Sleep (command)

{{Short description|Unix command}} {{lowercase}} {{Infobox software | name = sleep | logo = | screenshot = Sleepunix.png | screenshot size = | caption = The {{code|sleep}} command | developer = AT&T Bell Laboratories, Microsoft, Microware, Trane Francks | released = {{Start date and age|1973|11}} | latest release version = | latest release date = | programming language = C | operating system = Unix, Unix-like, V, Plan 9, Inferno, OS-9, MSX-DOS, FreeDOS, Windows, KolibriOS, IBM i | platform = Cross-platform | genre = Command | license = coreutils: GPLv3+<br />FreeDOS: GPLv2<br />Plan 9: MIT License | website = }} In computing, '''sleep''' is a command in Unix, Unix-like and other operating systems that suspends program execution for a specified time.

==Overview== The sleep instruction suspends the calling process for at least the specified number of seconds (the default), minutes, hours or days.

{{code|sleep}} for Unix-like systems is part of the X/Open Portability Guide since issue 2 of 1987. It was inherited into the first version of POSIX and the Single Unix Specification.<ref>{{man|cu|sleep|SUS}}</ref> It first appeared in Version 4 Unix.<ref>{{man|1|sleep|FreeBSD}}</ref>

The version of <code>sleep</code> bundled in GNU coreutils was written by Jim Meyering and Paul Eggert.<ref>{{Cite web|url=https://linux.die.net/man/1/sleep|title=sleep(1): delay for specified amount of time - Linux man page|website=linux.die.net|access-date=2019-02-28|archive-date=2007-07-12|archive-url=https://web.archive.org/web/20070712184450/https://linux.die.net/man/1/sleep|url-status=live}}</ref> The command is also available in the OS-9 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> in the KolibriOS Shell,<ref>{{Cite web|url=http://wiki.kolibrios.org/wiki/Shell|title=Shell - KolibriOS wiki|website=wiki.kolibrios.org|access-date=2019-03-25|archive-date=2019-02-11|archive-url=https://web.archive.org/web/20190211231827/http://wiki.kolibrios.org/wiki/Shell|url-status=live}}</ref> and part of the FreeDOS ''Package group Utilities''.<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|access-date=2018-11-16|archive-date=2018-09-30|archive-url=https://web.archive.org/web/20180930110109/http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.2/repos/pkg-html/group-util.html|url-status=live}}</ref> The FreeDOS version was developed by Trane Francks and is licensed under the GPL.<ref>{{Cite web|url=http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.2/repos/pkg-html/sleep.html|title=ibiblio.org FreeDOS Package -- sleep (Unix-like)|website=www.ibiblio.org|access-date=2018-08-10|archive-date=2018-07-07|archive-url=https://web.archive.org/web/20180707064423/http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.2/repos/pkg-html/sleep.html|url-status=live}}</ref>

A <code>sleep</code> command is also part of ASCII's ''MSX-DOS2 Tools'' for MSX-DOS version 2.<ref>{{Cite web|url=https://archive.org/details/MSXDOS2TOOLS|title=MSX-DOS2 Tools User's Manual - MSX-DOS2 TOOLS ユーザーズマニュアル|date=April 1, 1993|via=Internet Archive}}</ref>

In PowerShell, <code>sleep</code> is a predefined command alias for the <code>Start-Sleep</code> cmdlet which serves the same purpose.<ref>{{Cite web|url=https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.utility/start-sleep|title=Start-Sleep (Microsoft.PowerShell.Utility) - PowerShell|website=docs.microsoft.com}}</ref> Microsoft also provides a <code>sleep</code> resource kit tool for Windows which can be used in batch files or the command prompt to pause the execution and wait for some time.<ref>{{Cite web |url=https://www.microsoft.com/en-us/download/details.aspx?id=17657 |title=Download Windows Server 2003 Resource Kit Tools from Official Microsoft Download Center |website=Microsoft |access-date=2018-08-10 |archive-date=2019-06-11 |archive-url=https://web.archive.org/web/20190611201442/http://www.microsoft.com/en-us/download/details.aspx?id=17657 |url-status=dead }}</ref> Another native version is the <code>timeout</code> command which is part of current versions of Windows.<ref>{{Cite web|url=https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-r2-and-2012/cc754891(v=ws.11)|title=Timeout|website=docs.microsoft.com|access-date=2020-09-13|archive-date=2020-08-06|archive-url=https://web.archive.org/web/20200806200456/https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-r2-and-2012/cc754891(v%3Dws.11)|url-status=live}}</ref>

