Wow. I never knew about the `compgen -c` command to show bash command completions. Also from this reference [1] I found these:

    % compgen -b # built-ins
    % compgen -k # keywords
    % compgen -A function # functions
    % compgen -abckA function # everything

[1] http://www.cyberciti.biz/open-source/command-line-hacks/comp...