fixed a bug that caused readline to reference freed memory when attmpting
+ to display a portion of the prompt.
+
+3. New Features in Bash
+
+a. Changed the parameter pattern replacement functions to not anchor the
+ pattern at the beginning of the string if doing global replacement - that
+ combination doesn't make any sense.
+
+b. When running in `word expansion only' mode (--wordexp option), inhibit
+ process substitution.
+
+c. Loadable builtins now work on MacOS X 10.[34].
+
+d. Shells running in posix mode no longer set $HOME, as POSIX requires.
+
+e. The code that checks for binary files being executed as shell scripts now
+ checks only for NUL rather than any non-printing character.
+
+f. Quoting the string argument to the [[ command's =~ operator now forces
+ string matching, as with the other pattern-matching operators.
+
+4. New Features in Readline
+
+a. Calling applications can now set the keyboard timeout to 0, allowing
+ poll-like behavior.
+
+b. The value of SYS_INPUTRC (configurable at compilation time) is now used as
+ the default last-ditch startup file.
+
+c. The history file reading functions now allow windows-like \r\n line
+ terminators.
+
+------------------------------------------------------------------------------
This document details the changes between this version, bash-3.1-release,
and the previous version, bash-3.1-rc2.
1. Changes to Bash
-a. Fixed a bug that could cause core dumps due of accessing the current
+a. Fixed a bug that could cause core dumps due to accessing the current
pipeline while in the middle of modifying it.
b. Fixed a bug that caused pathnames with backslashes still quoting characters
projects / thirdparty / bash.git / blobdiff