UALARM(3) BSD Library Functions Manual UALARM(3)NAMEualarm — schedule signal after specified time
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <unistd.h>
useconds_t
ualarm(useconds_t microseconds, useconds_t interval);
DESCRIPTION
This is a simplified interface to setitimer(2).
The ualarm() function waits a count of microseconds before asserting the
terminating signal SIGALRM. System activity or time used in processing
the call may cause a slight delay.
If the interval argument is non-zero, the SIGALRM signal will be sent to
the process every interval microseconds after the timer expires (e.g.
after microseconds microseconds have passed).
RETURN VALUES
When the signal has successfully been caught, ualarm() returns the amount
of time left on the clock. The maximum number of microseconds allowed is
2147483647. If there is an error setting the timer, ualarm() returns
((useconds_t) -1).
SEE ALSOgetitimer(2), setitimer(2), sigaction(2), sigsuspend(2), alarm(3),
signal(3), sigvec(3), sleep(3), usleep(3)STANDARDS
The ualarm() function conforms to IEEE Std 1003.1-2001 (“POSIX.1”). How‐
ever, the later IEEE Std 1003.1-2008 (“POSIX.1”) revision removed the
function from the specification.
HISTORY
The ualarm() function appeared in 4.3BSD.
BSD May 2, 2011 BSD
