# VI(Visual) Editor Reference manual

The vi is a text editor. It is small, powerful, and standard on most UNIX systems. The vi often frustrates new users with a unique distinction between its two modes: Command Mode and Insert/Overtype Mode. This distinction, although difficult to become accustomed to for many users, provides great power and ability to the editor. Insert/Overtype Mode is designed for inserting text only. All text manipulations and cursor moving should be done from with in Command Mode.

## Entering the vi

- `prompt$` `vi`
- `prompt$` `vi file1 file2 ...`
- `prompt$` `vi -r file` #Recover file from crash
- `prompt$` `vi +string file` #Execute ex command "string"
- `prompt$` `vi @rcfile` #Read commands from rcfile

## Insert/Overtype Mode

Insert/Overtype Mode is solely for entering text. To leave one of these two modes press the `[ESC]` key. if you wish to enter the `ESC` character or any other control character while in insert mode: type `[CONTROL]-V` and then the control sequence. The only difference between Insert Mode and Overtype Mode is that characters are placed in front of the text after the cursor in Insert Mode, where as existing characters are overwritten in Overtype Mode.

## Command Mode

### Entering Insert Mode

- `a` -- append text, after the cursor
- `i` -- insert text, before the cursor
- `R` -- enter Overtype Mode
- `A` -- append text, after end of line
- `I` -- insert text, before first non-whitespace character
- `o` -- open new line below cursor in Insert Mode
- `O` -- open new line above cursor in Insert Mode

### vi Syntax

vi commands follow the general form:
  n `operator` m `object`
which means:
  execute `operator` n times on m `objects`. If n and/or m are omitted, they default to 1.
Operators which take objects are(if the operator is pressed twice then the object is the current line)
  - `c` -- Change
  - `d` -- Deletion
  - "c `y` -- Yank, if "c is omitted, uses general buffer.
  - `<` -- shift lines left by shiftwidth variable
  - `>` -- shift lines right by shiftwidth variable
  - `!`cmd -- filter trough cmd
  `#The operators <, >, and ! are line based so the set of `objects` is diminished greatly.`
Operators which do not take objects:
  - `s` -- Substitute
  - `x` -- Delete character
  - `r` -- Replace character
  - `~` -- change case of character
Objects (if given with out an operator are interpreted as a cursor motion command):
  - `w` -- forward until beginning of word
  - `e` -- forward until end of word
  - `b` -- backward until beginning of word
  - `$` -- forward until end of line
  - `^` -- backward until first non-whitespace character
  - `0` -- backward until first column of line
  - n `G` -- line number n
  - n`|` -- column n of current line
  - `/`pat -- forward until beginning of pat, search
  - `?`pat -- backward until beginning of pat, backward search
  - `n` -- repeat last search
  - `N` -- repeat last search/backward search, but in opposite direction
  - `%` -- until match of parenthesis, brace, or bracket
  - `t` c -- until next appearance of c on current line
  - `T` c -- backward until next appearance of c on current line
  - `f` c -- until and including next appearance of c on current line
  - `F` c -- backward until and including next appearance of c on current line
  - `;` -- repeat last f, F, t, or T
  - `,` -- repeat last f, F, t, or T in reverse
  - `}` -- forward until end of paragraph
  - `{` -- backward until end of paragraph
  - `)` -- forward until end of sentence
  - `(` -- backward until end of sentence
  - `]]` -- forward until end of section
  - `[[` -- backward until end of section
  - n `H` -- n lines before first line on screen; n defaults to 0
  - n `L` -- n lines before last line on screen; n defaults to 0
  - `M` -- the middle line of the screen
  - `j` -- down one line
  - `k` -- up one line
  - `h` -- left one character
  - `l` -- right one character
  - `[BS]` -- left one character, backspace usually equals ^H
  - `[SPACE]` -- right one character
  - `_` -- the entire current line
  - `-` -- until first non-whitespace character on previous line
  - `+` -- until first non-whitespace character on next line
  - `[RETURN]` -- until first non-whitespace character on next line

### Miscellaneous 1

- `u` -- undo last change
- `U` -- undo entire line
- "c `p` -- put "c or general buffer after the cursor
- "c `P` -- put "c or general buffer before the cursor
- `m` c -- set mark with character c
- ```c -- goto mark c
- `'`c -- goto beginning of line with mark c
- ```` -- return to position before mark jump or search
- `''` -- return to beginning of line before mark jump or search
- `J` -- join two lines
- `D` -- delete rest of line
- `C` -- change rest of line
- `Y` -- yank current line into general buffer
- `&` -- execute last ex-style substitution
- `.` -- execute last modification
- `!` object command -- send object as stdin to command and replace with stdout
- `[Ctrl]-G` -- print information about file
- : `map` x y -- when character x is pressed, execute y
- : `map!` x y -- map input mode character x to string y
- : `ab` x y -- x is an abbreviation for y, changes are made on the fly
- : `su` -- Suspend the current editor session
- : `sh` -- run a shell

