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rostopic info /topic/name and nodelets

Running rostopic info /topic/name gives me output like:

Type: topic/Name

Publishers:
 * /nodelet_manager1 (http://...)

Subscribers:
 * /nodelet_manager2 (http://...)
 * /nodelet_manager3 (http://...)
 * /real/actual/node (http://...)

Using the C++ API, how can I drill down and find which nodelets within the three managers are the actual ones subscribed? Or can I instead develop a nodelet to query its nodelet manager to find out which nodelets actually publish and subscribe?

Asked by KenYN on 2018-10-11 22:36:25 UTC

Comments

What do you mean by "actual ones subscribed" ? The output tells you that the nodelet_manager1 publish data on the topic and then nodelet_manager2, nodelet_manager3 and real/actual/node will have their own callback function called. They all get the data published by nodelet_manager1.

Asked by Delb on 2018-10-12 02:08:26 UTC

I mean which actual nodelet - my managers can have up to 10 nodelets within them, so I wish to find out the actual nodelet, not merely the manager, that subscribes to the message.

Asked by KenYN on 2018-10-12 02:51:17 UTC

To clarify things : Are your /nodelet_manager1 and /nodelet_manager2 two different nodelets under the nodelet_manager or are they two different nodelet_manager containing nodelets ?

Then instead of rostopic info you should use rosnode info to have the correct topics.

Asked by Delb on 2018-10-12 03:33:08 UTC

So you should see #q208574 to use the rosnode API in C++.

Asked by Delb on 2018-10-12 03:34:16 UTC

Same frustration for 10 years now :) https://answers.ros.org/question/10013/what-topics-is-my-nodelet-listening-to-for-rgbd6d-playback/

Asked by stfn on 2019-08-13 14:12:53 UTC

Answers