---
layout: page
author: Alessandro Luini
category-page: advanced
category-title: Advanced commands
tags: advanced text editor hell quit help escape sos
title: Vi
---
<p>
The default editor that comes with the UNIX operating system is called
vi (visual editor).</p>

The UNIX vi editor is a full screen editor and has two modes of operation:
<ol>
    <li>Command mode commands which cause action to be taken on the file</li>
    <li>Insert mode in which entered text is inserted into the file.</li>
</ol>

In the command mode, every character typed is a command that does
something to the text file being edited; a character typed in the
command mode may even cause the vi editor to enter the insert mode.<br>

In the insert mode, every character typed is added to the text in the
file; pressing the {Esc} (Escape) key turns off the Insert mode.<br>

While there are a number of vi commands, just a handful of these
is usually sufficient for beginning vi users. To assist such users,
this Web page contains a sampling of basic vi commands. The most
basic and useful commands are marked with an asterisk (* or star)
in the tables below. With practice, these commands should become
automatic.<br>

Both UNIX and vi are <b>case-sensitive</b>. Be sure not to use a
capital letter in place of a lowercase letter; the
results will not be what you expect.<br>

<h3>How to start <code>vi</code></h3>
To use vi on a file, type in vi filename. If the file named
filename exists, then the first page (or screen) of the file
will be displayed; if the file does not exist, then an empty
file and screen are created into which you may enter text.</p>

<pre>
vi filename.txt
</pre>

<h3>How to exit <code>vi</code></h3>

Usually the new or modified file is saved when you leave vi.
However, it is also possible to quit vi without saving the file.<br>

The cursor moves to bottom of screen whenever a colon (:) is
typed. This type of command is completed by hitting the
&ltReturn&gt (or &ltEnter&gt) key.<br>

<pre>
:q
</pre>

Quit vi without saving

<pre>
:x
</pre>

Quit vi, writing out modified file to
file named in original invocationt modified file to file named in origin.

<pre>
:wq
</pre>

Quit vi, writing out modified file to file named in original invocation.

<pre>
:q!
</pre>

Quit vi even though latest changes have not been saved for this vi call.


<h3>Recover from a crash</h3>

Open vi using the <code>-r</code> flag to recover a file that was being edited when a crash
happened.
</p>