NEWS

   1 This is a terse description of the new features added to bash-2.05 since
   2 the release of bash-2.04.  As always, the manual page (doc/bash.1) is
   3 the place to look for complete descriptions.
   4
   5 1.  New Features in Bash
   6
   7 a.  Added a new `--init-file' invocation argument as a synonym for `--rcfile',
   8     per the new GNU coding standards.
   9
  10 b.  The /dev/tcp and /dev/udp redirections now accept service names as well as
  11     port numbers.
  12
  13 c.  `complete' and `compgen' now take a `-o value' option, which controls some
  14     of the aspects of that compspec.  Valid values are:
  15
  16         default - perform bash default completion if programmable
  17                   completion produces no matches
  18         dirnames - perform directory name completion if programmable
  19                    completion produces no matches
  20         filenames - tell readline that the compspec produces filenames,
  21                     so it can do things like append slashes to
  22                     directory names and suppress trailing spaces
  23
  24 d.  A new loadable builtin, realpath, which canonicalizes and expands symlinks
  25     in pathname arguments.
  26
  27 e.  When `set' is called without options, it prints function defintions in a
  28     way that allows them to be reused as input.  This affects `declare' and
  29     `declare -p' as well.  This only happens when the shell is not in POSIX
  30     mode, since POSIX.2 forbids this behavior.
  31
  32 f.  Bash-2.05 once again honors the current locale setting when processing
  33     ranges within pattern matching bracket expressions (e.g., [A-Z]).
  34
  35 2.  New Features in Readline
  36
  37 a.  The blink timeout for paren matching is now settable by applications,
  38     via the rl_set_paren_blink_timeout() function.
  39
  40 b.  _rl_executing_macro has been renamed to rl_executing_macro, which means
  41     it's now part of the public interface.
  42
  43 c.  Readline has a new variable, rl_readline_state, which is a bitmap that
  44     encapsulates the current state of the library; intended for use by
  45     callbacks and hook functions.
  46
  47 d.  New application-callable function rl_set_prompt(const char *prompt):
  48     expands its prompt string argument and sets rl_prompt to the result.
  49
  50 e.  New application-callable function rl_set_screen_size(int rows, int cols):
  51     public method for applications to set readline's idea of the screen
  52     dimensions.
  53
  54 f.  New function, rl_get_screen_size (int *rows, int *columns), returns
  55     readline's idea of the screen dimensions.
  56
  57 g.  The timeout in rl_gather_tyi (readline keyboard input polling function)
  58     is now settable via a function (rl_set_keyboard_input_timeout()).
  59
  60 h.  Renamed the max_input_history variable to history_max_entries; the old
  61     variable is maintained for backwards compatibility.
  62
  63 i.  The list of characters that separate words for the history tokenizer is
  64     now settable with a variable:  history_word_delimiters.  The default
  65     value is as before.
  66
  67 -------------------------------------------------------------------------------
  68 This is a terse description of the new features added to bash-2.04 since
  69 the release of bash-2.03.  As always, the manual page (doc/bash.1) is
  70 the place to look for complete descriptions.
  71
  72 1.  New Features in Bash
  73
  74 a.  The history builtin has a `-d offset' option to delete the history entry
  75     at position `offset'.
  76
  77 b.  The prompt expansion code has two new escape sequences: \j, the number of
  78     active jobs; and \l, the basename of the shell's tty device name.
  79
  80 c.  The `bind' builtin has a new `-x' option to bind key sequences to shell
  81     commands.
  82
  83 d.  There is a new shell option, no_empty_command_completion, which, when
  84     enabled, disables command completion when TAB is typed on an empty line.
  85
  86 e.  The `help' builtin has a `-s' option to just print a builtin's usage
  87     synopsis.
  88
  89 f.  There are several new arithmetic operators:  id++, id-- (variable
  90     post-increment/decrement), ++id, --id (variabl pre-increment/decrement),
  91     expr1 , expr2 (comma operator).
