sub REAPER 
{           # takes care of dead children
   $SIG{CHLD} = \&REAPER;
   my $pid = wait;
   if ($pid > -1)
   {
      $children --;
      print "child $pid died, only $children left\n";
      delete $children{$pid};
   }
   else
   {
      $children = 0;
   }
}