Vi Tutorial

Modes

Vi uses a modal system of editing, the two modes are command mode and insert mode. The editor initially comes up on command mode.

These commands move you from command mode to insert mode.

a append after cursor

A append at end of line

c begin change operation

C change to end of line

i insert before cursor

I insert at end of line

o open a line below current line

O open a line above current line

R begin overwriting text

s substitute a character

S substitute an entire line

The <Escape> key moves you from insert mode to command mode.

As a general rule it is a good habit to get into to remain in command mode except when you are actually typing in text. Learn to automatically hit <Escape> each time you finish editing.

Note: You can configure vi to display whether you are in insert mode or command mode. From command mode (the default when vi starts) type in:

:set showmode<Enter>

Starting vi

vi	begin editing unnamed file
vi file1	begin editing file1
vi file1 file2 file3	begin editing 3 files, file1 will appear initially
*vi .txt**	begin editing all files ending in '.txt'
vi -r important.file	view file 'important.file' in read-only mode
view important.file	same as vi -r

Related Commands

Note that the following commands are to be executed from command mode

If you started vi with more than 1 file name on the command line, you can type:
:n
to go to the next file in the list of files you supplied.
If you have entered :n one or more times to move through a list of files, you can return to the first file (the initial file that appeared when you started vi) by typing:
:rew
You can list all the files that you gave vi on the command line (the current file will appear inside '[' ']') using the following command:
:args
Once vi is running, you can jump directly to a new file by typing:
:e the.new.file.name
While you are running vi, if you have changed the current file via: :rew, :e, :n you can swap back to the previous file using:
:e#
This is especially useful when you are entering long pathnames after :e

Leaving vi

Note: the following commands are all executable only from command mode

:q quit (assumes no changes made)

:q! quit, discard any changes that were made

:wq write the file, then quit

ZZ write the file, then quit

:w newname write the file to 'newname'

One associated command is :w which writes the current file to disk, but does not exit vi. A good habit to develop is to periodically type :w during your editing session, as this prevents loss of data if the system crashes.

Insert Mode, the most useful commands
- i (insert text before the cursor)
  This is the command you will use most often. Adds new text before the character above the cursor.
- a (insert text after the cursor)
  This command is most useful when your cursor is at the end of a line and you wish to add more text. The i command can be used as a substitute for a (by repositioning the cursor) in all other situations, but a is a necessity for the above situation.
- A (insert text at end of line)
  Most useful when your cursor is in the middle of a line and you wish to add text to the next line. Use A<Enter> to achieve this effect.
- cw (change word)
  suppose you have a line of text:
  Now is the thyme for all good men ...
  move your cursor to the 't' in thyme and type cw, you will see:
  Now is the thym$ for all good men ...
  Type in 'time' and then hit <Escape>, the line will be corrected.
- R (replace text)
  most useful when the number of characters you want to replace is the same as the current number of characters. For example:
  The untied states of america
Command Mode, navigating the current file

Although the <PageUp> and <PageDown> and arrow keys work on some systems, I would strongly discourage their use. The following commands are guaranteed to work properly on all systems.

Action vi equivalent
Page Up ^F

Page Down ^B

Left Arrow h

Right Arrow l

Up Arrow k

Down Arrow j

Home 0

End $

Action	vi equivalent
Page Up	^F
Page Down	^B
Left Arrow	h
Right Arrow	l
Up Arrow	k
Down Arrow	j
Home	0
End	$

Command Mode, deleting text

Action vi equivalent
delete current line dd
delete from cursor to end of line D
delete character under cursor x
delete character before cursor (backspace) X

Action	vi equivalent
delete current line	dd
delete from cursor to end of line	D
delete character under cursor	x
delete character before cursor (backspace)	X

Note that many of the above commands can be preceeded by a number, for example:

9x delete 9 characters
3dd delete 3 lines

Command Mode, line numbers

Action	vi equivalent
show line numbers	:set nu
turn off line numbers	:set nonu
display current line number/file name	^g
go to line number (1 for example)	:1
go to last line in file	G

