bsd man page for alarm

ALARM(3F)																 ALARM(3F)

NAME
       alarm - execute a subroutine after a specified time

SYNOPSIS
       integer function alarm (time, proc)
       integer time
       external proc

DESCRIPTION
       This routine arranges for subroutine proc to be called after time seconds. If time is ``0'', the alarm is turned off and no routine will be
       called.	The returned value will be the time remaining on the last alarm.

FILES
       /usr/lib/libU77.a

SEE ALSO
       alarm(3C), sleep(3F), signal(3F)

BUGS
       Alarm and sleep interact. If sleep is called after alarm, the alarm process will never be called. SIGALRM will occur at the lesser  of  the
       remaining alarm time or the sleep time.

4.2 Berkeley Distribution					   May 15, 1985 							 ALARM(3F)