ros2 topic echo: No option to clear screen

[ahemwe]

Feature request

Feature description

In ROS 1 rostopic echo has an option "-c" $ rostopic echo -c /topic_name

Meaning: Clear the screen after each message is published. Cannot be used with -p.

See: http://wiki.ros.org/rostopic#rostopic_echo

This is very helpful when using a terminal session to monitor ros messages in a terminal.

In ROS 2 this option is not available as of now. I would highly appreciate if this could be implemented.

Implementation considerations

[torrhen]

Would require something like the "\033[2J\033[;H" ANSI control sequence prefixed for each message callback to clear display and reposition cursor.

No -p argument in this case, but --csv looks similar. Are they equivalent given this context?