$ gcc -c simple.c -o simple.o $ gcc -lm -lplayerc simple.o -o simpleMake sure that playerc.h is installed somewhere in you include path, and that libplayerc.a is in your library path.
The above program can be broken into six steps, as follows.
client = playerc_client_create(NULL, "localhost", 6665); playerc_client_connect(client);The create function creates a new client proxy and returns a pointer to be used in future function calls (localhost should be replaced with the network host name of the robot). The connect function notifies the Player server that a new client wishes to recieve data.
position = playerc_position_create(client, 0); playerc_position_subscribe(position, PLAYER_ALL_MODE);The create function creates a new position device proxy and returns a pointer to be used in future function calls. The subscribe function notifies the Player server that the client is using the position device, and that the client expects to both send commands and recieve data (PLAYER_MODE_ALL).
playerc_position_enable(position, 1); playerc_position_set_speed(position, 0, 0, 0.1);The enable function sends a configuration request to the server, changing the robot's motor state from off to on, thereby allowing the robot to move. The setspeed function sends a new motor speed, in this case commanding the robot to turn on the spot.
Note that most Player devices will accept both asynchronous command and synchronous configuration requests. Sending commands is analogous using the standard Unix write device interface, while sending configuration requests is analogous to using the ioctl interface. For the most part, libplayerc hides the distinction between these two interfaces. Users should be aware, however, that while commands are always handled promptly by the server, configuration requests may take significant time to complete. If possible, configuration requests should therefore be restricted to the initialization phase of the program.
playerc_client_read(client); printf("position : %f %f %f\n", position->px, ... );The read function blocks until new data arrives from the Player server. This data may be from one of the subscribed devices, or it may be from the server itself (which sends regular synchronization messages to all of its clients). The read function inspects the incoming data and automatically updates the elements in the appropriate device proxy. This function also returns a pointer to the proxy that was updated, so that user programs may, if desired, trigger appropriate events on the arrival of different kinds of data.
playerc_position_unsubscribe(position); playerc_position_destroy(position);The unsubscribe function tells the Player server that the client is no longer using this device. The destroy function then frees the memory associated with the device proxy; the device pointer is now invalid and should be not be re-used.
playerc_client_disconnect(client); playerc_client_destroy(client);The disconnect function tells the server that the client is shutting down. The destroy function then frees the memory associated with the client proxy; the client pointer is now invalid and should be not be re-used.