#!/usr/bin/perl -w
use strict;
use IO::Socket;

my $port = shift || 9999;
my $sock = new IO::Socket::INET(
  LocalPort => $port,
  Proto => 'tcp',
  Listen => SOMAXCONN,
  Reuse => 1); 
$sock or die "socket: $!";
my($new_sock, $c_addr, $buf);
while (($new_sock, $c_addr) = $sock->accept()) 
{
  my ($client_port, $client_ip) = sockaddr_in($c_addr);  
  print $new_sock "<ip>" . inet_ntoa($client_ip) . "</ip>\000";
  $new_sock->close();
}