vi for Beginners

Many new Linux administrators find the vi editor complex and daunting. It is not as user friendly as other editors that they might have used before, but with a little practice, vi can be a powerful tool for managing files.

This article is not going to make you a master of vi. Instead, it tries to get you comfortable with the editor so that you can learn the more advanced tools as you need them.

Background

vi was originally called the "VIsual editor" because you could see the entire file on screen at one time. It was first developed in a world without function keys and a mouse. Administrators had just the basic keyboard keys and so had to make the most of what they had to work with. Every key has a function within vi, but how do you separate the text from the commands?

Modes

vi has two modes: command and input.

Command mode is the default when you first opens a file. In this mode, your keystrokes perform different actions within the editor. Be careful, however; to extend the number of possible commands, vi is case sensitive, so the upper- and lowercase letters almost always have different behaviors. Certain characters — most notably the colon (:) and forward slash (/) — activate an in-application command line for multi-character commands.

Input mode enables you to enter text in the file. You activate this mode with a set of command mode characters. A status bar at the bottom of the screen indicates which input mode is in use. The <esc> key exits input mode and returns the editor to command mode.

Movement

Although you can use arrow keys to move through a file in modern incarnations of vi, part of the editor's strength is that you never need to move your hands from the home keys. This means less wasted movement and better efficiency.

The simple movement keys are h, j, k, and l.

Many administrators only use these four keys to navigate their files. After you get comfortable with the basic movements, the next step is to learn how to move more efficiently.

Managing Text

Multiple commands start input mode, depending on where and how you place the text in the file.

To manipulate text, the major commands are x (character delete or "strike out"), d (delete), y (copy or "yank"), and p (paste). The y and d commands require additional characters to indicate the amount of text to copy or delete. Prepending a number repeats an action that number of times.

Closing a File

Like an text editor, vi allows you multiple ways to exit a file, with and without saving. Some of the files require the : character which allows you to see the commands you type on screen.