VI stands for "Visual Interpreter". It's the only text editor found on every UNIX system.

You must be logged onto UNIX , and be in the directory where you want to work.

To start, type vi filename (the name of the file you want to edit)--or just vi if you're creating a file but don't want to name it yet.

VI has two basic modes--the command mode, and the text-entry mode.

When in doubt, hit the escape key which always returns you to the command mode.

In comand mode, use your keyboard's arrow keys to navigate. You can also use shift-4 to go to the end of a line, and shift-6 to go to the beginning of a line. Moreover, shift-9 and shift-0, respectively, take you to the beginning and end of a sentence.

In command mode, w moves you forward one "word". Furthermore, including a number, such as 8w, will take you forward, in this case, eight words. Similarly, b takes you "back" one word, while 20b, for example, would move you back twenty words.

To go into text-entry mode, type i and now you can "insert" new text where the cursor is. In contrast, typing a prepares you to "append" or add new text, AFTER the current cursor position.

In command mode, use x to delete characters.

In command mode, o will start a new line and put you into text-entry mode.

In command mode, use dw to delete a word, dd to delete a line, and d$ to delete to the end of a line.

In command mode, you can "undo" your last change with u (but don't follow it with enter). Hitting u again will restore the change, and you can toggle back and forth betwen the two.

To save your work, go into command mode and type :w for "write". You'll be asked to name your file if it doesn't already have one.

To quit VI, type :q in command mode.

The above two commands can be combined as :wq. Furthermore, :q! quits without saving any changes.

To learn more VI commands, exit VI and view the online manual by typing man vi