1.\" $OpenBSD: sleep.1,v 1.24 2022/07/30 16:42:08 jsg Exp $ 2.\" $NetBSD: sleep.1,v 1.9 1995/07/25 19:37:43 jtc Exp $ 3.\" 4.\" Copyright (c) 1990, 1993, 1994 5.\" The Regents of the University of California. All rights reserved. 6.\" 7.\" This code is derived from software contributed to Berkeley by 8.\" the Institute of Electrical and Electronics Engineers, Inc. 9.\" 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 3. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)sleep.1 8.3 (Berkeley) 4/18/94 35.\" 36.Dd $Mdocdate: July 30 2022 $ 37.Dt SLEEP 1 38.Os 39.Sh NAME 40.Nm sleep 41.Nd suspend execution for an interval of time 42.Sh SYNOPSIS 43.Nm sleep 44.Ar seconds 45.Sh DESCRIPTION 46The 47.Nm 48utility suspends execution for at least the given number of 49.Ar seconds . 50.Ar seconds 51must be a non-negative decimal value and may contain a fraction. 52.Sh ASYNCHRONOUS EVENTS 53.Bl -tag -width "SIGALRMXXX" 54.It Dv SIGALRM 55Terminate early, with a zero exit status. 56.El 57.Sh EXIT STATUS 58.Ex -std sleep 59.Sh EXAMPLES 60Wait five seconds before running a command: 61.Pp 62.Dl $ sleep 5 ; echo Hello, World! 63.Pp 64List a file twice per second: 65.Bd -literal -offset indent 66while ls -l file; do 67 sleep 0.5 68done 69.Ed 70.Sh SEE ALSO 71.Xr at 1 72.Sh STANDARDS 73The 74.Nm 75utility is compliant with the 76.St -p1003.1-2008 77specification. 78.Pp 79Support for fractional 80.Ar seconds 81is an extension to that specification. 82.Sh HISTORY 83A 84.Nm 85utility first appeared in 86.At v4 . 87.Pp 88This implementation of 89.Nm 90first appeared in 91.Bx 4.3 Tahoe . 92