Ksh Alternatives

ksh reviews and mentions

• Faster Shell Startup with Shell Switching
  3 projects | news.ycombinator.com | 16 Jan 2024

  David Korn's ksh93 was passed on to a new set of developers, who attempted to release a new version; AT&T rolled back these changes due to performance problems which raised questions of support status. It does appear that ksh93 development has resumed, and a new version was released late last year.

  https://github.com/ksh93/ksh/releases

  The independent pdksh spawned mksh, which is the default shell used in Android (as it has a BSD license); mksh appears to be very much active.

  http://www.mirbsd.org/mksh.htm [https site has cert problems]

  OpenBSD also forked oksh from pdksh. This is certainly well-maintained.

  https://github.com/ibara/oksh

• Classic Unix Code Available as FLOSS (Free/Libre/Open Source Software)
  5 projects | /r/unix | 1 Jul 2023
• ksh 93u+m/1.0.5 is out, with another large amount of bugfixes
  1 project | /r/ksh | 9 Jun 2023
• Announcing: KornShell 93u+m/1.0.5
  1 project | /r/ksh | 9 Jun 2023

  Announcing: KornShell 93u+m/1.0.5 https://github.com/ksh93/ksh This is the fifth ksh 93u+m/1.0 bugfix release, again with a wide range of bugfixes and robustness enhancements. Many thanks to all contributors for their hard work! Further below is an overview of the main changes. For greater detail, see the NEWS file in the distribution. For complete detail, see the git(1) commit log, which has full documentation of every significant change. ### HOW TO GET IT ### Please download the source code tarball from our GitHub releases page: https://github.com/ksh93/ksh/releases To build, follow the instructions in README.md or src/cmd/ksh93/README. Or ask your distribution package manager to upgrade ksh to this version. ### ABOUT KSH ### KornShell (ksh) is a full-featured and very fast shell script interpreter and interactive command shell with a distinguished lineage: it is a direct descendant of the Bourne shell and, like its ancestor, was developed at AT&T, the birthplace of UNIX. ksh has been open source since 2000. But when AT&T terminated development in 2020, ksh was left buggy and unreliable. ksh 93u+m aims to fix this situation whilst maintaining and growing the tradition. For now, we are focusing mostly on fixing bugs and egregious flaws but we also prioritise backward compatibility, performance, portability, and occasionally adding a feature. Work on ksh 93u+m started in May 2020, based on the last AT&T stable release, ksh 93u+. Unique ksh features include discipline functions (every variable expansion or assignment can trigger a shell function call determining its value), static scoping of local variables in functions, the ability to define your own data types, customisable tilde expansion (new in 93u+m), a shell option for file system case (in)sensitivity detection for pathname expansion and file name completion (new in 93u+m), and much more. ### CONTRIBUTORS ### Main ksh 93u+m developers: Martijn Dekker, Johnothan King, hyenias Direct contributors: Andy Fiddaman, Anuradha Weeraman, atheik, Chase, Cy Schubert, Govind Kamat, Harald van Dijk, K. Eugene Carlson, Lev Kujawski, Marc Wilson, Phi, Ryan Schmidt, rymrg, Sterling Jensen, Trey Valenta, Vincent Mihalkovic Also includes backported contributions by: David Korn, Glenn Fowler, Lefteris Koutsofios, Siteshwar Vashisht, Kurtis Rader, Roland Mainz, Finnbarr P. Murphy, Lijo George, OpenSUSE ksh 93u+ patch authors, Red Hat ksh 93u+ path authors, Solaris ksh 93u+ patch authors, Debian ksh 93u+ patch authors, Apple ksh 93u+ patch authors, Graphviz maintainers Many fixes have also been backported from the AT&T 93v- beta as well as the former AT&T ksh2020 project lead by Kurtis Rader and Siteshwar Vashisht; we appreciate and benefit from their work. Many thanks also to Siteshwar for graciously donating his 'ksh93' GitHub organisation account! ### HOW TO GET INVOLVED ### To report a bug, please open an issue at our GitHub page (see above). Alternatively, email me at [email protected] with your report. To get involved in development, read the brief policy information in README.md and then jump right in with a pull request or email a patch. Feel free to use Discussions to introduce yourself to the community. You can also join the mailing list/Google group at: https://groups.google.com/g/korn-shell ### MAIN CHANGES between ksh 93u+m/1.0.4 and 93u+m/1.0.5 ### - Fixed various bugs causing crashes. - Fixed many bugs in the emacs and vi line editors, in command completion, and in file name completion. - Fixed various bugs in the handling of quotes, backslash escapes and braces when processing shell glob patterns (e.g. in pathname expansion and 'case'). - ksh now throws a panic and exits if a read error (such as an I/O error) occurs while trying to read the next command(s) from a running script. - Fixed many bugs in 'printf' and 'print -f' built-in commands, including: . Multiple bugs causing incorrect output for relative date specifications, e.g., printf %T\\n 'exactly 20 months ago' now outputs a correct result. . More printf bugs with mix and match of % and %x$. . A data corruption bug when using %B with 'printf -v varname'. . A bug causing double evaluation of arithmetic expressions. - Fixed a bug where 'unset -f commandname', executed in a subshell, hides any built-in command by the same name for the duration of that subshell. - Fixed ${var/#/string} and ${var/%/string} (with anchored empty pattern) to work as on mksh, bash and zsh; these are no longer ineffective. - Fixed incorrect result of array slicing ${array[@]:offset:length} where 'length' is a nested expansion involving an array. - Command names can now end in ':' as they can on other shells. - Fixed a spurious syntax error in compound assignments upon encountering a pair of repeated opening parentheses '(('. - Fixed spurious syntax error in ${parameter:offset:length}: the arithmetic expressions 'offset' and 'length' may now contain the operators ( ) & |. - Fixed a parsing bug in the declaration of .sh.math.