Touch (command): Difference between revisions

Browse history interactively ← Previous editContent deleted Content addedVisual WikitextInline

Revision as of 17:44, 4 May 2018 editCpt Wise (talk \| contribs)Extended confirmed users543 editsmNo edit summary← Previous edit		Latest revision as of 13:15, 27 September 2023 edit undoCitation bot (talk \| contribs)Bots5,409,223 edits Removed parameters. \| Use this bot. Report bugs. \| #UCB_CommandLine
(51 intermediate revisions by 16 users not shown)
Line 1:		Line 1:
			{{Short description\|File modification command on various operating systems}}
	{{manual\|date=May 2014}}
		⚫	{{lowercase}}
			{{Infobox software
			\| name = touch
			\| logo =
			\| screenshot = Touch-example.png
			\| screenshot size =
			\| caption = Example of <code>touch</code> usage
			\| author = ]
			\| developer = Paul Rubin, Arnold Robbins, Jim Kingdon, David MacKenzie, Randy Smith, ], ], ], ], ], Kris Heidenstrom
			\| released = {{Start date and age\|1979\|1}}
			\| latest release version =
			\| latest release date =
			\| programming language = ]
			\| operating system = ], ], ], ], ], ], ], ], ], ], ], ], ], ]
			\| platform = ]
			\| genre = ]
			\| license = ]: ]<br />FreeDOS: ]<br />ReactOS: ]<br />]: ]<br />]: ]<br />Plan 9: ]
			\| website =
			}}
			In ], '''<code>touch</code>''' is a ] used to update the access date and/or modification date of a ] or ]. It is included in ] and ] ]s, ]'s ],<ref>{{Cite web\|url=http://www.flexusergroup.com/flexusergroup/pdfs/swflexum.pdf\|title=FLEX 9.0 User's Manual}}</ref> ]/] ], the ] shell,<ref>{{Cite web\|url=https://aros.sourceforge.io/documentation/users/shell/index.php\|title=AROS Research Operating System\|website=aros.sourceforge.io}}</ref> the ] ] shell,<ref>{{cite book\|author=Paul S. Dayan\|year=1992\|title=The OS-9 Guru - 1 : The Facts\|publisher=Galactic Industrial Limited\|isbn=0-9519228-0-7}}</ref> and ].<ref>{{Cite web\|url=https://github.com/reactos/reactos\|title=reactos/reactos\|website=GitHub}}</ref>
			The command is also available for ]<ref>{{Cite web\|url=http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.2/repos/pkg-html/group-util.html\|title=ibiblio.org FreeDOS Group -- Utilities\|website=www.ibiblio.org}}</ref> and ].<ref>{{Cite web\|url=https://sourceforge.net/projects/touchforwindows/\|title=touch for Windows}}</ref>

		⚫	==Overview==
	~~'''touch''' is a standard ] ] ] which is used to update the access date and/or modification date of a ] or directory.~~ In its default usage, it is the equivalent of creating or opening a file and saving it without any change to the file contents. ~~Touch~~ avoids opening, saving, and closing the file. Instead it simply updates the dates associated with the file or directory. An updated access or modification date can be important for a variety of other programs such as ] utilities or the ] command-line interface programming utility. Typically these types of programs are only concerned with files which have been created or modified after the program was last run. ~~Touch~~ can also be useful for quickly creating files for programs or scripts that require a file with a specific name to exist for successful operation of the program, but do not require the file to have any specific content.		In its default usage, it is the equivalent of creating or opening a file and saving it without any change to the file contents. <code>touch</code> avoids opening, saving, and closing the file. Instead it simply updates the dates associated with the file or directory. An updated access or modification date can be important for a variety of other programs such as ] utilities or the ] ] programming utility. Typically these types of programs are only concerned with files which have been created or modified after the program was last run. The <code>touch</code> command can also be useful for quickly creating files for programs or scripts that require a file with a specific name to exist for successful operation of the program, but do not require the file to have any specific content.

		⚫	The ] (SUS) specifies that <code>touch</code> should change the access times, modification times, or both, for a file. The file is identified by a pathname supplied as a single argument. It also specifies that if the file identified does not exist, the file is created and the access and modification times are set as specified. If no new timestamps are specified, <code>touch</code> uses the current time.
⚫	== Overview ==
	A touch utility appeared in Version 7 AT&T UNIX. The version of <tt>touch</tt> bundled in ] ] was written by Paul Rubin, Arnold Robbins, Jim Kingdon, and David MacKenzie.

