VI Editor

To create or to open a file for editing
[root@comp1 ~]# vi

Example:-
[root@comp1 ~]# vi fullreport

To go to insert mode
i - inserts the text at current cursor position
r - replace a single char at current cursor position

Commands at Execute Mode
:q - quit without saving
:q! - quit forcefully without saving
:w - save
:wq - save & quit
:wq! - save & quit forcefully
:se nu - Setting line numbers
:se nonu - Removing line numbers
:84 - Press enter goes to line 84

Commands at Command Mode
dd - Deletes a line
2dd - Deletes 2 lines
yy - Copy a line
2yy - Copies 2 lines
p - put (deleted or copied text)
u - Undo (can undo 1000 times)
Ctrl+r - Redo
G - Moves cursor to last line of file
/ - To search for a particular word