1.\" $NetBSD: sleep.3,v 1.15 2003/08/07 16:42:57 agc Exp $ 2.\" 3.\" Copyright (c) 1986, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" @(#)sleep.3 8.1 (Berkeley) 6/4/93 31.\" 32.Dd June 4, 1993 33.Dt SLEEP 3 34.Os 35.Sh NAME 36.Nm sleep 37.Nd suspend process execution for interval of seconds 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In unistd.h 42.Ft unsigned int 43.Fn sleep "unsigned int seconds" 44.Sh DESCRIPTION 45The 46.Fn sleep 47function suspends execution of the calling process until either the 48number of seconds specified by 49.Fa seconds 50have elapsed or a signal is delivered to the calling process and its 51action is to invoke a signal-catching function or to terminate the 52process. 53The suspension time may be longer than requested due to the 54scheduling of other activity by the system. 55.Sh RETURN VALUES 56If the 57.Fn sleep 58function returns because the requested time has elapsed, the value 59returned will be zero. 60If the 61.Fn sleep 62function returns due to the delivery of a signal, the value returned 63will be the unslept amount (the request time minus the time actually 64slept) in seconds. 65.Sh SEE ALSO 66.Xr nanosleep 2 , 67.Xr usleep 3 68.Sh STANDARDS 69The 70.Fn sleep 71function conforms to 72.St -p1003.1-90 . 73.Sh HISTORY 74A 75.Fn sleep 76function appeared in 77.At v7 . 78