  92
  93 g.  There is a new ksh-93 style arithmetic for command:
  94         for ((expr1 ; expr2; expr3 )); do list; done
  95
  96 h.  The `read' builtin has a number of new options:
  97         -t timeout      only wait timeout seconds for input
  98         -n nchars       only read nchars from input instead of a full line
  99         -d delim        read until delim rather than newline
 100         -s              don't echo input chars as they are read
 101
 102 i.  The redirection code now handles several filenames specially:
 103     /dev/fd/N, /dev/stdin, /dev/stdout, and /dev/stderr, whether or
 104     not they are present in the file system.
 105
 106 j.  The redirection code now recognizes pathnames of the form
 107     /dev/tcp/host/port and /dev/udp/host/port, and tries to open a socket
 108     of the appropriate type to the specified port on the specified host.
 109
 110 k.  The ksh-93 ${!prefix*} expansion, which expands to the names of all
 111     shell variables with prefix PREFIX, has been implemented.
 112
 113 l.  There is a new dynamic variable, FUNCNAME, which expands to the name of
 114     a currently-executing function.  Assignments to FUNCNAME have no effect.
 115
 116 m.  The GROUPS variable is no longer readonly; assignments to it are silently
 117     discarded.  This means it can be unset.
 118
 119 n.  A new programmable completion facility, with two new builtin commands:
 120     complete and compgen.
 121
 122 o.  configure has a new option, `--enable-progcomp', to compile in the
 123     programmable completion features (enabled by default).
 124
 125 p.  `shopt' has a new option, `progcomp', to enable and disable programmable
 126     completion at runtime.
 127
 128 q.  Unsetting HOSTFILE now clears the list of hostnames used for completion.
 129
 130 r.  configure has a new option, `--enable-bash-malloc', replacing the old
 131     `--with-gnu-malloc' (which is still present for backwards compatibility).
 132
 133 s.  There is a new manual page describing rbash, the restricted shell.
 134
 135 t.  `bashbug' has new `--help' and `--version' options.
 136
 137 u.  `shopt' has a new `xpg_echo' option, which controls the behavior of
 138     `echo' with respect to backslash-escaped characters at runtime.
 139
 140 v.  If NON_INTERACTIVE_LOGIN_SHELLS is defined, all login shells read the
 141     startup files, even if they are not interactive.
 142
 143 w.  The LC_NUMERIC variable is now treated specially, and used to set the
 144     LC_NUMERIC locale category for number formatting, e.g., when `printf'
 145     displays floating-point numbers.
 146
 147 2.  New features in Readline
 148
 149 a.  Parentheses matching is now always compiled into readline, and enabled
 150     or disabled when the value of the `blink-matching-paren' variable is
 151     changed.
 152
 153 b.  MS-DOS systems now use ~/_inputrc as the last-ditch inputrc filename.
 154
 155 c.  MS-DOS systems now use ~/_history as the default history file.
 156
 157 d.  history-search-{forward,backward} now leave the point at the end of the
 158     line when the string to search for is empty, like
 159     {reverse,forward}-search-history.
 160
 161 e.  history-search-{forward,backward} now leave the last history line found
 162     in the readline buffer if the second or subsequent search fails.
 163
 164 f.  New function for use by applications:  rl_on_new_line_with_prompt, used
 165     when an application displays the prompt itself before calling readline().
 166
 167 g.  New variable for use by applications:  rl_already_prompted.  An application
 168     that displays the prompt itself before calling readline() must set this to
 169     a non-zero value.
 170
 171 h.  A new variable, rl_gnu_readline_p, always 1.  The intent is that an
 172     application can verify whether or not it is linked with the `real'
 173     readline library or some substitute.
 174
 175 -------------------------------------------------------------------------------
 176 This is a terse description of the new features added to bash-2.03 since
 177 the release of bash-2.02.  As always, the manual page (doc/bash.1) is
 178 the place to look for complete descriptions.
 179
 180 1.  New Features in Bash
 181
 182 a.  New `shopt' option, `restricted_shell', indicating whether or not the
 183     shell was started in restricted mode, for use in startup files.
 184
 185 b.  Filename generation is now performed on the words between ( and ) in
 186     array assignments (which it probably should have done all along).
