1.\" $NetBSD: sleep.3,v 1.12 2002/02/07 07:00:17 ross 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. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. 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.3 8.1 (Berkeley) 6/4/93 35.\" 36.Dd June 4, 1993 37.Dt SLEEP 3 38.Os 39.Sh NAME 40.Nm sleep 41.Nd suspend process execution for interval of seconds 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.Fd #include \*[Lt]unistd.h\*[Gt] 46.Ft unsigned int 47.Fn sleep "unsigned int seconds" 48.Sh DESCRIPTION 49The 50.Fn sleep 51function suspends execution of the calling process until either the 52number of seconds specified by 53.Fa seconds 54have elapsed or a signal is delivered to the calling process and its 55action is to invoke a signal-catching function or to terminate the 56process. The suspension time may be longer than requested due to the 57scheduling of other activity by the system. 58.Sh RETURN VALUES 59If the 60.Fn sleep 61function returns because the requested time has elapsed, the value 62returned will be zero. If the 63.Fn sleep 64function returns due to the delivery of a signal, the value returned 65will be the unslept amount (the request time minus the time actually 66slept) in seconds. 67.Sh SEE ALSO 68.Xr nanosleep 2 , 69.Xr usleep 3 70.Sh STANDARDS 71The 72.Fn sleep 73function conforms to 74.St -p1003.1-90 . 75.Sh HISTORY 76A 77.Fn sleep 78function appeared in 79.At v7 . 80