安装软件的时候需要加入环境变量（网上看别人的）
sudo vim /etc/bash.bashrc
添加了如下内容
QUOTE:
if [ -d /usr/local/arm/2.95.3 ] ; then
PATH=/usr/local/arm/2.95.3/bin:"${PATH}"
fi

使新的环境变量生效
# source /etc/profile

结果使用大部分命令都会显示如下
wangjun@my-desktop:~$ clear
Command 'clear' is available in '/usr/bin/clear'
The command could not be located because '/usr/bin' is not included in the PATH environment variable.
bash: clear：找不到命令

wangjun@my-desktop:~$ sudo cd test
Command 'sudo' is available in '/usr/bin/sudo'
The command could not be located because '/usr/bin' is not included in the PATH environment variable.
bash: sudo：找不到命令



终端关闭后再打开就会显示
bash: QUOTE:：找不到命令
bash: if[ -d /usr/local/arm/2.95.3 ]:then: 没有该文件或目录
bash: /etc/bash.bashrc: line 64: 在未预料的“fi”附近出现语法错误
bash: /etc/bash.bashrc: line 64: `fi'
Command 'lesspipe' is available in '/usr/bin/lesspipe'
The command could not be located because '/usr/bin' is not included in the PATH environment variable.
bash: lesspipe：找不到命令
Command 'dircolors' is available in '/usr/bin/dircolors'
The command could not be located because '/usr/bin' is not included in the PATH environment variable.
bash: dircolors：找不到命令
Command 'uname' is available in '/bin/uname'
The command could not be located because '/bin' is not included in the PATH environment variable.
bash: uname：找不到命令
Command 'uname' is available in '/bin/uname'
The command could not be located because '/bin' is not included in the PATH environment variable.
bash: uname：找不到命令
bash: [: !=: 需要单个参数
bash: [: 过多的参数
bash: [: 过多的参数
bash: [: =: 需要单个参数
bash: [: 过多的参数
bash: [: 过多的参数
bash: [: 过多的参数
bash: [: 过多的参数
bash: [: 过多的参数
bash: [: 过多的参数
bash: [: =: 需要单个参数
bash: [: =: 需要单个参数
bash: [: =: 需要单个参数
bash: [: =: 需要单个参数
bash: [: =: 需要单个参数
bash: [: =: 需要单个参数
bash: [: =: 需要单个参数
bash: [: =: 需要单个参数
bash: [: =: 需要单个参数
bash: [: =: 需要单个参数
bash: [: 过多的参数
bash: [: =: 需要单个参数
Command 'sed' is available in '/bin/sed'
The command could not be located because '/bin' is not included in the PATH environment variable.
bash: sed：找不到命令

由于现在sudo命令无法使用，所以不能修改／ 目录下你的文件内容了，求解决办法





在Ubuntu中，由于用户权限的问题，不能对一些文件进行编辑，也不能对一些文件夹进行写操作。用Ubuntu Tweak可以解决这个问题。步骤如下：
Ubuntu Tweak——个人设定——脚本——把右边“已禁用的脚本”中的“以管理员身份用文本编辑器打开”和“以管理员身份浏览”拖到左边。然后在文件浏览器中右键单击文本文件并选择“脚本——以管理员身份用文本编辑器打开”，就可以修改并保存系统文件了；或者右键单击文件夹选择“脚本——以管理员身份浏览”，就可以对系统文件夹里的文件进行操作了。

然后删除添加的东西就可以了

看不懂的就别乱改， 还改/etc 里的，

用 /usr/bin/nano 把文件改回去