| NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | CONFORMING TO | NOTES | SEE ALSO | COLOPHON | The Linux Programming Interface |
ALARM(2) Linux Programmer's Manual ALARM(2)
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 calling 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.
SVr4, POSIX.1-2001, 4.3BSD.
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)
This page is part of release 3.32 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can be found
at http://www.kernel.org/doc/man-pages/.
Linux 2008-06-12 ALARM(2)
HTML rendering created 2010-12-03 by Michael Kerrisk, author of The Linux Programming Interface