MOBI_RET mobi_search_links_kf7(MOBIResult *result, const unsigned char *data_start, const unsigned char *data_end) {
    if (!result) {
        debug_print("Result structure is null%s", "\n");
        return MOBI_PARAM_ERR;
    }
    result->start = result->end = NULL;
    *(result->value) = '\0';
    if (!data_start || !data_end) {
        debug_print("Data is null%s", "\n");
        return MOBI_PARAM_ERR;
    }
    const char *needle1 = "filepos=";
    const char *needle2 = "recindex=";
    const size_t needle1_length = strlen(needle1);
    const size_t needle2_length = strlen(needle2);
    const size_t needle_length = max(needle1_length,needle2_length);
    if (data_start + needle_length > data_end) {
        return MOBI_SUCCESS;
    }
    unsigned char *data = (unsigned char *) data_start;
    const unsigned char tag_open = '<';
    const unsigned char tag_close = '>';
    unsigned char last_border = tag_open;
    while (data <= data_end) {
        if (*data == tag_open || *data == tag_close) {
            last_border = *data;
        }
        if (data + needle_length <= data_end &&
            (memcmp(data, needle1, needle1_length) == 0 ||
             memcmp(data, needle2, needle2_length) == 0)) {
                /* found match */
                if (last_border != tag_open) {
                    /* opening char not found, not an attribute */
                    data += needle_length;
                    continue;
                }
                /* go to attribute  beginning */
                while (data >= data_start && !isspace(*data) && *data != tag_open) {
                    data--;
                }
                result->start = ++data;
                /* now go forward */
                int i = 0;
                while (data <= data_end && !isspace(*data) && *data != tag_close && i < MOBI_ATTRVALUE_MAXSIZE) {
                    result->value[i++] = (char) *data++;
                }
                /* self closing tag '/>' */
                if (data <= data_end && *(data - 1) == '/' && *data == '>') {
                    --data; --i;
                }
                result->end = data;
                result->value[i] = '\0';
                return MOBI_SUCCESS;
            }
        data++;
    }
    return MOBI_SUCCESS;
}
MOBI_RET mobi_search_links_kf7(MOBIResult *result, const unsigned char *data_start, const unsigned char *data_end) {
    if (!result) {
        debug_print("Result structure is null%s", "\n");
        return MOBI_PARAM_ERR;
    }
    result->start = result->end = NULL;
    *(result->value) = '\0';
    if (!data_start || !data_end) {
        debug_print("Data is null%s", "\n");
        return MOBI_PARAM_ERR;
    }
    const char *needle1 = "filepos=";
    const char *needle2 = "recindex=";
    const size_t needle1_length = strlen(needle1);
    const size_t needle2_length = strlen(needle2);
    const size_t needle_length = max(needle1_length,needle2_length);
    if (data_start + needle_length > data_end) {
        return MOBI_SUCCESS;
    }
    unsigned char *data = (unsigned char *) data_start;
    const unsigned char tag_open = '<';
    const unsigned char tag_close = '>';
    unsigned char last_border = tag_open;
    while (data <= data_end) {
        if (*data == tag_open || *data == tag_close) {
            last_border = *data;
        }
        if (data + needle_length <= data_end &&
            (memcmp(data, needle1, needle1_length) == 0 ||
             memcmp(data, needle2, needle2_length) == 0)) {
                 
                if (last_border != tag_open) {
                     
                    data += needle_length;
                    continue;
                }
                 
                while (data >= data_start && !isspace(*data) && *data != tag_open) {
                    data--;
                }
                result->start = ++data;
                 
                int i = 0;
                while (data <= data_end && !isspace(*data) && *data != tag_close && i < MOBI_ATTRVALUE_MAXSIZE) {
                    result->value[i++] = (char) *data++;
                }
                 
                if (data <= data_end && *(data - 1) == '/' && *data == '>') {
                    --data; --i;
                }
                result->end = data;
                result->value[i] = '\0';
                return MOBI_SUCCESS;
            }
        data++;
    }
    return MOBI_SUCCESS;
}