Object Storage Service:Retrieve bucket information (C SDK)

Notes

• In this topic, the public endpoint of the China (Hangzhou) region is used. If you want to access OSS from other Alibaba Cloud services in the same region as OSS, use an internal endpoint. For more information about OSS regions and endpoints, see Regions and endpoints.

• In this topic, an OSSClient instance is created by using an OSS endpoint. If you want to create an OSSClient instance by using custom domain names or Security Token Service (STS), see Initialization.

• To query information about a bucket, you must have the oss:GetBucketInfo permission. For more information, see Attach a custom policy to a RAM user.

Sample code

The following code shows how to retrieve information about a bucket. This information includes the region and creation date of the bucket.

#include "oss_api.h"
#include "aos_http_io.h"
/* Set yourEndpoint to the endpoint of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
const char *endpoint = "yourEndpoint";

/* Specify the bucket name. For example, examplebucket. */
const char *bucket_name = "examplebucket";
/* Set yourRegion to the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the region to cn-hangzhou. */
const char *region = "yourRegion";
void init_options(oss_request_options_t *options)
{
    options->config = oss_config_create(options->pool);
    /* Initialize an aos_string_t object with a char* string. */
    aos_str_set(&options->config->endpoint, endpoint);
    /* Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. */    
    aos_str_set(&options->config->access_key_id, getenv("OSS_ACCESS_KEY_ID"));
    aos_str_set(&options->config->access_key_secret, getenv("OSS_ACCESS_KEY_SECRET"));
    // You must configure the following two parameters.
    aos_str_set(&options->config->region, region);
    options->config->signature_version = 4;
    /* Specify whether to use a CNAME to access OSS. A value of 0 indicates that a CNAME is not used. */
    options->config->is_cname = 0;
    /* Set network parameters, such as the timeout period. */
    options->ctl = aos_http_controller_create(options->pool, 0);
}
int main(int argc, char *argv[])
{
    /* Call the aos_http_io_initialize method at the program entry to initialize global resources such as the network and memory. */
    if (aos_http_io_initialize(NULL, 0) != AOSE_OK) {
        exit(1);
    }
    /* The memory pool (pool) is used for memory management and is equivalent to apr_pool_t. The implementation code is in the apr library. */
    aos_pool_t *pool;
    /* Create a memory pool. The second parameter is NULL, which indicates that the new memory pool does not inherit from another memory pool. */
    aos_pool_create(&pool, NULL);
    /* Create and initialize options. The options include global configuration information, such as endpoint, access_key_id, access_key_secret, is_cname, and curl. */
    oss_request_options_t *oss_client_options;
    /* Allocate memory to options in the memory pool. */
    oss_client_options = oss_request_options_create(pool);
    /* Initialize the client options oss_client_options. */
    init_options(oss_client_options);
    /* Initialize the parameters. */
    aos_string_t bucket;
    oss_bucket_info_t bucket_info;
    aos_table_t *resp_headers = NULL; 
    aos_status_t *resp_status = NULL; 
    /* Assign the char* data to the aos_string_t bucket. */
    aos_str_set(&bucket, bucket_name);
    /* Get information about the bucket. */
    resp_status = oss_get_bucket_info(oss_client_options, &bucket, &bucket_info, &resp_headers);
    if (aos_status_is_ok(resp_status)) {
        printf("get bucket info succeeded\n");
        printf("location: %s\n", bucket_info.location.data);
        printf("owner_id: %s\n", bucket_info.owner_id.data);
        printf("owner_name: %s\n", bucket_info.owner_name.data);
        printf("created_date: %s\n", bucket_info.created_date.data);
        printf("location: %s\n", bucket_info.location.data);
    } else {
        printf("get bucket info failed\n");
    }
    /* Release the memory pool. This releases the memory allocated to resources during the request. */
    aos_pool_destroy(pool);
    /* Release the previously allocated global resources. */
    aos_http_io_deinitialize();
    return 0;
}

References

For more information about the API operation that you can call to retrieve information about a bucket, see GetBucketInfo.