How about sharing our tutorial answers?

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Hi, I just finished the questionnaire and I thought it'd be very interesting to share them to see what other possibilities there is for some answers and in that way learn a bit more about ROS.

Here are mine:

How do you find the sensor_msgs package? rospack find sensor_msgs

What is the path of the sensor_msgs package? /opt/ros/electric/stacks/common_msgs/sensor_msgs

What ROS messages are defined in the sensor_msgs package? vim manifest

msg/CameraInfo.msg msg/JointState.msg msg/PointCloud.msg msg/ChannelFloat32.msg msg/LaserScan.msg msg/PointField.msg msg/CompressedImage.msg msg/NavSatFix.msg msg/Range.msg msg/Image.msg msg/NavSatStatus.msg msg/RegionOfInterest.msg msg/Imu.msg msg/PointCloud2.msg msg/Joy.msg msg/JoyFeedback.msg msg/JoyFeedbackArray.msg

What nodes and topics are created when running roscore? /rosout

What ROS packages does the roscpp_tutorials package depend on? rospack depends roscpp_tutorials

rosbuild roslang cpp_common roscpp_traits rostime roscpp_serialization rospack roslib xmlrpcpp rosconsole std_msgs rosgraph_msgs roscpp std_srvs

alternative version: roscd roscpp_tutorials; vim manifest.xml roscpp, std_srvs, std_msgs

How do you run the talker and listener nodes in the roscpp_tutorials package? rosrun beginner_tutorials talker rosrun beginner_tutorials listener

What topic are the talker and listener nodes subscribing and publishing to? /chatter (talker publishing to and listener subscribing)

What is the message type of the topic in the previous question? std_msgs/String

How do you rename a node? __name:=<name>

What is the difference between a topic and a service? A service let's you query a node and receive a reply for it, while a topic let's you broadcast messages (nodes can subscribe to the topic).

What does rxconsole show you? rxconsole displays the messages being published to rosout.

What does roslaunch do? Allow you to initialize multiple nodes on your machine.

Cheers,