Comparison of command shells

For more details on this topic, see Shell (computing).

A command shell is a command line interface computer program to an operating system.

General characteristics

	Bourne shell	POSIX shell[1]	bash (v4.0)	csh	tcsh	Scsh	ksh (ksh93t+)	pdksh	zsh	ash	Windows cmd.exe[2]	TCC (formerly 4NT)	Windows PowerShell	COMMAND.COM	4DOS	OS/2 cmd.exe	rc	BeanShell	Python shell	Ruby shell	VMS DCL[3]
Usual environment	7th Ed. UNIX	POSIX	POSIX	POSIX	POSIX	POSIX	POSIX	POSIX	POSIX	POSIX	Win32	Win32	.NET	DOS	DOS	OS/2	Plan 9, POSIX	Java	Python	Ruby	OpenVMS
Usually invoked	sh	sh	bash, sh	csh	tcsh, csh	scsh	ksh	ksh, sh	zsh	sh	cmd	?	powershell	command	?	cmd	rc	?	python, ipython	irb	?
Introduced	1977	1992[4]	1989[5]	1978	1983[6]	1994	1983[7][8]	1989 ?	1990	1989	1993	1993	2006	1980	1989	1987	1989	2005	1991	1995	1977 ?
Platform-independent	No	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	No	No	No (3rd party in dev[9])	No (3rd party available[10])	No	No	Yes	Yes	Yes	Yes	No
Default login shell in	7th Ed. UNIX	N/A	GNU, Mac OS X 10.3+	?	FreeBSD, formerly Mac OS X	AIX	HP-UX	OpenBSD[11]	Grml, Gobolinux	Minix, BusyBox based systems	Windows NT, 2000, XP, Server 2003, Vista	?	Windows Server 2008, 7, Vista, XP[12]	DOS, Windows 95, 98, ME	?	OS/2	Plan 9, Version 10 Unix	?	?	?	VMS
Default script shell in	7h Ed. UNIX	POSIX	GNU, Haiku	?	?	?	OpenSolaris	OpenBSD[11]	Grml	FreeBSD, NetBSD, Minix, BusyBox based systems	Windows NT, 2000, XP, Server 2003, Vista	?	Windows Server 2008, 7	DOS, Windows 95, 98, ME	?	OS/2	Plan 9, Version 10 Unix	?	?	?	VMS
License	AT&T prop.[13]	N/A	GPL	BSD	BSD	BSD-style	Common Public License	Public Domain	BSD-style	BSD-style	MS-EULA[14]	Shareware	MS-EULA[14] or BSD/GPL (PASH)	MS-EULA[15] or BSD/GPL (free clones)	MIT License, with restrictions	IBM-EULA[16]	Lucent Public License	LGPL	Python	Ruby, GPL	?
Unicode	No	Yes, if used by configured locale	Yes	No	Yes	?	Yes	No	Yes	Yes	Yes	Yes	Yes	No	No	No	Yes	Yes	Yes	1.9: Yes 1.8: limited	No
Stream redirection	Yes (arbitrary fds)	Yes (arbitrary fds)	Yes (arbitrary fds)	Yes (stdin, out, out+err)	Yes (stdin, out, out+err)	Yes	Yes (arbitrary fds)	Yes (arbitrary fds)	Yes (arbitrary fds)	Yes (arbitrary fds)	Yes	Yes (stdin, out, err)	Yes	Yes (stdin, out, COMn/LPT only)	Yes (stdin, out, err)	Yes (stdin, out, err)	Yes	Yes	Yes	Yes	Yes (sys$input, sys$output assignment)
Native CIM/WBEM support	No	No	No	No	No	No	No	No	No	No	No	No	Yes	No	No	No	No	?	?	?	No
Blocking of unsigned scripts	No	No	No	No	No	No	No	No	No	No	No	No	Yes	No	No	No	No	No	No	No	No
available as statically linked, independent single file executable	Yes	N/A	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	No	No	Yes	No	?	Yes	Yes (bsh.jar)	Yes on Windows via py2exe	No	No
	Bourne shell	POSIX shell[17]	bash (v4.0)	csh	tcsh	Scsh	ksh (ksh93t+)	pdksh	zsh	ash	Windows cmd.exe[2]	TCC (formerly 4NT)	Windows PowerShell	COMMAND.COM	4DOS	OS/2 cmd.exe	rc	BeanShell	Python shell	Ruby shell	VMS DCL[18]

