[ Posted by Faizan ] getTopLevelDomain in php https://stackoverflow.com/questions/3211411/how-to-get-the-base-domain-name-from-an-url-using-php

fiddle_098607.php

<?php
function getTopLevelDomain($url){
    $urlData = parse_url($url);
    $urlHost = isset($urlData['host']) ? $urlData['host'] : '';
    $isIP = (bool)ip2long($urlHost);
    if($isIP){ /** To check if it's ip then return same ip */
        return $urlHost;
    }
    $urlMap = array('com', 'com.pk', 'co.uk');

    $host = "";
    $hostData = explode('.', $urlHost);
    if(isset($hostData[1])){ /** To check "localhost" because it'll be without any tld */
        $hostData = array_reverse($hostData);

        if(array_search($hostData[1] . '.' . $hostData[0], $urlMap) !== FALSE) {
            $host = $hostData[2] . '.' . $hostData[1] . '.' . $hostData[0];
        } elseif(array_search($hostData[0], $urlMap) !== FALSE) {
            $host = $hostData[1] . '.' . $hostData[0];
        }
        return $host;
    }
    return (isset($hostData[0]) ? $hostData[0] : 'error no domain'); /* You can change this error in future */
}
$string = 'http://googl.com.pk';
echo getTopLevelDomain( $string ) . '<br>';

$string = 'http://googl.com.pk:23';
echo getTopLevelDomain( $string ) . '<br>';

$string = 'http://googl.com';
echo getTopLevelDomain( $string ) . '<br>';

$string = 'http://googl.com:23';
echo getTopLevelDomain( $string ) . '<br>';

$string = 'http://adad.asdasd.googl.com.pk';
echo getTopLevelDomain( $string ) . '<br>';

$string = 'http://adad.asdasd.googl.com.pk:23';
echo getTopLevelDomain( $string ) . '<br>';

$string = 'http://adad.asdasd.googl.com';
echo getTopLevelDomain( $string ) . '<br>';

$string = 'http://adad.asdasd.googl.com:23';
echo getTopLevelDomain( $string ) . '<br>';

$string = 'http://192.168.0.101:23';
echo getTopLevelDomain( $string ) . '<br>';

$string = 'http://192.168.0.101';
echo getTopLevelDomain( $string ) . '<br>';

$string = 'http://localhost';
echo getTopLevelDomain( $string ) . '<br>';

$string = 'https;//';
echo getTopLevelDomain( $string ) . '<br>';

$string = '';
echo getTopLevelDomain( $string ) . '<br>';

/**
 * You'll get answers like this
 * googl.com.pk
 * googl.com.pk
 * googl.com
 * googl.com
 * googl.com.pk
 * googl.com.pk
 * googl.com
 * googl.com
 * 192.168.0.101
 * 192.168.0.101
 * localhost
 */
?>