usr/src/lib/libc/gen/ualarm.3

.\" Copyright (c) 1986, 1991, 1993
.\"     The Regents of the University of California.  All rights reserved.
.\"
.\" %sccs.include.redist.man%
.\"
.\"     @(#)ualarm.3    8.1 (Berkeley) %G%
.\"
.Dd
.Dt UALARM 3
.Os BSD 4.3
.Sh NAME
.Nm ualarm
.Nd schedule signal after specified time
.Sh SYNOPSIS
.Fd #include <unistd.h>
.Ft u_int
.Fn ualarm "u_int microseconds" "u_int interval"
.Sh DESCRIPTION
.Bf -symbolic
This is a simplified interface to setitimer(2).
.Ef
.Pp
The
.Fn ualarm
function
waits a count of
.Ar microseconds
before asserting the terminating signal
.Dv SIGALRM .
System activity or time used in processing the call may cause a slight
delay.
.Pp
If the
.Fa interval
argument is non-zero, the
.Dv SIGALRM
signal will be sent
to the process every
.Fa interval
microseconds after the timer expires (e.g. after
.Fa value
microseconds have passed).
.Sh RETURN VALUES
When the signal has successfully been caught,
.Fn alarm
returns the amount of time left on the clock.
The maximum mumber of
.Ar microseconds
allowed
is 2147483647.
.Sh SEE ALSO
.Xr getitimer 2 ,
.Xr setitimer 2 ,
.Xr sigpause 2 ,
.Xr sigvec 2 ,
.Xr signal 3 ,
.Xr sleep 3 ,
.Xr alarm 3 ,
.Xr usleep 3
.Sh HISTORY
The
.Fn ualarm
function appeared in
.Bx 4.3 .