			==History==
⚫	The ] (SUS) specifies that <tt>touch</tt> should change the access times, modification times, or both, for a file. The file is identified by a pathname supplied as a single argument. It also specifies that if the file identified does not exist, the file is created and the access and modification times are set as specified. If no new timestamps are specified, <tt>touch</tt> uses the current time.
		⚫	A <code>touch</code> utility first appeared in ] ]. Today, the command is available for a number of different operating systems, including many ] and ] systems, ], ] and the ].{{which\|date=January 2015 <!-- a short list here would be very useful -->}}

			The version of <code>touch</code> bundled in ] ] was written by Paul Rubin, Arnold Robbins, Jim Kingdon, David MacKenzie, and Randy Smith.<ref>{{Cite web\|url=https://linux.die.net/man/1/touch\|title=touch(1): change file timestamps - Linux man page\|website=linux.die.net}}</ref>
⚫	~~Programs that perform similar operations as the Unix~~ <code>touch</code> utility ~~are~~ available for ~~other~~ operating systems, including ] and the ].{{which\|date=January 2015 <!-- a short list here would be very useful -->}}

			The command is available as a separate package for Microsoft Windows as part of the ] collection of ] ] ] of common GNU Unix-like utilities.<ref>{{Cite web\|url=http://unxutils.sourceforge.net/\|title=Native Win32 ports of some GNU utilities\|website=unxutils.sourceforge.net}}</ref> The ] version was developed by Kris Heidenstrom and is licensed under the ].<ref>{{Cite web\|url=http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.2/repos/pkg-html/touch.html\|title=ibiblio.org FreeDOS Package -- touch (Unix-like)\|website=www.ibiblio.org}}</ref> ]<ref name="drdos6userguide"></ref> and ]<ref>{{Cite web\|url=http://wiki.kolibrios.org/Shell\|title=Shell - KolibriOS wiki\|website=wiki.kolibrios.org}}</ref> include an implementation of the {{code\|touch}} command. The {{Mono\|touch}} command has also been ported to the ] operating system.<ref>{{cite web \|title=IBM System i Version 7.2 Programming Qshell \|language=en \|author=IBM \|website=] \|author-link=IBM \|url=https://www.ibm.com/support/knowledgecenter/ssw_ibm_i_74/rzahz/rzahzpdf.pdf?view=kc \|access-date=2020-09-05 }}</ref>

	==See also==		==See also==
	*]		*]
	*]		*]

			==References==
			{{Reflist}}

			==Further reading==
			*{{Cite book\|author-last=McElhearn\|author-first=Kirk\|title=The Mac OS X Command Line: Unix Under the Hood\|date=2006\|publisher=]\|isbn=978-0470113851}}

	==External links==		==External links==
			{{Wikibooks\|Guide to Unix\|Commands}}
	* {{man\|cu\|touch\|SUS}}		* {{man\|cu\|touch\|SUS}}
			* {{man\|1\|touch\|die.net}}
			* {{man\|1\|touch\|Plan 9}}
			* {{man\|1\|touch\|Inferno}}
	*		*
	*

	{{Unix commands}}		{{Unix commands}}
			{{Plan 9 commands}}

			{{Core Utilities commands}}
	{{Use dmy dates\|date=March 2014}}		{{Use dmy dates\|date=March 2014}}
⚫	{{lowercase~~\|title=touch (Unix)~~}}

	]		]
	]		]
			]
			]
			]
			]

Latest revision as of 13:15, 27 September 2023

File modification command on various operating systems

touch
Example of `touch` usage
Original author(s)	AT&T Bell Laboratories
Developer(s)	Paul Rubin, Arnold Robbins, Jim Kingdon, David MacKenzie, Randy Smith, TSC, Microware, Apple, Digital Research, Novell, Kris Heidenstrom
Initial release	January 1979; 45 years ago (1979-01)
Written in	C
Operating system	Unix, Unix-like, Plan 9, Inferno, FLEX, OS-9, Classic Mac OS, Windows, DR DOS, AROS, FreeDOS, ReactOS, KolibriOS, IBM i
Platform	Cross-platform
Type	Command
License	coreutils: GPLv3+ FreeDOS: GPLv2 ReactOS: BSD-4-Clause BusyBox: GPL-2.0-only Toybox: 0BSD Plan 9: MIT License

In computing, touch is a command used to update the access date and/or modification date of a computer file or directory. It is included in Unix and Unix-like operating systems, TSC's FLEX, Digital Research/Novell DR DOS, the AROS shell, the Microware OS-9 shell, and ReactOS. The command is also available for FreeDOS and Microsoft Windows.

