c言語で排他的論理和を使って超簡単に暗号化、複合化

bar.txt

SLHFNLM

encrypt.c

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

int main(int argc, char *argv[])
{
    FILE *infile, *outfile;
    int ch;
    int key = 3;

    infile = fopen(argv[1], "rb");
    outfile = fopen(argv[2], "wb");
    while ((ch = fgetc(infile)) != EOF) {
        putc(ch ^ key, outfile);
        printf("%d %d\n", ch, ch ^ key);
    }

    return 0;
}

foo.txt

POKEMON

./a.out foo.txt bar.txt