1. I need to wait for the $pid instead of -1
2. I can check $? for the exit status
3. I need to check the result of waitpid for >0 instead of == -1

  if ($pid == 0) { # child
    print "  child: exec\n";
    exec("$prg arguments");
    exit;
  } else { # parent
    print "  parent: wait\n";
    my $time = time();
    my $kill_flag = 1;
    while (time() - $time < $timeout) {
      sleep 1;
      my $kid = waitpid($pid,WNOHANG);
      my $exit_value  = $? >> 8;
      if ($kid > 0) {
        $kill_flag = 0;
        $return_code = !$exit_value;
        last;
      }
    }
    if($kill_flag) {
      kill(9, $pid);
      $return_code = 0;
    }
  }
  return $return_code;
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