Command Mode, cutting, copying and pasting

Action	vi equivalent
copy current line to "clipboard"	yy
paste contents of "clipboard" below current line	p
paste contents of "clipboard" above current line	P
copy current line, and next 4 lines to "clipboard"	5yy
write lines 200 -> 205 to temp.file	:200,205w temp.file
write lines 100 -> end of file to temp.file	:100,$w temp.file
write current line -> line 300 to temp.file	:.,300w temp.file
write current line and the next 3 lines to temp.file	:.,.+3w temp.file
write lines 200 -> next to last line of the file to temp.file	:200, $-1w temp.file
read contents of temp.file into current file	:r temp.file

Command Mode, searching

Action vi equivalent
set case insensitive search :set ic

set case sensitive search :set noic

search forward (down) for "hello" /hello

search backward (up) for "hello" ?hello

search again, (same direction as original) n

search again, (opposite direction as original) N

search for "hello" at start of a line /^hello

search for "hello" at end of a line /hello$

search for "hello" or "Hello" /[hH]ello

search for "int" as a word (i.e. not print or sprint) /\<int\>

search for "eat" but not "beat" or "neat" /\[^bn]eat

Action	vi equivalent
set case insensitive search	:set ic
set case sensitive search	:set noic
search forward (down) for "hello"	/hello
search backward (up) for "hello"	?hello
search again, (same direction as original)	n
search again, (opposite direction as original)	N
search for "hello" at start of a line	/^hello
search for "hello" at end of a line	/hello$
search for "hello" or "Hello"	/[hH]ello
search for "int" as a word (i.e. not print or sprint)	/\<int\>
search for "eat" but not "beat" or "neat"	/\[^bn]eat

Command Mode, replacing

Action	vi equivalent
replace "dog" with "cat" (first occurrence of dog) on the current line	:s/dog/cat
replace "dog" with "cat" on lines 1 -> 3 (first occurrence of dog on each line) of the file	:1,3s/dog/cat
replace "dog" with "cat" on lines 1 -> 3 of the file, every occurrence	:1,3s/dog/cat/g
replace "dog" with "cat" (every occurrence) for the entire file	:1,$s/dog/cat/g
replace "dog" with "cat" (every occurrence) for the entire file (alternative method)	:%s/dog/cat/g
replace "dog" with "cat" (every occurrence) for the entire file but confirm each replacement	:%s/dog/cat/gc

Command Mode, swapping commands

Action	vi equivalent
swap two letters (i.e. cta -> cat) note that the cursor must be on the first of the two letters	xp
swap two lines (swaps current line with the line below it)	ddp

