Turtlesim Comms: Get Topic Info

Get Information About a Specific Topic

If we wish to get information about a specific topic, who is publishing to it, subscribed to it, or the type of message associated with it, we can use the command rostopic info .
Let’s check into the /turtle1/cmd_vel topic:

As you might expect, there are two nodes registered on this topic. One publisher, the teleop_turtle node, and one subscriber, the turtlesim node. Additionally, we see that the type of message used on this topic is geometry_msgs/Twist .