1.\" Copyright (c) 1980, 1991, 1993, 1994 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)alarm.3 8.2 (Berkeley) 4/19/94 33.\" $FreeBSD: src/lib/libc/gen/alarm.3,v 1.9.2.6 2003/02/23 19:45:53 trhodes Exp $ 34.\" 35.Dd April 19, 1994 36.Dt ALARM 3 37.Os 38.Sh NAME 39.Nm alarm 40.Nd set signal timer alarm 41.Sh LIBRARY 42.Lb libc 43.Sh SYNOPSIS 44.In unistd.h 45.Ft unsigned int 46.Fn alarm "unsigned int seconds" 47.Sh DESCRIPTION 48.Bf -symbolic 49This interface is made obsolete by 50.Xr setitimer 2 . 51.Ef 52.Pp 53The 54.Fn alarm 55function sets a timer to deliver the signal 56.Dv SIGALRM 57to the calling process after the specified number of 58.Fa seconds . 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. 68.Pp 69Due to 70.Xr setitimer 2 71restriction the maximum number of 72.Fa seconds 73allowed is 100000000. 74.Sh RETURN VALUES 75The return value of 76.Fn alarm 77is the amount of time left on the timer from a previous call to 78.Fn alarm . 79If no alarm is currently set, the return value is 0. 80.Sh SEE ALSO 81.Xr setitimer 2 , 82.Xr sigaction 2 , 83.Xr sigpause 2 , 84.Xr sigvec 2 , 85.Xr signal 3 , 86.Xr sleep 3 , 87.Xr ualarm 3 , 88.Xr usleep 3 89.\" .Sh STANDARDS 90.\" The 91.\" .Fn alarm 92.\" function conforms to 93.\" .St -p1003.1-90 . 94.Sh HISTORY 95An 96.Fn alarm 97function appeared in 98.At v7 . 99