Hello World ROS (Robot Operating System) - Talker and Listener

ros_listener.cpp

#include "ros/ros.h"
#include "std_msgs/String.h"

void callback(const std_msgs::String &msg) {
  ROS_INFO("I heard: [%s]", msg.data.c_str());
}

int main(int argc, char **argv) {
  ros::init(argv, argc, "listener");
  ros::NodeHandle n;
  ros::Subscriber sub = n.subscribe("chatter", 1, callback);
  ros::spin();
  return 0;
}

ros_talker.cpp

// ROS Hello World (Talker)
#include "ros/ros.h"
#include "std_msgs/String.h"

int main(int argc, char **argv) {
  ros::init(argc, argv, "talker");
  ros::NodeHandle n;
  ros:Publisher pub = n.advertise<std_msgs::String>("chatter", 1);
  ros::Rate loop_rate(10);
  while(ros::ok()) {
    pub.publish("Hello, World");
    ros::spinOnce();
  }
  return 0;
}