Getting list of names of Azure blob files in a container?

Question

I need to list names of Azure Blob file names. Currently I m able to list all files with URL but I just need list of names. I want to avoid parsing names. Can you please see my below code and guide:

CloudStorageAccount backupStorageAccount = CloudStorageAccount.Parse(blobConectionString);

var backupBlobClient = backupStorageAccount.CreateCloudBlobClient();
var backupContainer = backupBlobClient.GetContainerReference(container);

var list = backupContainer.ListBlobs();

Solution 1

If you're using Windows Azure Storage 4.3.0, try this code.

List<string> blobNames = list.OfType<CloudBlockBlob>().Select(b => b.Name).ToList();

Solution 2

Here is one more way to get this done:

CloudStorageAccount backupStorageAccount = CloudStorageAccount.Parse(blobConectionString);

var backupBlobClient = backupStorageAccount.CreateCloudBlobClient();
var backupContainer = backupBlobClient.GetContainerReference(container);

// useFlatBlobListing is true to ensure loading all files in
// virtual blob sub-folders as a plain list
var list = backupContainer.ListBlobs(useFlatBlobListing: true);
var listOfFileNames = new List<string>();

foreach (var blob in blobs) {
  var blobFileName = blob.Uri.Segments.Last();
  listOfFileNames.Add(blobFileName); 
}

return listOfFileNames;

Source: How to load list of Azure blob files recursively?

Solution 3

We can get some additional info like Size, Modified date and Name.

CloudStorageAccount backupStorageAccount = CloudStorageAccount.Parse(YOUR_CON_STRING);

var backupBlobClient = backupStorageAccount.CreateCloudBlobClient();
var backupContainer = backupBlobClient.GetContainerReference("CONTAINER");


var blobs = backupContainer.ListBlobs().OfType<CloudBlockBlob>().ToList();

foreach (var blob in blobs)
{
    string bName = blob.Name;
    long bSize = blob.Properties.Length;
    string bModifiedOn = blob.Properties.LastModified.ToString();        
}

Also you can download a specific file by Name.

 // Download file by Name
 string fileName = "Your_file_name";
 CloudBlockBlob blobFile = backupContainer.GetBlockBlobReference(fileName);
 blobFile.DownloadToFile(@"d:\"+ fileName, System.IO.FileMode.Create);

Solution 4

This works with WindowsAzure.Storage 9.3.3.

CloudBlobClient cloudBlobClient = storageAccount.CreateCloudBlobClient();
var cloudBlobContainer = cloudBlobClient.GetContainerReference(containerName);

var blobResultSegment = await cloudBlobContainer.ListBlobsSegmentedAsync(continuationToken);
var blobs = blobResultSegment.Results.Select(i => i.Uri.Segments.Last()).ToList();

Solution 5

Full answer with details.

        // Parse the connection string and return a reference to the storage account.
        CloudStorageAccount storageAccount = CloudStorageAccount.Parse(CloudConfigurationManager.GetSetting("AzureBlobConnectionString"));

        CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();

        // Retrieve reference to a previously created container.
        CloudBlobContainer container = blobClient.GetContainerReference("container_name");

        // Retrieve reference to a blob named "test.csv"
        CloudBlockBlob blockBlob = container.GetBlockBlobReference("BlobName.tex");

        //Gets List of Blobs
        var list = container.ListBlobs();
        List<string> blobNames = list.OfType<CloudBlockBlob>().Select(b => b.Name).ToList();

View more solutions

Comments

[Toubi]

thanks. Can it be done in Lambda/ Linq please ? Also just thinking this way it will call GetBlobProperties function for every blob file right ? Your advice please.

[Vignesh Raja]

We can get some additional info like Size, Modified date and more. Refer my answer at bottom.

[Rashik Hasnat]

I was facing problems regarding blobs with a space in its name. I was using the absolute uri and it wasn't serving my purpose. This answer solved the problem for me.

[mwilson]

What is continuationToken??

[mwilson]

What is list?

[mwilson]

What is list?

[Petra Stručić]

BlobContinuationToken continuationToken = null;

[NorwegianClassic]

list is found in askers post above.

[Raven]

@PetraStručić please provide some information, the comment you gave is not helpful!

[Petra Stručić]

@Peter please provide some information, the comment you gave is not helpful! On a more serious note, I think my comment is self-explanatory regarding the context of this whole thread, but can you ask a specific question? I would like to improve my comment if possible.

[Raven]

It's not clear what you mean by just commenting a line of code without writing what it's for... "The property is null if there are no more items to fetch" would have been motch more helpful and clear.

[Petra Stručić]

I focused on the scope of the original question, but sure. Since getting all blobs can be a heavy operation to do, it's good to granulate it in smaller chunks with maxResults parameter. ContinuationToken tracks the number of records left for listing. In this concrete code example of mine, its potential is not used. Here's an example of its use: do { var response = await ListBlobsSegmentedAsync(continuationToken); continuationToken = response.ContinuationToken; results.AddRange(response.Results); } while (continuationToken != null);

[Alex Gordon]

how would you iterate through all containers and all the blobs in those containers?

[Apollo]

I am glad I could help.

[Kavo]

I think list should be updated to blobs. i.e. var blobs = backupContainer.ListBlobs(useFlatBlobListing: true);

[NoChance]

Thanks for your answer. I am not setup on Azure yet, but I was wondering, if you know, how fast is listing say, 1000 blob names? I know it depends on several factors, but just a very general estimate would help me. Thanks.

[Jonathan Allen]

I don't remember, other than it was fast enough to not annoy me. I only have a few hundred objects, but I can't imagine you'll run into any problems with a thousand.

[Adam Kuzański]

Answer outdated - ListBlobs not available anymore - see this answer: stackoverflow.com/a/59474285/10133085