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SLEEP(1)		FreeBSD	General	Commands Manual		      SLEEP(1)

NAME
     sleep -- suspend execution	for an interval	of time

SYNOPSIS
     sleep seconds

DESCRIPTION
     The sleep command suspends	execution for a	minimum	of seconds.

     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 allows and honors a non-integer number of seconds to
     sleep in any form acceptable by strtod(3).	 This is a non-portable	exten-
     sion, but is also implemented in GNU sh-utils since version 2.0a (re-
     leased 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 run-
     ning 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 cre-
     ated).  The script	checks every five minutes for the file zzz.rawdata,
     when the file is found, then another portion processing is	done courte-
     ously 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") compati-
     ble.

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

FreeBSD	13.0		       December	31, 2020		  FreeBSD 13.0
NAME | SYNOPSIS | DESCRIPTION | IMPLEMENTATION NOTES | EXIT STATUS | EXAMPLES | SEE ALSO | STANDARDS | HISTORY

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