List of POSIX commands

This is a list of the shell commands of the most recent version of the Portable Operating System Interface (POSIX)

1. REDIRECT Template:En dash

Template:R protected IEEE Std 1003.1-2024 which is part of the Single UNIX Specification (SUS). These commands are implemented in many shells on modern Unix, Unix-like and other operating systems. This list does not cover commands for all versions of Unix and Unix-like shells nor other versions of POSIX.

Name	Category	Status (Option code)	Description	First appeared
Template:Codett	SCCS	Optional (XSI)	Create and administer SCCS files	PWB UNIX
[[alias (command)|Template:Codett]]	Misc	Template:Needs	Define or display aliases
[[ar (Unix)|Template:Codett]]	Misc	Template:Needs	Create and maintain library archives	Version 1 AT&T UNIX
Template:Codett	Text processing	Optional (FR)	Interpret carriage-control characters	System V
[[at (command)|Template:Codett]]	Process management	Template:Needs	Execute commands at a later time	Version 7 AT&T UNIX
[[AWK|Template:Codett]]	Text processing	Template:Needs	Pattern scanning and processing language	Version 7 AT&T UNIX
[[basename|Template:Codett]]	Filesystem	Template:Needs	Return non-directory portion of a pathname; see also dirname	Version 7 AT&T UNIX
[[batch (Unix)|Template:Codett]]	Process management	Template:Needs	Schedule commands to be executed in a batch queue
[[bc (programming language)|Template:Codett]]	Misc	Template:Needs	Arbitrary-precision arithmetic language	Version 6 AT&T UNIX
[[bg (Unix)|Template:Codett]]	Process management	Optional (UP)	Run jobs in the background
[[C compiler|Template:Codett]]/[[C17_(C_standard_revision)|Template:Codett]]	C programming	Optional (CD)	Compile standard C programs	IEEE Std 1003.1-2024
[[cal (command)|Template:Codett]]	Misc	Optional (XSI)	Print a calendar	Version 5 AT&T UNIX
[[cat (Unix)|Template:Codett]]	Filesystem	Template:Needs	Concatenate and print files	PDP-7 UNIX
[[cd (command)|Template:Codett]]	Filesystem	Template:Needs	Change the working directory	Version 6 AT&T UNIX
[[cflow|Template:Codett]]	C programming	Optional (XSI)	Generate a C-language call graph	System V
[[chgrp|Template:Codett]]	Filesystem	Template:Needs	Change the file group ownership	PWB UNIX
[[chmod|Template:Codett]]	Filesystem	Template:Needs	Change the file modes/attributes/permissions	PDP-7 UNIX
[[chown|Template:Codett]]	Filesystem	Template:Needs	Change the file ownership	PDP-7 UNIX
[[cksum|Template:Codett]]	Filesystem	Template:Needs	Write file checksums and sizes	4.4BSD
[[cmp (Unix)|Template:Codett]]	Filesystem	Template:Needs	Compare two files; see also diff	Version 1 AT&T UNIX
[[comm|Template:Codett]]	Text processing	Template:Needs	Select or reject lines common to two files	Version 4 AT&T UNIX
[[command (Unix)|Template:Codett]]	Shell programming	Template:Needs	Execute a simple command
[[compress|Template:Codett]]	Filesystem	Optional (XSI)	Compress data	4.3BSD
[[cp (Unix)|Template:Codett]]	Filesystem	Template:Needs	Copy files	PDP-7 UNIX
[[crontab|Template:Codett]]	Misc	Template:Needs	Schedule periodic background work	System V
[[csplit|Template:Codett]]	Text processing	Template:Needs	Split files based on context	PWB UNIX
[[ctags|Template:Codett]]	C programming	Optional (SD)	Create a tags file	3BSD
