Get Object
s3_get_object | R Documentation |
Retrieves an object from Amazon S3¶
Description¶
Retrieves an object from Amazon S3.
In the get_object
request, specify the full key name for the object.
General purpose buckets - Both the virtual-hosted-style requests and
the path-style requests are supported. For a virtual hosted-style
request example, if you have the object
photos/2006/February/sample.jpg
, specify the object key name as
/photos/2006/February/sample.jpg
. For a path-style request example, if
you have the object photos/2006/February/sample.jpg
in the bucket
named examplebucket
, specify the object key name as
/examplebucket/photos/2006/February/sample.jpg
. For more information
about request types, see HTTP Host Header Bucket
Specification
in the Amazon S3 User Guide.
Directory buckets - Only virtual-hosted-style requests are
supported. For a virtual hosted-style request example, if you have the
object photos/2006/February/sample.jpg
in the bucket named
examplebucket--use1-az5--x-s3
, specify the object key name as
/photos/2006/February/sample.jpg
. Also, when you make requests to this
API operation, your requests are sent 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 - You must have the required permissions in a policy. To use
get_object
, you must have theREAD
access to the object (or version). If you grantREAD
access to the anonymous user, theget_object
operation returns the object without using an authorization header. For more information, see Specifying permissions in a policy in the Amazon S3 User Guide.If you include a
versionId
in your request header, you must have thes3:GetObjectVersion
permission to access a specific version of an object. Thes3:GetObject
permission is not required in this scenario.If you request the current version of an object without a specific
versionId
in the request header, only thes3:GetObject
permission is required. Thes3:GetObjectVersion
permission is not required in this scenario.If the object that you request doesn’t exist, the error that Amazon S3 returns depends on whether you also have the
s3:ListBucket
permission.-
If you have the
s3:ListBucket
permission on the bucket, Amazon S3 returns an HTTP status code404 Not Found
error. -
If you don’t have the
s3:ListBucket
permission, Amazon S3 returns an HTTP status code403 Access Denied
error.
-
-
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 thes3express:CreateSession
permission to the directory bucket in a bucket policy or an IAM identity-based policy. Then, you make thecreate_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 anothercreate_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, seecreate_session
.
Storage classes¶
If the object you are retrieving is stored in the S3 Glacier Flexible
Retrieval storage class, the S3 Glacier Deep Archive storage class, the
S3 Intelligent-Tiering Archive Access tier, or the S3
Intelligent-Tiering Deep Archive Access tier, before you can retrieve
the object you must first restore a copy using restore_object
.
Otherwise, this operation returns an InvalidObjectState
error. For
information about restoring archived objects, see Restoring Archived
Objects
in the Amazon S3 User Guide.
Directory buckets - For directory buckets, only the S3 Express One
Zone storage class is supported to store newly created objects.
Unsupported storage class values won't write a destination object and
will respond with the HTTP status code 400 Bad Request
.
Encryption¶
Encryption request headers, like x-amz-server-side-encryption
, should
not be sent for the get_object
requests, if your object uses
server-side encryption with Amazon S3 managed encryption keys (SSE-S3),
server-side encryption with Key Management Service (KMS) keys (SSE-KMS),
or dual-layer server-side encryption with Amazon Web Services KMS keys
(DSSE-KMS). If you include the header in your get_object
requests for
the object that uses these types of keys, you’ll get an HTTP
400 Bad Request
error.
Overriding response header values through the request¶
There are times when you want to override certain response header values
of a get_object
response. For example, you might override the
Content-Disposition
response header value through your get_object
request.
You can override values for a set of response headers. These modified
response header values are included only in a successful response, that
is, when the HTTP status code 200 OK
is returned. The headers you can
override using the following query parameters in the request are a
subset of the headers that Amazon S3 accepts when you create an object.
The response headers that you can override for the get_object
response
are Cache-Control
, Content-Disposition
, Content-Encoding
,
Content-Language
, Content-Type
, and Expires
.
To override values for a set of response headers in the get_object
response, you can use the following query parameters in the request.
-
response-cache-control
-
response-content-disposition
-
response-content-encoding
-
response-content-language
-
response-content-type
-
response-expires
When you use these parameters, you must sign the request by using either an Authorization header or a presigned URL. These parameters cannot be used with an unsigned (anonymous) request.
HTTP Host header syntax¶
Directory buckets - The HTTP Host header syntax is
Bucket_name.s3express-az_id.region.amazonaws.com
.
