1.\" Copyright (c) 1990 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" the Institute of Electrical and Electronics Engineers, Inc. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. All advertising materials mentioning features or use of this software 16.\" must display the following acknowledgement: 17.\" This product includes software developed by the University of 18.\" California, Berkeley and its contributors. 19.\" 4. Neither the name of the University nor the names of its contributors 20.\" may be used to endorse or promote products derived from this software 21.\" without specific prior written permission. 22.\" 23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33.\" SUCH DAMAGE. 34.\" 35.\" @(#)sleep.1 6.6 (Berkeley) 7/27/91 36.\" 37.Dd July 27, 1991 38.Dt SLEEP 1 39.Os 40.Sh NAME 41.Nm sleep 42.Nd suspend execution for an interval of time 43.Sh SYNOPSIS 44.Nm sleep 45.Ar seconds 46.Sh DESCRIPTION 47The 48.Nm sleep 49command 50suspends execution for a minimum of 51.Ar seconds . 52.Nm Sleep 53is used to schedule the execution of other commands (see 54.Sx EXAMPLES 55below). 56.Pp 57The 58.Nm Sleep 59utility exits with one of the following values: 60.Bl -tag -width flag 61.It Li \&0 62On successful completetion, or if the signal 63.Dv SIGALRM 64was received. 65.It Li \&>\&0 66An error occurred. 67.El 68.Sh EXAMPLES 69To schedule the execution of a command for 70.Va x 71number seconds later: 72.Pp 73.Dl (sleep 1800; sh command_file >& errors)& 74.Pp 75This incantation would wait a half hour before 76running the script command_file. (See the 77.Xr at 1 78utility.) 79.Pp 80To reiteratively run a command (with the 81.Xr csh 1 ) : 82.Pp 83.Bd -literal -offset indent -compact 84while (1) 85 if (! -r zzz.rawdata) then 86 sleep 300 87 else 88 foreach i (`ls *.rawdata`) 89 sleep 70 90 awk -f collapse_data $i >> results 91 end 92 break 93 endif 94end 95.Ed 96.Pp 97The scenario for a script such as this might be: a program currently 98running is taking longer than expected to process a series of 99files, and it would be nice to have 100another program start processing the files created by the first 101program as soon as it is finished (when zzz.rawdata is created). 102The script checks every five minutes for the file zzz.rawdata, 103when the file is found, then another portion processing 104is done curteously by sleeping for 70 seconds in between each 105awk job. 106.Sh SEE ALSO 107.Xr setitimer 2 , 108.Xr alarm 3 , 109.Xr sleep 3 , 110.Xr at 1 111.Sh STANDARDS 112The 113.Nm sleep 114command is expected to be 115.St -p1003.2 116compatible. 117