A minimal plugin example for ROS 2 command line tools.
Calling,
ros2 hello world
produces the following print in the terminal,
__
_(\ |@@|
(__/\__ \--/ __
\___|----| | __
\ }{ /\ )_ / _\
_ _ _ _ __ __ ___ ___ __ __ _ _ _ /\__/\ \__O (__
| || |___| | |___ | _ \/ _ \/ __| |_ ) \ \ / /__ _ _| |__| | | | (--/\--) \__/
| __ / -_) | / _ \_ | / (_) \__ \ / / \ \/\/ / _ \| '_| / _` | |_| _)( )(_
|_||_\___|_|_\___( ) |_|_\\___/|___/ /___| \_/\_/\___/|_| |_\__,_| (_) `---''---`
|/