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ALARM(2)		   Linux Programmer's Manual		      ALARM(2)

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 SIGALRM signal	to be delivered	to the calling
       process in seconds seconds.

       If seconds is 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	previ-
       ously scheduled alarm.

CONFORMING TO
       SVr4, POSIX.1-2001, 4.3BSD.

NOTES
       alarm() and setitimer(2)	share the same timer; calls to one will	inter-
       fere 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),  sig-
       nal(2), sleep(3), time(7)

COLOPHON
       This  page  is  part of release 3.74 of the Linux man-pages project.  A
       description of the project, information about reporting bugs,  and  the
       latest	  version     of     this    page,    can    be	   found    at
       http://www.kernel.org/doc/man-pages/.

Linux				  2014-02-23			      ALARM(2)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | CONFORMING TO | NOTES | SEE ALSO | COLOPHON

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