phpは2文字間のサブ文字列を抽出する

 public function func_process($content) {
        $str = substr($content, 0, 9); //               
        if($str == "   ") {
      $func = substr($content, strlen("[")+strpos($content, "["), (strlen($content)-strpos($content, "]"))*(-1)); //           

        }
    }