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.\" $FreeBSD$ 34.\" 35.Dd April 19, 1994 36.Dt ALARM 3 37.Os BSD 4 38.Sh NAME 39.Nm alarm 40.Nd set signal timer alarm 41.Sh SYNOPSIS 42.Fd #include <unistd.h> 43.Ft unsigned int 44.Fn alarm "unsigned int seconds" 45.Sh DESCRIPTION 46.Bf -symbolic 47This interface is made obsolete by setitimer(2). 48.Ef 49.Pp 50The 51.Fn alarm 52function sets a timer to deliver the signal 53.Dv SIGALRM 54to the calling process after the specified number of 55.Fa seconds . 56If an alarm has already been set with 57.Fn alarm 58but has not been delivered, another call to 59.Fn alarm 60will supersede the prior call. 61The request 62.Fn alarm "0" 63voids the current 64alarm and the signal SIGALRM will not be delivered. 65.Pp 66Due to 67.Xr setitimer 2 68restriction the maximum number of 69.Ar seconds 70allowed is 100000000. 71.Sh RETURN VALUES 72.Pp 73The return value of 74.Fn alarm 75is the amount of time left on the timer from a previous call to 76.Fn alarm . 77If no alarm is currently set, the return value is 0. 78.Sh SEE ALSO 79.Xr setitimer 2 , 80.Xr sigaction 2 , 81.Xr sigpause 2 , 82.Xr sigvec 2 , 83.Xr signal 3 , 84.Xr sleep 3 , 85.Xr ualarm 3 , 86.Xr usleep 3 87.\" .Sh STANDARDS 88.\" The 89.\" .Fn alarm 90.\" function conforms to 91.\" .St -p1003.1-90 . 92.Sh HISTORY 93An 94.Fn alarm 95function appeared in 96.At v7 . 97