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PHP function to determine if IP address is private

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If you parse an IP address to this function, it will return whether or not the ip address is private (RFC1918). Not sure if there is a better way of achieving this?

$private = DetermineLocal('192.168.1.1');
if ($private) {echo 'This IP address is a private IP address';} else
echo 'This IP address is not private';

function DetermineLocal($ip) {
$private_ip = array("/^0\./", "/^127\.0\.0\.1/", "/^192\.168\..*/",
"/^172\.((1[6-9])|(2[0-9])|(3[0-1]))\..*/", "/^10\..*/", "/^224\..*/",
"/^240\..*/");
while (list ($key, $val) = each ($private_ip)) {
if (preg_match($val, $ip))
{
return true;
}
}
}
?>
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