sub time_stamp {
    my $time = shift;
    $time = time() if ! defined $time;
    my ($sec, $min, $hour, $mday, $mon, $year) = localtime($time);
    return sprintf("%02d:%02d:%02d %02d/%02d/%04d", $hour,
      $min, $sec, $mday, $mon+1, $year+1900);
}
sub d {
    print "[".time_stamp()."] ".(caller(0))[0].", ";
    print shift;
    print "\n";
}