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

int main(void) {
    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;
}