1.\" Copyright (c) 1986, 1991, 1993 2.\" The Regents of the University of California. 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: @(#)ualarm.3 8.2 (Berkeley) 4/19/94 33.\" $FreeBSD$ 34.\" 35.Dd April 19, 1994 36.Dt UALARM 3 37.Os BSD 4.3 38.Sh NAME 39.Nm ualarm 40.Nd schedule signal after specified time 41.Sh SYNOPSIS 42.Fd #include <unistd.h> 43.Ft u_int 44.Fn ualarm "u_int microseconds" "u_int interval" 45.Sh DESCRIPTION 46.Bf -symbolic 47This is a simplified interface to setitimer(2). 48.Ef 49.Pp 50The 51.Fn ualarm 52function 53waits a count of 54.Ar microseconds 55before asserting the terminating signal 56.Dv SIGALRM . 57System activity or time used in processing the call may cause a slight 58delay. 59.Pp 60If the 61.Fa interval 62argument is non-zero, the 63.Dv SIGALRM 64signal will be sent 65to the process every 66.Fa interval 67microseconds after the timer expires (e.g. after 68.Fa value 69microseconds have passed). 70.Sh RETURN VALUES 71When the signal has successfully been caught, 72.Fn ualarm 73returns the amount of time left on the clock. 74The maximum number of 75.Ar microseconds 76allowed 77is 2147483647. 78.Sh SEE ALSO 79.Xr getitimer 2 , 80.Xr setitimer 2 , 81.Xr sigpause 2 , 82.Xr sigvec 2 , 83.Xr alarm 3 , 84.Xr signal 3 , 85.Xr sleep 3 , 86.Xr usleep 3 87.Sh HISTORY 88The 89.Fn ualarm 90function appeared in 91.Bx 4.3 . 92