[humble]Recording and playing back data

ros2 run turtlesim turtlesim_node

ros2 run turtlesim turtle_teleop_key

ros2 topic list

/parameter_events
/rosout
/turtle1/cmd_vel
/turtle1/color_sensor
/turtle1/pose

 

 

ros2 topic echo /turtle1/cmd_vel

linear:
  x: 2.0
  y: 0.0
  z: 0.0
angular:
  x: 0.0
  y: 0.0
  z: 0.0
  ---

 

 

 ros2 bag record

#ros2 bag record <topic_name>
ros2 bag record /turtle1/cmd_vel

 

Record multiple topics

#
ros2 bag record -o subset /turtle1/cmd_vel /turtle1/pose

#

 

ros2 bag info

#ros2 bag info <bag_file_name>
ros2 bag info subset

#

 

 

ros2 bag play

#
ros2 bag play subset

 

 

Rosbag Read..........ddshoagbtlqk

from rosbags.rosbag2 import Reader
from rosbags.typesys import Stores, get_typestore


# Create a typestore and get the string class.
typestore = get_typestore(Stores.LATEST)

# Create reader instance and open for reading.
with Reader('subset') as reader:
    # Topic and msgtype information is available on .connections list.
    for connection in reader.connections:
        print(connection.topic, connection.msgtype)

    # Iterate over messages.
    for connection, timestamp, rawdata in reader.messages():
        if connection.topic == '/turtle1/cmd_vel':
            msg = typestore.deserialize_cdr(rawdata, connection.msgtype)
            print(msg.header.frame_id)

    # The .messages() method accepts connection filters.
    connections = [x for x in reader.connections if x.topic == '/turtle1/cmd_pose']
    for connection, timestamp, rawdata in reader.messages(connections=connections):
        msg = typestore.deserialize_cdr(rawdata, connection.msgtype)
        print(msg.header.frame_id)