Using Vi editor

You can use the vi editor in almost all the Unix Systems to edit text in the console, so you can use it in Linux and Mac OS.

The syntax to use vi, is the following:

Create a new file or Edit an existing one with vi



Edit the file

When you enter in the file, you are in command mode, in this mode you cannot enter new characters, in this mode you can navigate into the file and make a lot of things. If you are going to insert or edit the current file, you need to enter to insert mode, to do that, you can just type the "i" letter, you can be sure that you are in the Insert mode if you see the INSERT key word below the console.



Save the file

1. Press the key ESC to exit from the Insert mode
2. Type :w
3. Press the key RETURN

Exit from the file

1. Press the key ESC to exit from the Insert mode
2. Type :q
3. Press the key RETURN

Exit from the file and discard any change

1. Press the key ESC to exit from the Insert mode
2. Type :q!
3. Press the key RETURN

More info here