<?php

require('Net/IPv4.php');

$cidr = '192.168.0.50/16';
$net = Net_IPv4::parseAddress($cidr);
echo $net->network;   // 192.168.0.0
echo $net->ip;        // 192.168.0.50
echo $net->broadcast; // 192.168.255.255
echo $net->bitmask;   // 16
echo $net->long;      // 3232235520 (long/double version of 192.168.0.50)
echo $net->netmask;   // 255.255.0.0

?>