Editing Unix shell (section)

{{short description|Command-line interpreter for Unix operating system}}
[[File:Tcsh ejecutándose en escritorio Mac OSX.png|thumb|300px|right|tcsh and sh shell windows on a [[Mac OS X Leopard]]<ref name="Vleck" /> desktop]]

A '''Unix shell''' is a [[Command-line_interface#Command-line_interpreter|command-line interpreter]] or [[shell (computing)|shell]] that provides a command line [[user interface]] for [[Unix-like]] [[operating system]]s.  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 [[shell script]]s.<ref>{{cite news | url=https://archive.org/stream/byte-magazine-1983-10/1983_10_BYTE_08-10_UNIX#page/n187/mode/2up | title=The Unix Shell | work=BYTE | date=October 1983 | access-date=30 January 2015 | author=Bourne, Stephen R. | pages=187}}</ref>

Users typically interact with a Unix shell using a [[terminal emulator]]; however, direct operation via serial hardware connections or [[Secure Shell]] are common for server systems.  All Unix shells provide filename [[Wildcard character|wildcarding]], [[Pipeline (Unix)|piping]], [[here document]]s, [[command substitution]], [[Variable (programming)|variables]] and [[control flow|control structures]] for [[Conditional (programming)|condition-testing]] and [[iteration]].