/**
* Return the domain name for the current request. Heuristics are used to
* detect the the domain name. This will fail horribly for extremely short
* domain names. A domain name is assumed to be the rightmost part of the
* full hostname. A test on very short strings is used to detect top level
* domains such as .com, .nl and double ones like .co.uk. This obviously
* fails for longer top level domains and extremely short domain names.
*
* \return Domain name for the current request.
*/
public static function domain()
{
$host = AnewtRequest::host();
/* If it looks like an ip address we just return the IP address */
if (preg_match('/^[0-9]{1,3}(\\.[0-9]{1,3}){3}$/', $host)) {
return $host;
}
$parts = explode('.', $host);
$num_parts = count($parts);
if ($num_parts <= 2) {
/* The hostname doesn't contain a subdomain part, or it is not
* a canonical hostname after all (eg. localhost). */
$domain = $host;
} else {
/* There's at least 3 parts: xx.yy.zz. Return either:
* - yy.zz if yy is > 2 characters (example.com)
* - xx.yy..zz if yy is <= 2 characters (example.co.uk)
*/
$zz = array_pop($parts);
$yy = array_pop($parts);
if (strlen($yy) > 2) {
$domain = sprintf('%s.%s', $yy, $zz);
} else {
$xx = array_pop($parts);
$domain = sprintf('%s.%s.%s', $xx, $yy, $zz);
}
}
return $domain;
}