 187
 188 c.  OLDPWD is now auto-exported, as POSIX.2 seems to require.
 189
 190 d.  ENV and BASH_ENV are read-only variables in a restricted shell.
 191
 192 e.  A change was made to the startup file code so that any shell begun with
 193     the `--login' option, even non-interactive shells, will source the login
 194     shell startup files.
 195
 196 2.  New Features in Readline
 197
 198 a.  Many changes to the signal handling:
 199         o Readline now catches SIGQUIT and cleans up the tty before returning;
 200         o A new variable, rl_catch_signals, is available to application writers
 201           to indicate to readline whether or not it should install its own
 202           signal handlers for SIGINT, SIGTERM, SIGQUIT, SIGALRM, SIGTSTP,
 203           SIGTTIN, and SIGTTOU;
 204         o A new variable, rl_catch_sigwinch, is available to application
 205           writers to indicate to readline whether or not it should install its
 206           own signal handler for SIGWINCH, which will chain to the calling
 207           applications's SIGWINCH handler, if one is installed;
 208         o There is a new function, rl_free_line_state, for application signal
 209           handlers to call to free up the state associated with the current
 210           line after receiving a signal;
 211         o There is a new function, rl_cleanup_after_signal, to clean up the
 212           display and terminal state after receiving a signal;
 213         o There is a new function, rl_reset_after_signal, to reinitialize the
 214           terminal and display state after an application signal handler
 215           returns and readline continues
 216
 217 b.  There is a new function, rl_resize_terminal, to reset readline's idea of
 218     the screen size after a SIGWINCH.
 219
 220 c.  New public functions: rl_save_prompt and rl_restore_prompt.  These were
 221     previously private functions with a `_' prefix.
 222
 223 d.  New function hook: rl_pre_input_hook, called just before readline starts
 224     reading input, after initialization.
 225
 226 e.  New function hook: rl_display_matches_hook, called when readline would
 227     display the list of completion matches.  The new function
 228     rl_display_match_list is what readline uses internally, and is available
 229     for use by application functions called via this hook.
 230
 231 f.  New bindable function, delete-char-or-list, like tcsh.
 232
 233 g.  A new variable, rl_erase_empty_line, which, if set by an application using
 234     readline, will cause readline to erase, prompt and all, lines on which the
 235     only thing typed was a newline.
 236
 237 h.  New bindable variable: `isearch-terminators'.
 238
 239 i.  New bindable function: `forward-backward-delete-char' (unbound by default).
 240
 241 -------------------------------------------------------------------------------
 242 This is a terse description of the new features added to bash-2.02 since
 243 the release of bash-2.01.1.  As always, the manual page (doc/bash.1) is
 244 the place to look for complete descriptions.
 245
 246 1. New Features in Bash
 247
 248 a.  A new version of malloc, based on the older GNU malloc, that has many
 249     changes, is more page-based, is more conservative with memory usage,
 250     and does not `orphan' large blocks when they are freed.
 251
 252 b.  A new version of gmalloc, based on the old GLIBC malloc, with many
 253     changes and range checking included by default.
 254
 255 c.  A new implementation of fnmatch(3) that includes full POSIX.2 Basic
 256     Regular Expression matching, including character classes, collating
 257     symbols, equivalence classes, and support for case-insensitive pattern
 258     matching.
 259
 260 d.  ksh-88 egrep-style extended pattern matching ([@+*?!](patlist)) has been
 261     implemented, controlled by a new `shopt' option, `extglob'.
 262
 263 e.  There is a new ksh-like `[[' compound command, which implements
 264     extended `test' functionality.
 265
 266 f.  There is a new `printf' builtin, implemented according to the POSIX.2
 267     specification.
 268
 269 g.  There is a new feature for command substitution: $(< filename) now expands
 270     to the contents of `filename', with any trailing newlines removed
 271     (equivalent to $(cat filename)).
 272
 273 h.  There are new tilde prefixes which expand to directories from the
 274     directory stack.
 275
 276 i.  There is a new `**' arithmetic operator to do exponentiation.
