loksh – Linux port of the Korn shell

loksh is a Linux port of the Korn shell supplied by OpenBSD. It follows the OpenBSD source closely and deliberately keeps platform-specific changes to a minimum rather than adding its own extensions.

The shell is intended for both interactive use and shell scripting. Its command language is a superset of the traditional Bourne shell language, with Korn shell facilities for arithmetic, arrays, job control, command-line editing and reusable functions. loksh targets Linux exclusively, which helps keep the port compact and makes it suitable for lightweight or resource-constrained systems.

This is public domain software.

Key Features

• Linux port of OpenBSD’s Korn shell.
• Closely tracks the upstream OpenBSD implementation.
• Keeps downstream modifications and additional features to a minimum.
• Suitable for interactive use and shell scripts.
• Mostly compatible with POSIX shell and AT&T Korn shell behaviour.
• Run commands, functions, builtins and external executables.
• Variables, positional parameters and indexed arrays.
• Parameter, command, arithmetic and tilde substitution.
• Integer arithmetic expressions using (( expression )).
• Conditional expressions using [[ expression ]].
• Filename globbing and pattern matching.
• Brace expansion and tilde expansion.
• Input and output redirection, including here documents.
• Construct pipelines and optionally enable pipefail behaviour.
• Conditional execution using && and ||.
• Asynchronous commands and background pipelines.
• Co-process support using the |& operator.
• If, case, for, select, while and until compound commands.
• User-defined shell functions.
• Interactive job control with jobs, fg, bg, wait and kill builtins.
• Command history and the fc history editor.
• Emacs, gmacs and Vi command-line editing modes.
• Aliases and command hashing.
• Signal and exit handling through shell traps.
• Login-shell processing through /etc/profile and the user’s .profile.
• Interactive startup configuration through the ENV parameter.
• Restricted-shell mode prevents directory changes, path modifications and unsafe redirections.
• Privileged-shell mode uses a separate system profile.
• Can be invoked as ksh, sh or restricted rksh.
• Small implementation without an external plugin or scripting framework.

Website: github.com/dimkr/loksh
Support:
Developer: dimkr and OpenBSD developers
License: Public Domain

loksh is written in C. Learn C with our recommended free books and free tutorials.

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