Update to bash-4.1

1 files changed, 321 insertions, 0 deletions

diff --git a/NEWS b/NEWS
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--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,318 @@
+This is a terse description of the new features added to bash-4.1 since
+the release of bash-4.0.  As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1.  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 if the compatibility level
+    is greater than 40.
+
+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.
+
+v.  The mapfile/readarray builtin no longer stores the commands it invokes via
+    callbacks in the history list.
+
+w.  There is a new `compat40' shopt option.
+
+2.  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 is a terse description of the new features added to bash-4.0 since
+the release of bash-3.2.  As always, the manual page (doc/bash.1) is
+the place to look for complete descriptions.
+
+1.  New Features in Bash
+
+a.  When using substring expansion on the positional parameters, a starting
+    index of 0 now causes $0 to be prefixed to the list.
+
+b.  The `help' builtin now prints its columns with entries sorted vertically
+    rather than horizontally.
+
+c.  There is a new variable, $BASHPID, which always returns the process id of
+    the current shell.
+
+d.  There is a new `autocd' option that, when enabled, causes bash to attempt
+    to `cd' to a directory name that is supplied as the first word of a
+    simple command.
+
+e.  There is a new `checkjobs' option that causes the shell to check for and
+    report any running or stopped jobs at exit.
+
+f.  The programmable completion code exports a new COMP_TYPE variable, set to
+    a character describing the type of completion being attempted.
+
+g.  The programmable completion code exports a new COMP_KEY variable, set to
+    the character that caused the completion to be invoked (e.g., TAB).
+
+h.  If creation of a child process fails due to insufficient resources, bash
+    will try again several times before reporting failure.
+
+i.  The programmable completion code now uses the same set of characters as
+    readline when breaking the command line into a list of words.
+
+j.  The block multiplier for the ulimit -c and -f options is now 512 when in
+    Posix mode, as Posix specifies.
+
+k.  Changed the behavior of the read builtin to save any partial input received
+    in the specified variable when the read builtin times out.  This also
+    results in variables specified as arguments to read to be set to the empty
+    string when there is no input available.  When the read builtin times out,
+    it returns an exit status greater than 128.
+
+l.  The shell now has the notion of a `compatibility level', controlled by
+    new variables settable by `shopt'.  Setting this variable currently
+    restores the bash-3.1 behavior when processing quoted strings on the rhs
+    of the `=~' operator to the `[[' command.
+
+m.  The `ulimit' builtin now has new -b (socket buffer size) and -T (number
+    of threads) options.
+
+n.  The -p option to `declare' now displays all variable values and attributes
+    (or function values and attributes if used with -f).
+
+o.  There is a new `compopt' builtin that allows completion functions to modify
+    completion options for existing completions or the completion currently
+    being executed.
+
+p.  The `read' builtin has a new -i option which inserts text into the reply
+    buffer when using readline.
+
+q.  A new `-E' option to the complete builtin allows control of the default
+    behavior for completion on an empty line.
+
+r.  There is now limited support for completing command name words containing
+    globbing characters.
+
+s.  Changed format of internal help documentation for all builtins to roughly
+    follow man page format.
+
+t.  The `help' builtin now has a new -d option, to display a short description,
+    and a -m option, to print help information in a man page-like format.
+
+u.  There is a new `mapfile' builtin to populate an array with lines from a
+    given file.  The name `readarray' is a synonym.
+
+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.
+
+ll. A value of 0 for the -t option to `read' now returns success if there is
+    input available to be read from the specified file descriptor.
+
+mm. CDPATH and GLOBIGNORE are ignored when the shell is running in privileged
+    mode.
+
+nn. New bindable readline functions shell-forward-word and shell-backward-word,
+    which move forward and backward words delimited by shell metacharacters
+    and honor shell quoting.
+
+oo.  New bindable readline functions shell-backward-kill-word and shell-kill-word
+    which kill words backward and forward, but use the same word boundaries
+    as shell-forward-word and shell-backward-word.
+
+2.  New Features in Readline
+
+a.  A new variable, rl_sort_completion_matches; allows applications to inhibit
+    match list sorting (but beware: some things don't work right if
+    applications do this).
+
+b.  A new variable, rl_completion_invoking_key; allows applications to discover
+    the key that invoked rl_complete or rl_menu_complete.
+
+c.  The functions rl_block_sigint and rl_release_sigint are now public and
+    available to calling applications who want to protect critical sections
+    (like redisplay).
+
+d.  The functions rl_save_state and rl_restore_state are now public and
+    available to calling applications; documented rest of readline's state
+    flag values.
+
+e.  A new user-settable variable, `history-size', allows setting the maximum
+    number of entries in the history list.
+
+f.  There is a new implementation of menu completion, with several improvements
+    over the old; the most notable improvement is a better `completions
+    browsing' mode.
+
+g.  The menu completion code now uses the rl_menu_completion_entry_function
+    variable, allowing applications to provide their own menu completion
+    generators.
+
+h.  There is support for replacing a prefix  of a pathname with a `...' when
+    displaying possible completions.  This is controllable by setting the
+    `completion-prefix-display-length' variable.  Matches with a common prefix
+    longer than this value have the common prefix replaced with `...'.
+
+i.  There is a new `revert-all-at-newline' variable.  If enabled, readline will
+    undo all outstanding changes to all history lines when `accept-line' is
+    executed.
+
+j.  If the kernel supports it, readline displays special characters
+    corresponding to a keyboard-generated signal when the signal is received.
+
+-------------------------------------------------------------------------------
 This is a terse description of the new features added to bash-3.2 since
 the release of bash-3.1.  As always, the manual page (doc/bash.1) is
 the place to look for complete descriptions.
@@ -1212,3 +1527,9 @@ e.  There are new library functions and variables available to application
 
 f.  The NEWLINE character (^J) is now treated as a search terminator by the
     incremental search functions.
+-------------------------------------------------------------------------------
+
+Copying and distribution of this file, with or without modification,
+are permitted in any medium without royalty provided the copyright
+notice and this notice are preserved.  This file is offered as-is,
+without any warranty.