Vi Editor shortcuts

dd	delete the line
u	Undo
U	Undo all changes on a line
CTRL+R	Redo
/	Search
n	Search the same phrase again
N	Search in the opposite direction
?	Search in backward direction(use instead of /)
CTRL+O	Go back to where we came from
CTRL+I	Go to newer position
%	Move the cursor to the matching parenthesis
:s/old/new/ge	Replace all occurrences of old with new
ge in above command	Find every occurrence in the whole file, with a prompt whether to substitute or not
CTRL+G	Displays your current location in the file and file status
G	Moves to the end of the file
<number>G	Moves to that line number
gg	Moves to first line
:!<command>	To execute a shell command from within the shell
v	Select line
:r!dir	Reads the output of the command and put it below cursor
y ->	Copies text (y -yank)
p ->	Pastes text (p -paste)
:set xxx	Sets search option xxx where options are: ic :- ignore case is  :- incsearch -->show partial search h|s :- highlight all matching phrases