1.\" $NetBSD: sleep.1,v 1.17 2002/11/21 15:02:03 kim Exp $ 2.\" 3.\" Copyright (c) 1990, 1993, 1994 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" the Institute of Electrical and Electronics Engineers, Inc. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. All advertising materials mentioning features or use of this software 18.\" must display the following acknowledgement: 19.\" This product includes software developed by the University of 20.\" California, Berkeley and its contributors. 21.\" 4. Neither the name of the University nor the names of its contributors 22.\" may be used to endorse or promote products derived from this software 23.\" without specific prior written permission. 24.\" 25.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35.\" SUCH DAMAGE. 36.\" 37.\" @(#)sleep.1 8.3 (Berkeley) 4/18/94 38.\" 39.Dd April 18, 1994 40.Dt SLEEP 1 41.Os 42.Sh NAME 43.Nm sleep 44.Nd suspend execution for an interval of time 45.Sh SYNOPSIS 46.Nm 47.Ar seconds 48.Sh DESCRIPTION 49The 50.Nm 51utility 52suspends execution for a minimum of 53.Ar seconds . 54It is usually used to schedule the execution of other commands (see 55.Sx EXAMPLES 56below). 57.Pp 58Note: The 59.Nx 60.Nm 61command will accept and honor a non-integer number of specified seconds. 62This is a non-portable extension, and its use will nearly guarantee that 63a shell script will not execute properly on another system. 64.Sh EXIT STATUS 65The 66.Nm 67utility exits with one of the following values: 68.Bl -tag -width flag 69.It Li \&0 70On successful completion, or if the signal 71.Dv SIGALRM 72was received. 73.It Li \&\*[Gt]\&0 74An error occurred. 75.El 76.Sh EXAMPLES 77To schedule the execution of a command for 78.Va x 79number seconds later: 80.Pp 81.Dl (sleep 1800; sh command_file \*[Gt]\*[Am] errors)\*[Am] 82.Pp 83This incantation would wait a half hour before 84running the script command_file. 85(See the 86.Xr at 1 87utility.) 88.Pp 89To reiteratively run a command (with the 90.Xr csh 1 ) : 91.Pp 92.Bd -literal -offset indent -compact 93while (1) 94 if (! -r zzz.rawdata) then 95 sleep 300 96 else 97 foreach i (*.rawdata) 98 sleep 70 99 awk -f collapse_data $i \*[Gt]\*[Gt] results 100 end 101 break 102 endif 103end 104.Ed 105.Pp 106The scenario for a script such as this might be: a program currently 107running is taking longer than expected to process a series of 108files, and it would be nice to have 109another program start processing the files created by the first 110program as soon as it is finished (when zzz.rawdata is created). 111The script checks every five minutes for the file zzz.rawdata, 112when the file is found, then another portion processing 113is done courteously by sleeping for 70 seconds in between each 114awk job. 115.Sh SEE ALSO 116.Xr at 1 , 117.Xr nanosleep 2 , 118.Xr sleep 3 119.Sh STANDARDS 120The 121.Nm 122command is expected to be 123.St -p1003.2 124compatible. 125