alarm - set an alarm clock for delivery of a signal
unsigned int alarm(unsigned int seconds);
() arranges for a SIGALRM
signal to be delivered to the
calling process in seconds
is zero, any pending alarm is canceled.
In any event any previously set alarm
() is canceled.
() returns the number of seconds remaining until any previously
scheduled alarm was due to be delivered, or zero if there was no previously
POSIX.1-2001, POSIX.1-2008, SVr4, 4.3BSD.
() and setitimer
(2) share the same timer; calls to one will
interfere with use of the other.
Alarms created by alarm
() are preserved across execve
(2) and are
not inherited by children created via fork
(3) may be implemented using SIGALRM
; mixing calls to
() 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.