Contents

The vi editor

This file:

  • Provides the basic instructions for using the vi editor.

Keywords: ASCII, vi, command mode, insert mode, vim

Associated material:

The vi editor is the basic ASCII text editor that comes with essentially all Linux/Unix systems. It works on the command line without GUI. It is very lightweight.

vi differs from most editors (with or without GUI) in that it has two modes: 1) command mode and 2) editing or insert mode. As the names suggest, these modes serve for different purposes. In the command mode, one can enter commands such as copy, paste, save, quit and so on. Editing text is not possible in the command mode. For editing text, one has to enter the editing or insert mode. That mode is exclusively for editing text and for saving the file, one has to switch to command mode. Understanding the two modes is the key to using the vi editor.

Why vi

First, since it ships with all Linux/Unix systems, it is always there without any additional installations. Second, is also extremely lightweight. Those two factors are very important if something goes wrong with the systems and some of the system files need to be edited; in such case no GUI based editors (even if they are ASCII editors) may be impossible to use. Although switching between the modes may sound cumbersome, it is very easy to get used to that and vi is a favorite of many.

Switching between the modes

  • When vi is started, it is always in the command mode.

  • Commands are case sensitive

  • Switch from the command mode to the insert mode: press the key i.

  • Switch from the insert mode to the command mode: press the esc key.

Starting vi

To open a file or to create a new file, simply type

vi filename.txt

If filename.txt exists it will be simply opened. If it doesn’t exist, it will be created.

vi
vi search
vi save

vi command summary

Below is a summary of some of the most common commands. Open a test file and try them.

COMMAND (the commands must be given in the command mode)

FUNCTION

NOTES

vi filename.txt

edit/create a file called filename.txt

On the command line terminal. Starts vi in command mode

i

Switch to insert mode

Shows the text -- INSERT -- at the bottom of the screen

esc

Switch to command mode

x

delete character to the right of the cursor

4x

delete 4 characters (to the right of the cursor)

X

delete character to the left of the cursor

dw

delete word to the right of the cursor

2dw

delete 2 words to the right of the cursor

dd

delete the current line

2dd

delete 2 (current and the next) lines

D

delete all characters from the cursor to end of the line

o

insert an empty line below the cursor

Switches to insert mode

O

insert an empty line above the cursor

Switches to insert mode

r

replace the character under the cursor

Switches to insert mode

a

append text to the right of the cursor

Switches to insert mode

cw

replace the word

Switches to insert mode

3cw

replace 3 words (to the right; leaves the rest the line after the two words intact)

Switches to insert mode

C

delete the text from cursor to end of line

Switches to insert mode

J

join the line below to the current line

Switches to insert mode. The cursor can be anywhere on the line

3J

join the 3 following lines below to the current line

Switches to insert mode. The cursor can be anywhere on the line

u

undo

Switches to insert mode

ZZ

save the file and quit

Switches to insert mode

:w

save the file

Switches to insert mode

:w newname.txt

save the file with name newname.txt

Switches to insert mode

:r name.txt

read text into the current file from file named name.txt

Switches to insert mode

:wq

save the file and quit

Switches to insert mode

:q!

discard all changes since last save and quit

Switches to insert mode

w

move forward word-by-word

b

move backward word-by-word

$

move to the end of the current line

0

move to the beginning of the current line

H

go to the top line of the current screen

M

go to the middle line of the current screen

L

go to last line of the current screen

G

go to the last line of the file

1G

go to first line of the file

Ctrl-f

scroll forward one screen

Ctrl-b

scroll backward one screen

Ctrl-d

scroll down one-half screen

Ctrl-u

scroll up one-half screen

:/ keyword + return

search for keyword in the current text

To repeat the search forward press n, backward: N

:s/ keyword + return

search for keyword in the current line

To repeat the search forward press n, backward: N

:s/word1/word2 + return

search for word1 on the current line AND replace it by word2

in command mode.

:%s/word1/word2 + return

search for all occurrences of word1 AND replace them by word2

in command mode.

vi cursor movements:

Instead of using the arrows, the cursors (in command mode) can be moved using the following keys:

COMMAND

FUNCTION

h

move left one space

j

move down one line

k

move up one line

l

move right one space

vi in readonly-mode

vi can also be used in readonly-mode. The search and movement functions work as listed above, but editing and saving is not possible in the readonly mode. Here’s how:

vi -R filename.txt

vim the basic vi improved

vim is an improved vi and a very popular ASCII text editor - vi and vim are arguably the most popular text editor in Linux/Unix. vim adds several features to the basic vim and all of the above commands work also in vim. It comes (just like the basic vi) with most (if not all) current Linux/Unix systems as well as Mac.

vim stands for Vi IMproved. It adds features to the basic vi and is highly customizable. It also has many plugins including git integration and a scripting language. vim is available for essentially all operating systems including iOS and Android.

Jupyter Notebook / Jupyter Lab Editing ASCII files