Obtaining Object Properties

If you have any questions during development, post them on the Issues page of GitHub.

You can call get_object_metadata to obtain properties of an object, including the length, MIME type, and customized metadata.

Parameter Description

Field	Type	Mandatory or Optional	Description
option	The context of the bucket. For details, see Configuring option.	Mandatory	Bucket parameter
object_info	obs_object_info *	Mandatory	Object name and version number. For non-multi-version objects, set version to 0.
encryption_params	server_side_encryption_params *	Optional	Parameters related to server-side encryption
handler	obs_get_object_handler *	Mandatory	Callback function
callback_data	void *	Optional	Callback data

Sample Code

Sample code:

static void test_get_object_metadata()
{
    obs_status ret_status = OBS_STATUS_BUTT;
    // Create and initialize option.
    obs_options option;
    init_obs_options(&option);
    option.bucket_options.host_name = "<your-endpoint>";
    option.bucket_options.bucket_name = "<Your bucketname>";

    // Hard-coded or plaintext AK/SK are risky. For security purposes, encrypt your AK/SK and store them in the configuration file or environment variables. In this example, the AK/SK are stored in environment variables for identity authentication. Before running this example, configure environment variables ACCESS_KEY_ID and SECRET_ACCESS_KEY.
    // Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/intl/en-us/usermanual-ca/ca_01_0003.html.
    option.bucket_options.access_key = getenv("ACCESS_KEY_ID");
    option.bucket_options.secret_access_key = getenv("SECRET_ACCESS_KEY");
    // Object information
    obs_object_info object_info;
    memset(&object_info,0,sizeof(obs_object_info));
    object_info.key = "<object key>";
    object_info.version_id = "<object version ID>";
    // Set response callback function.
    obs_response_handler response_handler =
    { 
        &response_properties_callback, &response_complete_callback
    };
    // Obtain object properties.
    get_object_metadata(&option,&object_info,0, &response_handler,&ret_status);
    if (OBS_STATUS_OK == ret_status) {
        printf("get object metadata successfully. \n");
    }
    else
    {
        printf("get object metadata failed.\n", obs_get_status_name(ret_status));
    }
}