[[cut (Unix)|Template:Codett]]	Text processing	Template:Needs	Cut out selected fields of each line of a file	System III
[[cxref|Template:Codett]]	C programming	Optional (XSI)	Generate a C-language program cross-reference table	System V
[[Date (Unix command)|Template:Codett]]	Misc	Template:Needs	Sets or displays the date and time	Version 1 AT&T UNIX
[[dd (Unix)|Template:Codett]]	Filesystem	Template:Needs	Convert and copy a file	Version 5 AT&T UNIX
[[delta (Unix)|Template:Codett]]	SCCS	Optional (XSI)	Make a delta (change) to an SCCS file	PWB UNIX
[[df (Unix)|Template:Codett]]	Filesystem	Template:Needs	Report free disk space	Version 1 AT&T UNIX
[[diff|Template:Codett]]	Text processing	Template:Needs	Compare two files; see also cmp	Version 5 AT&T UNIX
[[dirname|Template:Codett]]	Filesystem	Template:Needs	Return the directory portion of a pathname; see also basename	System III
[[du (Unix)|Template:Codett]]	Filesystem	Template:Needs	Estimate file space usage	Version 1 AT&T UNIX
[[echo (command)|Template:Codett]]	Shell programming	Template:Needs	Write arguments to standard output	Version 2 AT&T UNIX
[[ed (text editor)|Template:Codett]]	Text processing	Template:Needs	The standard text editor	PDP-7 UNIX
[[env (shell)|Template:Codett]]	Misc	Template:Needs	Set the environment for command invocation	System III
[[ex (text editor)|Template:Codett]]	Text processing	Optional (UP)	Text editor	1BSD
[[expand (Unix)|Template:Codett]]	Text processing	Template:Needs	Convert tabs to spaces	3BSD
[[expr|Template:Codett]]	Shell programming	Template:Needs	Evaluate arguments as an expression	Version 7 AT&T UNIX
[[false (Unix)|Template:Codett]]	Shell programming	Template:Needs	Return false value	Version 7 AT&T UNIX
[[fc (Unix)|Template:Codett]]	Misc	Optional (UP)	Process the command history list
[[fg (Unix)|Template:Codett]]	Process management	Optional (UP)	Run jobs in the foreground
[[file (command)|Template:Codett]]	Filesystem	Template:Needs	Determine file type	Version 4 AT&T UNIX
[[find (Unix)|Template:Codett]]	Filesystem	Template:Needs	Find files	Version 1 AT&T UNIX
[[fold (Unix)|Template:Codett]]	Text processing	Template:Needs	Filter for folding lines	1BSD
[[fuser (Unix)|Template:Codett]]	Process management	Optional (XSI)	List process IDs of all processes that have one or more files open	System V
[[gencat|Template:Codett]]	Misc	Template:Needs	Generate a formatted message catalog
Template:Codett	SCCS	Optional (XSI)	Get a version of an SCCS file	PWB UNIX
[[getconf|Template:Codett]]	Misc	Template:Needs	Get configuration values
[[getopts|Template:Codett]]	Shell programming	Template:Needs	Parse utility options
[[gettext|Template:Codett]]	Misc	Template:Needs	Retrieve text string from messages object
[[grep|Template:Codett]]	Misc	Template:Needs	Search text for a pattern	Version 4 AT&T UNIX
[[hash (Unix)|Template:Codett]]	Misc	Template:Needs	Hash database access method
[[head (Unix)|Template:Codett]]	Text processing	Template:Needs	Copy the first part of files	PWB UNIX
[[iconv|Template:Codett]]	Text processing	Template:Needs	Codeset conversion	HP-UX
[[id (Unix)|Template:Codett]]	Misc	Template:Needs	Return user identity	System V
[[ipcrm|Template:Codett]]	Misc	Optional (XSI)	Remove a message queue, semaphore set, or shared memory segment identifier	System V
[[ipcs|Template:Codett]]	Misc	Optional (XSI)	Report interprocess communication facilities status	System V
