}

    int ch;
    char *tmp = malloc(512);
    size_t s = 512;
    size_t r = 0;
    while ((ch = fgetc(h)) != EOF) {
        if (r == s) {
        if (r+1 == s) {
            // grow the array (by golden ratio)
            char *ttmp = realloc(tmp, (13*s) / 8);
            if (ttmp) {
                tmp = ttmp;
                s = (13*s) / 8;
            } else {
                free(tmp);
                return 0;
            }
        }
        tmp[r++] = ch;
    }
    fclose(h);
    tmp[r] = 0;
    *dst = tmp;

    return r;
}

unsigned distance(unsigned a, unsigned b) {
    if (a > b) return a - b;