vividSec 
vi commands
- i - insert before cursor
- a - append after cursor
- A - insert at start of line
- I - append at end of line
- O - open new line above cursor
replace commands
- r - replace character under cursor (type new character)
- R - enter replace mode until ESC is pressed
- c <scope> - change text, specifying size of text to change; stays in insert mode until ESC is pressed.
- cc - change complete line
- cw - change to start of next word
- c3l - change next three characters
- c0 - change to start of line
- c1G - change to start of file
- cG - change to end of file
- c$ - change to end of line
- C - change to end of line
delete commands
- x - delete character under cursor
- X - delete character to left of cursor
- d <scope> - delete to buffer, specifying size of text to change
- dd - delete complete line
- dw - delete to start of next word
- d3l - delete next 3 characters
- d0 - delete to start of line
- d1G - delete to start of file
- dG - delete to end of file
- d$ - delete to end of line
- D - delete to end of line
copy & paste (yank & put) commands
- yy - yank complete line
- yw - yank to start of next word
- y0 - yank to start of line
- yG - yank to end of file
- p - paste buffer after current position
- P - paste buffer before current position
undo commands
- u - undo last edit (or insert)
- U - restore the current line to original
- m <letter> - set mark for current line
- ‘ <letter> - go to mark
- d <letter> - delete to mark
- y’ <letter> - yank (copy) to mark
- yyp - duplicate lines
- xp - swap characters
- J - join current and next line
- . - repeat last edit (or insert)
- ~ - invert letter case and move 1 character right
search and replace commands
- /pattern - search forwards for pattern
- ?pattern - search backwards for a pattern
- n - repeat last search
- N - repeat last search in opposite direction
- :1,$s/old/new/g - replace all instance of old with new
- :1,20s/old/new/gc - in the first 20 lines, replaces all old with new; ask for confirmation of each change
- :n,ms/old/new/g - replace all instances of old with new between lines n and m
vi session options
- aShowmode - show command/ insert mode
- autoindent - autoindent on insert
- number - number lines
- nomagic - disable regular expressions
misc. commands
- :r <file> - read file and place contents after current line (merge)
- :w - write file
- :w! - write file, overriding protection mode
- W <file> - write to named file
- :wq - write file and quit
- :x - write file and quit
- :q - quite without writing
- :q! - force quit, even if file is not written
- :w! - write file, overriding protection mode
- :! <cmd> - execute shell command
- :r!<cmd> - insert contents of shell command