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List Objects V2

s3_list_objects_v2 R Documentation

Returns some or all (up to 1,000) of the objects in a bucket with each request

Description

Returns some or all (up to 1,000) of the objects in a bucket with each request. You can use the request parameters as selection criteria to return a subset of the objects in a bucket. A ⁠200 OK⁠ response can contain valid or invalid XML. Make sure to design your application to parse the contents of the response and handle it appropriately. For more information about listing objects, see Listing object keys programmatically in the Amazon S3 User Guide. To get a list of your buckets, see list_buckets.

Directory buckets - For directory buckets, you must make requests for this API operation to the Zonal endpoint. These endpoints support virtual-hosted-style requests in the format ⁠https://bucket_name.s3express-az_id.region.amazonaws.com/key-name ⁠. Path-style requests are not supported. For more information, see Regional and Zonal endpoints in the Amazon S3 User Guide.

Permissions

  • General purpose bucket permissions - To use this operation, you must have READ access to the bucket. You must have permission to perform the s3:ListBucket action. The bucket owner has this permission by default and can grant this permission to others. For more information about permissions, see Permissions Related to Bucket Subresource Operations and Managing Access Permissions to Your Amazon S3 Resources in the Amazon S3 User Guide.

  • Directory bucket permissions - To grant access to this API operation on a directory bucket, we recommend that you use the create_session API operation for session-based authorization. Specifically, you grant the s3express:CreateSession permission to the directory bucket in a bucket policy or an IAM identity-based policy. Then, you make the create_session API call on the bucket to obtain a session token. With the session token in your request header, you can make API requests to this operation. After the session token expires, you make another create_session API call to generate a new session token for use. Amazon Web Services CLI or SDKs create session and refresh the session token automatically to avoid service interruptions when a session expires. For more information about authorization, see create_session .

Sorting order of returned objects

  • General purpose bucket - For general purpose buckets, list_objects_v2 returns objects in lexicographical order based on their key names.

  • Directory bucket - For directory buckets, list_objects_v2 does not return objects in lexicographical order.

HTTP Host header syntax

Directory buckets - The HTTP Host header syntax is Bucket_name.s3express-az_id.region.amazonaws.com.

This section describes the latest revision of this action. We recommend that you use this revised API operation for application development. For backward compatibility, Amazon S3 continues to support the prior version of this API operation, list_objects.

The following operations are related to list_objects_v2:

  • get_object

  • put_object

  • create_bucket

Usage

s3_list_objects_v2(Bucket, Delimiter, EncodingType, MaxKeys, Prefix,
  ContinuationToken, FetchOwner, StartAfter, RequestPayer,
  ExpectedBucketOwner, OptionalObjectAttributes)

Arguments

Bucket

[required] Directory buckets - When you use this operation with a directory bucket, you must use virtual-hosted-style requests in the format Bucket_name.s3express-az_id.region.amazonaws.com. Path-style requests are not supported. Directory bucket names must be unique in the chosen Availability Zone. Bucket names must follow the format bucket_base_name--az-id--x-s3 (for example, DOC-EXAMPLE-BUCKET--usw2-az2--x-s3). For information about bucket naming restrictions, see Directory bucket naming rules in the Amazon S3 User Guide.

Access points - When you use this action with an access point, you must provide the alias of the access point in place of the bucket name or specify the access point ARN. When using the access point ARN, you must direct requests to the access point hostname. The access point hostname takes the form AccessPointName-AccountId.s3-accesspoint.Region.amazonaws.com. When using this action with an access point through the Amazon Web Services SDKs, you provide the access point ARN in place of the bucket name. For more information about access point ARNs, see Using access points in the Amazon S3 User Guide.

Access points and Object Lambda access points are not supported by directory buckets.

S3 on Outposts - When you use this action with Amazon S3 on Outposts, you must direct requests to the S3 on Outposts hostname. The S3 on Outposts hostname takes the form AccessPointName-AccountId.outpostID.s3-outposts.Region.amazonaws.com. When you use this action with S3 on Outposts through the Amazon Web Services SDKs, you provide the Outposts access point ARN in place of the bucket name. For more information about S3 on Outposts ARNs, see What is S3 on Outposts? in the Amazon S3 User Guide.