* arithmetic functions. - Fixed nameref self-reference loop detection for more than two namerefs. - Several improvements to the POSIX compatibility mode. - Many more minor and/or esoteric bugfixes. ### MAIN CHANGES between ksh 93u+m/1.0.3 and 93u+m/1.0.4 ### - Fixed multiple scoping-related bugs in the += additive assignment operator. - A number of crashing bugs have been fixed. - Various fixes for the Haiku operating system, notably 'ulimit -a' now works. - Fixed the expansion of out-of-range \n back references in the string part of ${parameter//pattern/string}. For example: v=AB; echo "${v/@(A)B/\0:\1:\2}" now yields 'AB:A:' instead of 'AB:A:\2'. - Fixed quoted '!', '^' and '-' within [bracket] expressions in glob patterns; single or double quotes failed to disable their operator behaviour. - Fixed a bug introduced on 2021-04-04 that incorrectly allowed 'typeset' to turn off the readonly and export attributes on a readonly variable. - In the emacs line editor, the Ctrl+R reverse-search prompt is now visually distinct from a literal control character ("^R: " instead of "^R"). - In the vi line editor, fixed the behaviour of 'C', 'c$' and 'I' to be consistent with standard vi(1) and with Bolsky & Korn (1995, p. 121). - Aliases for many GNU long options have been added to the /opt/ast/bin built-in commands. Additionally, 'kill -s' now has a --signal long option alias compatible with the util-linux option. - Backported support for 'print -u p' from ksh 93v- for compatibility with scripts written for 93v-/ksh2020 (this is equivalent to 'print -p'). ### MAIN CHANGES between ksh 93u+m/1.0.2 and 93u+m/1.0.3 ### This point release fixes the following: - An old bug in history expansion (set -H) where any use of the history comment character caused processing to be aborted as if it were an invalid history expansion. - A bug in command line options processing that caused short-form option equivalents on some built-in commands to be ignored after one use, e.g., the new read -a equivalent of read -A. - Ksh freezing or using excessive memory if HISTSIZE is assigned a pathologically large value. - A bug that caused ksh in the vi editor mode to crash or produce invalid completions if ESC = was used at the beginning of a line. ### MAIN CHANGES between ksh 93u+m/1.0.1 and 93u+m/1.0.2 ### This bugfix release fixes the interactive shell crashing when one of the predefined aliases (currently 'history' and 'r') is redefined, whether from a profile/kshrc script or manually. This crash occurred in two scenarios: 1. when redefining and then unsetting a predefined alias; 2. when redefining a predefined alias and then executing a shell script that does not begin with a #! path. ### MAIN CHANGES between ksh 93u+m/1.0.0 and 93u+m/1.0.1 ### This is an urgent bugfix release that removes an incorrect exec optimization that was capable of terminating the execution of scripts prematurely in certain corner cases. It is known to make the build scripts of GNU binutils produce corrupted results if ksh is used as /bin/sh. See https://github.com/ksh93/ksh/issues/507 for more information. ### MAIN CHANGES between ksh 93u+ and 93u+m/1.0.0 ### Roughly a thousand bugs have been fixed, including many serious/critical bugs. See the NEWS file for more information, and the git commit log for complete documentation of every fix. Incompatible changes have been minimised, but not at the expense of fixing bugs. For a list of potentially incompatible changes, see src/cmd/ksh93/COMPATIBILITY. Though there was a "no new features, bugfixes only" policy, some new features were found necessary, either to fix serious design flaws or to complete functionality that was evidently intended, but not finished. Below is a summary of these new features. New command line editor features: - The forward-delete and End keys are now handled as expected in the emacs and vi built-in line editors. - In the vi and emacs line editors, repeat counts can now also be used for arrow keys and the forward-delete key, e.g., 7 works. - Various keys on extended PC keyboards are now handled as expected in the emacs and vi built-in line editors. New shell language features: - Pathname expansion (a.k.a. globbing) now never matches the special names '.' (current directory) and '..' (parent directory). This change makes a pattern like .* useful; it now matches all hidden files (dotfiles) in the current directory, without the harmful inclusion of '.' and '..'