private function createMyCnf(array $db_info, $path)
    {
        $this->db_info = $db_info;
        $data = array(
            'head' => '[client]',
            'user' => 'user = ' . $this->db_info['user'],
            'password' => 'password = ' . $this->db_info['password'],
            'host' => 'host = ' . $this->db_info['host']
        );
        
        $content = implode(PHP_EOL, $data);
        $path = $path . DIRECTORY_SEPARATOR . 'my.cnf';
        
        $fp = fopen($path, "wb");
        fwrite($fp, $content);
        fclose($fp);
        return $path;
    }