更改Ubuntu 12.04默认的shell

Ubuntu 12.04默认的shell是dash.

kevin1@kevin1-desktop:~$ ls -ls /bin/sh
0 lrwxrwxrwx 1 root root 4 Oct 18 20:40 /bin/sh -> dash

但我们常用的是bash. 更改命令如下：
kevin1@kevin1-desktop:~$ sudo unlink /bin/sh
kevin1@kevin1-desktop:~$ ls -ls /bin/sh
ls: cannot access /bin/sh: No such file or directory
kevin1@kevin1-desktop:~$ sudo ln -s /bin/bash /bin/sh


更改后：
kevin1@kevin1-desktop:~$ ls -ls /bin/sh
0 lrwxrwxrwx 1 root root 9 Oct 18 22:08 /bin/sh -> /bin/bash