 277
 278 j.  There are new configuration options to control how bash is linked:
 279     `--enable-profiling', to allow bash to be profiled with gprof, and
 280     `--enable-static-link', to allow bash to be linked statically.
 281
 282 k.  There is a new configuration option, `--enable-cond-command', which
 283     controls whether or not the `[[' command is included.  It is on by
 284     default.
 285
 286 l.  There is a new configuration option, `--enable-extended-glob', which
 287     controls whether or not the ksh extended globbing feature is included.
 288     It is enabled by default.
 289
 290 m.  There is a new configuration #define in config.h.top that, when enabled,
 291     will cause all login shells to source /etc/profile and one of the user-
 292     specific login shell startup files, whether or not the shell is
 293     interactive.
 294
 295 n.  There is a new invocation option, `--dump-po-strings', to dump
 296     a shell script's translatable strings ($"...") in GNU `po' format.
 297
 298 o.  There is a new `shopt' option, `nocaseglob', to enable case-insensitive
 299     pattern matching when globbing filenames and using the `case' construct.
 300
 301 p.  There is a new `shopt' option, `huponexit', which, when enabled, causes
 302     the shell to send SIGHUP to all jobs when an interactive login shell
 303     exits.
 304
 305 q.  `bind' has a new `-u' option, which takes a readline function name as an
 306     argument and unbinds all key sequences bound to that function in a
 307     specified keymap.
 308
 309 r.  `disown' now has `-a' and `-r' options, to limit operation to all jobs
 310     and running jobs, respectively.
 311
 312 s.  The `shopt' `-p' option now causes output to be displayed in a reusable
 313     format.
 314
 315 t.  `test' has a new `-N' option, which returns true if the filename argument
 316     has been modified since it was last accessed.
 317
 318 u.  `umask' now has a `-p' option to print output in a reusable format.
 319
 320 v.  A new escape sequence, `\xNNN', has been added to the `echo -e' and $'...'
 321     translation code.  It expands to the character whose ascii code is NNN
 322     in hexadecimal.
 323
 324 w.  The prompt string expansion code has a new `\r' escape sequence.
 325
 326 x.  The shell may now be cross-compiled for the CYGWIN32 environment on
 327     a Unix machine.
 328
 329 2. New Features in Readline
 330
 331 a.  There is now an option for `iterative' yank-last-arg handline, so a user
 332     can keep entering `M-.', yanking the last argument of successive history
 333     lines.
 334
 335 b.  New variable, `print-completions-horizontally', which causes completion
 336     matches to be displayed across the screen (like `ls -x') rather than up
 337     and down the screen (like `ls').
 338
 339 c.  New variable, `completion-ignore-case', which causes filename completion
 340     and matching to be performed case-insensitively.
 341
 342 d.  There is a new bindable command, `magic-space', which causes history
 343     expansion to be performed on the current readline buffer and a space to
 344     be inserted into the result.
 345
 346 e.  There is a new bindable command, `menu-complete', which enables tcsh-like
 347     menu completion (successive executions of menu-complete insert a single
 348     completion match, cycling through the list of possible completions).
 349
 350 f.  There is a new bindable command, `paste-from-clipboard', for use on Win32
 351     systems, to insert the text from the Win32 clipboard into the editing
 352     buffer.
 353
 354 g.  The key sequence translation code now understands printf-style backslash
 355     escape sequences, including \NNN octal escapes.  These escape sequences
 356     may be used in key sequence definitions or macro values.
 357
 358 h.  An `$include' inputrc file parser directive has been added.
 359
 360 -------------------------------------------------------------------------------
 361 This is a terse description of the new features added to bash-2.01 since
 362 the release of bash-2.0.  As always, the manual page (doc/bash.1) is the
 363 place to look for complete descriptions.
 364
 365 1. New Features in Bash
 366
 367 a.  There is a new builtin array variable: GROUPS, the set of groups to which
 368     the user belongs.  This is used by the test suite.
 369
 370 2.  New Features in Readline
 371
 372 a.  If a key sequence bound to `universal-argument' is read while reading a
 373     numeric argument started with `universal-argument', it terminates the
 374     argument but is otherwise ignored.  This provides a way to insert multiple
 375     instances of a digit string, and is how GNU emacs does it.
