Help Center/ Object Storage Service/ API Reference/ APIs/ Operations on Buckets/ Listing Objects in a Bucket
Updated on 2024-05-31 GMT+08:00
View PDF

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

1
2
3
4
 
GET / HTTP/1.1 
Host: bucketname.obs.region.myhuaweicloud.eu 
Date: date
Authorization: authorization

Request Syntax (for multi-version objects)

1
2
3
4
 
GET /?versions HTTP/1.1  
Host: bucketname.obs.region.myhuaweicloud.eu
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.

For a parallel file system, if this parameter is not specified, all the content in the directory is recursively listed by default, and subdirectories are also listed. In big data scenarios, parallel file systems usually have deep directory levels and each directory has a large number of files. In such case, you are advised to configure [delimiter=/] to list the content in the current directory, but not list subdirectories, thereby improving the listing efficiency.

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

1
2
3
4
5
6
 
HTTP/1.1 status_code
Date: date
x-obs-bucket-location: region
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

The 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 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

StorageClass

Storage class of an object

Type: string

Value options: STANDARD, WARM, COLD

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

StorageClass

Storage class of an object

Type: string

Value options: STANDARD, WARM, COLD

Parent: ListVersionsResult.Version

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

1
2
3
4
5
6
 
GET / HTTP/1.1
User-Agent: curl/7.29.0
Host: examplebucket.obs.region.myhuaweicloud.eu
Accept: */*
Date: WED, 01 Jul 2015 02:28:25 GMT
Authorization: OBS H4IPJX0TQTHTHEBQQCEC:KiyoYze4pmRNPYfmlXBfRTVxt8c=

Sample Response: Listing All Objects

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
 
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.eu-west-101.myhuaweicloud.eu/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>
    <StorageClass>STANDARD</StorageClass>
  </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.myhuaweicloud.eu
Accept: */*
Date: WED, 01 Jul 2015 02:28:25 GMT
Authorization: OBS H4IPJX0TQTHTHEBQQCEC:KiyoYze4pmRNPYfmlXBfRTVxt8c=

Sample Response: Listing Some Objects

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
 
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.eu-west-101.myhuaweicloud.eu/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>
    <StorageClass>STANDARD</StorageClass>
  </Contents>
</ListBucketResult>

Sample Request: Listing Some Objects

Assume that bucket examplebucket contains three objects: abcd, abcde, and bbcde. Set the prefix and the delimiter to a and d respectively to define a CommonPrefixes of abcd. The specific request format is as follows:

GET /?prefix=a&delimiter=d HTTP/1.1
Authorization: OBS H4IPJX0TQTHTHEBQQCEC:iqSPeUBl66PwXDApxjRKk6hlcN4=
User-Agent: curl/7.29.0
Host: examplebucket.obs.region.myhuaweicloud.com
Date: WED, 01 Jul 2015 02:37:22 GMT
Content-Type: application/xml;charset=UTF-8

Sample Response: Listing Some Objects

x-obs-id-2: 32AAAQAAEAABAAAQAAEAABAAAQAAEAABCSsokG49mPTa0cU5U/4gjFYLmYPgfYs/
x-obs-request-id: 0000018A2A563686D2C61543407D6ABF
Server: OBS
x-obs-bucket-location: region
Content-Length: 333
Date: WED, 01 Jul 2015 02:37:22 GMT
Content-Type: application/xml
 
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ListBucketResult  xmlns="http://obs.myhwclouds.com/doc/2015-06-30/">
    <Name>examplebucket</Name>
    <Prefix>a</Prefix>
    <Marker>
    </Marker>
    <MaxKeys>1000</MaxKeys>
    <Delimiter>d</Delimiter>
    <IsTruncated>false</IsTruncated>
    <CommonPrefixes>
        <Prefix>abcd</Prefix>
    </CommonPrefixes>
</ListBucketResult>

Sample Request: Listing Object Versions

1
2
3
4
5
6
 
GET /?versions HTTP/1.1
User-Agent: curl/7.29.0
Host: examplebucket.obs.region.myhuaweicloud.eu
Accept: */*
Date: WED, 01 Jul 2015 02:29:45 GMT
Authorization: OBS H4IPJX0TQTHTHEBQQCEC:iZeDESIMxBK2YODk7vIeVpyO8DI=

Sample Response: Listing Object Versions

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
 
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.eu-west-101.myhuaweicloud.eu/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>
    <StorageClass>STANDARD</StorageClass>
  </Version>
</ListVersionsResult>

Sample Request: Listing Objects (Including Archive Objects) in a Bucket

GET / HTTP/1.1
Authorization: OBS H4IPJX0TQTHTHEBQQCEC:iqSPeUBl66PwXDApxjRKk6hlcN4=
User-Agent: curl/7.29.0
Host: examplebucket.obs.region.myhuaweicloud.com
Date: WED, 01 Jul 2015 02:37:22 GMT
Content-Type: application/xml;charset=UTF-8

Sample Response: Listing Objects (Including Archive Objects) in a Bucket

HTTP/1.1 200 OK
x-obs-id-2: 32AAAQAAEAABAAAQAAEAABAAAQAAEAABCSWqA48YKdA2aExVAgcpwubHQO5wd9ww
x-obs-request-id: 0000018A2A5FE372D308213442F9065F
Server: OBS
x-obs-bucket-location: region
Content-Length: 497
Date: WED, 01 Jul 2015 02:37:22 GMT
Content-Type: application/xml
 
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ListBucketResult  xmlns="http://obs.myhwclouds.com/doc/2015-06-30/">
    <Name>examplebucket</Name>
    <Prefix>
    </Prefix>
    <Marker>
    </Marker>
    <MaxKeys>1000</MaxKeys>
    <IsTruncated>false</IsTruncated>
    <Contents>
        <Key>abcd.txt</Key>
        <LastModified>2014-08-25T01:47:00.838Z</LastModified>
        <ETag>"d41d8cd98f00b204e9800998ecf8427e"</ETag>
        <Size>0</Size>
        <Owner>
            <ID>d029cb567d464a93pdl9v800575ee4cf</ID>
        </Owner>
        <StorageClass>COLD</StorageClass>
    </Contents>
</ListBucketResult>
Parent topic: Operations on Buckets