1.\" $OpenBSD: alarm.3,v 1.9 2001/02/04 22:33:49 millert 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.Dd April 19, 1994 35.Dt ALARM 3 36.Os 37.Sh NAME 38.Nm alarm 39.Nd set signal timer alarm 40.Sh SYNOPSIS 41.Fd #include <unistd.h> 42.Ft unsigned int 43.Fn alarm "unsigned int seconds" 44.Sh DESCRIPTION 45.Bf -symbolic 46This interface is made obsolete by 47.Xr setitimer 2 . 48.Ef 49.Pp 50The 51.Fn alarm 52function waits a count of 53.Ar seconds 54before asserting the terminating signal 55.Dv SIGALRM . 56When the signal has successfully been caught, 57.Fn alarm 58returns the amount of time left on the clock. 59The maximum number of 60.Ar seconds 61allowed 62is 100000000. 63.Pp 64If an alarm has been set with 65.Fn alarm , 66another call to 67.Fn alarm 68will supersede the prior call. 69The request 70.Fn alarm "0" 71voids the current 72alarm. 73.Sh RETURN VALUES 74If the call succeeds, any time left remaining from a previous call is returned. 75If an error occurs, the value \-1 is returned, and a more precise 76error code is placed in the global variable 77.Va errno . 78.Sh SEE ALSO 79.Xr setitimer 2 , 80.Xr sigaction 2 , 81.Xr signal 3 , 82.Xr sigpause 3 , 83.Xr sigvec 3 , 84.Xr sleep 3 , 85.Xr ualarm 3 , 86.Xr usleep 3 87.Sh STANDARDS 88The 89.Fn alarm 90function conforms to 91.St -p1003.1-90 . 92.Sh HISTORY 93An 94.Fn alarm 95function appeared in 96.At v7 . 97