ALARM(2)                                                 ALARM(2)

          alarm - schedule signal after specified time

          unsigned seconds;

          Alarm causes signal SIGALRM, see signal(2), to be sent to
          the invoking process in a number of seconds given by the
          argument.  Unless caught or ignored, the signal terminates
          the process.

          Alarm requests are not stacked; successive calls reset the
          alarm clock.  If the argument is 0, any alarm request is
          canceled.  Because the clock has a 1-second resolution, the
          signal may occur up to one second early; because of schedul-
          ing delays, resumption of execution of when the signal is
          caught may be delayed an arbitrary amount.  The longest
          specifiable delay time is 2147483647 seconds.

          The return value is the amount of time previously remaining
          in the alarm clock.

          pause(2), signal(2), sleep(3)