Editing Bash (Unix shell) (section)

=== Programmable Completion ===
Bash supports programmable [[Command-line completion|completion]] via built-in <code>complete</code>, {{Code|compopt}}, and <code>compgen</code> commands.<ref>{{Cite web |title=Bash Reference Manual     |url=https://tiswww.case.edu/php/chet/bash/bashref.html#Programmable-Completion     |website=tiswww.case.edu  }}</ref> The feature has been available since the beta version of 2.04 released in 2000.<ref name="auto1"/><ref>{{Cite web |title=Index of /gnu/bash     |url=https://ftp.swin.edu.au/gnu/bash/     |url-status=live     |archive-url=https://web.archive.org/web/20200308104032/http://ftp.swin.edu.au/gnu/bash/     |archive-date=March 8, 2020     |access-date=September 15, 2019     |website=ftp.swin.edu.au  }}</ref> These commands enable complex and intelligent completion specification for commands (i.e. installed programs), functions, variables, and filenames.<ref name=":1">{{Cite web |title=An Introduction to Programmable Completion     |url=https://tldp.org/LDP/abs/html/tabexpansion.html     |access-date=2022-01-21     |website=tldp.org  }}</ref>

The <code>complete</code> and {{Code|compopt}} two commands specify how arguments of some available commands or options are going to be listed in the [[readline]] input. As of version 5.1 completion of the command or the option is usually activated by the {{Key|tab}} keystroke after typing its name.<ref name=":1" />
<!--
=== Shell-native Pattern Matching ===
'''+++ Wildcards (a.k.a., "Globs"): <code>*</code> <code>[...]</code> and <code>?</code>'''

'''+++ Pattern Matching Contexts'''
--><!--
=== Regular Expressions ===
'''+++ The Regex Operator (<code>=~</code>) of the Double Bracket Keyword (<code>[[</code>)'''

'''+++ <code>BASH_REMATCH</code>'''
--><!--
=== Coprocesses ===
-->