Function esp_idf_sys::nvs_entry_find_in_handle
source · pub unsafe extern "C" fn nvs_entry_find_in_handle(
handle: nvs_handle_t,
type_: nvs_type_t,
output_iterator: *mut nvs_iterator_t,
) -> esp_err_t
Expand description
@brief Create an iterator to enumerate NVS entries based on a handle and type
\code{c} // Example of listing all the key-value pairs of any type under specified handle (which defines a partition and namespace) nvs_iterator_t it = NULL; esp_err_t res = nvs_entry_find_in_handle(<nvs_handle>, NVS_TYPE_ANY, &it); while(res == ESP_OK) { nvs_entry_info_t info; nvs_entry_info(it, &info); // Can omit error check if parameters are guaranteed to be non-NULL printf(“key ‘%s’, type ‘%d’ \n”, info.key, info.type); res = nvs_entry_next(&it); } nvs_release_iterator(it); \endcode
@param[in] handle Handle obtained from nvs_open function.
@param[in] type One of nvs_type_t values.
@param[out] output_iterator Set to a valid iterator to enumerate all the entries found. Set to NULL if no entry for specified criteria was found. If any other error except ESP_ERR_INVALID_ARG occurs, \c output_iterator is NULL, too. If ESP_ERR_INVALID_ARG occurs, \c output_iterator is not changed. If a valid iterator is obtained through this function, it has to be released using \c nvs_release_iterator when not used any more, unless ESP_ERR_INVALID_ARG is returned.
@return - ESP_OK if no internal error or programming error occurred. - ESP_ERR_NVS_NOT_FOUND if no element of specified criteria has been found. - ESP_ERR_NO_MEM if memory has been exhausted during allocation of internal structures. - ESP_ERR_NVS_INVALID_HANDLE if unknown handle was specified. - ESP_ERR_INVALID_ARG if output_iterator parameter is NULL. Note: don’t release \c output_iterator in case ESP_ERR_INVALID_ARG has been returned