ROS Tools: rqt_bag

rqt_bag is a ROS tool used to play back bag files. To record a bag file, use the command rosbag record -o bag_name /topics /to /record. The generated bag file now contains data from the various recorded rostopics which can be subscribed to when the bag file is played back. To play back a bag file, in the directory containing the bag, run:

rqt_bag bag_name.bag

This should open a window:

To play back topic(s), right-click on the panel's empty space and select Publish > Publish All:

You can also publish individual topics by right-clicking a specific topic and selecting Publish. After selecting topics to be published, hit the play button in the top right. If you rostopic list, you should now see the topics you are publishing and can view their content in rviz, subscribe to them, etc.

For more information on rqt_bag and its other uses, refer to the ROS wiki page.