 376
 377 -------------------------------------------------------------------------------
 378 This is a terse description of the new features added to bash-2.0 since
 379 the release of bash-1.14.7.  As always, the manual page (doc/bash.1) is
 380 the place to look for complete descriptions.
 381
 382 1.  New Features in Bash
 383
 384 a.  There is a new invocation option, -D, that dumps translatable strings
 385     in a script.
 386
 387 b.  The `long' invocation options must now be prefixed with `--'.
 388
 389 c.  New long invocation options:  --dump-strings, --help, --verbose
 390
 391 d.  The `nolineediting' invocation option was renamed to `noediting'.
 392
 393 e.  The `nobraceexpansion' and `quiet' long invocation options were removed.
 394
 395 f.  The `--help' and `--version' long options now work as the GNU coding
 396     standards specify.
 397
 398 g.  If invoked as `sh', bash now enters posix mode after reading the
 399     startup files, and reads and executes commands from the file named
 400     by $ENV if interactive (as POSIX.2 specifies).  A login shell invoked
 401     as `sh' reads $ENV after /etc/profile and ~/.profile.
 402
 403 h.  There is a new reserved word, `time', for timing pipelines, builtin
 404     commands, and shell functions.  It uses the value of the TIMEFORMAT
 405     variable as a format string describing how to print the timing
 406     statistics.
 407
 408 i.  The $'...' quoting syntax expands ANSI-C escapes in ... and leaves the
 409     result single-quoted.
 410
 411 j.  The $"..." quoting syntax performs locale-specific translation of ...
 412     and leaves the result double-quoted.
 413
 414 k.  LINENO now works correctly in functions.
 415
 416 l.  New variables: DIRSTACK, PIPESTATUS, BASH_VERSINFO, HOSTNAME, SHELLOPTS,
 417     MACHTYPE.  The first three are array variables.
 418
 419 m.  The BASH_VERSION and BASH_VERSINFO variables now include the shell's
 420     `release status' (alpha[N], beta[N], release).
 421
 422 n.  Some variables have been removed:  MAIL_WARNING, notify, history_control,
 423     command_oriented_history, glob_dot_filenames, allow_null_glob_expansion,
 424     nolinks, hostname_completion_file, noclobber, no_exit_on_failed_exec, and
 425     cdable_vars.  Most of them are now implemented with the new `shopt'
 426     builtin; others were already implemented by `set'.
 427
 428 o.  Bash now uses some new variables:  LC_ALL, LC_MESSAGES, LC_CTYPE,
 429     LC_COLLATE, LANG, GLOBIGNORE, HISTIGNORE.
 430
 431 p.  The shell now supports integer-indexed arrays of unlimited length,
 432     with a new compound assignment syntax and changes to the appropriate
 433     builtin commands (declare/typeset, read, readonly, etc.).  The array
 434     index may be an arithmetic expression.
 435
 436 q.  ${!var}: indirect variable expansion, equivalent to eval \${$var}.
 437
 438 r.  ${paramter:offset[:length]}: variable substring extraction.
 439
 440 s.  ${parameter/pattern[/[/]string]}: variable pattern substitution.
 441
 442 t.  The $[...] arithmetic expansion syntax is no longer supported, in
 443     favor of $((...)).
 444
 445 u.  Aliases can now be expanded in shell scripts with a shell option
 446     (shopt expand_aliases).
 447
 448 v.  History and history expansion can now be used in scripts with
 449     set -o history and set -H.
 450
 451 w.  All builtins now return an exit status of 2 for incorrect usage.
 452
 453 x.  Interactive shells resend SIGHUP to all running or stopped children
 454     if (and only if) they exit due to a SIGHUP.
 455
 456 y.  New prompting expansions: \a, \e, \H, \T, \@, \v, \V.
 457
 458 z.  Variable expansion in prompt strings is now controllable via a shell
 459     option (shopt promptvars).
 460
 461 aa. Bash now defaults to using command-oriented history.
