sub ip_to_dotless {
        return 0+ eval " 0x" . sprintf("%02x%02x%02x%02x", split(/\./, shift));
}
sub dotless_to_ip {
        my $hex=reverse sprintf("%x", shift);
        my @ip;
        for(0..3) {
                push(@ip, 0+ eval "0x" . reverse substr($hex, 0, 2, ""));
        }
        join('.',  reverse @ip);
}