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author | Jari Aalto <jari.aalto@cante.net> | 1996-12-23 17:02:34 +0000 |
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committer | Jari Aalto <jari.aalto@cante.net> | 2009-09-12 16:46:49 +0000 |
commit | ccc6cda312fea9f0468ee65b8f368e9653e1380b (patch) | |
tree | b059878adcfd876c4acb8030deda1eeb918c7e75 /NEWS | |
parent | 726f63884db0132f01745f1fb4465e6621088ccf (diff) | |
download | bash-ccc6cda312fea9f0468ee65b8f368e9653e1380b.tar.gz |
Imported from ../bash-2.0.tar.gz.
Diffstat (limited to 'NEWS')
-rw-r--r-- | NEWS | 284 |
1 files changed, 277 insertions, 7 deletions
@@ -1,10 +1,280 @@ -This file documents the bugs fixed between this release, bash-1.14.7, -and the last public bash release, 1.14.6. +This is a terse description of the new features added to bash-2.0 since +the release of bash-1.14.7. As always, the manual page (doc/bash.1) is +the place to look for complete descriptions. -1. Bugs fixed in Bash +1. New Features in Bash -a. A memory leak that caused long-running scripts to eventually consume - all available memory was fixed. +a. There is a new invocation option, -D, that dumps translatable strings + in a script. -b. A sign-extension bug that caused a security hole for non-interactive - shells was fixed. +b. The `long' invocation options must now be prefixed with `--'. + +c. New long invocation options: --dump-strings, --help, --verbose + +d. The `nolineediting' invocation option was renamed to `noediting'. + +e. The `nobraceexpansion' and `quiet' long invocation options were removed. + +f. The `--help' and `--version' long options now work as the GNU coding + standards specify. + +g. If invoked as `sh', bash now enters posix mode after reading the + startup files, and reads and executes commands from the file named + by $ENV if interactive (as POSIX.2 specifies). A login shell invoked + as `sh' reads $ENV after /etc/profile and ~/.profile. + +h. There is a new reserved word, `time', for timing pipelines, builtin + commands, and shell functions. It uses the value of the TIMEFORMAT + variable as a format string describing how to print the timing + statistics. + +i. The $'...' quoting syntax expands ANSI-C escapes in ... and leaves the + result single-quoted. + +j. The $"..." quoting syntax performs locale-specific translation of ... + and leaves the result double-quoted. + +k. LINENO now works correctly in functions. + +l. New variables: DIRSTACK, PIPESTATUS, BASH_VERSINFO, HOSTNAME, SHELLOPTS, + MACHTYPE. The first three are array variables. + +m. The BASH_VERSION and BASH_VERSINFO variables now include the shell's + `release status' (alpha[N], beta[N], release). + +n. Some variables have been removed: MAIL_WARNING, notify, history_control, + command_oriented_history, glob_dot_filenames, allow_null_glob_expansion, + nolinks, hostname_completion_file, noclobber, no_exit_on_failed_exec, and + cdable_vars. Most of them are now implemented with the new `shopt' + builtin; others were already implemented by `set'. + +o. Bash now uses some new variables: LC_ALL, LC_MESSAGES, LC_CTYPE, + LC_COLLATE, LANG, GLOBIGNORE, HISTIGNORE. + +p. The shell now supports integer-indexed arrays of unlimited length, + with a new compound assignment syntax and changes to the appropriate + builtin commands (declare/typeset, read, readonly, etc.). The array + index may be an arithmetic expression. + +q. ${!var}: indirect variable expansion, equivalent to eval \${$var}. + +r. ${paramter:offset[:length]}: variable substring extraction. + +s. ${parameter/pattern[/[/]string]}: variable pattern substitution. + +t. The $[...] arithmetic expansion syntax is no longer supported, in + favor of $((...)). + +u. Aliases can now be expanded in shell scripts with a shell option + (shopt expand_aliases). + +v. History and history expansion can now be used in scripts with + set -o history and set -H. + +w. All builtins now return an exit status of 2 for incorrect usage. + +x. Interactive shells resend SIGHUP to all running or stopped children + if (and only if) they exit due to a SIGHUP. + +y. New prompting expansions: \a, \e, \H, \T, \@, \v, \V. + +z. Variable expansion in prompt strings is now controllable via a shell + option (shopt promptvars). + +aa. Bash now defaults to using command-oriented history. + +bb. The history file ($HISTFILE) is now truncated to $HISTFILESIZE after + being written. + +cc. The POSIX.2 conditional arithmetic evaluation syntax (expr ? expr : expr) + has been implemented. + +dd. Each builtin now accepts `--' to signify the end of the options, except + as documented (echo, etc.). + +ee. All builtins use -p to display values in a re-readable format where + appropriate, except as documented (echo, type, etc.). + +ff. The `alias' builtin has a new -p option. + +gg. Changes to the `bind' builtin: + o has new options: -psPSVr. + o the `-d' option was renamed to `-p' + o the `-v' option now dumps variables; the old `-v' is now `-P' + +hh. The `bye' synonym for `exit' was removed. + +ii. The -L and -P options to `cd' and `pwd' have been documented. + +jj. The `cd' builtin now does spelling correction on the directory name + by default. This is settable with a shell option (shopt cdspell). + +kk. The `declare' builtin has new options: -a, -F, -p. + +ll. The `dirs' builtin has new options: -c, -p, -v. + +mm. The new `disown' builtin removes jobs from the shell's jobs table + or inhibits the resending of SIGHUP when the shell receives a + SIGHUP. + +nn. The `echo' builtin has a new escape character: \e. + +oo. The `enable' builtin can now load new builtins dynamically from shared + objects on systems with the dlopen/dlsym interface. There are a number + of examples in the examples/loadables directory. There are also + new options: -d, -f, -s, -p. + +pp. The `-all' option to `enable' was removed in favor of `-a'. + +qq. The `exec' builtin has new options: -l, -c, -a. + +rr. The `hash' builtin has a new option: -p. + +ss. The `history' builtin has new options: -c, -p, -s. + +tt. The `jobs' builtin has new options: -r, -s. + +uu. The `kill' builtin has new options: -n signum, -l signame. + +vv. The `pushd' and `popd' builtins have a new option: -n. + +ww. The `read' builtin has new options: -p prompt, -e, -a. + +xx. The `readonly' builtin has a new -a option, and the -n option was removed. + +yy. Changes to the `set' builtin: + o new options: -B, -o keyword, -o onecmd, -o history + o options removed: -l, -d, -o nohash + o options changed: +o, -h, -o hashall + o now displays variables in a format that can be re-read as input + +zz. The new `shopt' builtin controls shell optional behavior previously + done by setting and unsetting certain shell variables. + +aaa. The `test' builtin has new operators: -o option, s1 == s2, s1 < s2, + and s1 > s2, where s1 and s2 are strings. + +bbb. There is a new trap, DEBUG, executed after every simple command. + +ccc. The `trap' builtin has a new -p option. + +ddd. The `ulimit' builtin has a new -l option on 4.4BSD-based systems. + +eee. The PS1, PS2, PATH, and IFS variables may now be unset. + +fff. The restricted shell mode has been expanded and is now documented. + +ggg. Security improvements: + o functions are not imported from the environment if running setuid + or with -p + o no startup files are sourced if running setuid or with -p + +hhh. The documentation has been overhauled: the texinfo manual was + expanded, and HTML versions of the man page and texinfo manual + are included. + +iii. Changes to Posix mode: + o Command lookup now finds special builtins before shell functions. + o Failure of a special builtin causes a non-interactive shell to + exit. Failures are defined in the POSIX.2 specification. + o If the `cd' builtin finds a directory to change to using $CDPATH, + the value assigned to PWD when `cd' completes does not contain + any symbolic links. + o A non-interactive shell exits if a variable assignment error + occurs when no command name follows the assignment statements. + o A non-interactive shell exits if the interation variable in a + `for' statement or the selection variable in a `select' statement + is read-only or another variable assignment error occurs. + o The `<>' redirection operator now opens a file for both stdin and + stdout by default, not just when in posix mode. + o Assignment statements preceding special builtins now persist in + the shell's environment when the builtin completes. + + Posix mode is now completely POSIX.2-compliant (modulo bugs). When + invoked as sh, bash should be completely POSIX.2-compliant. + +jjj. The default value of PS1 is now "\s-\v\$ ". + +kkk. The ksh-like ((...)) arithmetic command syntax has been implemented. + This is exactly equivalent to `let "..."'. + +lll. Integer constants have been extended to base 64. + +mmm. The `ulimit' builtin now sets both hard and soft limits and reports the + soft limit by default. + +2. New Features in Readline + +a. New variables: enable-keypad, input-meta (new name for meta-flag), + mark-directories, visible-stats (now documented), disable-completion, + comment-begin. + +b. New bindable commands: kill-region, copy-region-as-kill, + copy-backward-word, copy-forward-word, set-mark, exchange-point-and-mark, + character-search, character-search-backward, insert-comment, + glob-expand-word, glob-list-expansions, dump-variables, dump-macros. + +c. New emacs keybindings: delete-horizontal-space (M-\), + insert-completions (M-*), possible-completions (M-=). + +d. The history-search-backward and history-search-forward commands were + modified to be the same as previous-line and next-line if point is at + the start of the line. + +e. More file types are available for the visible-stats mode. + +3. Changes of interest in the Bash implementation + +a. There is a new autoconf-based configuration mechanism. + +b. More things have been moved from Posix mode to standard shell behavior. + +c. The trace output (set -x) now inserts quotes where necessary so it can + be reused as input. + +d. There is a compile-time option for a system-wide interactive shell + startup file (disabled by default). + +e. The YACC grammar is smaller and tighter, and all 66 shift-reduce + conflicts are gone. Several parsing bugs have been fixed. + +f. Builtin option parsing has been regularized (using internal_getopt()), + with the exception of `echo', `type', and `set'. + +g. Builtins now return standard usage messages constructed from the + `short doc' used by the help builtin. + +h. Completion now quotes using backslashes by default, but honors + user-supplied quotes. + +i. The GNU libc malloc is available as a configure-time option. + +j. There are more internationalization features; bash uses gettext if + it is available. The $"..." translation syntax uses the current + locale and gettext. + +k. There is better reporting of job termination when the shell is not + interactive. + +l. The shell is somewhat more efficient: it uses a little less memory and + makes fewer system calls. + +4. Changes of interest in the Readline implementation + +a. There is now support for readline `callback' functions. + +b. There is now support for user-supplied input, redisplay, and terminal + preparation functions. + +c. Most of the shell-specific code in readline has been generalized or + removed. + +d. Most of the annoying redisplay bugs have been fixed, notably the problems + with incremental search and excessive redrawing when special characters + appear in the prompt string. + +e. There are new library functions and variables available to application + writers, most having to do with completion and quoting. + +f. The NEWLINE character (^J) is now treated as a search terminator by the + incremental search functions. |