Delimiter

A delimiter is a character that you use to group keys.

  • Directory buckets - For directory buckets, / is the only supported delimiter.

  • Directory buckets - When you query list_objects_v2 with a delimiter during in-progress multipart uploads, the CommonPrefixes response parameter contains the prefixes that are associated with the in-progress multipart uploads. For more information about multipart uploads, see Multipart Upload Overview in the Amazon S3 User Guide.

EncodingType

Encoding type used by Amazon S3 to encode object keys in the response.

MaxKeys

Sets the maximum number of keys returned in the response. By default, the action returns up to 1,000 key names. The response might contain fewer keys but will never contain more.

Prefix

Limits the response to keys that begin with the specified prefix.

Directory buckets - For directory buckets, only prefixes that end in a delimiter (/) are supported.

ContinuationToken

ContinuationToken indicates to Amazon S3 that the list is being continued on this bucket with a token. ContinuationToken is obfuscated and is not a real key. You can use this ContinuationToken for pagination of the list results.

FetchOwner

The owner field is not present in list_objects_v2 by default. If you want to return the owner field with each key in the result, then set the FetchOwner field to true.

Directory buckets - For directory buckets, the bucket owner is returned as the object owner for all objects.

StartAfter

StartAfter is where you want Amazon S3 to start listing from. Amazon S3 starts listing after this specified key. StartAfter can be any key in the bucket.

This functionality is not supported for directory buckets.

RequestPayer

Confirms that the requester knows that she or he will be charged for the list objects request in V2 style. Bucket owners need not specify this parameter in their requests.

This functionality is not supported for directory buckets.

ExpectedBucketOwner

The account ID of the expected bucket owner. If the account ID that you provide does not match the actual owner of the bucket, the request fails with the HTTP status code ⁠403 Forbidden⁠ (access denied).

OptionalObjectAttributes

Specifies the optional fields that you want returned in the response. Fields that you do not specify are not returned.

This functionality is not supported for directory buckets.

Value

A list with the following syntax: 

list(
  IsTruncated = TRUE|FALSE,
  Contents = list(
    list(
      Key = "string",
      LastModified = as.POSIXct(
        "2015-01-01"
      ),
      ETag = "string",
      ChecksumAlgorithm = list(
        "CRC32"|"CRC32C"|"SHA1"|"SHA256"
      ),
      Size = 123,
      StorageClass = "STANDARD"|"REDUCED_REDUNDANCY"|"GLACIER"|"STANDARD_IA"|"ONEZONE_IA"|"INTELLIGENT_TIERING"|"DEEP_ARCHIVE"|"OUTPOSTS"|"GLACIER_IR"|"SNOW"|"EXPRESS_ONEZONE",
      Owner = list(
        DisplayName = "string",
        ID = "string"
      ),
      RestoreStatus = list(
        IsRestoreInProgress = TRUE|FALSE,
        RestoreExpiryDate = as.POSIXct(
          "2015-01-01"
        )
      )
    )
  ),
  Name = "string",
  Prefix = "string",
  Delimiter = "string",
  MaxKeys = 123,
  CommonPrefixes = list(
    list(
      Prefix = "string"
    )
  ),
  EncodingType = "url",
  KeyCount = 123,
  ContinuationToken = "string",
  NextContinuationToken = "string",
  StartAfter = "string",
  RequestCharged = "requester"
)

Request syntax

svc$list_objects_v2(
  Bucket = "string",
  Delimiter = "string",
  EncodingType = "url",
  MaxKeys = 123,
  Prefix = "string",
  ContinuationToken = "string",
  FetchOwner = TRUE|FALSE,
  StartAfter = "string",
  RequestPayer = "requester",
  ExpectedBucketOwner = "string",
  OptionalObjectAttributes = list(
    "RestoreStatus"
  )
)

Examples

## Not run: 
# The following example retrieves object list. The request specifies max
# keys to limit response to include only 2 object keys.
svc$list_objects_v2(
  Bucket = "DOC-EXAMPLE-BUCKET",
  MaxKeys = "2"
)

## End(Not run)