vi commands

vi -R filename          /*readonly
view filename           /*readonly

0                       /*begin at the head of a line
$                       /*begin at the tail of a line
w                       /*go to next word
b                       /*go back to the previous word
W/B                     /*do not count the punctuation
(                       /*the begian of this sentense
)                       /*the begian of next sentense

:x                      /*put the cursor to the specific line
Ctrl+G                  /*the get the position of the cursor now
ZZ/:x                   /*the same as :wq
Ctrl+G                  /*the get the position of the cursor now
:e!                     /*reopen the file without your modification

dw                      /*remove the character until the begian of next word
D                       /*remove the character until the end of the line
cc                      /*remove the whole line then go to insert mode
cw
r
R
s
S                       /*remove the whole line then go to insert mode
yw
U                       /*only recover the current line

:!command               /*for example: :!ls
s/misspelled/correct spelled    /*only replace the fist object in the line
s/misspelled/correct spelled/g  /*replace all the objects in the line(globally)
x,ys/characters to be replaced/what to replace with     /*x,y is the line number
x,ys/characters to be replaced/what to replace with/g   /*x,y is the line number
1,$s/mispelled/correct spelled/g    /*replace all the mispelled word in the file
1,$s/mispelled/correct spelled/gc   /*confirm the every replaced word
1,$s/mispelled*/correct spelled/gc   
1,$s/\*/hello/g         /*use hello to replace all the * in the file
1,$s/1,$s/>the/none/g