Command Mode, other useful commands
- u and U, undo commands. u undoes the last action performed, U restores the current line to its original state (when the cursor first was put on that line)
- :g, the "global" command. Most useful for performing a deletion on lines that match a certain pattern.
  delete all lines containing "dog"
  :g/dog/d
  delete all blank lines
  :g/^$/d
- J, the join command. Use this command to cause the next line to be joined to the end of the current line.
- m, the mark command. Suppose you are editing a large text file and you wish to be able to mark your place at several spots in the file and return to them immediately.
  mark the current line as "line a"
  ma
  mark the current line as "line b"
  mb
  return to the line marked "a"
  'a
  write all lines between mark "a" and mark "b" to temp.file
  :'a,'bw temp.file
- %, the "pair matching" command. If you put your cursor on a '[', '{', or '(' character when you type % the cursor will jump to the matching ']', '}' or ')' character.
- ., the "do it again" command. Suppose you have two lines of text:
  here is line one here is line two
  you change the first line to read
  Here is line one
  Put your cursor on the "here" of "here is line two" and type ., the same change will be repeated.
  The dot command is extremely powerful. It can be used to "do it again" with a surprising number of vi editing commands
- &, the "do that substitution again" command. Suppose you have a line that reads:
  rats live on no evil star
  you type:
  :s/rats/bats
  changing the line to:
  bats live on no evil star
  then you move your cursor to another line reading:
  rats, rats, rats!
  when you type & you'll see
  bats, rats, rats!
  pressing & twice more will convert "rats" to "bats" for the entire line
- ~, the "reverse case" command. If you have a line that reads:
  i am shouting
  placing your cursor on the initial 'i' and holding down the ~ key results in:
  I AM SHOUTING
- f, the "find within a line" command. Suppose your cursor is on the first 'I' on the following line.
  I think therefore I am
  you wish to change "am" into "spam"
  You type
  fa
  which puts your cursor directly on the 'a' in 'am'
  Note that F searches to the left (f searches to the right). Also ; searches for subsequent matching characters (next occurrence) and , searches for the next match in the opposite direction of the initial search.
- w, the "move by words" command. Useful to move your cursor to the right on a line, a word at a time. Note that w considers punctuation characters as words, you can also use W which only considers whitespace in determining the next word.
- using "named" buffers this technique is primarily useful for copying lines of text from one file to another. If you use dd or yy to cut/copy a line of text then use :e to open a new file, you will find that the "clipboard" no longer contains the text you saved.
  To solve this problem, save your text in a "named" buffer.
  "a10yy
  :e temp.file
  "ap
  copies 10 lines into the named buffer "a" then puts the contents of buffer "a" into the newly opened temp.file.
  the only real difference between using yy or dd with named buffers is you preceed the command with " then the buffer name (a-z)
- command mapping this can be used to make a "macro" for a series of keystrokes. It is a good idea to map your macros to unused letters (see below for a table of unused letters).
  Note that to use "special" keys (<Enter> and <Esc>) for example in a macro, you must type ^v before the special character.
  map '>' to "indent the current line by 3 spaces"
  :map > :s/^/ /^M
  Note that the ^M is formed by typing: ^v<Enter>
  map 'q' to make a copy of the current line and append it to itself
  :map q yyPJ
  To turn off a mapping we created:
  :unmap q
  To list all the current mappings:
  :map
- abbreviations used to make abbreviations for long, frequently typed phrases
  You type:
  :ab zgs Zeh Graphics Systems, Inc.
  then while editing you type:
  I work for zgs<Esc>
  The line expands to:
  I work for Zeh Graphics Systems, Inc.
  To turn off the abbreviation we just created:
  :unab zgs
  To list all current abbreviations
  :ab
Table of unused letters/symbols

Letters: g, K, q, V, v

Control keys: ^a, ^k, ^o, ^t, ^w, ^x

Symbols: _, *, \, =

The .exrc file

Located in your home directory ($HOME). This file allows you to customize your vi environment, and preserve your settings between sessions.

Note that although the set and map commands are preceeded by a : when we enter them directly in vi, they have not starting : in the .exrc file. Here is an example .exrc file

      """""""""""""""""""""""""""""""""""""""""""""""""""""""""
      " Note that a " at the start of a line is a comment in
      " the .exrc file
      """""""""""""""""""""""""""""""""""""""""""""""""""""""""

      " Map [>] to [Indent current line by 3 spaces]
      map > :s/^/   /^M

      " Map [<] to [Delete all spaces / tabs from the beginning 
      " of the current line]
      map < :s/^[     ]*//^M

      " enable mode (input/command) display
      set showmode

      " default to ignore case for all searching
      set ic

a	append after cursor
A	append at end of line
c	begin change operation
C	change to end of line
i	insert before cursor
I	insert at end of line
o	open a line below current line
O	open a line above current line
R	begin overwriting text
s	substitute a character
S	substitute an entire line

:q	quit (assumes no changes made)
:q!	quit, discard any changes that were made
:wq	write the file, then quit
ZZ	write the file, then quit
:w newname	write the file to 'newname'

Letters:	g, K, q, V, v
Control keys:	^a, ^k, ^o, ^t, ^w, ^x
Symbols:	_, *, \, =