Template:Codett	Process management	Optional (UP)	Display status of jobs in the current session
[[join (Unix)|Template:Codett]]	Text processing	Template:Needs	Merges two sorted text files based on the presence of a common field	Version 7 AT&T UNIX
[[kill (command)|Template:Codett]]	Process management	Template:Needs	Terminate or signal processes	Version 4 AT&T UNIX
[[lex programming tool|Template:Codett]]	C programming	Optional (CD)	Generate programs for lexical tasks	Version 7 AT&T UNIX
[[link (Unix)|Template:Codett]]	Filesystem	Optional (XSI)	Create a hard link to a file	Version 1 AT&T UNIX
[[ln (Unix)|Template:Codett]]	Filesystem	Template:Needs	Link files	Version 1 AT&T UNIX
Template:Codett	Misc	Template:Needs	Get locale-specific information
[[localedef|Template:Codett]]	Misc	Template:Needs	Define locale environment
Template:Codett	Shell programming	Template:Needs	Log messages	4.3BSD
[[logname|Template:Codett]]	Misc	Template:Needs	Return the user's login name	4.4BSD
[[lp (Unix)|Template:Codett]]	Text processing	Template:Needs	Send files to a printer	System V
[[ls|Template:Codett]]	Filesystem	Template:Needs	List directory contents	Version 1 AT&T UNIX
[[M4 (computer language)|Template:Codett]]	Misc	Template:Needs	Macro processor	PWB UNIX
[[mailx|Template:Codett]]	Misc	Template:Needs	Process messages	Version 1 AT&T UNIX
[[make (software)|Template:Codett]]	Programming	Optional (SD)	Maintain, update, and regenerate groups of programs	PWB UNIX
[[man page|Template:Codett]]	Misc	Template:Needs	Display system documentation	Version 2 AT&T UNIX
[[mesg|Template:Codett]]	Misc	Template:Needs	Permit or deny messages	Version 1 AT&T UNIX
[[mkdir|Template:Codett]]	Filesystem	Template:Needs	Make directories	Version 1 AT&T UNIX
[[mkfifo|Template:Codett]]	Filesystem	Template:Needs	Make FIFO special files	4.4BSD
[[more (command)|Template:Codett]]	Text processing	Optional (UP)	Display files on a page-by-page basis	3BSD
[[msgfmt|Template:Codett]]	Misc	Template:Needs	Create messages objects from messages object files
[[Mv (Unix)|Template:Codett]]	Filesystem	Template:Needs	Move or rename files	Version 1 AT&T UNIX
[[newgrp|Template:Codett]]	Misc	Template:Needs	Change to a new group	Version 6 AT&T UNIX
[[gettext|Template:Codett]]	Misc	Template:Needs	Retrieve text string from messages object with plural form
[[nice (Unix)|Template:Codett]]	Process management	Template:Needs	Invoke a utility with an altered nice value	Version 4 AT&T UNIX
[[nl (Unix)|Template:Codett]]	Text processing	Optional (XSI)	Line numbering filter	System III
[[nm (Unix)|Template:Codett]]	C programming	Optional (SD, XSI)	Write the name list of an object file	Version 1 AT&T UNIX
[[nohup|Template:Codett]]	Process management	Template:Needs	Invoke a utility immune to hangups	Version 4 AT&T UNIX
[[od (Unix)|Template:Codett]]	Misc	Template:Needs	Dump files in various formats	Version 1 AT&T UNIX
[[paste (Unix)|Template:Codett]]	Text processing	Template:Needs	Merge corresponding or subsequent lines of files	Version 32V AT&T UNIX
[[patch (Unix)|Template:Codett]]	Text processing	Template:Needs	Apply changes to files	4.3BSD
[[pathchk|Template:Codett]]	Filesystem	Template:Needs	Check pathnames
[[pax (command)|Template:Codett]]	Misc	Template:Needs	Portable archive interchange	4.4BSD
