Listing Objects in a Bucket

Functions

This operation lists objects in a bucket. To use this operation, you must have the permission to read the bucket.

If you specify only the bucket name in the request, OBS returns descriptions for some or all of the objects (a maximum of 1,000 objects) in the bucket. If you also specify one or more parameters among prefix, marker, max-keys, and delimiter in the request, OBS returns a list of objects based on the semantics specified in Table 1.

You can also add the versions parameter to the request to list multiple versions of an object in a bucket.

Request Syntax

    
         GET / HTTP/1.1 
 
Host: bucketname.obs.region.example.com
Date: date
Authorization: authorization

Request Syntax (for multi-version objects)

    
         GET /?versions HTTP/1.1  
Host: bucketname.obs.region.example.com
Date: date
Authorization: authorization

Request Parameters

This request uses parameters to list some objects in a bucket. Table 1 describes the parameters.

**Table 1** Request parameters
Parameter	Description	Mandatory
prefix	Lists objects that begin with the specified prefix. Type: string	No
marker	Specifies a marker when listing objects in a bucket. With a marker configured, objects after this marker will be returned in alphabetical order. This field is used only for listing objects. Type: string	No
max-keys	Specifies the maximum number (from 1 to 1000) of objects returned (in alphabetical order) in the response. If the value is beyond this range, only 1,000 objects are returned by default. Type: integer	No
delimiter	Separator used to group object names. If a prefix is specified, objects with the same string from the prefix to the first delimiter are grouped into one CommonPrefixes. If no prefix is specified, objects with the same string from the first character to the first delimiter are grouped into one CommonPrefixes. For example, there are three objects (abcd, abcde, and bbcde) in a bucket. If delimiter is set to d and prefix is set to a, objects abcd and abcde are grouped into a CommonPrefixes with abcd as the prefix. If only delimiter is set to d, objects abcd and abcde are grouped into a CommonPrefixes with abcd as the prefix, and bbcde is grouped separately into another CommonPrefixes with bbcd as the prefix. Type: string	No
key-marker	Position to start with when objects are listed. This field is used only for listing versioned objects. Type: string Valid value: value of NextKeyMarker in the response body of the last request	No
version-id-marker	This parameter applies only when versioning is enabled. Specifies the version ID to start with when objects in a bucket are listed. Objects are listed in alphabetical order (a maximum of 1,000 objects are displayed at a time). This parameter is used together with the key-marker in the request. If the value of version-id-marker is not a version ID specified by key-marker, version-id-marker is invalid. Type: string Valid value: object version ID, that is, the value of NextVersionIdMarker in the response body of the last request	No

Request Headers

This request uses common request headers. For details, see Table 3.

Request Elements

This request contains no elements.

Response Syntax

    
         HTTP/1.1 status_code
Date: date
Content-Type: application/xml 
Content-Length: length
<Response Body>

Response Headers

The response to the request uses common headers. For details, see Table 1.

Response Elements

This response lists objects in XML format. Specific elements are described in Table 2.

**Table 2** Response elements
Element	Description
ListBucketResult	A list of objects in a bucket Type: XML
Contents	Object metadata Type: XML Parent: ListBucketResult
CommonPrefixes	Group information. If you specify a delimiter in the request, the response contains group information in CommonPrefixes. Type: XML Parent: ListBucketResult
Delimiter	The delimiter parameter specified in a request Type: string Parent: ListBucketResult
ETag	Base64-encoded 128-bit MD5 digest of an object. ETag is the unique identifier of the object content. It can be used to determine whether the object content is changed. For example, if the ETag value is A when an object is uploaded, but this value has changed to B when the object is downloaded, it indicates that the object content has been changed. The ETag value is a hash of the object. The ETag reflects changes to the object content, rather than the object metadata. An uploaded object or copied object has a unique ETag after being encrypted using MD5. (If the object is encrypted on the server side, the ETag value is not the MD5 digest of the object, but the unique identifier calculated through server-side encryption.) Type: string Parent: ListBucketResult.Contents
Type	Object type. This parameter is returned when the object type is not Normal. Type: string Parent: ListBucketResult.Contents
ID	Domain ID of the object owner Type: string Parent: ListBucketResult.Contents.Owner
IsTruncated	Determines whether the returned list of objects is truncated. The value true indicates that the list was truncated and false indicates that the list was not truncated. Type: boolean Parent: ListBucketResult
Key	Object name Type: string Parent: ListBucketResult.Contents
LastModified	Time (UTC) when an object was last modified Type: date Parent: ListBucketResult.Contents
Marker	Marker for the position from which objects in a bucket will be listed Type: string Parent: ListBucketResult
NextMarker	A marker for the last returned object in the list. NextMarker is returned when not all the objects are listed. You can set the Marker value to list the remaining objects in follow-up requests. Type: string Parent: ListBucketResult
MaxKeys	Maximum number of objects returned Type: string Parent: ListBucketResult
Name	Name of the requested bucket Type: string Parent: ListBucketResult
Owner	User information, including the domain ID and name of the object owner Type: XML Parent: ListBucketResult.Contents
DisplayName	Name of the object owner Type: string Parent: ListBucketResult.Contents.Owner
Prefix	Prefix of an object name. Only objects whose names have this prefix are listed. Type: string Parent: ListBucketResult
Size	Object size in bytes Type: string Parent: ListBucketResult.Contents

