Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help 
SLEEP(1)		    General Commands Manual		      SLEEP(1)

NAME
       sleep --	suspend	execution for an interval of time

SYNOPSIS
       sleep number[unit] [...]

DESCRIPTION
       The  sleep  command  suspends execution for a minimum of	number seconds
       (the default, or	unit s), minutes (unit m), hours  (unit	 h),  or  days
       (unit  d).   Intervals can be written in	any form allowed by strtod(3).
       If multiple intervals are given,	they are added together.  If the final
       sum is zero or negative,	sleep exits immediately.

       If the sleep command receives a signal, it takes	the  standard  action.
       When the	SIGINFO	signal is received, the	estimate of the	amount of sec-
       onds left to sleep is printed on	the standard output.

IMPLEMENTATION NOTES
       The SIGALRM signal is not handled specially by this implementation.

EXIT STATUS
       The sleep utility exits 0 on success, and >0 if an error	occurs.

EXAMPLES
       To run a	command	after half an hour:

	     (sleep 0.5h; sh command_file >out 2>err)&

       This  incantation  would	 wait  half  an	hour before running the	script
       command_file.  See the at(1) utility for	another	way to do this.

       To reiteratively	run a command:

	     while :; do
		     if	! [ -r zzz.rawdata ] ; then
			     sleep 5m
		     else
			     for i in *.rawdata	; do
				     sleep 70
				     awk -f collapse_data "$i"
			     done >results
			     break
		     fi
	     done

       The scenario for	a script such as this might be:	 a  program  currently
       running	is  taking  longer than	expected to process a series of	files,
       and it would be nice to have another program start processing the files
       created	by  the	 first	program	 as  soon  as  it  is  finished	 (when
       zzz.rawdata  is created).  The script checks every five minutes for the
       file zzz.rawdata, when the file is found, then another portion process-
       ing is done courteously by sleeping for	70  seconds  in	 between  each
       awk(1) job.

SEE ALSO
       nanosleep(2), sleep(3)

STANDARDS
       The sleep command is expected to	be IEEE	Std 1003.2 ("POSIX.2") compat-
       ible.

       Support for non-integer intervals, units	other than seconds, and	multi-
       ple  intervals  which  are  added  together are non-portable extensions
       first introduced	in GNU sh-utils	2.0a (released in 2002).

HISTORY
       A sleep command appeared	in Version 4 AT&T UNIX.

FreeBSD	15.0			March 22, 2024			      SLEEP(1)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=sleep&sektion=1&manpath=FreeBSD+15.0-RELEASE+and+Ports>

home | help