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.<ref>{{Cite web|url=https://unxutils.sourceforge.net/|title=Native Win32 ports of some GNU utilities|website=unxutils.sourceforge.net|access-date=2025-08-11|archive-date=2006-02-09|archive-url=https://web.archive.org/web/20060209022842/http://unxutils.sourceforge.net/|url-status=live}}</ref> The {{Mono|sleep}} command has also been ported to the IBM i operating system.<ref>{{cite web |title=IBM System i Version 7.2 Programming Qshell |language=en |author=IBM |website=IBM |author-link=IBM |url=https://www.ibm.com/support/knowledgecenter/ssw_ibm_i_74/rzahz/rzahzpdf.pdf?view=kc |access-date=2020-09-05 |archive-date=2020-09-18 |archive-url=https://web.archive.org/web/20200918130823/https://www.ibm.com/support/knowledgecenter/ssw_ibm_i_74/rzahz/rzahzpdf.pdf?view=kc |url-status=live }}</ref>

==Usage== <syntaxhighlight lang="bash"> sleep number </syntaxhighlight>

Where '''number''' is an integer<ref>{{cite web|url=https://linux.die.net/man/3/sleep|title=sleep(3): sleep for specified number of seconds - Linux man page|website=linux.die.net|access-date=19 April 2018|archive-date=6 April 2019|archive-url=https://web.archive.org/web/20190406104546/https://linux.die.net/man/3/sleep|url-status=live}}</ref> number to indicate the time period in seconds. Some implementations support floating point numbers.

===Options=== None.

==Examples== <syntaxhighlight lang="bash"> sleep 30 </syntaxhighlight> Causes the current terminal session to wait 30 seconds.

<syntaxhighlight lang="bash"> sleep 18000 </syntaxhighlight> Causes the current terminal session to wait 5 hours

===GNU sleep=== <syntaxhighlight lang="bash"> sleep 3h ; mplayer foo.mp3 </syntaxhighlight>

Wait 3 hours then play the file {{mono|foo.mp3}}

Note that <code>sleep 5h30m</code> and <code>sleep 5h 30m</code> are illegal since sleep takes only one value and unit as argument. However, <code>sleep 5.5h</code> (a floating point<ref name="gnu.org">{{cite web|url=http://www.gnu.org/software/coreutils/sleep|title=GNU Coreutils: sleep invocation|website=www.gnu.org|access-date=19 April 2018}}</ref>) is allowed. Consecutive executions of sleep can also be used.

<syntaxhighlight lang="bash"> sleep 5h; sleep 30m </syntaxhighlight>

Sleep 5 hours, then sleep another 30 minutes.

The GNU Project's implementation of sleep (part of coreutils) allows the user to pass an arbitrary floating point<ref name="gnu.org"/> or multiple arguments, therefore <code>sleep 5h 30m</code> (a space separating hours and minutes is needed) will work on any system which uses GNU sleep, including Linux.

Possible uses for <code>sleep</code> include scheduling tasks and delaying execution to allow a process to start, or waiting until a shared network connection most likely has few users to wget a large file.

==See also== *Sleep (system call)

==References== {{Reflist}}

==External links== {{Wikibooks|Guide to Unix|Commands}} * {{man|cu|sleep|SUS}} * {{man|1|sleep|Plan 9}} * {{man|1|sleep|Inferno}}

Category:Unix SUS2008 utilities Category:Unix process- and task-management-related software Category:Plan 9 commands Category:Inferno (operating system) commands Category:IBM i Qshell commands Category:Microcomputer software