List root directory using ListBlobsByHierarchy using azure sdk

Question

I'm trying to list root directory in container. Storage account : Data Lake Storage with hierarchical namespace ON Interface used: BlobContainerClient

Folder structure
ROOT DIR:
dir1->blob2
blob1

---

    auto listBlobOptions = Azure::Storage::Blobs::ListBlobsOptions();
    auto blobPages = containerClient.ListBlobsByHierarchy("/", listBlobOptions);

    std::cout << "Blob Reading" << std::endl;
    for (const auto& blobItem : blobPages.Blobs)
    {
        std::cout << "******************" << std::endl;
        std::cout << blobItem.Name << std::endl;
    }

If I use "/" as delimiter, the directories that were created from Azure portal are not included. If I remove it, that all the blobs are being listed. With "/" I would get only blob1, but without I would get

• dir1,
• blob1
• dir1/blob2

Reason for Storage account and interface missmatch is because we are using private endpoints with subresource type BLOB, and DFS is forbidden in such case. If I would use ListBlobs or not use "/" that would read all the blobs in the storage accounts, which is kind of problematic since there could be huge amount of it.

Answer 1

List root directory using ListBlobsByHierarchy using azure sdk

You can use the below code that will list the root folder with files using Azure C++ SDK.

Code:

#include <iostream>
#include <azure/storage/blobs.hpp>

using namespace Azure::Storage::Blobs;

int main() {
    // Define your storage account connection string and container name
    std::string connectionString = "xxxxxx";
    std::string containerName = "xxx";

    // Create a BlobContainerClient
    BlobContainerClient containerClient = BlobContainerClient::CreateFromConnectionString(connectionString, containerName);
    ListBlobsOptions listBlobOptions;

    // Use "/" as the delimiter to list only the root contents
    auto blobPages = containerClient.ListBlobsByHierarchy("/", listBlobOptions);

    std::cout << "Listing contents of root directory in container: " << containerName << std::endl;

    // List directories (BlobPrefixes)
    for (const auto& prefix : blobPages.BlobPrefixes) {
        std::cout << "[Directory] " << prefix << std::endl;  // FIX: Use prefix as a string
    }

    // List files (Blobs)
    for (const auto& blobItem : blobPages.Blobs) {
        std::cout << "[File] " << blobItem.Name << std::endl;  // BlobItem is an object with .Name
    }

    return 0;
}

The above code lists files and directories at the root level using ListBlobsByHierarchy("/"), and prints them. Directories are retrieved from BlobPrefixes, while files are listed from Blobs.

Output:

Listing contents of root directory in container: sample
[Directory] folder1/
[Directory] folder2/
[File] 001.csv
[File] 002.csv
[File] 003.csv
[File] demo.csv