The following operations are related to get_object
:
-
list_buckets
-
get_object_acl
Usage¶
s3_get_object(Bucket, IfMatch, IfModifiedSince, IfNoneMatch,
IfUnmodifiedSince, Key, Range, ResponseCacheControl,
ResponseContentDisposition, ResponseContentEncoding,
ResponseContentLanguage, ResponseContentType, ResponseExpires,
VersionId, SSECustomerAlgorithm, SSECustomerKey, SSECustomerKeyMD5,
RequestPayer, PartNumber, ExpectedBucketOwner, ChecksumMode)
Arguments¶
Bucket
[required] The bucket name containing the object.
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 formatbucket_base_name--az-id--x-s3
(for example,DOC-EXAMPLE-BUCKET--usw2-az1--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.
Object Lambda access points - When you use this action with an Object Lambda access point, you must direct requests to the Object Lambda access point hostname. The Object Lambda access point hostname takes the form AccessPointName-AccountId.s3-object-lambda.Region.amazonaws.com.
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.IfMatch
Return the object only if its entity tag (ETag) is the same as the one specified in this header; otherwise, return a
412 Precondition Failed
error.If both of the
If-Match
andIf-Unmodified-Since
headers are present in the request as follows:If-Match
condition evaluates totrue
, and;If-Unmodified-Since
condition evaluates tofalse
; then, S3 returns200 OK
and the data requested.For more information about conditional requests, see RFC 7232.
IfModifiedSince
Return the object only if it has been modified since the specified time; otherwise, return a
304 Not Modified
error.If both of the
If-None-Match
andIf-Modified-Since
headers are present in the request as follows:If-None-Match
condition evaluates tofalse
, and;If-Modified-Since
condition evaluates totrue
; then, S3 returns304 Not Modified
status code.For more information about conditional requests, see RFC 7232.
IfNoneMatch
Return the object only if its entity tag (ETag) is different from the one specified in this header; otherwise, return a
304 Not Modified
error.If both of the
If-None-Match
andIf-Modified-Since
headers are present in the request as follows:If-None-Match
condition evaluates tofalse
, and;If-Modified-Since
condition evaluates totrue
; then, S3 returns304 Not Modified
HTTP status code.For more information about conditional requests, see RFC 7232.
IfUnmodifiedSince
Return the object only if it has not been modified since the specified time; otherwise, return a
412 Precondition Failed
error.If both of the
If-Match
andIf-Unmodified-Since
headers are present in the request as follows:If-Match
condition evaluates totrue
, and;If-Unmodified-Since
condition evaluates tofalse
; then, S3 returns200 OK
and the data requested.For more information about conditional requests, see RFC 7232.
Key
[required] Key of the object to get.
Range
Downloads the specified byte range of an object. For more information about the HTTP Range header, see https://www.rfc-editor.org/rfc/rfc9110.html#name-range.
Amazon S3 doesn't support retrieving multiple ranges of data per
GET
request.ResponseCacheControl
Sets the
Cache-Control
header of the response.ResponseContentDisposition
Sets the
Content-Disposition
header of the response.ResponseContentEncoding
Sets the
Content-Encoding
header of the response.ResponseContentLanguage
Sets the
Content-Language
header of the response.ResponseContentType
Sets the
Content-Type
header of the response.ResponseExpires
Sets the
Expires
header of the response.VersionId
Version ID used to reference a specific version of the object.
By default, the
get_object
operation returns the current version of an object. To return a different version, use theversionId
subresource.If you include a
versionId
in your request header, you must have thes3:GetObjectVersion
permission to access a specific version of an object. Thes3:GetObject
permission is not required in this scenario.If you request the current version of an object without a specific
versionId
in the request header, only thes3:GetObject
permission is required. Thes3:GetObjectVersion
permission is not required in this scenario.Directory buckets - S3 Versioning isn't enabled and supported for directory buckets. For this API operation, only the
null
value of the version ID is supported by directory buckets. You can only specifynull
to theversionId
query parameter in the request.
For more information about versioning, see
put_bucket_versioning
.SSECustomerAlgorithm
Specifies the algorithm to use when decrypting the object (for example,
AES256
).If you encrypt an object by using server-side encryption with customer-provided encryption keys (SSE-C) when you store the object in Amazon S3, then when you GET the object, you must use the following headers:
x-amz-server-side-encryption-customer-algorithm
x-amz-server-side-encryption-customer-key
x-amz-server-side-encryption-customer-key-MD5
For more information about SSE-C, see Server-Side Encryption (Using Customer-Provided Encryption Keys) in the Amazon S3 User Guide.
This functionality is not supported for directory buckets.
SSECustomerKey
Specifies the customer-provided encryption key that you originally provided for Amazon S3 to encrypt the data before storing it. This value is used to decrypt the object when recovering it and must match the one used when storing the data. The key must be appropriate for use with the algorithm specified in the
x-amz-server-side-encryption-customer-algorithm
header.If you encrypt an object by using server-side encryption with customer-provided encryption keys (SSE-C) when you store the object in Amazon S3, then when you GET the object, you must use the following headers:
x-amz-server-side-encryption-customer-algorithm
x-amz-server-side-encryption-customer-key
x-amz-server-side-encryption-customer-key-MD5
For more information about SSE-C, see Server-Side Encryption (Using Customer-Provided Encryption Keys) in the Amazon S3 User Guide.
