-------------------------------------------------------------------------------
Perl Fast IP Lookup
This uses /etc/hosts and local named cache, before using DNS
Thus if the host is already known it will report it almost instantally!

 perl -le 'print join(".", unpack("C4",(gethostbyname(shift))[4]))' host

-------------------------------------------------------------------------------
Perl Network Broadcast...

$port = 8080;
$sockaddr = "S n a4 x8";($name,$aliases,$proto) = getprotobyname('udp');

chop($hostname = `hostname`);
($name,$aliases,$type,$len,$myaddr) = gethostbyname($hostname);
@myaddr=unpack("C4",$myaddr);
pop(@myaddr);push(@myaddr,255); # works only for ff:ff:ff:00 subnet mask
$broadaddr=pack("C4",@myaddr);

$me   = pack($sockaddr,&AF_INET, 0,     $myaddr);
$them = pack($sockaddr,&AF_INET, $port, $broadaddr);

socket(S, &AF_INET, &SOCK_DGRAM, $proto) || die $!;
setsockopt(S,&SOL_SOCKET,&SO_BROADCAST,1) || die $1;
bind(S, $me) || die $!;

send(S,"01234567 Hello everyone 01234567\n",0,$them) || die $!;

-------------------------------------------------------------------------------