ROS

To see a list of nodes and topics and their subscription status, run rqt_graph

To interface with topics, the master command is: rostopic

There are subcommands for it. rostopic list Nodes can subscribe to nonexisting topics.

rostopic info /fixedwing/state Shows a topic's state, the publisher, and the subscribers.

rostopic echo -c /fixedwing/state -c is for clear screen so that the messages always show up in the same place

rostopic hz /fixedwing/baro Shows the rate of publishing to the topic

rosnode list Lists existing nodes

Services are a secondary way of communicating between nodes. Topics are many-to-many communications; services are request-response.

rosservice rosrun As in, rosrun rosplane

rosbag You can use it to record stuff rqt_bag opens a bagfile but gives you all the hinformation in the bag.

rosed roscd

rqt_graph rqt_plot rqt_bag