       alarm seconds
              Instructs  the  system  to send a SIGALRM signal in
              the specified number of seconds.  This is a  float
              ing  point number, so fractions of a section may be
              specified.  If seconds is 0.0, any  previous  alarm
              request  is canceled.  Only one alarm at a time may
              be active; the command returns the number  of  sec
              onds  left in the previous alarm.  On systems with
              out the setitimer system call, seconds  is  rounded
              up to an integer number of seconds.

              The  alarm  command  is  not  available  on Windows
              95/NT.
