Want to write a script to do the batch conversion from domain name to IP.

[Hongyi Zhao]

#!/usr/bin/perl
use warnings;
use strict;
use Socket;

while ( <> ) {
chomp;
my ( $address, $port ) = split /:/ or next;
my $number = inet_aton $address;
my $name = gethostbyaddr $number, AF_INET;

Considering that NOT ALL IPs can be resolved to host or FQDN name
correctly, it may be more robust adding this line here:

$name ||= '?';