 462
 463 bb. The history file ($HISTFILE) is now truncated to $HISTFILESIZE after
 464     being written.
 465
 466 cc. The POSIX.2 conditional arithmetic evaluation syntax (expr ? expr : expr)
 467     has been implemented.
 468
 469 dd. Each builtin now accepts `--' to signify the end of the options, except
 470     as documented (echo, etc.).
 471
 472 ee. All builtins use -p to display values in a re-readable format where
 473     appropriate, except as documented (echo, type, etc.).
 474
 475 ff. The `alias' builtin has a new -p option.
 476
 477 gg. Changes to the `bind' builtin:
 478         o has new options: -psPSVr.
 479         o the `-d' option was renamed to `-p'
 480         o the `-v' option now dumps variables; the old `-v' is now `-P'
 481
 482 hh. The `bye' synonym for `exit' was removed.
 483
 484 ii. The -L and -P options to `cd' and `pwd' have been documented.
 485
 486 jj. The `cd' builtin now does spelling correction on the directory name
 487     by default.  This is settable with a shell option (shopt cdspell).
 488
 489 kk. The `declare' builtin has new options: -a, -F, -p.
 490
 491 ll. The `dirs' builtin has new options: -c, -p, -v.
 492
 493 mm. The new `disown' builtin removes jobs from the shell's jobs table
 494     or inhibits the resending of SIGHUP when the shell receives a
 495     SIGHUP.
 496
 497 nn. The `echo' builtin has a new escape character: \e.
 498
 499 oo. The `enable' builtin can now load new builtins dynamically from shared
 500     objects on systems with the dlopen/dlsym interface.  There are a number
 501     of examples in the examples/loadables directory.  There are also
 502     new options: -d, -f, -s, -p.
 503
 504 pp. The `-all' option to `enable' was removed in favor of `-a'.
 505
 506 qq. The `exec' builtin has new options: -l, -c, -a.
 507
 508 rr. The `hash' builtin has a new option: -p.
 509
 510 ss. The `history' builtin has new options: -c, -p, -s.
 511
 512 tt. The `jobs' builtin has new options: -r, -s.
 513
 514 uu. The `kill' builtin has new options: -n signum, -l signame.
 515
 516 vv. The `pushd' and `popd' builtins have a new option: -n.
 517
 518 ww. The `read' builtin has new options: -p prompt, -e, -a.
 519
 520 xx. The `readonly' builtin has a new -a option, and the -n option was removed.
 521
 522 yy. Changes to the `set' builtin:
 523         o new options: -B, -o keyword, -o onecmd, -o history
 524         o options removed: -l, -d, -o nohash
 525         o options changed: +o, -h, -o hashall
 526         o now displays variables in a format that can be re-read as input
 527
 528 zz. The new `shopt' builtin controls shell optional behavior previously
 529     done by setting and unsetting certain shell variables.
 530
 531 aaa. The `test' builtin has new operators: -o option, s1 == s2, s1 < s2,
 532      and s1 > s2, where s1 and s2 are strings.
 533
 534 bbb. There is a new trap, DEBUG, executed after every simple command.
 535
 536 ccc. The `trap' builtin has a new -p option.
 537
 538 ddd. The `ulimit' builtin has a new -l option on 4.4BSD-based systems.
 539
 540 eee. The PS1, PS2, PATH, and IFS variables may now be unset.
 541
 542 fff. The restricted shell mode has been expanded and is now documented.
 543
 544 ggg. Security improvements:
 545         o functions are not imported from the environment if running setuid
 546           or with -p
 547         o no startup files are sourced if running setuid or with -p
 548
 549 hhh. The documentation has been overhauled:  the texinfo manual was
 550      expanded, and HTML versions of the man page and texinfo manual
 551      are included.
 552
 553 iii. Changes to Posix mode:
 554         o Command lookup now finds special builtins before shell functions.
 555         o Failure of a special builtin causes a non-interactive shell to
 556           exit.  Failures are defined in the POSIX.2 specification.
 557         o If the `cd' builtin finds a directory to change to using $CDPATH,
 558           the value assigned to PWD when `cd' completes does not contain
 559           any symbolic links.
