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 previously scheduled alarm.

CONFORMING TO

       SVr4, POSIX.1-2001, 4.3BSD.

NOTES

       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.

SEE ALSO

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

COLOPHON

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       project,    and    information    about    reporting    bugs,    can    be    found     at
       http://www.kernel.org/doc/man-pages/.