/**<br /> * get_redirect_url()<br /> * Gets the address that the provided URL redirects to,<br /> * or FALSE if there’s no redirect.<br /> *<br /> * @param string $url<br /> * @return string<br /> */<br /> function get_redirect_url($url){<br /> $redirect_url = null; </p> <p> $url_parts = @parse_url($url);<br /> if (!$url_parts) return false;<br /> if (!isset($url_parts[‘host’])) return false; //can’t process relative URLs<br /> if (!isset($url_parts[‘path’])) $url_parts[‘path’] = ‘/’;</p> <p> $sock = fsockopen($url_parts[‘host’], (isset($url_parts[‘port’]) ? (int)$url_parts[‘port’] : 80), $errno, $errstr, 30);<br /> if (!$sock) return false;</p> <p> $request = “HEAD ” . $url_parts[‘path’] . (isset($url_parts[‘query’]) ? ‘?’.$url_parts[‘query’] : ”) . ” HTTP/1.1\r\n”;<br /> $request .= ‘Host: ‘ . $url_parts[‘host’] . “\r\n”;<br /> $request .= “Connection: Close\r\n\r\n”;<br /> fwrite($sock, $request);<br /> $response=””;<br /> while(!feof($sock)) $response .= fread($sock, 8192);<br /> fclose($sock);</p> <p> if (preg_match(‘/^Location: (.+?)$/m’, $response, $matches)){<br /> if ( substr($matches[1], 0, 1) == “/” )<br /> return $url_parts[‘scheme’] . “://” . $url_parts[‘host’] . trim($matches[1]);<br /> else<br /> return trim($matches[1]);</p> <p> } else {<br /> return false;<br /> }</p> <p>}</p> <p>/**<br /> * get_all_redirects()<br /> * Follows and collects all redirects, in order, for the given URL.<br /> *<br /> * @param string $url<br /> * @return array<br /> */<br /> function get_all_redirects($url){<br /> $redirects = array();<br /> while ($newurl = get_redirect_url($url)){<br /> if (in_array($newurl, $redirects)){<br /> break;<br /> }<br /> $redirects[] = $newurl;<br /> $url = $newurl;<br /> }<br /> return $redirects;<br /> }</p> <p>/**<br /> * get_final_url()<br /> * Gets the address that the URL ultimately leads to.<br /> * Returns $url itself if it isn’t a redirect.<br /> *<br /> * @param string $url<br /> * @return string<br /> */<br /> function get_final_url($url){<br /> $redirects = get_all_redirects($url);<br /> if (count($redirects)>0){<br /> return array_pop($redirects);<br /> } else {<br /> return $url;<br /> }<br /> }<br />