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Object Storage Service:Gerencie links simbólicos usando o OSS SDK for C

Última atualização: Jul 03, 2026

Links simbólicos funcionam como atalhos de arquivo no Windows e permitem acessar rapidamente objetos associados no Object Storage Service (OSS).

Observações de uso

  • Este tópico utiliza o endpoint público da região China (Hangzhou). Para acessar o OSS a partir de outros serviços da Alibaba Cloud na mesma região, use um endpoint interno. Para obter mais informações sobre regiões e endpoints do OSS, consulte Regiões e endpoints.

  • O exemplo abaixo demonstra a criação de uma instância OSSClient com um endpoint do OSS. Para configurações alternativas, como uso de domínio personalizado ou autenticação com credenciais do Security Token Service (STS), consulte Inicialização (C SDK).

  • Criar um link simbólico exige a permissão oss:PutObject. Consultar um link simbólico exige a permissão oss:GetObject. Para obter mais informações, consulte Conceder uma política personalizada.

Crie um link simbólico

O código de exemplo a seguir mostra como criar um link simbólico:

#include "oss_api.h"
#include "aos_http_io.h"
/* Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
const char *endpoint = "yourEndpoint";
/* Specify the name of the bucket. Example: examplebucket. */
const char *bucket_name = "examplebucket";
/* Specify the full path of the object. Do not include the bucket name in the full path. Example: exampledir/exampleobject.txt. */
const char *object_name = "exampledir/exampleobject.txt";
/* Specify the full path of the symbolic link that you want to create. */
const char *link_object_name = "yourLinkObjectName";
/* Specify the region in which the bucket is located. For example, if the bucket is located 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);
    /* Use a char* string to initialize data of the aos_string_t type. */
    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"));
    // Specify two additional parameters.
    aos_str_set(&options->config->region, region);
    options->config->signature_version = 4;
    /* Specify whether to use CNAME. The value 0 indicates that CNAME is not used. */
    options->config->is_cname = 0;
    /* Specify 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 in main() to initialize global resources, such as network resources and memory resources. */
    if (aos_http_io_initialize(NULL, 0) != AOSE_OK) {
        exit(1);
    }
    /* Create a memory pool to manage memory. aos_pool_t is equivalent to apr_pool_t. The code used to create a memory pool is included in the APR library. */
    aos_pool_t *pool;
    /* Create a memory pool. The value of the second parameter is NULL. This value indicates that the pool does not inherit other memory pools. */
    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 the memory resources in the memory pool to the options. */
    oss_client_options = oss_request_options_create(pool);
    /* Initialize oss_client_options. */
    init_options(oss_client_options);
    /* Initialize the parameters. */
    aos_string_t bucket;
    aos_string_t object;
    aos_string_t sym_object;
    aos_table_t *resp_headers = NULL; 
    aos_status_t *resp_status = NULL; 
    aos_str_set(&bucket, bucket_name);
    aos_str_set(&object, object_name);
    aos_str_set(&sym_object, link_object_name);
    resp_status = oss_put_symlink(oss_client_options, &bucket, &sym_object, &object, &resp_headers);
    if (aos_status_is_ok(resp_status)) {
        printf("put symlink succeeded\n");
    } else {
        printf("put symlink failed\n");      
    }
    /* Release the memory pool. This operation releases the memory resources allocated for the request. */
    aos_pool_destroy(pool);
    /* Release the allocated global resources. */
    aos_http_io_deinitialize();
    return 0;
}

Consultar um link simbólico

Consultar um link simbólico exige permissões de leitura sobre ele. O código de exemplo a seguir mostra como consultar um link simbólico e obter o nome do objeto ao qual ele aponta:

#include "oss_api.h"
#include "aos_http_io.h"
/* Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
const char *endpoint = "yourEndpoint";
/* Specify the name of the bucket. Example: examplebucket. */
const char *bucket_name = "examplebucket";
/* Specify the full path of the symbolic link that you want to query. */
const char *link_object_name = "yourLinkObjectName";
/* Specify the region in which the bucket is located. For example, if the bucket is located 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);
    /* Use a char* string to initialize data of the aos_string_t type. */
    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"));;
    // Specify two additional parameters.
    aos_str_set(&options->config->region, region);
    options->config->signature_version = 4;
    /* Specify whether to use CNAME. The value 0 indicates that CNAME is not used. */
    options->config->is_cname = 0;
    /* Specify 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 in main() to initialize global resources, such as network resources and memory resources. */
    if (aos_http_io_initialize(NULL, 0) != AOSE_OK) {
        exit(1);
    }
    /* Create a memory pool to manage memory. aos_pool_t is equivalent to apr_pool_t. The code used to create a memory pool is included in the APR library. */
    aos_pool_t *pool;
    /* Create a memory pool. The value of the second parameter is NULL. This value indicates that the pool does not inherit other memory pools. */
    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 the memory resources in the memory pool to the options. */
    oss_client_options = oss_request_options_create(pool);
    /* Initialize oss_client_options. */
    init_options(oss_client_options);
    /* Initialize the parameters. */
    aos_string_t bucket;
    aos_string_t link_object;
    aos_table_t *resp_headers = NULL; 
    aos_status_t *resp_status = NULL; 
    char *target_object_name = NULL;
    aos_str_set(&bucket, bucket_name);
    aos_str_set(&link_object, link_object_name);
    resp_status = oss_get_symlink(oss_client_options, &bucket, &link_object, &resp_headers);
    if (aos_status_is_ok(resp_status)) {
        printf("get symlink succeeded\n");
        target_object_name = (char*)(apr_table_get(resp_headers, OSS_CANNONICALIZED_HEADER_SYMLINK));
        printf("target_object_name: %s \n", target_object_name);
    } else {
        printf("get symlink failed\n");      
    }
    /* Release the memory pool. This operation releases the memory resources allocated for the request. */
    aos_pool_destroy(pool);
    /* Release the allocated global resources. */
    aos_http_io_deinitialize();
    return 0;
}

Referências

  • Para obter mais informações sobre a operação de API usada para criar um link simbólico, consulte PutSymlink.

  • Para obter mais informações sobre a operação de API usada para consultar um link simbólico, consulte GetSymlink.