IP Range CIDR to ALL IP LIST

ip-range-CIDR-to-IP-list.php

<?php 
// IP Range CIDR to ALL IP LIST
// e.g. 220.78.168.0/21 to all IP list Range 
$start_ip = '220.78.168.0'; 
$prefix = '28';
$ip_count = 1 << (32 - $prefix);

$start = ip2long($start_ip);
for ($i = 0; $i < $ip_count; $i++) {
	echo $ip = long2ip($start + $i) . '<br />';
    // do stuff with $ip...
}

// Output : 
/*
220.78.168.0
220.78.168.1
220.78.168.2
220.78.168.3
220.78.168.4
220.78.168.5
220.78.168.6
220.78.168.7
220.78.168.8
220.78.168.9
220.78.168.10
220.78.168.11
220.78.168.12
220.78.168.13
220.78.168.14
220.78.168.15

*/

// Source: Learn IPv4 Range CIDR 
// http://aprelium.com/data/doc/2/abyssws-linux-doc-html/ipformat.html

Checks if IP is in Given IP CIDR range or not.

Another logic
NOT TESTED FULLY YET

function cidr_match($ip, $cidr)
{
    list($subnet, $mask) = explode('/', $cidr);

    if ((ip2long($ip) & ~((1 << (32 - $mask)) - 1) ) == ip2long($subnet))
    { 
        return true;
    }

    return false;
}

// Usage 
cidr_match("127.0.0.1", "127.0.0.1/32")