UALARM(3)

NAME
ualarm - schedule signal after specified time

LIBRARY
libc

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 number of microseconds have passed).

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

RETURN VALUES
When the signal has successfully been caught, ualarm() returns the amount of time left on the clock.

NOTES
A microsecond is 0.000001 seconds.

SEE ALSO
getitimer(2), setitimer(2), sigaction(2), sigsuspend(2), alarm(3), signal(3), sleep(3), usleep(3)

HISTORY
The ualarm() function appeared in 4.3BSD.