1.\" $OpenBSD: ualarm.3,v 1.15 2007/05/31 19:19:29 jmc Exp $ 2.\" 3.\" Copyright (c) 1986, 1991, 1993 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. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.Dd $Mdocdate: May 31 2007 $ 31.Dt UALARM 3 32.Os 33.Sh NAME 34.Nm ualarm 35.Nd schedule signal after specified time 36.Sh SYNOPSIS 37.Fd #include <unistd.h> 38.Ft useconds_t 39.Fn ualarm "useconds_t microseconds" "useconds_t interval" 40.Sh DESCRIPTION 41.Bf -symbolic 42This is a simplified interface to 43.Xr setitimer 2 . 44.Ef 45.Pp 46The 47.Fn ualarm 48function waits a count of 49.Fa microseconds 50before asserting the terminating signal 51.Dv SIGALRM . 52System activity or time used in processing the call may cause a slight 53delay. 54.Pp 55If the 56.Fa interval 57argument is non-zero, the 58.Dv SIGALRM 59signal will be sent 60to the process every 61.Fa interval 62microseconds after the timer expires (e.g., after 63.Fa microseconds 64number of microseconds have passed). 65.Sh RETURN VALUES 66When the signal has successfully been caught, 67.Fn ualarm 68returns the amount of time left on the clock. 69The maximum value for 70.Fa microseconds 71allowed 72is 2147483647. 73.Sh SEE ALSO 74.Xr getitimer 2 , 75.Xr setitimer 2 , 76.Xr sigaction 2 , 77.Xr alarm 3 , 78.Xr signal 3 , 79.Xr sigpause 3 , 80.Xr sigvec 3 , 81.Xr sleep 3 , 82.Xr usleep 3 83.Sh STANDARDS 84The 85.Fn ualarm 86function conforms to 87.St -xpg4.2 . 88.Sh HISTORY 89The 90.Fn ualarm 91function appeared in 92.Bx 4.3 . 93