solution to bash error (because of the PATH)

由于修改了/etc/bash.bashrc时，将PATH变量中路径设置错误（路径拼写错误，呵呵，低级错误），所以当再次打开bash时，出现

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: command not found
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: command not found
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: command not found
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: command not found
bash: [: !=: unary operator expected
bash: [: too many arguments
bash: [: too many arguments
bash: [: =: unary operator expected
bash: [: too many arguments
bash: [: too many arguments
bash: [: too many arguments
bash: [: too many arguments
bash: [: too many arguments
bash: [: too many arguments
bash: [: =: unary operator expected
bash: [: =: unary operator expected
bash: [: =: unary operator expected
bash: [: =: unary operator expected
bash: [: =: unary operator expected
bash: [: =: unary operator expected
bash: [: =: unary operator expected
bash: [: =: unary operator expected
bash: [: =: unary operator expected
bash: [: =: unary operator expected
bash: [: too many arguments
bash: [: =: unary operator expected
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: command not found
xuqiang@ubuntu:~$