Function percentDecode

src/redis-cli.c:197–224

#define decodeHex(h, l) ((decodeHexChar(h) << 4) + decodeHexChar(l))

static sds percentDecode(const char *pe, size_t len) {
    const char *end = pe + len;
    sds ret = sdsempty();
    const char *curr = pe;

    while (curr < end) {
        if (*curr == '%') {
            if ((end - curr) < 2) {
                fprintf(stderr, "Incomplete URI encoding\n");
                exit(1);
            }

            char h = tolower(*(++curr));
            char l = tolower(*(++curr));
            if (!isHexChar(h) || !isHexChar(l)) {
                fprintf(stderr, "Illegal character in URI encoding\n");
                exit(1);
            }
            char c = decodeHex(h, l);
            ret = sdscatlen(ret, &c, 1);
            curr++;
        } else {
            ret = sdscatlen(ret, curr++, 1);
        }
    }

    return ret;
}

/* Parse a URI and extract the server connection information.
 * URI scheme is based on the the provisional specification[1] excluding support