command (Unix)

command
Operating system	Unix and Unix-like
Type	Command

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command is a shell command for Unix and Unix-like operating systems. It is used to execute a command whilst suppressing normal shell function lookup.^[1]

It is specified in the POSIX standard and is often implemented in Unix shells as a shell builtin function. Built-in functions take precedence over programs when resolving the name of a command. A user may suppress the lookup of built-in functions in order to execute a program with the same name as a built-in function.^{[citation needed]}

The arguments passed specify the name of the command to be executed, along with its arguments. If the specified command name is the name of a shell built-in function, the command will be processed as if such function did not exist. In all other circumstances the command will be processed as normal.^[2]

Examples

In the following, the ls command is run without any shell functions or aliases that may exist with the same name:

$ command ls

References

^ "command - manned.org". POSIX Programmer's Manual. Retrieved 13 February 2025.
^ "command(1p)". Linux manual page. Retrieved 13 February 2025.

External links

command – Shell and Utilities Reference, The Single UNIX Specification, Version 5 from The Open Group

[1] "command - manned.org". POSIX Programmer's Manual. Retrieved 13 February 2025.

[2] "command(1p)". Linux manual page. Retrieved 13 February 2025.

[1]

[2]

v t e Unix command-line interface programs and shell builtins
File system	cat chattr chmod chown chgrp cksum cmp cp dd du df file fuser ln ls mkdir mv pax pwd rm rmdir split tee touch type umask
Processes	at bg crontab fg kill nice ps time
User environment	env exit logname mesg talk tput uname who write
Text processing	awk basename comm csplit cut diff dirname ed ex fold head iconv join m4 more nl paste patch printf read sed sort strings tail tr troff uniq vi wc xargs
Shell builtins	alias cd echo test unset wait
Searching	find grep
Documentation	man
Software development	ar ctags lex make nm strip yacc
Miscellaneous	bc cal expr lp od sleep true and false
Categories Standard Unix programs Unix SUS2008 utilities List

Examples

See also

References

External links