ubuntu环境变量如何恢复

恢复ubuntu环境变量的示例：

在终端输入ls命令后，显示如下结果:

root@wei:/etc# ls 
Command 'ls' is available in '/bin/ls' 
The command could not be located because '/bin' is not included in the PATH environment variable. 
ls: command not found 

解决方法：

直接在终端输入以下命令即可。

export PATH=/usr/bin:/bin