vi editor :
The VI editor is a screen-based editor used by many Unix users. The VI editor has powerful features to aid programmers, but many beginning users avoid using VI because the different features overwhelm them. This tutorial is written to help beginning users get accustomed to using the VI editor, but also contains sections relevant to regular users of VI as well.
Getting Started:
General Startup
To use vi: vi filename
To exit vi and save changes: ZZ or :wq
To exit vi without saving changes: :q!
To enter vi command mode: [esc]
 Counts
A number preceding any vi command tells vi to repeat
that command that many times.
 Cursor Movement
h move left (backspace)
j move down
k move up
l move right (spacebar)
[return] move to the beginning of the next line
$ last column on the current line
0 move cursor to the first column on the
current line
^ move cursor to first nonblank column on the
current line
w move to the beginning of the next word or
punctuation mark
W move past the next space
b move to the beginning of the previous word
or punctuation mark
B move to the beginning of the previous word,
ignores punctuation
e end of next word or punctuation mark
E end of next word, ignoring punctuation
H move cursor to the top of the screen
M move cursor to the middle of the screen
L move cursor to the bottom of the screen
Screen Movement
G move to the last line in the file
xG move to line x
z+ move current line to top of screen
z move current line to the middle of screen
z- move current line to the bottom of screen
^F move forward one screen
^B move backward one line
^D move forward one half screen
^U move backward one half screen
^R redraw screen
( does not work with VT100 type terminals )
^L redraw screen
( does not work with Televideo terminals )
Inserting
r replace character under cursor with next
character typed
R keep replacing character until [esc] is hit
i insert before cursor
a append after cursor
A append at end of line
O open line above cursor and enter append mode
Deleting
x delete character under cursor
dd delete line under cursor
dw delete word under cursor
db delete word before cursor
Copying Code
yy (yank)'copies' line which may then be put by
the p(put) command. Precede with a count for
multiple lines.
Put Command
brings back previous deletion or yank of lines,
words, or characters
P bring back before cursor
p bring back after cursor
Have a nice day!.......
