ALARM(3)                  OpenBSD Programmer's Manual                 ALARM(3)

NAME
     alarm - set signal timer alarm

SYNOPSIS
     #include <unistd.h>

     unsigned int
     alarm(unsigned int seconds);

DESCRIPTION
     This interface is made obsolete by setitimer(2).

     The alarm() function waits a count of seconds before asserting the termi-
     nating signal SIGALRM.  When the signal has successfully been caught,
     alarm() returns the amount of time left on the clock.  The maximum number
     of seconds allowed is 100000000.

     If an alarm has been set with alarm(), another call to alarm() will su-
     persede the prior call.  The request alarm(0) voids the current alarm.

RETURN VALUES
     If the call succeeds, any time left remaining from a previous call is re-
     turned.  If an error occurs, the value -1 is returned, and a more precise
     error code is placed in the global variable errno.

SEE ALSO
     setitimer(2), sigaction(2), signal(3), sigpause(3), sigvec(3), sleep(3),
     ualarm(3), usleep(3)

STANDARDS
     The alarm() function conforms to IEEE Std 1003.1-1990 (``POSIX'').

HISTORY
     An alarm() function appeared in Version 7 AT&T UNIX.

OpenBSD 3.5                     April 19, 1994                               1
