UALARM(3) BSD Programmer's Manual UALARM(3)
ualarm - schedule signal after specified time
#include <unistd.h> useconds_t 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 microseconds number of microseconds have passed).
When the signal has successfully been caught, ualarm() returns the amount of time left on the clock. The maximum value for microseconds allowed is 2147483647.
getitimer(2), setitimer(2), sigaction(2), alarm(3), signal(3), sigpause(3), sigvec(3), sleep(3), usleep(3)
The ualarm() function conforms to X/Open Portability Guide Issue 4, Version 2 ("XPG4.2").
The ualarm() function appeared in 4.3BSD. MirBSD #10-current November 4, 1997 1