#include <stdio.h>
#include <stdlib.h>

struct Data {
  char *str1;
  char *str2;
  char *str3;
};

void
callback(void *data_) {
  struct Data *data = (struct Data *)data_;

  printf("%s %s %s\n", data->str1, data->str2, data->str3);
}


int
main(int argc, char **argv)
{
  struct Data data;

  data.str1 = "string1";
  data.str2 = "string2";
  data.str3 = "string3";

  callback(&data);
  /* g_signal_connect(button, "clicked", G_CALLBACK(callback), &data); */

  exit(EXIT_SUCCESS);
}