bash ：- ： no such file or directory

登录进入ubuntu 10.04.5之后，报了很多-bash ：- ： no such file or directory 错误，进入之后，不管输入什么命令，都会显示 bash ：命令名 ： no such file or directory。
下面是复制的错误：

Last login: Sat May  5 17:07:04 2012 from 219.217.240.58
-bash: export: `/usr/local/jdk1.6.0_31': not a valid identifier
-bash: export: `/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/bin': not a valid identifier
-bash: lesspipe: No such file or directory
-bash: dircolors: No such file or directory
-bash: uname: No such file or directory
-bash: [: !=: unary operator expected
-bash: [: too many arguments
-bash: [: too many arguments
-bash: [: too many arguments
-bash: [: =: unary operator expected
-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: sed: No such file or directory
-bash: [: too many arguments
-bash: [: =: unary operator expected
-bash: [: too many arguments
-bash: [: too many arguments
-bash: [: =: unary operator expected
-bash: [: =: unary operator expected
-bash: [: =: unary operator expected
-bash: [: =: unary operator expected
administrator@imss:~$ cd /etc
administrator@imss:/etc$ ls
-bash: ls: No such file or directory
administrator@imss:/etc$
administrator@imss:/etc$ echo $JAVA_HOME

administrator@imss:/etc$ echo $LANG
en_US.UTF-8
administrator@imss:/etc$ ls ~
-bash: ls: No such file or directory
administrator@imss:/etc$ cd ~
administrator@imss:~$ cd a-bash: expr: No such file or directory
-bash: [: : integer expression expected

-bash: cd: a: No such file or directory
administrator@imss:~$ sudo reboot
-bash: sudo: No such file or directory
administrator@imss:~$ la
-bash: ls: No such file or directory
administrator@imss:~$ ls
-bash: ls: No such file or directory