php獲取301跳轉URL簡單實例

 這篇文章主要介紹了php獲取301跳轉URL簡單實例，有需要的朋友可以參考一下

 代碼如下: /**  * get_redirect_url()  * Gets the address that the provided URL redirects to,  * or FALSE if there's no redirect.   *  * @param string $url  * @return string  */ function get_redirect_url($url){     $redirect_url = null;        $url_parts = @parse_url($url);     if (!$url_parts) return false;     if (!isset($url_parts['host'])) return false; //can't process relative URLs     if (!isset($url_parts['path'])) $url_parts['path'] = '/';       $sock = fsockopen($url_parts['host'], (isset($url_parts['port']) ? (int)$url_parts['port'] : 80), $errno, $errstr, 30);     if (!$sock) return false;       $request = "HEAD " . $url_parts['path'] . (isset($url_parts['query']) ? '?'.$url_parts['query'] : '') . " HTTP/1.1rn";      $request .= 'Host: ' . $url_parts['host'] . "rn";      $request .= "Connection: Closernrn";      fwrite($sock, $request);     $response = '';     while(!feof($sock)) $response .= fread($sock, 8192);     fclose($sock);     if (preg_match('/^Location: (.+?)$/m', $response, $matches)){         if ( substr($matches[1], 0, 1) == "/" )             return $url_parts['scheme'] . "://" . $url_parts['host'] . trim($matches[1]);         else             return trim($matches[1]);       } else {         return false;     }   } /**  * get_all_redirects()  * Follows and collects all redirects, in order, for the given URL.   *  * @param string $url  * @return array  */ function get_all_redirects($url){     $redirects = array();     while ($newurl = get_redirect_url($url)){         if (in_array($newurl, $redirects)){             break;         }         $redirects[] = $newurl;         $url = $newurl;     }     return $redirects; }       php實現用socket獲取301跳轉地址，可以提取跳轉過程中的url