local $SIG{HUP} = 'IGNORE';
$SIG{HUP} = \&SIGKILL_handler;

while ( $#todo >= 0 && $result == 0) {
  last if($result > 0);
  my $cmd  =  pop(@todo);
  $sem->down();                  # nur n Tasks gleichzeitig
  if (  $result == 0) {
    my $thread = threads->new(
      \&Task,
      $cmd,            # neuen Thread erzeugen
        );
      }
}

#-------------------------------------------------------------------------
sub Task {
  my (
    $cmd,    # Parameter
  ) = @_;
  my $id = threads->self->tid;
  $thread_run++;
  $result += system ($cmd)/256;;
  if ($debug == 1) { print " Return:  $result \n\n"; }
  $sem->up();
  $thread_run--;
  printf "Thread %02d: fertig.\n", $id;
  if ($result >0){print "\n\n Fehler !!!!!!!!\n\n";
    kill ("HUP", -$$);
      }
 
}

#-------------------------------------------------------------------------
sub SIGKILL_handler {
  print "SIG_KILL\n";
    kill ("HUP", -$$);
}