UALARM(3) Library Functions Manual UALARM(3)

ualarmschedule signal after specified time

Standard C Library (libc, -lc)

#include <unistd.h>

useconds_t
ualarm(useconds_t useconds, useconds_t interval);

This is a simplified interface to setitimer(2).

The () function waits a count of useconds 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 useconds number of microseconds have passed).

Due to a setitimer(2) restriction, the maximum number of useconds and interval is limited to 100,000,000,000,000 (in case this value fits in the unsigned integer).

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), sleep(3), usleep(3)

The ualarm() function appeared in 4.3BSD.

April 19, 1994 Mac OS X 12