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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).  If multiple arguments are passed, the delay will be the sum
       of all values.

       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.

       The sleep command supports other	time units than	seconds, honors	a non-
       integer	number	of  time  units	 to  sleep  in	any form acceptable by
       strtod(3), and accepts more than	 one  delay  value.   These  are  non-
       portable	 extensions,  but  they	 have also been	implemented in GNU sh-
       utils since version 2.0a	(released in 2002).

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

EXAMPLES
       To schedule the execution of a command for x number seconds later (with
       csh(1)):

	     (sleep 1800; sh command_file >& errors)&

       This incantation	would wait a half hour before running the script  com-
       mand_file.  (See	the at(1) utility.)

       To reiteratively	run a command (with the	csh(1)):

	     while (1)
		     if	(! -r zzz.rawdata) then
			     sleep 300
		     else
			     foreach i (`ls *.rawdata`)
				     sleep 70
				     awk -f collapse_data $i >>	results
			     end
			     break
		     endif
	     end

       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.raw-
       data is created).  The script checks every five minutes	for  the  file
       zzz.rawdata, when the file is found, then another portion processing is
       done courteously	by sleeping for	70 seconds in between each awk job.

SEE ALSO
       nanosleep(2), sleep(3)

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

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

FreeBSD	13.2			 May 25, 2022			      SLEEP(1)

NAME | SYNOPSIS | DESCRIPTION | IMPLEMENTATION NOTES | EXIT STATUS | EXAMPLES | SEE ALSO | STANDARDS | HISTORY

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