libhomeradar

Connecting to 2 hosts and show all contacts

This example will connect to two SBS-1 hosts and will show all the contacted aircrafts on stdout. The library will be initialized with the LHR_AUTOCONNECT flag to immediatly connect to added hosts. New contacted aircrafts will also be written to stdout with a special marker.
The hosts will be added with the LHR_ONAIRCONTACT event listener. So later we must only add the event listener for the LHR_ONCONTACT event.
There is NO CHECK for successfully connects! (This will be done in a different example). This program will run appr. 120 seconds.

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/* System includes */
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

/* libhomeradar header include */
#include "libhomeradar.h"

/* Show new contacted aircrafts */
void onair(LHR handle,const int *id, LHR_CONTACT *C) {
  char tstr[64];

  printf("*** NEW CONTACT ***\n===================\n");
  if (id != NULL) printf("[%s]\n",homeradar_gethostbyid(handle,*(id)));
  printf("Contact: %s [%s]\n",
          C->icao24,(C->reg)?C->reg:"UNKNOWN - Lookup not enabled?!");
  strftime(tstr,sizeof(tstr),"%d %m %Y %H:%M:%S",localtime(&C->contacted));
  printf("Date: %s\n===================\n",tstr);

  /* Free used memory */
  homeradar_freecontact(C);
}

/* Callback function to show aircraft informations */
void newcontact(void *handle,const int *id, LHR_CONTACT *C) {

  /* Show icao24 code */
  printf("Contact: %s [%s]\n",C->icao24,
          (C->reg)?C->reg:"UNKNOWN - Lookup not enabled?!");

  /* Free LHR_CONTACT struct */
  homeradar_freecontact(C); 
}

/* Main program */
int main(int argc, char **argv) {
  int e;
  LHR H = homeradar_init(16,LHR_AUTOCONNECT,&e,NULL);

  /* No error */
  if (H == NULL) {
    printf("Error initializing libhomeradar. Errorcode #%d\n",e);
    return 255;
  }

  /* Add host */
  e = homeradar_addhost(H, "sbs1.libhomeradar.org", 33033, LHR_SBS1, LHR_ONAIRCONTACT, onair);

  /* Setup the event listener for the LHR_ONCONTACT event */
  if (homeradar_onhandler(H, LHR_ONCONTACT, e, newcontact)==0) {
    printf("Unable to add event listener\n");
  }

  /* Add a second host */
  e = homeradar_addhost(H, "sbs2.libhomeradar.org", 0, LHR_SBS1, LHR_ONAIRCONTACT, onair);

  /* Setup the event listener for the LHR_ONCONTACT event */
  if (homeradar_onhandler(H, LHR_ONCONTACT, e, newcontact)==0) {
    printf("Unable to add event listener\n");
  }

  /* Do nothing - in this example - loop will be finished after 120 seconds 
     In your real program you can do now what you want */
  e = 20;
  while (e--) sleep(6);

  /* Shutdown libhomeradar and free all alocated memory */
  printf("Shutdown libhomeradar...\n");
  homeradar_destroy(H);

  /* Return success */
  return 0;
}