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 process in
       seconds seconds.

       If seconds is zero, no new alarm() is scheduled.

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

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.

NOTES
       alarm() and setitimer() share the same timer; calls to one will  inter-
       fere with use of the other.

       sleep()  may  be implemented using SIGALRM; mixing calls to alarm() and
       sleep() is a bad idea.

       Scheduling delays can, as ever, cause the execution of the  process  to
       be delayed by an arbitrary amount of time.

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

SEE ALSO
       gettimeofday(2),  pause(2), select(2), setitimer(2), sigaction(2), sig-
       nal(2), sleep(3)

Linux                             1993-07-21                          ALARM(2)