 560         o A non-interactive shell exits if a variable assignment error
 561           occurs when no command name follows the assignment statements.
 562         o A non-interactive shell exits if the interation variable in a
 563           `for' statement or the selection variable in a `select' statement
 564           is read-only or another variable assignment error occurs.
 565         o The `<>' redirection operator now opens a file for both stdin and
 566           stdout by default, not just when in posix mode.
 567         o Assignment statements preceding special builtins now persist in
 568           the shell's environment when the builtin completes.
 569
 570      Posix mode is now completely POSIX.2-compliant (modulo bugs).  When
 571      invoked as sh, bash should be completely POSIX.2-compliant.
 572
 573 jjj. The default value of PS1 is now "\s-\v\$ ".
 574
 575 kkk. The ksh-like ((...)) arithmetic command syntax has been implemented.
 576      This is exactly equivalent to `let "..."'.
 577
 578 lll. Integer constants have been extended to base 64.
 579
 580 mmm. The `ulimit' builtin now sets both hard and soft limits and reports the
 581      soft limit by default.
 582
 583 2.  New Features in Readline
 584
 585 a.  New variables:  enable-keypad, input-meta (new name for meta-flag),
 586     mark-directories, visible-stats (now documented), disable-completion,
 587     comment-begin.
 588
 589 b.  New bindable commands:  kill-region, copy-region-as-kill,
 590     copy-backward-word, copy-forward-word, set-mark, exchange-point-and-mark,
 591     character-search, character-search-backward, insert-comment,
 592     glob-expand-word, glob-list-expansions, dump-variables, dump-macros.
 593
 594 c.  New emacs keybindings:  delete-horizontal-space (M-\),
 595     insert-completions (M-*), possible-completions (M-=).
 596
 597 d.  The history-search-backward and history-search-forward commands were
 598     modified to be the same as previous-line and next-line if point is at
 599     the start of the line.
 600
 601 e.  More file types are available for the visible-stats mode.
 602
 603 3.  Changes of interest in the Bash implementation
 604
 605 a.  There is a new autoconf-based configuration mechanism.
 606
 607 b.  More things have been moved from Posix mode to standard shell behavior.
 608
 609 c.  The trace output (set -x) now inserts quotes where necessary so it can
 610     be reused as input.
 611
 612 d.  There is a compile-time option for a system-wide interactive shell
 613     startup file (disabled by default).
 614
 615 e.  The YACC grammar is smaller and tighter, and all 66 shift-reduce
 616     conflicts are gone.  Several parsing bugs have been fixed.
 617
 618 f.  Builtin option parsing has been regularized (using internal_getopt()),
 619     with the exception of `echo', `type', and `set'.
 620
 621 g.  Builtins now return standard usage messages constructed from the
 622     `short doc' used by the help builtin.
 623
 624 h.  Completion now quotes using backslashes by default, but honors
 625     user-supplied quotes.
 626
 627 i.  The GNU libc malloc is available as a configure-time option.
 628
 629 j.  There are more internationalization features; bash uses gettext if
 630     it is available.  The $"..." translation syntax uses the current
 631     locale and gettext.
 632
 633 k.  There is better reporting of job termination when the shell is not
 634     interactive.
 635
 636 l.  The shell is somewhat more efficient: it uses a little less memory and
 637     makes fewer system calls.
 638
 639 4.  Changes of interest in the Readline implementation
 640
 641 a.  There is now support for readline `callback' functions.
 642
 643 b.  There is now support for user-supplied input, redisplay, and terminal
 644     preparation functions.
 645
 646 c.  Most of the shell-specific code in readline has been generalized or
 647     removed.
 648
 649 d.  Most of the annoying redisplay bugs have been fixed, notably the problems
 650     with incremental search and excessive redrawing when special characters
 651     appear in the prompt string.
 652
 653 e.  There are new library functions and variables available to application
 654     writers, most having to do with completion and quoting.
 655
 656 f.  The NEWLINE character (^J) is now treated as a search terminator by the
 657     incremental search functions.