alarm — set an alarm clock for delivery of a signal
#include <unistd.h>
unsigned int alarm( |
unsigned int | seconds); |
alarm() arranges for a
SIGALRM signal to be delivered
to the process in seconds seconds.
If seconds is
zero, no new alarm() is
scheduled.
In any event any previously set alarm() is canceled.
alarm() returns the number
of seconds remaining until any previously scheduled alarm was
due to be delivered, or zero if there was no previously
scheduled alarm.
alarm() and setitimer(2) share the same
timer; calls to one will interfere with use of the other.
sleep(3) may be implemented
using SIGALRM; mixing calls to
alarm() and sleep(3) is a bad idea.
Scheduling delays can, as ever, cause the execution of the process to be delayed by an arbitrary amount of time.
gettimeofday(2), pause(2), select(2), setitimer(2), sigaction(2), signal(2), sleep(3), time(7)