php写配置文件

public function update()
    {
        $datas = input("post.");
        $this->saveConfig($datas);
        config("sysconfig", $datas);
        foreach ($datas as $key => $data) {
            var_dump(config("sysconfig.$key"));
        }
    }



private function saveConfig($datas)
    {
        $settingstr = "
  $v) {

            $settingstr .= "\t'" . $key . "'=>'" . $v . "',\n";

        }

        $settingstr .= "];";

        file_put_contents(CONF_PATH . "/extra/sysconfig.php", $settingstr);
    }