1.\" Copyright (c) 1986, 1991 Regents of the University of California. 2.\" 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.\" @(#)ualarm.3 6.5 (Berkeley) 4/19/91 33.\" 34.Dd April 19, 1991 35.Dt UALARM 3 36.Os BSD 4.3 37.Sh NAME 38.Nm ualarm 39.Nd schedule signal after specified time 40.Sh SYNOPSIS 41.Fd #include <unistd.h> 42.Ft u_int 43.Fn ualarm "u_int microseconds" "u_int interval" 44.Sh DESCRIPTION 45.Bf -symbolic 46This is a simplified interface to setitimer(2). 47.Ef 48.Pp 49The 50.Fn ualarm 51function 52waits a count of 53.Ar 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 value 68microseconds have passed). 69.Sh RETURN VALUES 70When the signal has successfully been caught, 71.Fn alarm 72returns the amount of time left on the clock. 73The maximum mumber of 74.Ar microseconds 75allowed 76is 2147483647. 77.Sh SEE ALSO 78.Xr getitimer 2 , 79.Xr setitimer 2 , 80.Xr sigpause 2 , 81.Xr sigvec 2 , 82.Xr signal 3 , 83.Xr sleep 3 , 84.Xr alarm 3 , 85.Xr usleep 3 86.Sh HISTORY 87The 88.Fn ualarm 89function appeared in 90.Bx 4.3 . 91