Object Storage Service:List buckets (C SDK)

Usage 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 list buckets, you must have the oss:ListBuckets permission. For more information, see Attach a custom policy to a RAM user.

Sample code

The following sample code provides an example on how to list buckets in all regions within the current Alibaba Cloud account:

#include "oss_api.h"
#include "aos_http_io.h"
/* Set yourEndpoint to the endpoint of the region where the bucket is located. For example, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com for the China (Hangzhou) region. */
const char *endpoint = "yourEndpoint";
/* Set yourRegion to the region where the bucket is located. For example, set the region to cn-hangzhou for the China (Hangzhou) region. */
const char *region = "yourRegion";
void init_options(oss_request_options_t *options)
{
    options->config = oss_config_create(options->pool);
    /* Initialize the aos_string_t type with a char* string. */
    aos_str_set(&options->config->endpoint, endpoint);
    /* Obtain access credentials from environment variables. Before you run this sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set. */
    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"));
    // 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 used for memory management. It 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. This parameter includes 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 parameters. */
    aos_table_t *resp_headers = NULL; 
    aos_status_t *resp_status = NULL; 
    oss_list_buckets_params_t *params = NULL;
    oss_list_bucket_content_t *content = NULL;
    int size = 0;
    params = oss_create_list_buckets_params(pool);
    /* List buckets. */
    resp_status = oss_list_bucket(oss_client_options, params, &resp_headers);
    if (aos_status_is_ok(resp_status)) {
        printf("list buckets succeeded\n");
    } else {
        printf("list buckets failed\n");
    }
    /* Print the buckets. */
    aos_list_for_each_entry(oss_list_bucket_content_t, content, &params->bucket_list, node) {
        printf("BucketName: %s\n", content->name.data);
        ++size;
    }
    /* 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 for listing buckets, see ListBuckets (GetService).