This functionality is not supported for directory buckets.
SSECustomerKeyMD5
Specifies the 128-bit MD5 digest of the customer-provided encryption key according to RFC 1321. Amazon S3 uses this header for a message integrity check to ensure that the encryption key was transmitted without error.
If you encrypt an object by using server-side encryption with customer-provided encryption keys (SSE-C) when you store the object in Amazon S3, then when you GET the object, you must use the following headers:
x-amz-server-side-encryption-customer-algorithm
x-amz-server-side-encryption-customer-key
x-amz-server-side-encryption-customer-key-MD5
For more information about SSE-C, see Server-Side Encryption (Using Customer-Provided Encryption Keys) in the Amazon S3 User Guide.
This functionality is not supported for directory buckets.
RequestPayer
PartNumber
Part number of the object being read. This is a positive integer between 1 and 10,000. Effectively performs a 'ranged' GET request for the part specified. Useful for downloading just a part of an object.
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).ChecksumMode
To retrieve the checksum, this mode must be enabled.
In addition, if you enable checksum mode and the object is uploaded with a checksum and encrypted with an Key Management Service (KMS) key, you must have permission to use the
kms:Decrypt
action to retrieve the checksum.
Value¶
A list with the following syntax:
list(
Body = raw,
DeleteMarker = TRUE|FALSE,
AcceptRanges = "string",
Expiration = "string",
Restore = "string",
LastModified = as.POSIXct(
"2015-01-01"
),
ContentLength = 123,
ETag = "string",
ChecksumCRC32 = "string",
ChecksumCRC32C = "string",
ChecksumSHA1 = "string",
ChecksumSHA256 = "string",
MissingMeta = 123,
VersionId = "string",
CacheControl = "string",
ContentDisposition = "string",
ContentEncoding = "string",
ContentLanguage = "string",
ContentRange = "string",
ContentType = "string",
Expires = as.POSIXct(
"2015-01-01"
),
ExpiresString = "string",
WebsiteRedirectLocation = "string",
ServerSideEncryption = "AES256"|"aws:kms"|"aws:kms:dsse",
Metadata = list(
"string"
),
SSECustomerAlgorithm = "string",
SSECustomerKeyMD5 = "string",
SSEKMSKeyId = "string",
BucketKeyEnabled = TRUE|FALSE,
StorageClass = "STANDARD"|"REDUCED_REDUNDANCY"|"STANDARD_IA"|"ONEZONE_IA"|"INTELLIGENT_TIERING"|"GLACIER"|"DEEP_ARCHIVE"|"OUTPOSTS"|"GLACIER_IR"|"SNOW"|"EXPRESS_ONEZONE",
RequestCharged = "requester",
ReplicationStatus = "COMPLETE"|"PENDING"|"FAILED"|"REPLICA"|"COMPLETED",
PartsCount = 123,
TagCount = 123,
ObjectLockMode = "GOVERNANCE"|"COMPLIANCE",
ObjectLockRetainUntilDate = as.POSIXct(
"2015-01-01"
),
ObjectLockLegalHoldStatus = "ON"|"OFF"
)
Request syntax¶
svc$get_object(
Bucket = "string",
IfMatch = "string",
IfModifiedSince = as.POSIXct(
"2015-01-01"
),
IfNoneMatch = "string",
IfUnmodifiedSince = as.POSIXct(
"2015-01-01"
),
Key = "string",
Range = "string",
ResponseCacheControl = "string",
ResponseContentDisposition = "string",
ResponseContentEncoding = "string",
ResponseContentLanguage = "string",
ResponseContentType = "string",
ResponseExpires = as.POSIXct(
"2015-01-01"
),
VersionId = "string",
SSECustomerAlgorithm = "string",
SSECustomerKey = raw,
SSECustomerKeyMD5 = "string",
RequestPayer = "requester",
PartNumber = 123,
ExpectedBucketOwner = "string",
ChecksumMode = "ENABLED"
)
Examples¶
## Not run:
# The following example retrieves an object for an S3 bucket.
svc$get_object(
Bucket = "examplebucket",
Key = "HappyFace.jpg"
)
# The following example retrieves an object for an S3 bucket. The request
# specifies the range header to retrieve a specific byte range.
svc$get_object(
Bucket = "examplebucket",
Key = "SampleFile.txt",
Range = "bytes=0-9"
)
## End(Not run)