Interactive features

	Bourne shell	POSIX shell	bash (v4.0)	csh	tcsh	Scsh	ksh (ksh93t+)	pdksh	zsh	ash	Windows cmd.exe	TCC (formerly 4NT)	Windows PowerShell	COMMAND.COM	4DOS	OS/2 cmd.exe	rc	BeanShell	Python shell	Ruby shell	VMS DCL
Completion	No	No	Yes (extendable)	Yes (via the ESC key)	Yes (extendable)	No	Yes (extendable)	Yes	Yes (extendable)	No	Yes (partial)	Yes (partial)	Yes (extendable)	No	Yes	Yes	Yes[19]	Yes	Yes (provided by the rlcompleter module or IPython)	Yes	No
Directory stack (pushd/popd)	No	No	Yes	Yes	Yes	No	No	No	Yes	Yes	Yes	Yes	Yes (all location types)[20]	No	Yes	?	?	?	Yes (provided by IPython)	Yes (pass a block to Dir.chdir() method)	No
Directory History Window (popup)	No	No	No	No	No	No	No	No	No	No	No	Yes	Yes	No	Yes	No	No	No	No	No	No
Implicit Directory Change - If command is dir name changes to it	No	No	Yes (optional)	Yes (optional)	Yes (optional)	No	No	No	Yes (optional)	No	No	Yes	No	No	Yes	No	No	No	No	No	No
Command history	No	Yes	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Yes (F7)	Yes	Yes	No[21][22]	Yes	Yes	Yes[19]	Yes	Yes	Yes	Yes
History completion	No	No	Yes	Yes	Yes	No	Yes	?	Yes	Yes	Yes (F8)	Yes	Yes (F8)	No[21][22]	Yes	?	Yes[19]	?	Yes (provided by IPython)	Yes (with UtilityBelt gem)	No
Spell checking	No	No	No	No	experimental	No	No	No	Yes	No	No	No	No	No	No	No	No	No	No	No	No
Default user prompt[23]	$	$	bash-<version number>$	%	>	>	$	$	<hostname>%	$	<path>>	[<path>]	PS <path>>	<path or drive name>>	<path>>	[<path>]	term%, ;	bsh %	>>>	irb(main):001:0>	$
Custom command prompt	Yes (variable: $PS1)	Yes (variable: $PS1)	Yes (variable: $PS1)	Yes (variable: $prompt	Yes (variable: $prompt	No	Yes (variable: $PS1, and more)	Yes (variable: $PS1)	Yes (variable: $PS1, and more)	Yes (variable: $PS1)	Yes (environment variable: %PROMPT%)	Yes (environment variable: %PROMPT)	Yes (function: prompt)	Yes (environment variable: %PROMPT%)	Yes (environment variable: %PROMPT)	Yes (environment variable: %PROMPT%)	Yes (function: prompt, or variable: $prompt)	Yes (variable: bsh.prompt, or method: getBshPrompt())	Yes (variable: sys.ps1)	Yes	Yes (SET PROMPT command)
Aliases	No	Yes	Yes	Yes	Yes	Yes (macro and procedure definitions)	Yes	Yes	Yes	Yes	Yes ("macros", via doskey)	Yes	Yes	Yes (using SET or registry)	Yes	No	Yes (functions)	?	Yes (functions)	Yes	Yes
Binary prefix notation	No	No	No	No	No	Yes	No	No	No	No	No	?	Yes	No	?	No	No	?	?	?	Yes
Job control	No	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	No	No	Yes	No	No	No	Handled by rio	?	Yes	Yes	Yes
Startup scripts	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes (4start)	Yes	No[24]	Yes (4start)	No	Yes	Yes (.bshrc)	Yes ($PYTHONSTARTUP or ipythonrc)	Yes (.irbrc)	Yes (login.com)

