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The Bourne shell was once standard on all branded Unix systems, although historically BSD-based systems had many scripts written in csh. As the basis of POSIX sh syntax, Bourne shell scripts can typically be run with Bash or dash on Linux or other Unix-like systems; Bash itself is a free clone of Bourne.
Consider the following model examples: Bourne shell All shells related to Bourne shell (sh) — for example: Thompson shell (sh), Bash (bash), KornShell (ksh), Z shell (zsh) — allow the stdout and stderr to be attached to a named pipe and redirected to the tee command, for example:
tcsh and sh shell windows on a Mac OS X Leopard [1] desktop. A Unix shell is a command-line interpreter or shell that provides a command line user interface for Unix-like operating systems. The shell is both an interactive command language and a scripting language, and is used by the operating system to control the execution of the system using ...
One example of this is Bash, which offers the same grammar and syntax as the Bourne shell, and which also provides a POSIX-compliant mode. [13] As such, most shell scripts written for the Bourne shell can be run in BASH, but the reverse may not be true since BASH has extensions which are not present in the Bourne shell.
There are many variants of Unix shell: Bourne shell sh. Almquist shell (ash) Debian Almquist shell (dash) Bash (Unix shell) bash; KornShell ksh. Z shell zsh; C shell csh. TENEX C shell tcsh; Ch shell ch; Emacs shell eshell; Friendly interactive shell fish; PowerShell pwsh; rc shell rc, a shell for Plan 9 from Bell Labs and Unix; Stand-alone ...
Rc uses C-like control structures instead of the original Bourne shell's ALGOL-like structures, except that it uses an if not construct instead of else, and has a Bourne-like for loop to iterate over lists. In rc, all variables are lists of strings, which eliminates the need for constructs like "$@". Variables are not re-split when expanded.
Here documents originate in the Unix shell, [1] and are found in the Bourne shell since 1979, and most subsequent shells. Here document-style string literals are found in various high-level languages , notably the Perl programming language (syntax inspired by Unix shell) and languages influenced by Perl, such as PHP and Ruby .
Bash can execute the vast majority of Bourne shell scripts without modification, with the exception of Bourne shell scripts stumbling into fringe syntax behavior interpreted differently in Bash or attempting to run a system command matching a newer Bash builtin, etc. Bash command syntax includes ideas drawn from the Korn Shell (ksh) and the C ...