Vi was the original terminal based text editor created for Unix. It is as small and as simple as it gets. The binary resides within the Unix and Linux bins, and can easily be placed on a removable media for ultimate emergency portability. There are three modes to vi:
1. command mode
2. ex mode
3. insert mode
First open a file. Open your grub configuration file. Sudo vi “/boot/grub/menu.lst”. Use up, down, left, and right to navigate eh terminal. Press escape and it will return the mode you are in. Press R to enter replacement mode. Use i or a to insert text rather than replace it. To exit vi use :wq or ZZ. To save without exiting use :w. Or to quit without saving use :q.
Or you can use nano. Type:
sudo nano /boot/grub/menu.lst
Nano is always in edit mode. Move the cursor to the position you want to edit, and backspace to remove text, or type to add. Then press control-o to save, and control-x to quit. After looking into vi, its easy to realize both have the same functionality, and ultimately have various commands to do things. The commands are quirky, especially for us who grew up with graphical editors. But once you know the commands to save and exit you can corrolate functionality with any graphical text editor.