插入命令
a append after the cursor
A append after the current line
i insert before the cursor
I insert before the current line
o append new line
O insert new line
移动命令
h move the cursor to the left
j move the cursor to the next line
k move ... to the front line
l move ... to the to the right
H (High) move ... to the top
M (Medium) //in the current page
L (Low)
$ move ..to header of line
0 move ..to footer of line
定位命令