Overview

In its default usage, it is the equivalent of creating or opening a file and saving it without any change to the file contents. touch avoids opening, saving, and closing the file. Instead it simply updates the dates associated with the file or directory. An updated access or modification date can be important for a variety of other programs such as backup utilities or the make command-line interface programming utility. Typically these types of programs are only concerned with files which have been created or modified after the program was last run. The touch command can also be useful for quickly creating files for programs or scripts that require a file with a specific name to exist for successful operation of the program, but do not require the file to have any specific content.

The Single Unix Specification (SUS) specifies that touch should change the access times, modification times, or both, for a file. The file is identified by a pathname supplied as a single argument. It also specifies that if the file identified does not exist, the file is created and the access and modification times are set as specified. If no new timestamps are specified, touch uses the current time.

History

A touch utility first appeared in Version 7 AT&T UNIX. Today, the command is available for a number of different operating systems, including many Unix and Unix-like systems, DOS, Microsoft Windows and the classic Mac OS.

The version of touch bundled in GNU coreutils was written by Paul Rubin, Arnold Robbins, Jim Kingdon, David MacKenzie, and Randy Smith.

The command is available as a separate package for Microsoft Windows as part of the UnxUtils collection of native Win32 ports of common GNU Unix-like utilities. The FreeDOS version was developed by Kris Heidenstrom and is licensed under the GPL. DR DOS 6.0 and KolibriOS include an implementation of the touch command. The touch command has also been ported to the IBM i operating system.

References

"FLEX 9.0 User's Manual" (PDF).
"AROS Research Operating System". aros.sourceforge.io.
Paul S. Dayan (1992). The OS-9 Guru - 1 : The Facts. Galactic Industrial Limited. ISBN 0-9519228-0-7.
"reactos/reactos". GitHub.
"ibiblio.org FreeDOS Group -- Utilities". www.ibiblio.org.
"touch for Windows".
"touch(1): change file timestamps - Linux man page". linux.die.net.
"Native Win32 ports of some GNU utilities". unxutils.sourceforge.net.
"ibiblio.org FreeDOS Package -- touch (Unix-like)". www.ibiblio.org.
DR DOS 6.0 User Guide Optimisation and Configuration Tips
"Shell - KolibriOS wiki". wiki.kolibrios.org.
IBM. "IBM System i Version 7.2 Programming Qshell" (PDF). IBM. Retrieved 5 September 2020.

External links

touch – Shell and Utilities Reference, The Single UNIX Specification, Version 4 from The Open Group
touch(1) – Linux User Commands Manual
touch(1) – Plan 9 Programmer's Manual, Volume 1
touch(1) – Inferno General commands Manual
examples showing how to use touch

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

v t e Plan 9 command-line interface programs and shell builtins
File system	chmod chgrp cmp cp dd du file gzip ls mkdir pwd rm split tee touch
Processes	kill ps
User environment	passwd who
Text processing	awk basename comm diff ed eqn join sed sort spell strings tail tr troff uniq wc
Shell builtins	echo test
Networking	ip/ipconfig ip/ping netstat
Searching	grep
Software development	ar hoc lex nm strip yacc
Miscellaneous	bc cal fortune sleep
Category

v t e GNU Core Utilities command-line interface programs
File system	chcon chmod chown chgrp cksum cp dd df dir dircolors install ln ls mkdir mkfifo mknod mktemp mv realpath rm rmdir shred sync touch truncate vdir
Text utilities	b2sum base32 base64 cat cksum comm csplit cut expand fmt fold head join md5sum nl numfmt od paste ptx pr sha1sum shuf sort split sum tac tail tr tsort unexpand uniq wc
Shell utilities	arch basename chroot date dirname du echo env expr factor false groups hostid id link logname nice nohup nproc pathchk pinky printenv printf pwd readlink runcon seq sleep stat stdbuf stty tee test timeout true tty uname unlink uptime users who whoami yes

Categories:

Latest revision as of 13:15, 27 September 2023

Overview

History

See also

References

Further reading

External links