1.\" $OpenBSD: ualarm.3,v 1.13 2000/12/24 00:30:53 aaron 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. 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 November 4, 1997 35.Dt UALARM 3 36.Os 37.Sh NAME 38.Nm ualarm 39.Nd schedule signal after specified time 40.Sh SYNOPSIS 41.Fd #include <unistd.h> 42.Ft useconds_t 43.Fn ualarm "useconds_t microseconds" "useconds_t interval" 44.Sh DESCRIPTION 45.Bf -symbolic 46This is a simplified interface to 47.Xr setitimer 2 . 48.Ef 49.Pp 50The 51.Fn ualarm 52function waits a count of 53.Fa microseconds 54before asserting the terminating signal 55.Dv SIGALRM . 56System activity or time used in processing the call may cause a slight 57delay. 58.Pp 59If the 60.Fa interval 61argument is non-zero, the 62.Dv SIGALRM 63signal will be sent 64to the process every 65.Fa interval 66microseconds after the timer expires (e.g., after 67.Fa microseconds 68number of microseconds have passed). 69.Sh RETURN VALUES 70When the signal has successfully been caught, 71.Fn ualarm 72returns the amount of time left on the clock. 73The maximum value for 74.Fa microseconds 75allowed 76is 2147483647. 77.Sh SEE ALSO 78.Xr getitimer 2 , 79.Xr setitimer 2 , 80.Xr sigaction 2 , 81.Xr alarm 3 , 82.Xr signal 3 , 83.Xr sigpause 3 , 84.Xr sigvec 3 , 85.Xr sleep 3 , 86.Xr usleep 3 87.Sh STANDARDS 88The 89.Fn ualarm 90function conforms to 91.St -xpg4.2 . 92.Sh HISTORY 93The 94.Fn ualarm 95function appeared in 96.Bx 4.3 . 97