Programming features

	Bourne shell	POSIX shell	bash (v4.0)	csh	tcsh	Scsh	ksh (ksh93t+)	pdksh	zsh	ash	Windows cmd.exe	TCC (formerly 4NT)	Windows PowerShell	COMMAND.COM	4DOS	OS/2 cmd.exe	rc	BeanShell	Python shell	Ruby shell	VMS DCL
Functions	No	Yes	Yes	No	No	Yes	Yes	Yes	Yes	Yes	Yes (via "call :label")	Yes	Yes	No	Yes	No	Yes	Yes	Yes	Yes	Yes
Exception handling	Yes (via trap)	Yes (via trap)	Yes (via trap)	No	No	?	Yes (via trap)	Yes (via trap)	Yes	Yes (via trap)	No	No	Yes	No	No	No	Yes	Yes	Yes	Yes	Yes
Search and replace on variables	No	No	Yes (via ${//} syntax)	No	Yes (via ${:s//} syntax	Yes (via string functions and regular expressions)	Yes (via ${//} syntax and builtin commands)	No	Yes (via ${:s//} and ${//} syntax)	No	Yes (via set %varname:expression syntax)	Yes (via %@replace[ ] function)	Yes (-replace operator)	No	Yes (via %@replace[ ] function)	No	No	?	Yes (via string methods and regular expressions)	Yes (via string functions and regular expressions)	No
Parallel assignment	No	No	No	No	No	No	?	?	?	No	No	No	Yes	No	No	No	?	?	Yes	Yes	No
Variadic functions	No	Yes	Yes	No	No	Yes	Yes	Yes	Yes	Yes	No	No	Yes	No	?	No	Yes	No	Yes	Yes	No
Default arguments	No	No	Yes	No	No	No	Yes	Yes	Yes	Yes	No	No	Yes	No	No	No	Yes	No	Yes	Yes	No
Named parameters	No	No	No	No	No	No	Yes (for user-defined "types")	No	No	No	No	No	Yes	No	?	No	?	No	Yes	Yes	No
Lambda functions	No	No	No	No	No	Yes	No	No	No	No	No	No	Yes	No	No	No	No	No	Yes	Yes	No
eval function	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes	No	Yes	No	Yes	Yes	Yes	Yes	No
Pseudorandom number generation	No	No	Yes ($RANDOM)	No	No	Yes (random-integer, random-real)	Yes ($RANDOM)	Yes ($RANDOM)	Yes ($RANDOM)	No	Yes (%random%)	Yes (%@random[ ] function)	Yes	No	Yes (%@random[ ] function)	No	No	Yes	Yes	Yes	No
Bytecode	No	No	No	No	No	Yes (compiler is Scheme48 virtual machine, "scshvm")	Yes (compiler is called "shcomp")	No	Yes (built-in command "zcompile")	No	No	No	Yes, automatic	No	No	No	No	Yes	Yes (standard CPython, IronPython or Jython)	Yes (NetRuby, JRuby, version 1.9/YARV)	No

