恢复默认的.bashrc文件

jack@omnisky:~$ source ~/.bashrc
-bash: /home/jack/.bashrc: line 1: syntax error near unexpected token `('
-bash: /home/jack/.bashrc: line 1: `STFILESIZE=2# ~/.bashrc: executed by bash(1)       for non-login shells.'

可能是修改PS1变量的时候，不小心添加或删除了其他内容

解决办法：恢复默认的.bashrc文件

Ubuntu系统的/etc/skel/目录中有.bashrc文件的默认版本

cd /etc/skel
cp .bashrc ~/  (覆盖了搞坏的文件）