#include<stdio.h>

void main()
{
  FILE *f_in;
  char c;
  int index,resultat;

  f_in = fopen("place.txt","w+");

   printf("position avant fseek %d\n",ftell(f_in));
   resultat=fseek(f_in,19,0);
   printf("position après fseek %d\n",ftell(f_in));

   fputc('Z',f_in);
  
 fclose(f_in);

}