. - Tilde expansion can now be extended or modified by defining a .sh.tilde.get or .sh.tilde.set discipline function. See the manual for details. - The &>file redirection shorthand (for >file 2>&1) is now available for all scripts and interactive sessions and not only for profile/login scripts. - Arithmetic expressions in native ksh mode no longer interpret a number with a leading zero as octal in any context. Use 8#octalnumber instead (e.g. 8#400 == 256). Arithmetic expressions now also behave identically within and outside ((...)) and $((...)). If the POSIX mode is turned on, a leading zero now denotes an octal number in all arithmetic contexts. New features in built-in commands: - Usage error messages now show the --help/--man self-documentation options. - Path-bound built-ins (such as /opt/ast/bin/cat) can now be executed by invoking the canonical path, so the following will now work as expected: $ /opt/ast/bin/cat --version version cat (AT&T Research) 2012-05-31 - 'cd' now supports an -e option that, when combined with -P, verifies that $PWD is correct after changing directories; this helps detect access permission problems. See: https://www.austingroupbugs.net/view.php?id=253 - 'command -x' now looks for external commands only, skipping built-ins. In addition, its xargs-like functionality no longer freezes the shell on Linux and macOS, making it effectively a new feature on these systems. - 'printf' now supports a -v option as in bash. This assigns formatted output directly to variables, which is very fast and will not strip final newline (\n) characters. - 'redirect' now checks if all arguments are valid redirections before performing them. If an error occurs, it issues an error message instead of terminating the shell. - 'return', when used to return from a function, can now return any status value in the 32-bit signed integer range, like on zsh. However, due to a traditional Unix kernel limitation, $? is still trimmed to its least significant 8 bits whenever a shell or subshell exits. - 'suspend' now refuses to suspend a login shell, as there is probably no parent shell to return to and the login session would freeze. - 'test'/'[' now supports all the same operators as [[ (including =~, \<, \>) except for the different 'and'/'or' operators. Note that 'test'/'[' remains deprecated due to its unfixable pitfalls; [[ ... ]] is recommended instead. - 'times' now gives high precision output in a POSIX compliant format. - 'type'/'whence': Two bash-like flags were backported from ksh 93v-: - 'whence -P/type -P' is an alias to the existing -p flag. - 'whence -t/type -t' will print only the type of a command in a simple format that is designed to be easy to use for scripts. - 'typeset' has a new '-g' flag that forces variables to be created or modified at the global scope regardless of context, as on bash 4.2+. - 'typeset' now gives an informative error message if an incompatible combination of options is given. - 'ulimit': Added three options inspired by bash: - 'ulimit -k' sets the maximum number of kqueues. - 'ulimit -P' sets the maximum number of pseudo-terminals. - 'ulimit -R' sets the maximum time in microseconds a real-time process can run before blocking. Note that not all operating systems support the limits set by these options. - 'whence -v/-a' now reports the location of autoloadable functions. New features in shell options: - When the -b/--notify shell option is on and the vi or emacs/gmacs shell line editor is in use, 'Done' and similar notifications from completed background jobs are now inserted directly above the line you're typing, without affecting your command line display. - A new --functrace long-form shell option causes the -x/--xtrace option's state and the DEBUG trap action to be inherited by function scopes instead of being reset to default. Changes made to them within a function scope still do not propagate back to the parent scope. Similarly, this option also causes the DEBUG trap action to be inherited by subshells. - A new --globcasedetect shell option is added on operating systems where we can check for a case-insensitive file system (currently Linux, macOS, QNX 7.0+, and Windows/Cygwin). When this option is turned on, pathname expansion (globbing), as well as tab completion on interactive shells, automatically become case-insensitive depending on the file system. This is separately determined for each pathname component. - Enhancement to -G/--globstar: symbolic links to directories are now followed if they match a normal (non-**) glob pattern. For example, if '/lnk' is a symlink to a directory, '/lnk/**' and '/l?k/**' now work as you would expect. - The new --histreedit and --histverify options modify history expansion (--histexpand). If --histreedit is on and a history expansion fails, the command line is reloaded into the next prompt's edit buffer, allowing corrections. If --histverify is on, the results of a history expansion are not immediately executed but instead loaded into the next prompt's edit buffer, allowing further changes. - A new --nobackslashctrl shell option disables the special escaping behaviour of the backslash character in the emacs and vi built-in editors. Particularly in the emacs editor, this makes it much easier to go back, insert a forgotten backslash into a command, and then continue editing without having your next arrow key replace your backslash with garbage. - A new --posix shell option has been added to ksh 93u+m that makes the ksh language more compatible with other shells by following the POSIX standard more closely. See the manual page for details. It is enabled by default if ksh is invoked as sh, otherwise it is disabled by default.

