The vi Editor (Linux in a Nutshell, 3rd Edition)

vi is the classic screen-editing program for Unix. A number of enhanced versions exist, including nvi, vim, vile, and elvis. On Linux, the vi command is usually a link to one of these programs.

11.1. Review of vi Operations

This section provides a review of the following:

Command-line options
vi modes
Syntax of vi commands
Status-line commands

11.1.1. Command Mode

Once the file is opened, you are in command mode. From command mode, you can:

Invoke insert mode
Issue editing commands
Move the cursor to a different position in the file
Invoke ex commands
Invoke a Linux shell
Save or exit the current version of the file

11.1.2. Insert Mode

In insert mode, you can enter new text in the file. Press the Esc or Ctrl-[ keys to exit insert mode and return to command mode. The following commands invoke insert mode:

a: Append after cursor
A: Append at end-of-line
c: Begin change operation (must be followed by a movement command)
C: Change to end-of-line
i: Insert before cursor
I: Insert at beginning 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 entire line

11.1.3. Syntax of vi Commands

In vi, commands have the following general form:

[n] operator [m] object

The basic editing operators are:

c: Begin a change
d: Begin a deletion
y: Begin a yank (or copy)

If the current line is the object of the operation, then the operator is the same as the object: cc, dd, yy. Otherwise, the editing operators act on objects specified by cursor-movement commands or pattern-matching commands. n and m are the number of times the operation is performed or the number of objects the operation is performed on. If both n and m are specified, the effect is n × m.

An object can represent any of the following text blocks:

word: Includes characters up to a space or punctuation mark. A capitalized object is a variant form that recognizes only blank spaces.
sentence: Extends to ., !, ? followed by two spaces.
paragraph: Extends to next blank line or nroff/troff paragraph macro (defined by para= option).
section: Extends to next nroff/troff section heading (defined by sect= option).

11.1.3.1. Examples

2cw: Change the next two words
d}: Delete up to next paragraph
d^: Delete back to beginning of line
5yy: Copy the next five lines into temporary buffer (for future pasting)
y]]: Copy up to the next section into temporary buffer (for future pasting)

11.1.4. Status-Line Commands

Most commands are not echoed on the screen as you input them. However, the status line at the bottom of the screen is used to echo input for the following commands:

/: Search forward for a pattern
?: Search backward for a pattern
:: Invoke an ex command
!: Pipe the text indicated by a subsequent movement command through the following shell command, and replace the text with the output of the shell command

Commands that are input on the status line must be entered by pressing the Return key. In addition, error messages and output from the Ctrl-G command are displayed on the status line.