Syntax

	Bourne shell	POSIX shell	bash (v4.0)	csh	tcsh	Scsh	ksh (ksh93t+)	pdksh	zsh	ash	Windows cmd.exe	TCC (formerly 4NT)	Windows PowerShell	COMMAND.COM	4DOS	OS/2 cmd.exe	rc	BeanShell	Python shell	Ruby shell	VMS DCL
Quoting	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes (Backtick: `)	Yes	No	Yes (Backtick: `)	?	Yes	?	Yes	Yes	Yes
Escaping	Yes (Backslash: \)	Yes (Backslash: \)	Yes (Backslash: \)	Yes (Backslash: \)	Yes (Backslash: \)	Yes (Backslash: \)	Yes (Backslash: \)	Yes (Backslash: \)	Yes (Backslash: \)	Yes (Backslash: \)	Yes (Caret: ^)	Yes	Yes (Backtick: `)	No	Yes	Yes	Yes	Yes (Backslash: \)	Yes (Backslash: \)	Yes (Backslash: \)	Yes (quotes or string assignment)
Comments	No	Yes (#)	Yes (#)	Yes (#)	Yes (#)	Yes (; and #| ... |# for multi-line comments)	Yes (#)	Yes (#)	Yes (#)	Yes (#)	Yes (rem and unofficially the invalid label ::)	Yes (rem and unofficially the invalid label ::)	Yes (#); and <# ... #> for multi-line comments	Yes (rem and unofficially the invalid label ::)	Yes (rem and unofficially the invalid label ::)	Yes (rem and unofficially the invalid label ::)	Yes (#)	Yes (//)	Yes (#)	Yes (#)	Yes (!)
Scientific notation	No	No	No	No	No	Yes	Yes (including C99-style base16 notation %a/%A and typeset -X)	No	Yes	No	No	Yes[25]	Yes	No	No	No	No	Yes	Yes	Yes	No
Here documents	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes	No	No	No	Yes	No	Equivalent feature ("""string""" syntax)	Yes	Yes Lines without $ in COM file

Data types

	Bourne shell	POSIX shell	bash (v4.0)	csh	tcsh	Scsh	ksh (ksh93t+)	pdksh	zsh	ash	Windows cmd.exe	TCC (formerly 4NT)	Windows PowerShell	COMMAND.COM	4DOS	OS/2 cmd.exe	rc	BeanShell	Python shell	Ruby shell	VMS DCL
Integer arithmetic	No	Yes (via $(( )) )	Yes (via $(( )), (( )) and let syntax)	Yes (via @ syntax)	Yes (via @ syntax)	Yes	Yes (via $(( )), (( )), let syntax and expr builtin)	Yes (via $(( )) syntax)	Yes (via $(( )), (( )) and let syntax)	Yes[26]	Yes (via "set /a")	Yes (via %@eval[ ] function)	Yes	No	Yes (via %@eval[ ] function)	No	No	Yes	Yes	Yes	Yes
Typing discipline	only one type	dynamic weak	dynamic weak	dynamic weak	dynamic weak	dynamic strong	dynamic weak	dynamic weak	dynamic weak	dynamic weak	dynamic weak	dynamic weak	dynamic or static strong	dynamic weak	dynamic weak	dynamic weak	?	dynamic strong	dynamic strong	dynamic strong	dynamic weak
Floating point arithmetic	No	No	No	No	No	Yes	Yes (including C99-style extensions)	No	Yes	No	No	Yes (via %@eval[ ] function)	Yes	No	Yes (via %@eval[ ] function)	No	No	Yes	Yes	Yes	No
Date & time arithmetic	No	No	No	No	No	?	No	No	No	No	No	Yes	Yes	No	Yes	No	No	Yes	Yes	Yes	Yes
Hash tables	No	No	Yes (via associative arrays)	No	No	Yes (via module)	Yes (via associative arrays)	No	Yes	No	No	No	Yes	No	No	No	No	Yes	Yes	Yes	No
Compound Variables	No	No	No	No	No	Yes (via records or lists)	Yes	No	?	No	No	No	Yes	No	No	?	?	?	Yes (via tuples)	Yes	No
One-dimensional array variables	No	No	Yes	Yes	Yes	Yes	Yes	Yes	Yes	No	No	No	Yes	No	No	No	Yes	Yes	Yes	Yes	No
Multi-dimensional array variables	No	No	No	No	No	Yes	Yes (both indexed and associative arrays)	No	Yes (via associative arrays)	No	No	No	Yes	No	No	No	Yes	Yes	Yes	Yes	No
Array slicing	No	No	Yes (${var:offset:length} syntax)	No	No	No	Yes (${var:offset:length} and [${from}..${to}] syntax)	No	Yes (${var[from,to]} syntax)	No	No	No	Yes	No	No	No	Yes ($var(i j k))	No	Yes	Yes	No
(De-)Serialization of composite datatypes	No	No	No	No	?	No	Yes (print -C var, read -C var)	No	?	No	No	No	Yes	No	No	No	?	Yes	Yes	Yes	No

