Shell/Recall Previous Commands

Within these castle walls be forged Mavens of Computer Science ...

— Merlin, The Coder

Recall Previous Commands

Sometimes it's expedient to quickly recall a previous command without the need to re-type it. The most common means of accomplishing this is to use the up-arrow. Let's try it:

john-williams@codermerlin:~$  ls

Now, let's repeat the command, but rather than type ls again, try typing the up-arrow:

john-williams@codermerlin:~$  ↑

Try pressing the ↑ and ↓ several times.

Observe

Observe, Ponder, and Journal: : Section 5

1. What happens each time you press the ↑?
2. What happens each time you press the ↓?