1.\" $FreeBSD: src/lib/libc/sys/nanosleep.2,v 1.8.2.5 2002/12/20 18:39:35 ceri Exp $ 2.\" $DragonFly: src/lib/libc/sys/nanosleep.2,v 1.2 2003/06/17 04:26:47 dillon Exp $ 3.\" $OpenBSD: nanosleep.2,v 1.1 1997/04/20 20:56:20 tholo Exp $ 4.\" $NetBSD: nanosleep.2,v 1.1 1997/04/17 18:12:02 jtc Exp $ 5.\" 6.\" Copyright (c) 1986, 1991, 1993 7.\" The Regents of the University of California. All rights reserved. 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.3 8.1 (Berkeley) 6/4/93 38.\" 39.Dd April 17, 1997 40.Dt NANOSLEEP 2 41.Os 42.Sh NAME 43.Nm nanosleep 44.Nd suspend process execution for an interval measured in nanoseconds 45.Sh LIBRARY 46.Lb libc 47.Sh SYNOPSIS 48.In time.h 49.Ft int 50.Fn nanosleep "const struct timespec *rqtp" "struct timespec *rmtp" 51.Sh DESCRIPTION 52.Fn Nanosleep 53causes the process to sleep for the specified time. An unmasked signal will 54cause it to terminate the sleep early, regardless of the 55.Dv SA_RESTART 56value on the interrupting signal. 57.Sh RETURN VALUES 58If the 59.Fn nanosleep 60function returns because the requested time has elapsed, the value 61returned will be zero. 62.Pp 63If the 64.Fn nanosleep 65function returns due to the delivery of a signal, the value returned 66will be -1, and the global variable 67.Va errno 68will be set to indicate the interruption. 69If 70.Fa rmtp 71is 72.Pf non- Dv NULL , 73the timespec structure it references is updated to contain the 74unslept amount (the request time minus the time actually slept). 75.Sh ERRORS 76The 77.Fn nanosleep 78call fails if: 79.Bl -tag -width Er 80.It Bq Er EFAULT 81Either 82.Fa rqtp 83or 84.Fa rmtp 85points to memory that is not a valid part of the process 86address space. 87.It Bq Er EINTR 88.Fn nanosleep 89was interrupted by the delivery of a signal. 90.It Bq Er EINVAL 91.Fa rqtp 92specified a nanosecond value less than zero 93or greater than or equal to 1000 million. 94.It Bq Er ENOSYS 95.Fn nanosleep 96is not supported by this implementation. 97.El 98.Sh SEE ALSO 99.Xr sigsuspend 2 , 100.Xr sleep 3 101.Sh STANDARDS 102The 103.Fn nanosleep 104function conforms to 105.St -p1003.1b-93 . 106