String and filename matching

	Bourne shell	POSIX shell	bash (v4.0)	csh	tcsh	Scsh	ksh (ksh93t+)	pdksh	zsh	ash	Windows cmd.exe	TCC (formerly 4NT)	Windows PowerShell	COMMAND.COM	4DOS	OS/2 cmd.exe	rc	BeanShell	Python shell	Ruby shell	VMS DCL
Pattern Matching (regular expressions built-in)	No	No	Yes	No	Yes	Yes	Yes	No	Yes	No	Yes (via the findstr /r command)	Limited support	Yes (full regex support)[27]	No	No	No	No	Yes	Yes	Yes	No
Pattern Matching (globbing)	Yes (*, ?, [...])	Yes (*, ?, [...])	Yes (*, ?, [...], {...})	Yes	Yes	Yes	Yes (*, ?, [...])	Yes	Yes (*, ?, [...], ext'd globbing[28])	Yes	Yes (*, ?)	Yes (*, ?, [...])	Yes (*, ?, [...])	Yes (*, ?)	Yes (*, ?, [...])	Yes (*, ?)	Yes	?	Yes	Yes (via Dir.glob() method)	Yes
Globbing qualifiers (filename generation based on file attributes)	No	No	No	No	No	No	No	No	Yes	No	?	?	?	?	?	?	No	?	Yes (via glob module)	?	No
Recursive globbing (generating files from any level of subdirectories)	No	No	Yes (**/...)	No	No	No	Yes (with set -G, no following of symlinks)	No	Yes (**/... or ***/... to follow symlinks)	No	No	Yes (via FOR /R)	?	No	Yes (via FOR /R)	?	No	?	Yes (via glob module)	Yes (via Dir.glob() method)	Yes (via [SUBDIR...] )

Inter-process communication

	Bourne shell	POSIX shell	bash (v4.0)	csh	tcsh	Scsh	ksh (ksh93t+)	pdksh	zsh	ash	Windows cmd.exe	TCC (formerly 4NT)	Windows PowerShell	COMMAND.COM	4DOS	OS/2 cmd.exe	rc	BeanShell	Python shell	Ruby shell	VMS DCL
Pipes	bytes concurrent	bytes concurrent	bytes concurrent	bytes concurrent	bytes concurrent	text	bytes (may contain serialized objects if print -C is used) concurrent	bytes concurrent	bytes concurrent	bytes concurrent	text concurrent	text	objects concurrent	text sequential temporary files	text sequential temporary files	text concurrent	text concurrent	not supported	objects (when using IPython+IPipe)	not supported	text (via PIPE command)
Command substitution	Yes	Yes	Yes	Yes	Yes	?	Yes ($(...) and ${<space>...;})	Yes	Yes	Yes	Yes (via FOR /F command)	Yes (via FOR /F command)	Yes	No	Yes (via FOR /F command)	No	Yes	?	Yes	Yes	No
Process substitution	No	No	Yes (if system supports /dev/fd/<n> or named pipes	No	No	?	Yes (if system supports /dev/fd/<n>	No	Yes	No	No	?	?	No	?	No	Yes (via: <{cmd} if system supports /dev/fd/<n>)	?	Yes (via subprocess module)	Yes	No
Subshells	Yes	Yes	Yes	Yes	Yes	?	Yes	Yes	Yes	Yes	Yes (Backtick: ` in for /f usebackq)	Limited, via %@execstr[ ] and %@exec[ ]	Yes	No	Limited, via %@execstr[ ] and %@exec[ ]	?	Yes	?	Yes	Yes (Backtick: `)	Yes (spawn)
TCP/UDP connections as streams	No	No	Yes (client only)	No	No	Yes	Yes (and SCTP support, client only)	No	Yes (client and server but only TCP)	No	No	No	Yes	No	No	No	No	Yes	Yes	Yes	Yes (server TCP only)

