You can check to see if you're running bash by typing:

$ echo $SHELL
/bin/bash

If the above line gave you an error or didn't respond similarly to our example, then you may be running a shell other than bash. In that case, most of this tutorial should still apply, but it would be advantageous for you to switch to bash for the sake of preparing for the 101 exam. (See Part 2 of this tutorial series for information on changing your shell using the chsh command.)