#include <stdio.h>

struct str {
  int f1;
  double f2;
  char f3;
  char *f4;
};

int main(void){
  FILE *ofp;
  struct str rec= {5, 13.71, 'c', "xyz"};
  ofp = fopen("data", "w");

  fwrite(&rec, sizeof(struct str), 1, ofp);  
  fclose(ofp);
  return 0;
}