Simple Controller in Player
Documentation for the Client Libraries can be found at 
For C++, the first few lines of a controller (in a .cc file) will look something like:
using namespace PlayerCc; // Connect to Player server robot = new PlayerClient(gHostname, gPort); // Request sensor data pp = new Position2dProxy(robot, gIndex); sp = new SonarProxy(robot, gIndex);
This code creates a PlayerClient, the connection between your controller and your robot. In this case, the robot supplies 2d position data (x,y, and theta) and sonar data to the controller.