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 38.Sh NAME 39.Nm alarm 40.Nd set signal timer alarm 41.Sh LIBRARY 42.Lb libc 43.Sh SYNOPSIS 44.Fd #include <unistd.h> 45.Ft unsigned int 46.Fn alarm "unsigned int seconds" 47.Sh DESCRIPTION 48.Bf -symbolic 49This interface is made obsolete by setitimer(2). 50.Ef 51.Pp 52The 53.Fn alarm 54function sets a timer to deliver the signal 55.Dv SIGALRM 56to the calling process after the specified number of 57.Fa seconds . 58If an alarm has already been set with 59.Fn alarm 60but has not been delivered, another call to 61.Fn alarm 62will supersede the prior call. 63The request 64.Fn alarm "0" 65voids the current 66alarm and the signal SIGALRM will not be delivered. 67.Pp 68Due to 69.Xr setitimer 2 70restriction the maximum number of 71.Ar seconds 72allowed is 100000000. 73.Sh RETURN VALUES 74The return value of 75.Fn alarm 76is the amount of time left on the timer from a previous call to 77.Fn alarm . 78If no alarm is currently set, the return value is 0. 79.Sh SEE ALSO 80.Xr setitimer 2 , 81.Xr sigaction 2 , 82.Xr sigpause 2 , 83.Xr sigvec 2 , 84.Xr signal 3 , 85.Xr sleep 3 , 86.Xr ualarm 3 , 87.Xr usleep 3 88.\" .Sh STANDARDS 89.\" The 90.\" .Fn alarm 91.\" function conforms to 92.\" .St -p1003.1-90 . 93.Sh HISTORY 94An 95.Fn alarm 96function appeared in 97.At v7 . 98