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

FILE   *gfopen(char *file_name, char *mode);

int main(int argc, char **argv)
{
   int    c;
   FILE   *fp, *tmp_fp;

   if (argc != 2) {
      fprintf(stderr, "\n%s%s%s\n\n%s\n\n",
	 "Usage:  ", argv[0], "  file_name",
	 "The file will be doubled and some letters capitalized.");
      exit(1);
   }
   fp = gfopen(argv[1], "r+");
   tmp_fp = tmpfile();
   while ((c = getc(fp)) != EOF)
      putc(toupper(c), tmp_fp);
   rewind(tmp_fp);
   fprintf(fp, "---\n");
   while ((c = getc(tmp_fp)) != EOF)
      putc(c, fp);
   return 0;
}

FILE *gfopen(char *file_name, char *mode)
{
   FILE   *fp;

   if ((fp = fopen(file_name, mode)) == NULL) {
      fprintf(stderr, "Cannot open %s - bye!\n", file_name);
      exit(1);
   }
   return fp;
}