# compgen > A built-in command for auto-completion in Bash, which is called on pressing TAB key twice. > More information: . - 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 keywords: `compgen -k` - See all available commands/aliases starting with 'ls': `compgen -ac {{ls}}`