/** * \addtogroup helloworld * @{ *//** * \file *         An example of how to write uIP applications *         with protosockets. * \author *         Adam Dunkels <adam@sics.se> *//* * This is a short example of how to write uIP applications using * protosockets. *//* * We define the application state (struct hello_world_state) in the * hello-world.h file, so we need to include it here. We also include * uip.h (since this cannot be included in hello-world.h) and * <string.h>, since we use the memcpy() function in the code. */#include "hello-world.h"#include "uip.h"#include <string.h>/* * Declaration of the protosocket function that handles the connection * (defined at the end of the code). */static int handle_connection(struct hello_world_state *s);/*---------------------------------------------------------------------------*//* * The initialization function. We must explicitly call this function * from the system initialization code, some time after uip_init() is * called. */voidhello_world_init(void){  /* We start to listen for connections on TCP port 1000. */  uip_listen(HTONS(1000));}/*---------------------------------------------------------------------------*//* * In hello-world.h we have defined the UIP_APPCALL macro to * hello_world_appcall so that this funcion is uIP's application * function. This function is called whenever an uIP event occurs * (e.g. when a new connection is established, new data arrives, sent * data is acknowledged, data needs to be retransmitted, etc.). */voidhello_world_appcall(void){  /*   * The uip_conn structure has a field called "appstate" that holds   * the application state of the connection. We make a pointer to   * this to access it easier.   */  struct hello_world_state *s = &(uip_conn->appstate);  /*   * If a new connection was just established, we should initialize   * the protosocket in our applications' state structure.   */  if(uip_connected()) {    PSOCK_INIT(&s->p, s->inputbuffer, sizeof(s->inputbuffer));  }  /*   * Finally, we run the protosocket function that actually handles   * the communication. We pass it a pointer to the application state   * of the current connection.   */  handle_connection(s);}/*---------------------------------------------------------------------------*//* * This is the protosocket function that handles the communication. A * protosocket function must always return an int, but must never * explicitly return - all return statements are hidden in the PSOCK * macros. */static inthandle_connection(struct hello_world_state *s){  PSOCK_BEGIN(&s->p);  PSOCK_SEND_STR(&s->p, "Hello. What is your name?\n");  PSOCK_READTO(&s->p, '\n');  strncpy(s->name, s->inputbuffer, sizeof(s->name));  PSOCK_SEND_STR(&s->p, "Hello ");  PSOCK_SEND_STR(&s->p, s->name);  PSOCK_CLOSE(&s->p);    PSOCK_END(&s->p);}/*---------------------------------------------------------------------------*/