Manpage of ALARM

ALARM

Section: Linux Programmer's Manual (2)
Updated: 2015-08-08
Index
 

NAME

alarm - set an alarm clock for delivery of a signal  

SYNOPSIS

#include <unistd.h>unsigned int alarm(unsigned int seconds);
 

DESCRIPTION

alarm() arranges for a SIGALRMsignal to be delivered to the calling process in secondsseconds.

If secondsis zero, any pending alarm is canceled.

In any event any previously set alarm() is canceled.  

RETURN VALUE

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.  

CONFORMING TO

POSIX.1-2001, POSIX.1-2008, SVr4, 4.3BSD.  

NOTES

alarm() 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(2).

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.  

SEE ALSO

gettimeofday(2), pause(2), select(2), setitimer(2), sigaction(2), signal(2), sleep(3), time(7)


 

Index

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
CONFORMING TO
NOTES
SEE ALSO

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Time: 22:27:44 GMT, June 20, 2016