Unix Shell Languages

Unix Shell Languages are the command-line interpreters developed for Unix and Unix-like operating systems, each providing its own scripting dialect for running commands and automating tasks. The Bourne shell (sh), written by Stephen Bourne at Bell Labs, was the original Unix shell distributed with Version 7 Unix. The C shell (csh), written by Bill Joy, was modeled on the syntax of the C programming language. KornShell (ksh), written by David Korn, is described as an enhanced version of the Bourne shell, and Bash (the Bourne-Again shell) was written as part of the GNU Project to provide a superset of Bourne shell functionality; both are direct descendants of the Bourne shell line. Z shell (zsh) is a more modern shell that is partially backward compatible with Bash. The friendly interactive shell (fish), first released in 2005, is grouped among the shells that do not derive from either the Bourne or C shell lines but still serves the same interactive Unix shell role. Each member placed under this group carries its own separate citation for the specific fact that places it in this family.