PHP: Validate IP-Address

Since PHP version 5.2.0, you can use the function filter_var().

Here is a small example showing how to verify an IP address using filter_var().

$s = '192.168.0.0';

if (filter_var($s, FILTER_VALIDATE_IP)) {
    echo "$s is a valid ip address!";
} else {
    echo "$s is not a valid ip address!";
}

In this example, we are using filter_var() with the filter FILTER_VALIDATE_IP and we are checking the content of the variable $s.
2015-05-30 at 16:29