netbsd man page for alarm

ALARM(3)						   BSD Library Functions Manual 						  ALARM(3)

NAME
     alarm -- set signal timer alarm

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <unistd.h>

     unsigned int
     alarm(unsigned int seconds);

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

     The alarm() function sets a timer to deliver the signal SIGALRM to the calling process seconds after the call to alarm().	If an alarm has
     already been set with alarm() but has not been delivered, another call to alarm() will supersede the prior call.  The request alarm(0) voids
     the current alarm and the signal SIGALRM will not be delivered.  The maximum number of seconds allowed is 2147483647.

     The return value of alarm() is the amount of time left on the timer from a previous call to alarm().  If no alarm is currently set, the
     return value is 0.  If there is an error setting the timer, alarm() returns ((unsigned int) -1).

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

STANDARDS
     The alarm() function conforms to ISO/IEC 9945-1:1990 (``POSIX.1'').

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

BSD
								  April 19, 1994							       BSD