[[pr (Unix)|Template:Codett]]	Text processing	Template:Needs	Paginate or columnate files for printing	Version 1 AT&T UNIX
[[printf (Unix)|Template:Codett]]	Shell programming	Template:Needs	Write formatted output	4.3BSD-Reno
Template:Codett	SCCS	Optional (XSI)	Print an SCCS file	PWB UNIX
[[ps (Unix)|Template:Codett]]	Process management	Template:Needs	Report process status	Version 4 AT&T UNIX
[[pwd|Template:Codett]]	Filesystem	Template:Needs	Print working directory	Version 5 AT&T UNIX
[[read (Unix)|Template:Codett]]	Shell programming	Template:Needs	Read a line from standard input
Template:Codett	Filesystem	Template:Needs	Print destination of a symbolic link
Template:Codett	Filesystem	Template:Needs	Resolve a symbolic link
[[renice|Template:Codett]]	Process management	Template:Needs	Set nice values of running processes	4BSD
[[rm (Unix)|Template:Codett]]	Filesystem	Template:Needs	Remove directory entries	Version 1 AT&T UNIX
[[rmdel|Template:Codett]]	SCCS	Optional (XSI)	Remove a delta from an SCCS file	PWB UNIX
[[rmdir|Template:Codett]]	Filesystem	Template:Needs	Remove directories, if they are empty.	Version 1 AT&T UNIX
Template:Codett	SCCS	Optional (XSI)	Print current SCCS file-editing activity	System III
[[Source Code Control System|Template:Codett]]	SCCS	Optional (XSI)	Front end for the SCCS subsystem	4.3BSD
[[sed|Template:Codett]]	Text processing	Template:Needs	Stream editor	Version 7 AT&T UNIX
[[Bourne shell|Template:Codett]]	Shell programming	Template:Needs	Shell, the standard command language interpreter	Version 7 AT&T UNIX (in earlier versions, sh was either the Thompson shell or the PWB shell)
[[sleep (command)|Template:Codett]]	Shell programming	Template:Needs	Suspend execution for an interval	Version 4 AT&T UNIX
[[sort (Unix)|Template:Codett]]	Text processing	Template:Needs	Sort, merge, or sequence check text files	Version 1 AT&T UNIX
[[split (Unix)|Template:Codett]]	Misc	Template:Needs	Split files into pieces	Version 3 AT&T UNIX
[[strings (Unix)|Template:Codett]]	C programming	Template:Needs	Find printable strings in files	2BSD
[[strip (Unix)|Template:Codett]]	C programming	Optional (SD)	Remove unnecessary information from executable files	Version 1 AT&T UNIX
Template:Codett	Misc	Template:Needs	Set the options for a terminal	Version 2 AT&T UNIX
Template:Codett	Misc	Template:Needs	Set terminal tabs	PWB UNIX
[[tail (Unix)|Template:Codett]]	Text processing	Template:Needs	Copy the last part of a file	PWB UNIX
[[talk (software)|Template:Codett]]	Misc	Optional (UP)	Talk to another user	4.2BSD
[[tee (command)|Template:Codett]]	Shell programming	Template:Needs	Duplicate the standard output	Version 5 AT&T UNIX
[[test (Unix)|Template:Codett]]	Shell programming	Template:Needs	Evaluate expression	Version 7 AT&T UNIX
[[time (Unix)|Template:Codett]]	Process management	Template:Needs	Display elapsed, system and kernel time used by the current shell or designated process.	Version 3 AT&T UNIX
Template:Codett	Process management	Template:Needs	Run command with a time limit	Version 3 AT&T UNIX
[[touch (command)|Template:Codett]]	Filesystem	Template:Needs	Change file access and modification times	Version 7 AT&T UNIX
[[tput|Template:Codett]]	Misc	Template:Needs	Change terminal characteristics	System V
