1.\" Copyright (c) 1980, 1991 Regents of the University of California. 2.\" 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.\" from: @(#)alarm.3 6.4 (Berkeley) 4/19/91 33.\" $Id: alarm.3,v 1.8 1994/10/17 23:49:28 cgd Exp $ 34.\" 35.Dd April 19, 1991 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 53waits a count of 54.Ar seconds 55before asserting the terminating signal 56.Dv SIGALRM . 57When the signal has successfully been caught, 58.Fn alarm 59returns the amount of time left on the clock. 60The maximum number of 61.Ar seconds 62allowed 63is 2147483647. 64.Pp 65If an alarm has been set with 66.Fn alarm , 67another call to 68.Fn alarm 69will supersede the prior call. 70The request 71.Fn alarm "0" 72voids the current 73alarm. 74.Sh SEE ALSO 75.Xr sigaction 2 , 76.Xr setitimer 2 , 77.Xr sigpause 2 , 78.Xr sigvec 3 , 79.Xr signal 3 , 80.Xr sleep 3 , 81.Xr ualarm 3 , 82.Xr usleep 3 83.Sh STANDARDS 84The 85.Fn alarm 86function conforms to 87.St -p1003.1-90 . 88.Sh HISTORY 89An 90.Fn alarm 91function appeared in 92.At v7 . 93