/*
 * XOR Files
 *
 * Simple program to get the xor of two files.
 *
 * Copyright (c) Thomas Habets 2002
 *
 * It has bugs, I know. I just don't care right now.
 */
#include <stdio.h>

int main(int argc, char **argv)
{
        FILE *f1,*f2,*f3;
        char ch,ch2;

        if (argc < 4) {
                printf("Usage: %s <infile1> <infile2> <outfile>\n");
                return 1;
        }

        f1 = fopen(argv[1],"rb");
        f2 = fopen(argv[2],"rb");
        f3 = fopen(argv[3],"wb");

        if (!(f1 && f2 && f3)) {
                printf("Can't open files, or something\n");
                return 1;
        }

        for (;;) {
                int i;
                i = fread(&ch,1,1,f1);
                i = i + fread(&ch2,1,1,f2);
                if (feof(f1)) {
                        break;
                }
                if (i != 2) {
                        printf("Something bad happened\n");
                }
                ch ^= ch2;
                fwrite(&ch, 1, 1, f3);
        }
        return 0;
}