Taken from stack overflow page when looking up how to list all aliases, found this:

    compgen -c will list all the commands you could run.
    compgen -a will list all the aliases you could run.
    compgen -b will list all the built-ins you could run.
    compgen -k will list all the keywords you could run.
    compgen -A function will list all the functions you could run.
    compgen -A function -abck will list all the above in one go.

