VIM

vi improved.

vim file.txt

can also use vimtutor

Source

Notes

Modes

Switch between modes : Esc

Normal : on starup
Insert : i insert at the cursor position
Insert : a insert at the next cursor position
Insert : s remove letter and insert at the current position
Delete : dd delete line
Delete : x delete character
Change : cc delete line and insert mode
Change : ce or cw delete upto end of next word and insert mode
Undo : u
Redo : Ctrl-r
Copy and Paste: yank is copy, so y | yy is to copy current line | yw copy word | p paste
Copy in visual mode (bulk) : v and hjkl, press y, press p to paste
Copy in visual mode (line mode) : V and same as before, can do rectangular blocks with lh

Command line

By pressing :

:help :w

:sp split text into multiple windows. can work on same file at once.

:qa quit all open windows

More keybindings

w move cursor forward by one word

b opposite dir of w

e end of the word

0 begenning

$ end of line

^ goes to first non empty character

~ to change case of word or block

Ctrl u up scroll

Crtl d down scroll

G moves all the way down

gg moves all the way up

L to lowest visible line

M for visible middle line

H for highest

fo to find first o same for other letters

Fs find first s before cursor

/ search for something, n to match next, p for previous

Combining with numbers

3k do k 3 times (same for other arrow keys, useful to move)

+4 to move 4 lines forward

-4 to move 4 lines up

2dw delete words twice

c2w change 2 words

Relevant to programming

%% to jump back and forth between paranthesis, or braces

di( delete everything in the parenthesis

da( delete all in paranthesis

dw delete word

d0 delete to begenning of line

d$ delete to end of line

cw change word and become insert mode

Add custom keybinding

Example from SO.

Insert into ~/.vimrc

 Quickly insert an empty new line without entering insert mode
    nnoremap <Leader>o o<Esc>
    nnoremap <Leader>O O<Esc>