[[tr (Unix)|Template:Codett]]	Text processing	Template:Needs	Translate characters	Version 4 AT&T UNIX
[[true (Unix)|Template:Codett]]	Shell programming	Template:Needs	Return true value	Version 7 AT&T UNIX
[[tsort (Unix)|Template:Codett]]	Text processing	Template:Needs	Topological sort	Version 7 AT&T UNIX
[[tty (unix)|Template:Codett]]	Misc	Template:Needs	Return user's terminal name	Version 1 AT&T UNIX
[[type (Unix)|Template:Codett]]	Misc	Optional (XSI)	Displays how a name would be interpreted if used as a command
Template:Codett	Misc	Optional (XSI)	Set or report file size limit
[[umask|Template:Codett]]	Misc	Template:Needs	Get or set the file mode creation mask	System III
[[unalias|Template:Codett]]	Misc	Template:Needs	Remove alias definitions
[[uname|Template:Codett]]	Misc	Template:Needs	Return system name	PWB UNIX
[[uncompress|Template:Codett]]	Misc	Optional (XSI)	Expand compressed data	4.3BSD
[[unexpand|Template:Codett]]	Text processing	Template:Needs	Convert spaces to tabs	3BSD
Template:Codett	SCCS	Optional (XSI)	Undo a previous get of an SCCS file	System III
[[uniq|Template:Codett]]	Text processing	Template:Needs	Report or filter out repeated lines in a file	Version 3 AT&T UNIX
[[unlink (Unix)|Template:Codett]]	Filesystem	Optional (XSI)	Call the unlink function	Version 1 AT&T UNIX
[[uucp|Template:Codett]]	Network	Optional (UU)	System-to-system copy	Version 7 AT&T UNIX
[[uudecode|Template:Codett]]	Network	Template:Needs	Decode a binary file	4BSD
[[uuencode|Template:Codett]]	Network	Template:Needs	Encode a binary file	4BSD
[[uustat|Template:Codett]]	Network	Optional (UU)	uucp status inquiry and job control	System III
Template:Codett	Process management	Optional (UU)	Remote command execution	Version 7 AT&T UNIX
Template:Codett	SCCS	Optional (XSI)	Validate SCCS files	System III
[[Vi (text editor)|Template:Codett]]	Text processing	Optional (UP)	Screen-oriented (visual) display editor	1BSD
[[wait (command)|Template:Codett]]	Process management	Template:Needs	Await process completion	Version 4 AT&T UNIX
[[wc (Unix)|Template:Codett]]	Text processing	Template:Needs	Line, word and byte or character count	Version 1 AT&T UNIX
Template:Codett	SCCS	Optional (XSI)	Identify SCCS files	PWB UNIX
[[who (Unix)|Template:Codett]]	System administration	Optional (XSI)	Display who is on the system	Version 1 AT&T UNIX
[[write (Unix)|Template:Codett]]	Misc	Template:Needs	Write to another user's terminal	Version 1 AT&T UNIX
[[xargs|Template:Codett]]	Shell programming	Template:Needs	Construct argument lists and invoke utility	PWB UNIX
[[gettext|Template:Codett]]	C programming	Optional (CD)	Extract gettext calls from C source code strings	IEEE Std 1003.1-2024
[[yacc|Template:Codett]]	C programming	Optional (CD)	Yet another compiler compiler	PWB UNIX
[[zcat|Template:Codett]]	Text processing	Optional (XSI)	Expand and concatenate compressed data	4.3BSD

See also

• GNOME Core Applications
• GNU Core Utilities
• List of GNU packages
• List of KDE applications
• List of Unix daemons
• Unix philosophy
• [[util-linux|Template:Codett]]

External links

• IEEE Std 1003.1,2004 specifications
• IEEE Std 1003.1,2008 specifications
• IEEE Std 1003.1,2024 specifications
• Rosetta Stone For *Nix – configurable list of equivalent programs for *nix systems.
• The Unix Acronym List: Unix Commands – explains the names of many Unix commands.