tail head cat sleep
QR code linking to this page
Main index Section 3
Go to:
日本語Options

Manual Pages  — ALARM

NAME

alarm – set signal timer alarm

CONTENTS

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <unistd.h>

unsigned int
alarm(unsigned int seconds);

DESCRIPTION

This interface is made obsolete by setitimer(2).

The alarm() function sets a timer to deliver the signal SIGALRM to the calling process after the specified number of seconds. If an alarm has already been set with alarm() but has not been delivered, another call to alarm() will supersede the prior call. The request alarm() voids the current alarm and the signal SIGALRM will not be delivered.

Due to setitimer(2) restriction the maximum number of seconds allowed is 100000000.

RETURN VALUES

The return value of alarm() is the amount of time left on the timer from a previous call to alarm(). If no alarm is currently set, the return value is 0.

SEE ALSO

setitimer(2), sigaction(2), sigsuspend(2), signal(3), sleep(3), ualarm(3), usleep(3)

HISTORY

An alarm() function appeared in AT&T v7 .
ALARM (3) April 19, 1994
tail head cat sleep
QR code linking to this page
Main index Section 3
Go to:
日本語Options

Please direct any comments about this manual page service to Ben Bullock. Privacy policy.

“ Did you know that 7/5 people don't know how to use fractions? ”