92 lines
3.1 KiB
Groff
92 lines
3.1 KiB
Groff
.\" $NetBSD: usleep.3,v 1.13 2001/09/16 02:57:05 wiz Exp $
|
|
.\"
|
|
.\" Copyright (c) 1986, 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)usleep.3 8.1 (Berkeley) 6/4/93
|
|
.\"
|
|
.Dd June 4, 1993
|
|
.Dt USLEEP 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm usleep
|
|
.Nd suspend execution for interval of microseconds
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.Fd #include <unistd.h>
|
|
.Ft int
|
|
.Fn usleep "useconds_t microseconds"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn usleep
|
|
function
|
|
suspends execution of the calling process
|
|
until either the number of microseconds specified by
|
|
.Fa microseconds
|
|
have elapsed or a signal is delivered to the calling process and its
|
|
action is to invoke a signal catching function or to terminate the
|
|
process. The suspension time may be longer than requested due to the
|
|
scheduling of other activity by the system.
|
|
.Pp
|
|
The
|
|
.Fa microseconds
|
|
argument must be less than 1,000,000. If the value of
|
|
.Fa microseconds
|
|
is 0, then the call has no effect.
|
|
.Sh RETURN VALUES
|
|
On successful completition,
|
|
.Fn usleep
|
|
returns 0. Otherwhise, it returns -1 and sets errno to indicate the error.
|
|
.Sh ERRORS
|
|
The
|
|
.Fn usleep
|
|
function may fail if:
|
|
.Bl -tag -width Er
|
|
.It Bq Er EINVAL
|
|
The
|
|
.Fa microseconds
|
|
interval specified 1,000,000 or more microseconds.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr nanosleep 2 ,
|
|
.Xr sleep 3
|
|
.Sh STANDARDS
|
|
The
|
|
.Fn usleep
|
|
function conforms to
|
|
.St -xpg4.2 .
|
|
.Sh HISTORY
|
|
The
|
|
.Fn usleep
|
|
function appeared in
|
|
.Bx 4.3 .
|