(1) Begin
	vi <filename>	: begin vi

	+-------+	 	+---------+		+---------+
	| Input |  <- a,i,o --  | Command |  <-- : ---	| Ex Mode | 
	| Mode  |  --- ESC -->  | Mode    |  --- : -->	|	  |  
	+-------+		+---------+		+---------+

(2) End (Ex Mode)
	:wq		: write and quit
	:w <filename>	: write
	:q!		: quit no-save
	:q		: quit

(3) Editing (Input Mode)
	a 		: input after cursor
	A 		: input at the end of line
	i		: input before cursor
	I 		: input at the head of line
	o		: input in new line below cursor
	O		: input in new line above cursor
	r		: replace a character at cursor
	R		: overwrite from cursor
	o		: input in new line below cursor

	<n> x		: cut <n> characters
	<n> dw		: cut <n> words
	<n> dd		: cut <n> lines and store them in buffer
	    D		: cut to the end of line
	<n> yy		: copy <n> lines
	    p		: paste after cursor (line)
	    P		: paste after cursor (line)

	<n> s <string>	: substitute the <n> characters starting from
			: the current cursor position by <string>

	u		: undo
	.		: rddo
	
	ESC		: input end

(4) Cursor Movement (Command Mode)
			C-b : 1   page up
			C-u : 1/2 page up
			k   : 1   line up
	h : 1 char left			l : 1 char right
	b : 1 word left			w : 1 word right
					e : word end
	0 : 1st column
	^ : 1st word			$ : end of line
			j   : 1   line down
			C-d : 1/2 page down
			C-f : 1   page down

	<lineNo> G	: go to <lineNo>
		 G	: go to the last line

(5) Search (Command Mode)
	/<string>	: search forward
	?<string>	: search backward
	n		: next after cursor
	N		: next before cursor

(6) Editing in Ex Mode (:)
	[range]command[line]		 
		 range	= n[,m]	: line n (to m)
		 	  n = .	: current line
		 	  m = $	: last line
		 	= %	: all lines
		 	= none	: current line

		 command = m	: move range after line
		 	 = t	: copy range after line
		 	 = d	: delete range
		 
	[range]s/string1/string2/[gc]	: string substitution
		       g = global
		       c = interactive

(7) Customization in Ex Mode (:)
	set [no][option]

	e.g.)
		set showmode
		set noshowmode
		set number
		set nonumber
		set autoindent
		set noautoindent