1.\"- 2.\" Copyright (c) 1990, 1993, 1994 3.\" The Regents of the University of California. All rights reserved. 4.\" 5.\" This code is derived from software contributed to Berkeley by 6.\" the Institute of Electrical and Electronics Engineers, Inc. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 3. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.Dd May 25, 2022 33.Dt SLEEP 1 34.Os 35.Sh NAME 36.Nm sleep 37.Nd suspend execution for an interval of time 38.Sh SYNOPSIS 39.Nm 40.Ar number Ns Op Ar unit 41.Ar ... 42.Sh DESCRIPTION 43The 44.Nm 45command suspends execution for a minimum of 46.Ar number 47seconds (the default, or unit 48.Cm s ) , 49minutes (unit 50.Cm m ) , 51hours (unit 52.Cm h ) , 53or days (unit 54.Cm d ) . 55If multiple arguments are passed, the delay will be the sum of all values. 56.Pp 57If the 58.Nm 59command receives a signal, it takes the standard action. 60When the 61.Dv SIGINFO 62signal is received, the estimate of the amount of seconds left to 63sleep is printed on the standard output. 64.Sh IMPLEMENTATION NOTES 65The 66.Dv SIGALRM 67signal is not handled specially by this implementation. 68.Pp 69The 70.Nm 71command supports other time units than seconds, 72honors a non-integer number of time units to sleep in any form acceptable by 73.Xr strtod 3 , 74and accepts more than one delay value. 75These are non-portable extensions, but they have also been implemented 76in GNU sh-utils since version 2.0a (released in 2002). 77.Sh EXIT STATUS 78.Ex -std 79.Sh EXAMPLES 80To schedule the execution of a command for 81.Va x 82number seconds later (with 83.Xr csh 1 ) : 84.Pp 85.Dl (sleep 1800; sh command_file >& errors)& 86.Pp 87This incantation would wait a half hour before 88running the script command_file. 89(See the 90.Xr at 1 91utility.) 92.Pp 93To reiteratively run a command (with the 94.Xr csh 1 ) : 95.Pp 96.Bd -literal -offset indent -compact 97while (1) 98 if (! -r zzz.rawdata) then 99 sleep 300 100 else 101 foreach i (`ls *.rawdata`) 102 sleep 70 103 awk -f collapse_data $i >> results 104 end 105 break 106 endif 107end 108.Ed 109.Pp 110The scenario for a script such as this might be: a program currently 111running is taking longer than expected to process a series of 112files, and it would be nice to have 113another program start processing the files created by the first 114program as soon as it is finished (when zzz.rawdata is created). 115The script checks every five minutes for the file zzz.rawdata, 116when the file is found, then another portion processing 117is done courteously by sleeping for 70 seconds in between each 118awk job. 119.Sh SEE ALSO 120.Xr nanosleep 2 , 121.Xr sleep 3 122.Sh STANDARDS 123The 124.Nm 125command is expected to be 126.St -p1003.2 127compatible. 128.Sh HISTORY 129A 130.Nm 131command appeared in 132.At v4 . 133