vim相关设置
文件 /etc/.vimrc
set nu                                                 # 显示行号. set nonu
set mouse=v                                        # 鼠标选取复制
set noai nosi                                         # 取消了自动缩进和智能缩进
map :set paste                   # 粘贴前按F9，取消缩进
map :set nopaste                # 粘贴完成后，再按F10切换原模式