| UALARM(3) | Library Functions Manual | UALARM(3) |
ualarm — schedule
signal after specified time
Standard C Library (libc, -lc)
#include
<unistd.h>
useconds_t
ualarm(useconds_t
microseconds, useconds_t
interval);
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).
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).
getitimer(2), setitimer(2), sigaction(2), sigsuspend(2), alarm(3), signal(3), sigvec(3), sleep(3), usleep(3)
The ualarm() function conforms to
IEEE Std 1003.1-2001 (“POSIX.1”).
However, the later IEEE Std 1003.1-2008
(“POSIX.1”) revision removed the function from the
specification.
The ualarm() function appeared in
4.3BSD.
| May 2, 2011 | NetBSD 11.0 |