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		⚫	{{lowercase\|title=touch (Unix)}}
	{{Infobox Software		{{Infobox Software
	\| name = touch		\| name = touch
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	\| screenshot size =		\| screenshot size =
	\| caption =		\| caption =
	\| developer = Paul Rubin, Arnold Robbins, Jim Kingdon, David MacKenzie, Kris Heidenstrom		\| developer = Paul Rubin, Arnold Robbins, Jim Kingdon, David MacKenzie, Randy Smith, Kris Heidenstrom
	\| released = {{Start date and age\|1979\|1}}		\| released = {{Start date and age\|1979\|1}}
	\| latest release version =		\| latest release version =
	\| latest release date =		\| latest release date =
	\| operating system = ] and ], ], ], ]		\| operating system = ] and ], ], ], ], ]
	\| genre = ]		\| genre = ]
	\| license =		\| license =
	\| website =		\| website =
	}}		}}
	In ], '''<code>touch</code>''' is a ] in ] and ] ]s ~~used to update the access date and/or modification date of a ] or ]. The command is also available in~~ the ] shell<ref>http://aros.sourceforge.net/documentation/users/shell/index.php</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 for ].<ref>http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.2/repos/pkg-html/group-util.html</ref>		In ], '''<code>touch</code>''' is a ] in ] and ] ]s, the ] shell<ref>http://aros.sourceforge.net/documentation/users/shell/index.php</ref>, and 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> used to update the access date and/or modification date of a ] or ]. The command is also available for ]<ref>http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.2/repos/pkg-html/group-util.html</ref> and ].<ref></ref>
⚫	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.

	==Overview==		==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. <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 ] 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 <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.
⚫	~~A touch utility appeared in ] ].~~ The version of <tt>touch</tt> bundled in ] ] was written by Paul Rubin, Arnold Robbins, Jim Kingdon, and ~~David~~ ~~MacKenzie~~.

	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.		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.

			==History==
	~~Programs that perform similar operations as the Unix~~ <code>touch</code> utility ~~are~~ available for ~~other~~ operating systems, including ]~~<ref></ref>~~ and the ].{{which\|date=January 2015 <!-- a short list here would be very useful -->}}		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>https://linux.die.net/man/1/touch</ref>
	The ] version was developed by Kris Heidenstrom.<ref>http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.2/repos/pkg-html/touch.html</ref>

			The command is available as a separate package for ] as part the ] collection of ] ] ] of common ] ] ].<ref>http://unxutils.sourceforge.net/</ref> The ] version was developed by Kris Heidenstrom.<ref>http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.2/repos/pkg-html/touch.html</ref>

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

	==References==		==References==
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	{{Use dmy dates\|date=March 2014}}		{{Use dmy dates\|date=March 2014}}
⚫	{{lowercase\|title=touch (Unix)}}

	]		]

Revision as of 13:46, 27 January 2019

touch
Developer(s)	Paul Rubin, Arnold Robbins, Jim Kingdon, David MacKenzie, Randy Smith, Kris Heidenstrom
Initial release	January 1979; 45 years ago (1979-01)
Operating system	Unix and Unix-like, AROS, OS-9, FreeDOS, Microsoft Windows
Type	Command

In computing, touch is a command in Unix and Unix-like operating systems, the AROS shell, and the OS-9 shell used to update the access date and/or modification date of a computer file or directory. 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 the UnxUtils collection of native Win32 ports of common GNU Unix-like utilities. The FreeDOS version was developed by Kris Heidenstrom.

References

http://aros.sourceforge.net/documentation/users/shell/index.php
Paul S. Dayan (1992). The OS-9 Guru - 1 : The Facts. Galactic Industrial Limited. ISBN 0-9519228-0-7.
http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.2/repos/pkg-html/group-util.html
touch for Windows
https://linux.die.net/man/1/touch
http://unxutils.sourceforge.net/
http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.2/repos/pkg-html/touch.html

External links

touch – Shell and Utilities Reference, The Single UNIX Specification, Version 4 from The Open Group
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

Categories:

Revision as of 13:46, 27 January 2019

Overview

History

See also

References

External links