Unix Shells

How do I make the backspace button work..............?

Unix Shells in the NNIA

I am creating a spell that helps users run other spells. The spell takes the shape of a crab that can communicate with humans through the writing on its shell and the clack of its claws. 

The spell can also clone itself. Each of the child crabs it creates runs a single spell for the magic user before it disappears, while the original crab remains to listen for other requests.