Help Center/ Object Storage Service/ SDK Reference/ C/ Bucket APIs (SDK for C)/ Event Notifications (SDK for C)/ Setting Event Notifications (SDK for C)
Updated on 2026-08-03 GMT+08:00
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Setting Event Notifications (SDK for C)

You can call set_notification_configuration to set event notifications for a bucket.

Method

void set_notification_configuration(const obs_options *options, 
    obs_smn_notification_configuration* notification_conf, obs_response_handler *handler,
    void *callback_data);

Parameter Description

Parameter

Type

Mandatory (Yes/No)

Description

options

The context of the bucket request. For details, see Configuring option (SDK for C).

Mandatory

Bucket parameter

notification_conf

obs_smn_notification_configuration*

Mandatory

Indicates the container for configuring the event notification.

handler

obs_response_handler *

Mandatory

Callback function

callback_data

void *

Optional

Callback data

The following table describes the parameter obs_smn_notification_configuration.

Parameter

Type

Mandatory (Yes/No)

Description

topic_conf

obs_smn_topic_configuration*

Container for configuring the event notification topic

topic_conf_num

unsigned int

Number of topic_conf

The following table describes the parameter obs_smn_topic_configuration.

Parameter

Type

Mandatory (Yes/No)

Description

topic

char *

URN of the event notification topic. After detecting a specific event in the bucket, OBS sends a message to the topic.

id

char *

Unique ID of each event notification. If no ID is specified, the system automatically assigns one.

filter_rule

obs_smn_filter_rule *

Container that defines key-value pairs of filter rules

filter_rule_num

unsigned int

Number of filter_rule

event

obs_smn_event_enum*

Type of events that need to be notified

event_num

unsigned int

Number of event types

Code Examples

static void test_set_notification_configuration()
{
    obs_options option; 
    obs_status  ret_status = OBS_STATUS_BUTT;
    obs_smn_notification_configuration notification_conf; 
    obs_smn_topic_configuration topic_conf;
    obs_smn_event_enum topic1_event[2];
    obs_smn_filter_rule filter_rule;
    // Set option.
    init_obs_options(&option);
    option->bucket_options.hostName = "<your-endpoint>";
    option->bucket_options.bucketName = "<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");
    // Set callback function.
    obs_response_handler response_handler =
    { 
        NULL, &response_complete_callback
    };
    // Set the unique ID of the notification configuration.
    topic_conf.id    = "Id001"; 
    // Set the URN of the event notification topic.
    topic_conf.topic = "urn:smn:southchina:ea79855fbe0642718cb4df1551c3cb4e:test_cwx298983";
    // Set the event types for notification.
    topic_conf.event = topic1_event; 
    topic_conf.event[0] = SMN_EVENT_OBJECT_CREATED_ALL; 
    topic_conf.event[1] = SMN_EVENT_OBJECT_CREATED_POST; 
    topic_conf.event_num = 2; 
    // Set filtering rules for notification objects.
    filter_rule.name = OBS_SMN_FILTER_PREFIX; 
    filter_rule.value = "aaa"; 
    topic_conf.filter_rule = &filter_rule; 
    topic_conf.filter_rule_num = 1; 
      
    memset(&notification_conf, 0, sizeof(obs_smn_notification_configuration)); 
    notification_conf.topic_conf = &topic_conf; 
    notification_conf.topic_conf_num = 1;
    set_notification_configuration(&option, &notification_conf, &response_handler, &ret_status);
    if (OBS_STATUS_OK == ret_status) {
        printf("set_notification_configuration success.\n");
    }
    else {
        printf("set_notification_configuration failed(%s).\n",
                    obs_get_status_name(ret_status));
    }
}