• Globbing EREs?
  1 project | /r/ksh | 18 May 2023

  curl -L -o ksh.tgz https://github.com/ksh93/ksh/tarball/1.0 gzip -dc ksh.tgz | tar xf - cd ksh93-ksh-* bin/package make bin/package use

• What repository of KSH is on the best track to become the NEW New KSH?
  2 projects | /r/ksh | 1 May 2023

  ksh93 u+m is making good progress on that front. It's now the default ksh in:

• Linking custom ksh93 builtins
  1 project | /r/linuxquestions | 31 Mar 2023

  So, I've recently switched from bash to ksh93u+m (this one), because I heard it was faster and more "unix-like", and I'm in love so far. One of the cool features is runtime library loading for custom builtins, which is a really cool idea, and it works really well for simple functions that don't require access to the shell's internals, but whenever I try to use any function from the shell's headers (for example sh_addbuiltin), I get a bunch of undefined references, even when I link my builtin source file against every single library that I compiled along with the shell. Is there a tutorial for something like this? The documentation on ksh is pretty poor in general and I wouldn't have found out how to write custom builtins without this and this blog post. Any help would be greatly appreciated!

• Implementing a simple shell in C
  2 projects | /r/programminghorror | 11 Mar 2023

  You can take a look at the ksh source: https://github.com/ksh93/ksh or one of the other shells. They are probably more complicated than you want.

• Luddite curmudgeon here - I don't like zsh, but.. I want to embrace change.
  1 project | /r/MacOS | 13 Aug 2022

  Apple ships the last ATT-released official ksh93, 20120801 u+. And u+m 1.0.2 was just released.

• Announcing: KornShell 93u+m/1.0.0 stable
  2 projects | /r/ksh | 1 Aug 2022

  1.0.2 bugfix release now out.

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