Hands-On ROS for Robotics Programming

The rosmsg command

rosmsg provides information about the types of message used by topics during runtime. To give you a practical example, we select the distance_sensor/distance topic and get the following information about it:

$ rostopic info distance_sensor/distance

This command tells us that the topic has a message type of sensor_msgs/Range. Then, rosmsg informs us of the message structure:

$ rosmsg info sensor_msgs/Range

The output of this command is what we showed and explained in the Setting up the msg_range object subsection of the Case study 1 – writing a ROS package – distance sensor section. In the next chapter, we will provide extended explanations about the new message types we will be using in the GoPiGo3 ROS package.