**Table 3** Elements in the response message for listing multi-version objects.
Element	Description
ListVersionsResult	Container for the list of objects (including objects with multiple version IDs) Type: container
Name	Bucket name Type: string Parent: ListVersionsResult
Prefix	Prefix of an object name. Only objects whose names have this prefix are listed. Type: string Parent: ListVersionsResult
KeyMarker	Marker for the object key from which objects will be listed Type: string Parent: ListVersionsResult
VersionIdMarker	Object version ID to start with when objects are listed Type: string Parent: ListVersionsResult
NextKeyMarker	Key marker for the last returned object in the list. NextKeyMarker is returned when not all the objects are listed. You can set the KeyMarker value to list the remaining objects in follow-up requests. Type: string Parent: ListVersionsResult
NextVersionIdMarker	Version ID marker for the last returned object in the list. NextVersionIdMarker is returned when not all the objects are listed. You can set the VersionIdMarker value to list the remaining objects in follow-up requests. Type: string Parent: ListVersionsResult
MaxKeys	Maximum number of objects returned Type: string Parent: ListVersionsResult
IsTruncated	Indicates whether the returned list of objects is truncated. The value true indicates that the list was truncated and false indicates that the list was not truncated. Type: boolean Parent: ListVersionsResult
Version	Container of version information Type: container Parent: ListVersionsResult
DeleteMarker	Container for objects with delete markers Type: container Parent: ListVersionsResult
Key	Object name Type: string Parent: ListVersionsResult.Version \| ListVersionsResult.DeleteMarker
VersionId	Object version ID Type: string Parent: ListVersionsResult.Version \| ListVersionsResult.DeleteMarker
IsLatest	Whether the object is the latest version. If the parameter value is true, the object is the latest version. Type: boolean Parent: ListVersionsResult.Version \| ListVersionsResult.DeleteMarker
LastModified	Time (UTC) when an object was last modified Type: date Parent: ListVersionsResult.Version \| ListVersionsResult.DeleteMarker
ETag	Base64-encoded 128-bit MD5 digest of an object. ETag is the unique identifier of the object content. It can be used to determine whether the object content is changed. The actual ETag is the hash value of the object. For example, if the ETag value is A when an object is uploaded, but this value has changed to B when the object is downloaded, it indicates that the object content has been changed. The ETag reflects changes to the object content, rather than the object metadata. An uploaded object or copied object has a unique ETag after being encrypted using MD5. Type: string Parent: ListVersionsResult.Version
Type	Object type. This parameter is returned when the object type is not Normal. Type: string Parent: ListVersionsResult.Version
Size	Object size in bytes Type: string Parent: ListVersionsResult.Version
Owner	User information, including the domain ID and name of the object owner Type: container Parent: ListVersionsResult.Version \| ListVersionsResult.DeleteMarker
ID	Domain ID of the object owner Type: string Parent: ListVersionsResult.Version.Owner \| ListVersionsResult.DeleteMarker.Owner
DisplayName	Name of the object owner Type: string Parent: ListVersionsResult.Version.Owner \| ListVersionsResult.DeleteMarker.Owner
CommonPrefixes	Group information. If you specify a delimiter in the request, the response contains group information in CommonPrefixes. Type: container Parent: ListVersionsResult
Prefix	Indicates a different prefix in the group information in CommonPrefixes. Type: string Parent: ListVersionsResult.CommonPrefixes

Error Responses

No special error responses are returned. For details about error responses, see Table 2.

