ualarm -- schedule signal after specified time
Standard C Library (libc, -lc)
ualarm(useconds_t microseconds, useconds_t interval);
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 value microseconds have passed).
Due to setitimer(2) restriction the maximum number of microseconds and
interval is limited to 100000000000000 (in case this value fit in the
When the signal has successfully been caught, ualarm() returns the amount
of time left on the clock.
A microsecond is 0.000001 seconds.
getitimer(2), setitimer(2), sigpause(2), sigvec(2), alarm(3), signal(3),
The ualarm() function appeared in 4.3BSD.
FreeBSD 5.2.1 April 19, 1994 FreeBSD 5.2.1 [ Back ]