#include <stdio.h>
#include <ctype.h>
int main() {
   int c;
   FILE *infile, *outfile;
   infile=fopen("infile.txt", "r");
   if (infile==NULL) {
      printf("Kan file infile.txt niet openen!");
   }
   else {
      outfile=fopen("outfile.txt", "w");
      if (outfile==NULL) {
         printf("Kan file outfile.txt niet openen!");
      }
      else {
         c=getc(infile);
         while (c!=EOF) {
            c=putc(toupper(c), outfile);
            if (c==EOF) {
               printf("Fout tijdens schrijven in outfile.txt!");
            }
            else {
               c=getc(infile);
            }
         }
         fclose(outfile);
      }
      fclose(infile);
   }
   getchar();
   return 0;
}