seat.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <wayland-client.h>
#include <wayland-server.h>
#include <wayland-client-protocol.h>

struct wl_display *display = NULL;
struct wl_seat *seat = NULL;

static void seat_handle_capabilities(void *data, struct wl_seat *seat,
    enum wl_seat_capability caps)
{
  if (caps & WL_SEAT_CAPABILITY_POINTER) {
    printf("Display has a pointer\n");
  } 

  if (caps & WL_SEAT_CAPABILITY_KEYBOARD) {
    printf("Display has a keyboard\n");
  }

  if (caps & WL_SEAT_CAPABILITY_TOUCH) {
    printf("Display has a touch screen\n");
  }
}

static const struct wl_seat_listener seat_listener = {
  seat_handle_capabilities,
};

void global_registry_handler(void *data, struct wl_registry *registry, uint32_t id,
    const char *interface, uint32_t version)
{
  if (strcmp(interface, "wl_seat") == 0) {
    seat = wl_registry_bind(registry, id,
        &wl_seat_interface, 1);
    wl_seat_add_listener(seat, &seat_listener, NULL);
  }
}

static void global_registry_remover(void *data, struct wl_registry *registry, uint32_t id)
{
  printf("Got a registry losing event for %d\n", id);
}

static const struct wl_registry_listener registry_listener = {
  global_registry_handler,
  global_registry_remover
};

int main(int argc, char **argv) {

  display = wl_display_connect(NULL);
  if (display == NULL) {
    fprintf(stderr, "Can't connect to display\n");
    exit(1);
  }
  printf("connected to display\n");

  struct wl_registry *registry = wl_display_get_registry(display);
  wl_registry_add_listener(registry, &registry_listener, NULL);

  wl_display_dispatch(display);
  wl_display_roundtrip(display);

  wl_display_disconnect(display);
  printf("disconnected from display\n");

  exit(0);
}