ros2

Retrieve information about ROS 2 network

Since R2019b

Syntax

ros2 msg list

ros2 msg show msgType

ros2 node list

ros2 topic list

ros2 service list

ros2 service type svcname

ros2 action list

ros2 action type actionname

ros2 bag info folderpath

msgList = ros2("msg","list")

msgInfo = ros2("msg","show",msgType)

nodeList = ros2("node","list")

topicList = ros2("topic","list")

serviceList = ros2("service","list")

serviceTypes = ros2("service","type",svcname)

actionList = ros2("action","list")

actionTypes = ros2("action","type",actionname)

nodeList = ros2("node","list","DomainID",ID)

topicList = ros2("topic","list","DomainID",ID)

bag2info = ros2("bag","info",folderpath)

Description

ros2 msg list returns a list of all available ROS 2 message types that can be used in MATLAB.

ros2 msg show msgType provides the definition of the ROS 2 message, msgType.

ros2 node list lists nodes on the ROS 2 network.

ros2 topic list lists topic names with registered publishers or subscribers on the ROS 2 network.

ros2 service list lists service names that are registered on the ROS 2 network through either servers or clients.

ros2 service type svcname lists service types that are registered on the ROS 2 network for the provided svcname.

ros2 action list lists action names that are registered on the ROS 2 network through either servers or clients.

ros2 action type actionname lists action types that are registered on the ROS 2 network for the provided actionname.

ros2 bag info folderpath displays the information about the contents of the ros2bag at folderpath in the MATLAB^® Command Window. The information include the contents of the bag2info structure.

Note

If the ROS 2 bag log file contains custom messages, generate MATLAB interfaces to ROS 2 custom messages using ros2genmsg function before using this command.

msgList = ros2("msg","list") returns a list of all available ROS 2 message types that can be used in MATLAB.

msgInfo = ros2("msg","show",msgType) provides the definition of the ROS 2 message, msgType.

nodeList = ros2("node","list") lists nodes on the ROS 2 network.

topicList = ros2("topic","list") lists topic names with registered publishers or subscribers on the ROS 2 network.

serviceList = ros2("service","list") lists service names that are registered on the ROS 2 network through either servers or clients.

serviceTypes = ros2("service","type",svcname) lists service types that are registered on the ROS 2 network for the provided svcname.

actionList = ros2("action","list") lists action names that are registered on the ROS 2 network through either servers or clients.

actionTypes = ros2("action","type",actionname) lists action types that are registered on the ROS 2 network for the provided actionname.

nodeList = ros2("node","list","DomainID",ID) lists nodes on the ROS 2 network for the specified network domain ID. By default, the value of "DomainID" is 0 unless otherwise specified by the ROS_DOMAIN_ID environment variable.

topicList = ros2("topic","list","DomainID",ID) lists topic names with registered publishers or subscribers on the ROS 2 network for the specified network domain ID.

Note

The "DomainID" name-value pair applies only to information gathered from the active network, such as the node and topic list, and not to static ROS 2 data such as message information.

The first time ros2 is called for a specific domain ID not all information on the network may be immediately available. If incomplete network information is returned from ros2, wait for a short time before trying again.

bag2info = ros2("bag","info",folderpath) returns information about the contents of the ros2bag as a structure, bag2info at folderpath.

Note

If the ROS 2 bag log file contains custom messages, generate MATLAB interfaces to ROS 2 custom messages using ros2genmsg function before using this function.

Examples

Get Definition of ROS 2 Message

Show the definition of the geometry_msgs/Accel message.

ros2 msg show geometry_msgs/Accel

# This expresses acceleration in free space broken into its linear and angular parts.
Vector3  linear
Vector3  angular

Get Definition of ROS 2 Message

Show the definition of the geometry_msgs/Accel message.

ros2 msg show geometry_msgs/Accel

# This expresses acceleration in free space broken into its linear and angular parts.
Vector3  linear
Vector3  angular

Get List of ROS 2 Nodes

Create sample node, myNode, on the ROS 2 network.

node = ros2node("myNode");

Lists the nodes on the network.

ros2 node list

/myNode

Remove myNode from the network.

delete(node)

Get List of ROS 2 Topics

List the available ROS 2 topics.

ros2 topic list

/parameter_events
/rosout

Input Arguments

msgType — Message type

string scalar | character vector

Message type, specified as a string scalar or character vector. The string is case-sensitive and no partial matches are allowed. It must match a message on the list given by calling ros2("msg","list").

Function syntax:

Example: ros2("msg","show","sensor_msgs/LaserScan")

Command syntax:

Example: ros2 msg show sensor_msgs/LaserScan

Data Types: char | string

svcname — Service name

string scalar | character vector

Service name, specified as a string or character vector. The string is case-sensitive and no partial matches are allowed. It must match a service on the list given by calling ros2("service","list").

Function syntax:

Example: ros2("service","type","/example_service")

Command syntax:

Example: ros2 service type /example_service

Data Types: char | string

actionname — Action name

string scalar | character vector

Action name, specified as a string or character vector. The string is case-sensitive and no partial matches are allowed. It must match a service on the list given by calling ros2("action","list").

Function syntax:

Example: ros2("action","type","/example_action")

Command syntax:

Example: ros2 action type /example_action

Data Types: char | string

folderpath — Path to ros2bag files

string scalar | character vector

Path to the ros2bag files, specified as a string scalar or character vector.

Note

folderpath location must contain ROS 2 bag file (.db3) and metadata.yaml, which holds the meta information about the bag file. The folder name must be same as the ROS 2 bag file name.

Function syntax:

Example: ros2("bag","info","C:\Users\Jack\MATLAB\EM\alltopics")

Command syntax:

Example: ros2 bag info C:\Users\Jack\MATLAB\EM\alltopics

Data Types: char | string

ID — Domain identification of the network

non-negative scalar integer between 0 and 232

The domain identification of the ROS 2 network, specified as a non-negative scalar integer between 0 and 232.

Example: 2

Data Types: double

Output Arguments

msgList — List of all message types available in MATLAB

cell array of character vectors

List of all message types available in MATLAB, returned as a cell array of character vectors.

msgInfo — Details of message definition

character vector

Details of the information inside the ROS message definition, returned as a character vector.

topicList — List of topics on the ROS 2 network

cell array of character vectors

List of topics on the ROS 2 network, returned as a cell array of character vectors.

serviceList — List of services on the ROS 2 network

cell array of character vectors

List of services on the ROS 2 network, returned as a cell array of character vectors.

actionList — List of actions on the ROS 2 network

cell array of character vectors

List of actions on the ROS 2 network, returned as a cell array of character vectors.

nodeList — List of node names available

cell array of character vectors

List of node names available, returned as a cell array of character vectors.

bag2info — Information about contents of ros2bag

structure

Information about contents of the ros2bag, returned as a structure. This structure contains fields related to the ros2bag log file and its contents. A sample output for a ros2bag as a structure is:

         Path: 'C:\Users\Jack\MATLAB\EM\alltopics\alltopics.db3'
      Version: '1'
    StorageId: 'sqlite3'
     Duration: 102.396644003
        Start: [1×1 struct]
          End: [1×1 struct]
         Size: 4965433
     Messages: 36503
        Types: [5×1 struct]
       Topics: [5×1 struct]

Data Types: struct

Version History

Introduced in R2019b