mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-23 11:18:54 +00:00
102 lines
3.1 KiB
Groff
102 lines
3.1 KiB
Groff
.\" 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.
|
|
.\"
|
|
.\" From: @(#)ualarm.3 8.2 (Berkeley) 4/19/94
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd April 19, 1994
|
|
.Dt UALARM 3
|
|
.Os BSD 4.3
|
|
.Sh NAME
|
|
.Nm ualarm
|
|
.Nd schedule signal after specified time
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.Fd #include <unistd.h>
|
|
.Ft u_int
|
|
.Fn ualarm "u_int microseconds" "u_int interval"
|
|
.Sh DESCRIPTION
|
|
.Bf -symbolic
|
|
This is a simplified interface to setitimer(2).
|
|
.Ef
|
|
.Pp
|
|
The
|
|
.Fn ualarm
|
|
function
|
|
waits a count of
|
|
.Ar microseconds
|
|
before asserting the terminating signal
|
|
.Dv SIGALRM .
|
|
System activity or time used in processing the call may cause a slight
|
|
delay.
|
|
.Pp
|
|
If the
|
|
.Fa interval
|
|
argument is non-zero, the
|
|
.Dv SIGALRM
|
|
signal will be sent
|
|
to the process every
|
|
.Fa interval
|
|
microseconds after the timer expires (e.g. after
|
|
.Fa value
|
|
microseconds have passed).
|
|
.Pp
|
|
Due to
|
|
.Xr setitimer 2
|
|
restriction the maximum number of
|
|
.Ar microseconds
|
|
and
|
|
.Ar interval
|
|
is limited to 100000000000000
|
|
(in case this value fit in the unsigned integer).
|
|
.Sh RETURN VALUES
|
|
When the signal has successfully been caught,
|
|
.Fn ualarm
|
|
returns the amount of time left on the clock.
|
|
.Sh NOTES
|
|
.Pp
|
|
A microsecond is 0.000001 seconds.
|
|
.Sh SEE ALSO
|
|
.Xr getitimer 2 ,
|
|
.Xr setitimer 2 ,
|
|
.Xr sigpause 2 ,
|
|
.Xr sigvec 2 ,
|
|
.Xr alarm 3 ,
|
|
.Xr signal 3 ,
|
|
.Xr sleep 3 ,
|
|
.Xr usleep 3
|
|
.Sh HISTORY
|
|
The
|
|
.Fn ualarm
|
|
function appeared in
|
|
.Bx 4.3 .
|