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. Neither the name of the University nor the names of its contributors 18.\" may be used to endorse or promote products derived from this software 19.\" without specific prior written permission. 20.\" 21.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31.\" SUCH DAMAGE. 32.\" 33.\" @(#)sleep.3 8.1 (Berkeley) 6/4/93 34.\" 35.Dd April 17, 1997 36.Dt NANOSLEEP 2 37.Os 38.Sh NAME 39.Nm nanosleep 40.Nd suspend process execution for an interval measured in nanoseconds 41.Sh LIBRARY 42.Lb libc 43.Sh SYNOPSIS 44.In time.h 45.Ft int 46.Fn nanosleep "const struct timespec *rqtp" "struct timespec *rmtp" 47.Sh DESCRIPTION 48.Fn Nanosleep 49causes the process to sleep for the specified time. An unmasked signal will 50cause it to terminate the sleep early, regardless of the 51.Dv SA_RESTART 52value on the interrupting signal. 53.Sh RETURN VALUES 54If the 55.Fn nanosleep 56function returns because the requested time has elapsed, the value 57returned will be zero. 58.Pp 59If the 60.Fn nanosleep 61function returns due to the delivery of a signal, the value returned 62will be -1, and the global variable 63.Va errno 64will be set to indicate the interruption. 65If 66.Fa rmtp 67is 68.Pf non- Dv NULL , 69the timespec structure it references is updated to contain the 70unslept amount (the request time minus the time actually slept). 71.Sh ERRORS 72The 73.Fn nanosleep 74call fails if: 75.Bl -tag -width Er 76.It Bq Er EFAULT 77Either 78.Fa rqtp 79or 80.Fa rmtp 81points to memory that is not a valid part of the process 82address space. 83.It Bq Er EINTR 84.Fn nanosleep 85was interrupted by the delivery of a signal. 86.It Bq Er EINVAL 87.Fa rqtp 88specified a nanosecond value less than zero 89or greater than or equal to 1000 million. 90.It Bq Er ENOSYS 91.Fn nanosleep 92is not supported by this implementation. 93.El 94.Sh SEE ALSO 95.Xr sigsuspend 2 , 96.Xr sleep 3 97.Sh STANDARDS 98The 99.Fn nanosleep 100function conforms to 101.St -p1003.1b-93 . 102