1.\" $NetBSD: ualarm.3,v 1.15 2002/02/07 07:00:18 ross 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.\" @(#)ualarm.3 8.2 (Berkeley) 4/19/94 35.\" 36.Dd April 19, 1994 37.Dt UALARM 3 38.Os 39.Sh NAME 40.Nm ualarm 41.Nd schedule signal after specified time 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.Fd #include \*[Lt]unistd.h\*[Gt] 46.Ft useconds_t 47.Fn ualarm "useconds_t microseconds" "useconds_t interval" 48.Sh DESCRIPTION 49.Bf -symbolic 50This is a simplified interface to 51.Xr setitimer 2 . 52.Ef 53.Pp 54The 55.Fn ualarm 56function 57waits a count of 58.Ar microseconds 59before asserting the terminating signal 60.Dv SIGALRM . 61System activity or time used in processing the call may cause a slight 62delay. 63.Pp 64If the 65.Fa interval 66argument is non-zero, the 67.Dv SIGALRM 68signal will be sent 69to the process every 70.Fa interval 71microseconds after the timer expires (e.g. after 72.Fa microseconds 73microseconds have passed). 74.Sh RETURN VALUES 75When the signal has successfully been caught, 76.Fn ualarm 77returns the amount of time left on the clock. 78The maximum number of 79.Ar microseconds 80allowed 81is 2147483647. 82If there is an error setting the timer, 83.Fn ualarm 84returns ((useconds_t) -1). 85.Sh SEE ALSO 86.Xr getitimer 2 , 87.Xr setitimer 2 , 88.Xr sigaction 2 , 89.Xr sigsuspend 2 , 90.Xr alarm 3 , 91.Xr signal 3 , 92.Xr sigvec 3 , 93.Xr sleep 3 , 94.Xr usleep 3 95.Sh STANDARDS 96The 97.Fn ualarm 98functions conforms to 99.St -xpg4.2 . 100.Sh HISTORY 101The 102.Fn ualarm 103function appeared in 104.Bx 4.3 . 105