compgen

A built-in command for auto-completion in bash, which is called on pressing TAB key twice.

• List all commands that you could run:

compgen -c

• List all aliases:

compgen -a

• List all functions that you could run:

compgen -A function

• Show shell reserved key words:

compgen -k

• See all available commands/aliases starting with 'ls':

compgen -ac {{ls}}