Php Xampp/Lampp Mysql访问

我安装在Ubuntu 16.04 LTE Xampp（lampp）上，一切正常：

:~$ sudo /opt/lampp/lampp start
Starting XAMPP for Linux 5.6.20-0...
XAMPP: Starting Apache...already running.
XAMPP: Starting MySQL...ok.
XAMPP: Starting ProFTPD...already running.

:~$ sudo /opt/lampp/lampp status
Version: XAMPP for Linux 5.6.20-0
Apache is running.
MySQL is not running.
ProFTPD is running.

:~$ sudo service mysql start

:~$ sudo /opt/lampp/lampp status
Version: XAMPP for Linux 5.6.20-0
Apache is running.
MySQL is not running.
ProFTPD is running.

但当我想进入终端时，终端有mysql-u根：

错误1698（28000）：拒绝用户“root”@“localhost”的访问

如果我使用sudomysql-uroot，我可以通过终端使用mysql

但对于Firefox：

---

我将检查/var/lib和/var/run下的权限 我遇到了类似的情况，通过更改这些文件夹的权限，然后运行 $./etc/init.d/mysql start

Welcome to phpMyAdmin

Error

MySQL said: Documentation
Cannot connect: invalid settings.
Connection for controluser as defined in your configuration failed.
phpMyAdmin tried to connect to the MySQL server, and the server rejected the connection. You should check the host, username and password in your configuration and make sure that they correspond to the information given by the administrator of the MySQL server.