References

1. ^ IEEE (6 December 2001). 1003.1™ Standard for Information Technology — Portable Operating System Interface (POSIX®): Shell and Utilities, Issue 6. 
2. ^ ^{a b} Command extensions enabled, or "cmd /x".
3. ^ "HP OpenVMS DCL Dictionary". http://h71000.www7.hp.com/doc/732final/9996/9996pro_contents.html. Retrieved 2009-03-23. 
4. ^ As part of IEEE Std.1003.2-1992 (POSIX.2); integrated into IEEE Std.1003.1 with the 2001 revision.
5. ^ Brian Fox (forwarded by Leonard H. Tower Jr.) (Jun 7 1989). "Bash is in beta release!". gnu.announce. (Web link). Retrieved Oct 28 2010. 
6. ^ Ken Greer (Oct 3 1983). "C shell with command and filename recognition/completion". net.sources. (Web link). Retrieved Dec 29 2010. 
7. ^ Ron Gomes (Jun 9 1983). "Toronto USENIX Conference Schedule (tentative)". net.usenix. (Web link). Retrieved Dec 29 2010. 
8. ^ Guy Harris (Oct 10 1983). "csh question". net.flame. (Web link). Retrieved Dec 29 2010. 
9. ^ PASH, a third-party remake, is in development and almost half-finished. Activity seems to have stagnated early 2009.
10. ^ Third-party re-implementations, such as DosBox, Wine, and FreeDOS are available.
11. ^ ^{a b} Default shell in OpenBSD is ksh (pdksh).
12. ^ Windows PowerShell is installed with Windows 7, however, it is an optional download for users of Windows Vista or Windows XP.
13. ^ Now available under a BSD-style license through the Unix Heritage Society and others.
14. ^ ^{a b} Windows component — covered by a valid license for Microsoft Windows
15. ^ MS-DOS and Windows component — covered by a valid license for MS-DOS or Microsoft Windows
16. ^ OS/2 component — covered by a valid license for OS/2
17. ^ IEEE (6 December 2001). 1003.1™ Standard for Information Technology — Portable Operating System Interface (POSIX®): Shell and Utilities, Issue 6. 
18. ^ "HP OpenVMS DCL Dictionary". http://h71000.www7.hp.com/doc/732final/9996/9996pro_contents.html. Retrieved 2009-03-23. 
19. ^ ^{a b c} Handled by rio, GNU readline, editline or vrl
20. ^ PowerShell exposes more than just the file system as a navigable system: Windows Registry, functions, aliases, variables, certificate store, credential store etc. The location types are extensible through a provider architecture. Common commands will work with any compliant provider
21. ^ ^{a b} Added by TSR programs such as DOSKey
22. ^ ^{a b} Available in DR-DOS via the "history" command in config.sys; see this link
23. ^ Many shells in *nix environments change the root user's prompt to '#'.
24. ^ Limited support via AUTOEXEC.BAT.
25. ^ Scientific notation is supported for input only; numeric results are always displayed in common format.
26. ^ Available in modern versions of ash such as NetBSD's sh or Debian ash
27. ^ PowerShell leverages the full .NET regular expression engine which features named captures, zero-width lookahead/-behind, greedy/non-greedy, character classes, level counting etc.
28. ^ Zsh offers an almost overwhelming variety of globbing options.

External links

• Linux Magazine: Bash vs. Vista PowerShell
• IEEE. 1003.1™ Standard for Information Technology — Portable Operating System Interface (POSIX®): Shell and Utilities, Issue 7