cmd: Displays a hierarchical menu of all athenaCL commands.
help: To get help for a command or any available topic, enter "help" or "?" followed by a search string. If no command is provided, a menu of all commands available is displayed.
Begins an interactive Python session inside the current athenaCL session.
pypath: Lists all file paths in the Python search path.
q: Exit athenaCL.
quit: Exit athenaCL.
On UNIX-based platforms, the "shell" or "!" command executes a command-line argument in the default shell.