## ex Commands

### ex syntax

ex commands in the vi follow this general form:
  : `address` command
which means:
  Execute command on specific lines obtained from the `address` part of the general form. If `address` is omitted, current line is used. Keep in mind that the ex is a line based editor, so all actions are line based.
`address`es:
  - `%` -- all lines in file
  - `x,y` -- lines `x` to `y`
  - `.` -- current line
  - `n` -- line number: `n`
  - `$` -- last line of file
  - `x-n` -- `n` lines before line `x`
  - `x+n` -- `n` lines after line `x`
  - `/pat/` -- forward to line containing `pat`
  - `?pat?` -- backward to line containing `pat`
Some commands are:
  - `s/pat/text/` -- substitute 1st match of `pat` with `text`
  - `s/pat/text/g` -- substitute every match of `pat` with `text`
  - `s/pat/text/n` -- substitute the `nth` occurrence of `pat` with `text`
  - `ya` c -- yank into buffer c or the general buffer if c is omitted
  - `g address cmd` -- execute `cmd` on all lines which satisfy `address`
  - `>` -- shift right
  - `<` -- shift left
  - `d` -- delete line
  - `! UNIX-cmd` -- execute `UNIX-cmd` on line
  - `m` address -- move lines to address
  - `refer to ex manual page for more commands`

### The vi environment variables

`set`
  You can customize your environment with this command by typing `set var=value`, this will set the specified `var` to `value` for a scalar variable. For boolean variables, use `set var` to set and `set novar` to unset. You can see which variables are set by just typing the `set` by its self. You can see a list of all variables by typing `set all`. Some environment variables are specific to the ex editor and some are specific to the vi editor. I have included both.

boolean variables:
- `autoindent(ai)` -- begin editing next line at same level of indent-ion as this one.
- `autowrite(aw)` -- write current buffer before leaving
- `exrc(ex)` -- tells vi/ex if it should read the .exrc file in the current directory.
- `errorbells` -- editor sends a beep to the terminal when an incorrect
- `ignorecase(ic)` -- ignore case of characters in searches.
- `list` -- place a $ at the end of each line and a ^I on each tab.
- `magic -- allow ., [, and * to be interpreted as special characters in RE's.`
- `number(nu)` -- number lines in left margin
- `showmatch(sm)` -- when closing a paren., brace or bracket; move the visual cursor to opening item to check scope
- `showmode(smd)` -- show type of insert mode
- `wrapscan(ws)` -- when searching and at bottom of file, continue searching from the top
scalar variables:
- `shiftwidth` -- number of spaces to to insert on a shift operation

## File Saving and Loading

- : `wq` -- write file and quit
- : `w` -- write file
- : `w file` -- write to specified `file`
- : `w!` -- overwrite existing file
- : `e file` -- edit new `file`
- : `r file` -- put contents of `file`
- : `q` -- quit the editor
- : `q!` -- force quit the editor, do not save changes
- : `x` -- quit the editor, save file if it was modified
- `ZZ` -- quit the editor, save file if it was modified
- : `n` -- start editing next file in list
- : `rew` -- rewind file list, start editing 1st file on argument list again
- `Q` -- quit vi and enter ex
- : `pre` -- Preserve file.
- : `rec` file -- recover file

## Examples 2

- `j` -- move cursor down
- `k` -- move cursor up
- `h = [BS]` -- move cursor left
- `l = [SPACE]` -- move cursor right
- `+ = [RETURN]` -- first non-whitespace character on next line
- `cw` -- change word
- `dd = d_` -- delete line
- `yy = y_` -- yank current line into the general buffer
- `"ayj` -- yank current line and one below into buffer `a`
- `yfc` -- yank until next occurrence of `c` on current line into the general buffer
- `3dl = d3l` -- delete next 3 characters
- `4c( = 2c2( = c4(` -- change next 4 sentences
- `>%` -- while on a brace, paren., or bracket; shift right until closing brace, etc.
- `:%!sort = :1,$!sort` -- sort current file
- `:5,10s/foo/bar/2` -- change the second occurrence of `foo` with `bar` on lines 5-10
- `3J` -- Join next 2 lines to current one
- `3,9m$` -- move lines 3 through 9 to the end of the file
- `ab w/o with out` -- when `w/o` is typed change to `with out`
- `:?foo?,/bar/d` -- delete from the reverse match of foo until the next match of bar
- `g/{/,/}/<` -- shift all lines between, and including, a "`{`" and a "`}`" left
- `:$-4,$d` -- delete last five lines of buffer
- `:%s/^\(.*\) \(.*\)$/\2 \1/` -- swap everything before and after the first space

1 It is noteworthy to add that most control sequences are bound in the vi. I do not mention them here because they remind me of emacs and I hope to spare you such pain.

2 For the record, no animals were physically harmed during the testing of these examples; although some elephants are now in psychological therapy as a direct result of my actions. I kind of feel guilty about that one :(

I hope you liked my vi reference manual, if you have any questions or suggestions then feel free to send me mail.

BTW: RTFM

Last modified: 29 March 02000
About the author:
  William Totten (totten@pobox.com)

Copyleft: (C) 1996 2000, William Totten