6、 Common commands of ROS (I): rosnode, rostopic, rosmsg

1、rosnode: Node query , Operation command

1. rosnode ping talker( The node name )

• Test the connectivity to the node
• Return results ：

  rosnode ping talker
  rosnode: node is [/talker]
  pinging /talker with a timeout of 3.0s
  xmlrpc reply from http://d102-W65KJ1-KK1:35707/	time=0.540018ms
  xmlrpc reply from http://d102-W65KJ1-KK1:35707/	time=1.176357ms
  

2. rosnode list

• List active nodes
• Return results :

  rosnode list
  /listener
  /rosout
  /talker
  

3. rosnode info talker( The node name )

• Query node information
• Return results ：

  rosnode info talker
  --------------------------------------------------------------------------------
  Node [/talker]
  Publications: 
  * /chatter [std_msgs/String]
  * /rosout [rosgraph_msgs/Log]
  
  Subscriptions: None
  
  Services: 
  * /talker/get_loggers
  * /talker/set_logger_level
  
  
  contacting node http://d102-W65KJ1-KK1:35707/ ...
  Pid: 7033
  Connections:
  * topic: /rosout
      * to: /rosout
      * direction: outbound (39331 - 127.0.0.1:57890) [11]
      * transport: TCPROS
  * topic: /chatter
      * to: /listener
      * direction: outbound (39331 - 127.0.0.1:59130) [12]
      * transport: TCPROS
  
  

4. rosnode machin d102-W65KJ1-KK1( Device name )

• Lists the nodes on the specified device :ros Distributed control , Different nodes may be running on each device
• Return results ：

  rosnode machine d102-W65KJ1-KK1
  /rosout
  

5. rosnode kill listener( The node name )

• Kill a node
• Return results ：

  rosnode kill listener
  killing /listener
  killed
  

6. rosnode cleanup

• Kill zombie nodes
• Return results ： nothing

2、rostopic: Topic inquiry , Operation command

1. rostopic list (-v)

• Print the topic name in the current running state ,-v Get topic details
• Return results ：

  rostopic list
  /chatter
  /rosout
  /rosout_agg
  

  rostopic list -v
  
  Published topics:
  * /rosout_agg [rosgraph_msgs/Log] 1 publisher
  * /rosout [rosgraph_msgs/Log] 2 publishers
  * /chatter [public_massage/Person] 1 publisher
  
  Subscribed topics:
  * /rosout [rosgraph_msgs/Log] 1 subscriber
  * /chatter [public_massage/Person] 1 subscriber
  

2. rostopic pub Topic name Message type The message content

• Publish messages to subscribers through commands Remember source Next path , among , The topic name needs to be written by yourself , Message type and message content , Can pass TAB Key completion
• Return results ：

  rostopic pub chatter public_massage/Person "name: 'xiaomage' age: 13 height: 10.0" 
  publishing and latching message. Press ctrl-C to terminate
  

  Set the release frequency ：

  rostopic pub -r 10 chatter public_massage/Person "name: 'sd' age: 5 height: 0.30"
  

3. rostopic echo Topic name

• Get the message posted on the specified topic , Be sure to agree to the workspace , Other orders are required
• Return results :

  rostopic echo chatter
  name: "xiaomage"
  age: 37
  height: 1.78
  ---
  name: "xiaomage"
  age: 38
  height: 1.78
  ---
  name: "xiaomage"
  age: 39
  height: 1.78
  ---
  

4. rostopic info Topic name

• Get information about the current topic
• Return results ：

  rostopic info chatter
  Type: public_massage/Person
  
  Publishers: 
  * /talker (http://d102-W65KJ1-KK1:37521/)
  
  Subscribers: 
  * /listener (http://d102-W65KJ1-KK1:44919/)
  

5. rostopic type Topic name

• Get the message type of the topic
• Return results ：

  rostopic type chatter
  public_massage/Person
  

6. rostopic find Message type

• Find topics according to the message type
• Return results ：

  rostopic find public_massage/Person /chatter
  

7. rostopic hz Topic name

• List the frequency of news release
• Return results ：

  rostopic hz chatter
  subscribed to [/chatter]
  no new messages
  average rate: 1.000
      min: 1.000s max: 1.000s std dev: 0.00000s window: 2
  

8. rostopic bw Topic name

• List the message publishing bandwidth
• Return results ：

  rostopic bw chatter
  subscribed to [/chatter]
  average: 27.14B/s
      mean: 22.00B min: 22.00B max: 22.00B window: 2
  

3、rosmsg: Show message types , Information

1. rosmsg list

• List current ros All of the msg
• Return results ： Package name / Data format name

  visualization_msgs/Marker
  visualization_msgs/MarkerArray
  visualization_msgs/MenuEntry
  

2. rosmsg packages

• List all packages that contain messages
• Return results ：

  actionlib
  actionlib_msgs
  actionlib_tutorials
  bond
  control_msgs
  controller_manager_msgs
  diagnostic_msgs
  

3. rosmsg package Package name

• List all under a package msg
• Return results ：

  rosmsg package public_massage 
  public_massage/Person
  

4. rosmsg show Package name / Data name

• Displays the message description
• Return results ：

  rosmsg show public_massage/Person 
  string name
  uint16 age
  float64 height
  

5. rosmsg info Package name / Data name

• Displays the message description
• Return results ：

  osmsg info public_massage/Person 
  string name
  uint16 age
  float64 height
  

6. rosmsg md5

• Unknown
• Return results ：