ROS Programming: Building Powerful Robots

Playing back a bag file

Now that we have a bag file recorded, we can use it to play back all the messages for the topics contained in it; note that we need roscore running and nothing else. We will move to the folder in which the bag file is located (there are two examples in the bag folder of this chapter's tutorials) and run this command:

    $ rosbag play 2014-07-01-22-54-34.bag
  

Hopefully, rosbag will produce the following output:

    [ INFO] [1404248314.594700096]: Opening 2014-07-01-22-54-34.bag
    
    Waiting 0.2 seconds after advertising topics... done.
    
    Hit space to toggle paused, or 's' to step.
     [RUNNING]  Bag Time: 1404248078.757944   Duration: 2.801764 / 39.999515
  

In the terminal in which the bag file is being played, we can pause (hit spacebar ...