1.\" Copyright (c) 1990 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" %sccs.include.redist.man% 5.\" 6.\" @(#)sleep.1 6.4 (Berkeley) 03/14/91 7.\" 8.Vx 9.Vx 10.Dd 11.Dt SLEEP 1 12.Os 13.Sh NAME 14.Nm sleep 15.Nd suspend execution for an interval of time 16.Sh SYNOPSIS 17.Nm sleep 18.Ar seconds 19.Sh DESCRIPTION 20The 21.Nm sleep 22command 23suspends execution for a minimum of 24.Ar seconds . 25.Nm Sleep 26is used to schedule the execution of other commands (see 27EXAMPLES below). 28.Pp 29The 30.Nm Sleep 31utility exits with one of the following values: 32.Tw Ds 33.Tp Li \&0 34On successful completetion, or if the signal SIGALRM was received. 35.Tp Li \&>\&0 36An error occurred. 37.Tp 38.Sh EXAMPLES 39To schedule the execution of a command for 40.Va x 41number seconds later: 42.Pp 43.Dl (sleep 1800; sh command_file >& errors)& 44.Pp 45This incantation would wait a half hour before 46running the script command_file. (See the 47.Xr at 1 48utility.) 49.Pp 50To reiteratively run a command (with the 51.Xr csh 1 ) : 52.Pp 53.Ds I 54while (1) 55 if (! -r zzz.rawdata) then 56 sleep 300 57 else 58 foreach i (`ls *.rawdata`) 59 sleep 70 60 awk -f collapse_data $i >> results 61 end 62 break 63 endif 64end 65.De 66.Pp 67The scenario for a script such as this might be: a program currently 68running is taking longer than expected to process a series of 69files, and it would be nice to have 70another program start processing the files created by the first 71program as soon as it is finished (when zzz.rawdata is created). 72The script checks every five minutes for the file zzz.rawdata, 73when the file is found, then another portion processing 74is done curteously by sleeping for 70 seconds in between each 75awk job. 76.Sh SEE ALSO 77.Xr setitimer 2 , 78.Xr alarm 3 , 79.Xr sleep 3 , 80.Xr at 1 81.Sh STANDARDS 82The sleep function is expected to be POSIX 1003.2 compatible. 83