1.\" $NetBSD: alarm.3,v 1.11 1997/01/17 03:45:00 perry Exp $ 2.\" 3.\" Copyright (c) 1980, 1991, 1993, 1994 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.\" @(#)alarm.3 8.2 (Berkeley) 4/19/94 35.\" 36.Dd April 19, 1994 37.Dt ALARM 3 38.Os BSD 4 39.Sh NAME 40.Nm alarm 41.Nd set signal timer alarm 42.Sh SYNOPSIS 43.Fd #include <unistd.h> 44.Ft unsigned int 45.Fn alarm "unsigned int seconds" 46.Sh DESCRIPTION 47.Bf -symbolic 48This interface is made obsolete by setitimer(2). 49.Ef 50.Pp 51The 52.Fn alarm 53function sets a timer to deliver the signal 54.Dv SIGALRM 55to the calling proccess 56.Ar seconds 57after the call to 58.Fn alarm . 59If an alarm has already been set with 60.Fn alarm 61but has not been delivered, another call to 62.Fn alarm 63will supersede the prior call. 64The request 65.Fn alarm "0" 66voids the current 67alarm and the signal SIGALRM will not be delivered. The maximum number of 68.Ar seconds 69allowed 70is 2147483647. 71.Pp 72The return value of 73.Fn alarm 74is the amount of time left on the timer from a previous call to 75.Fn alarm . 76If no alarm is currently set, the return value is 0. 77.Sh SEE ALSO 78.Xr sigaction 2 , 79.Xr setitimer 2 , 80.Xr sigsuspend 2 , 81.Xr sigvec 3 , 82.Xr signal 3 , 83.Xr sleep 3 , 84.Xr ualarm 3 , 85.Xr usleep 3 86.Sh STANDARDS 87The 88.Fn alarm 89function conforms to 90.St -p1003.1-90 . 91.Sh HISTORY 92An 93.Fn alarm 94function appeared in 95.At v7 . 96