Sample Request: Listing All Objects

    
         GET / HTTP/1.1
User-Agent: curl/7.29.0
Host: examplebucket.obs.region.example.com
Accept: */*
Date: WED, 01 Jul 2015 02:28:25 GMT
Authorization: OBS H4IPJX0TQTHTHEBQQCEC:KiyoYze4pmRNPYfmlXBfRTVxt8c=

Sample Response: Listing All Objects

    
     
       
       
         HTTP/1.1 200 OK
Server: OBS
x-obs-request-id: BF260000016435D34E379ABD93320CB9
x-obs-id-2: 32AAAQAAEAABAAAQAAEAABAAAQAAEAABCSXiN7GPL/yXM6OSBaYCUV1zcY5OelWp
Content-Type: application/xml
Date: WED, 01 Jul 2015 02:23:30 GMT
Content-Length: 586

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ListBucketResult xmlns="http://obs.example.com/doc/2015-06-30/">
  <Name>examplebucket</Name>
  <Prefix/>
  <Marker/>
  <MaxKeys>1000</MaxKeys>
  <IsTruncated>false</IsTruncated>
  <Contents>
    <Key>object001</Key>
    <LastModified>2015-07-01T00:32:16.482Z</LastModified>
    <ETag>"2fa3bcaaec668adc5da177e67a122d7c"</ETag>
    <Size>12041</Size>
    <Owner>
      <ID>b4bf1b36d9ca43d984fbcb9491b6fce9</ID>
      <DisplayName>ObjectOwnerName</DisplayName>
    </Owner>
  </Contents>
</ListBucketResult>

        

      

    
   

Sample Request: Listing Some Objects

Assume that you have a bucket examplebucket that contains objects newfile, obj001, obj002, and obs001. If you want to list only object obj002, the request message is as follows:

GET /?marker=obj001&prefix=obj HTTP/1.1
User-Agent: curl/7.29.0
Host: examplebucket.obs.region.example.com
Accept: */*
Date: WED, 01 Jul 2015 02:28:25 GMT
Authorization: OBS H4IPJX0TQTHTHEBQQCEC:KiyoYze4pmRNPYfmlXBfRTVxt8c=

Sample Response: Listing Some Objects

    
     
       
       
         HTTP/1.1 200 OK
Server: OBS
x-obs-request-id: BF260000016435D758FBA857E0801874
x-obs-id-2: 32AAAQAAEAABAAAQAAEAABAAAQAAEAABCShn/xAyk/xHBX6qgGSB36WXrbco0X80
Content-Type: application/xml
Date: WED, 01 Jul 2015 02:29:48 GMT
Content-Length: 707

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ListBucketResult xmlns="http://obs.example.com/doc/2015-06-30/">
<Name>examplebucket</Name>
<Prefix>obj</Prefix>
<Marker>obj001</Marker>
<MaxKeys>1000</MaxKeys>
<IsTruncated>false</IsTruncated>
  <Contents>
    <Key>obj002</Key>
    <LastModified>2015-07-01T02:11:19.775Z</LastModified>
    <ETag>"a72e382246ac83e86bd203389849e71d"</ETag>
    <Size>9</Size>
    <Owner>
      <ID>b4bf1b36d9ca43d984fbcb9491b6fce9</ID>
      <DisplayName>ObjectOwnerName</DisplayName>
    </Owner>
  </Contents>
</ListBucketResult>

        

      

    
   

Sample Request: Listing Object Versions

    
         GET /?versions HTTP/1.1
User-Agent: curl/7.29.0
Host: examplebucket.obs.region.example.com
Accept: */*
Date: WED, 01 Jul 2015 02:29:45 GMT
Authorization: OBS H4IPJX0TQTHTHEBQQCEC:iZeDESIMxBK2YODk7vIeVpyO8DI=

Sample Response: Listing Object Versions

    
     
       
       
         HTTP/1.1 200 OK
Server: OBS
x-obs-request-id: BF260000016435D758FBA857E0801874
x-obs-id-2: 32AAAQAAEAABAAAQAAEAABAAAQAAEAABCShn/xAyk/xHBX6qgGSB36WXrbco0X80
Content-Type: application/xml
Date: WED, 01 Jul 2015 02:29:48 GMT
Content-Length: 707

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ListVersionsResult xmlns="http://obs.example.com/doc/2015-06-30/">
 <Name>bucket02</Name>
  <Prefix/>
  <KeyMarker/>
  <VersionIdMarker/>
  <MaxKeys>1000</MaxKeys>
  <IsTruncated>false</IsTruncated>
  <Version>
    <Key>object001</Key>
    <VersionId>00011000000000013F16000001643A22E476FFFF9046024ECA3655445346485a</VersionId>
    <IsLatest>true</IsLatest>
    <LastModified>2015-07-01T00:32:16.482Z</LastModified>
    <ETag>"2fa3bcaaec668adc5da177e67a122d7c"</ETag>
    <Size>12041</Size>
    <Owner>
      <ID>b4bf1b36d9ca43d984fbcb9491b6fce9</ID>
      <DisplayName>ObjectOwnerName</DisplayName>
    </Owner>
  </Version>
</ListVersionsResult>

        

      

    
   