1.\" Copyright (c) 1990, 1993, 1994 2.\" The Regents of the University of California. 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 8.3 (Berkeley) 4/18/94 36.\" $Id: sleep.1,v 1.7 1997/08/12 21:20:12 ache Exp $ 37.\" 38.Dd April 18, 1994 39.Dt SLEEP 1 40.Os 41.Sh NAME 42.Nm sleep 43.Nd suspend execution for an interval of time 44.Sh SYNOPSIS 45.Nm sleep 46.Ar seconds 47.Sh DESCRIPTION 48The 49.Nm 50command 51suspends execution for a minimum of 52.Ar seconds . 53.Nm Sleep 54is used to schedule the execution of other commands (see 55.Sx EXAMPLES 56below). 57.Pp 58If the 59.Nm 60command 61receives a SIGALRM signal, it terminates normally with a zero exit status, 62for any other signal it takes the standard action. 63.Pp 64The 65.Nm 66utility exits with one of the following values: 67.Bl -tag -width flag 68.It Li \&0 69On successful completion, or if the signal 70.Dv SIGALRM 71was received. 72.It Li \&>\&0 73An error occurred. 74.El 75.Sh EXAMPLES 76To schedule the execution of a command for 77.Va x 78number seconds later: 79.Pp 80.Dl (sleep 1800; sh command_file >& errors)& 81.Pp 82This incantation would wait a half hour before 83running the script command_file. (See the 84.Xr at 1 85utility.) 86.Pp 87To reiteratively run a command (with the 88.Xr csh 1 ) : 89.Pp 90.Bd -literal -offset indent -compact 91while (1) 92 if (! -r zzz.rawdata) then 93 sleep 300 94 else 95 foreach i (`ls *.rawdata`) 96 sleep 70 97 awk -f collapse_data $i >> results 98 end 99 break 100 endif 101end 102.Ed 103.Pp 104The scenario for a script such as this might be: a program currently 105running is taking longer than expected to process a series of 106files, and it would be nice to have 107another program start processing the files created by the first 108program as soon as it is finished (when zzz.rawdata is created). 109The script checks every five minutes for the file zzz.rawdata, 110when the file is found, then another portion processing 111is done courteously by sleeping for 70 seconds in between each 112awk job. 113.Sh SEE ALSO 114.Xr at 1 , 115.Xr setitimer 2 , 116.Xr alarm 3 , 117.Xr sleep 3 118.Sh STANDARDS 119The 120.Nm 121command is expected to be 122.St -p1003.2 123compatible. 124