Tcl

(using AWS Signature Version 2) Streaming Download to File

See more Amazon S3 (new) Examples

The main purpose of this example is to demonstrate how to use the older Signature Version 2 authentication w/ S3. It uses V2 authentication to download a file. Tcl

load ./chilkat.dll

set success 0

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

set rest [new_CkRest]

# Connect to the Amazon AWS REST server.
set bTls 1
set port 443
set bAutoReconnect 1
# The file is located in the bucket named "chilkat100", which becomes part of the domain:
set success [CkRest_Connect $rest "chilkat100.s3.amazonaws.com" $port $bTls $bAutoReconnect]

# Provide AWS credentials for the REST call.
set authAws [new_CkAuthAws]

CkAuthAws_put_AccessKey $authAws "AWS_ACCESS_KEY"
CkAuthAws_put_SecretKey $authAws "AWS_SECRET_KEY"
CkAuthAws_put_ServiceName $authAws "s3"

# For AWS Signature Version 2, the following two properties need to be set:
CkAuthAws_put_SignatureVersion $authAws 2
# See http://docs.aws.amazon.com/AmazonS3/latest/dev/RESTAuthentication.html#ConstructingTheCanonicalizedResourceElement
CkAuthAws_put_CanonicalizedResourceV2 $authAws "/chilkat100/starfish.jpg"

set success [CkRest_SetAuthAws $rest $authAws]

# Send the request to download the JPG.
set success [CkRest_SendReqNoBody $rest "GET" "/starfish.jpg"]
if {$success != 1} then {
    puts [CkRest_lastErrorText $rest]
    delete_CkRest $rest
    delete_CkAuthAws $authAws
    exit
}

# Read the response header.
set responseStatusCode [CkRest_ReadResponseHeader $rest]
if {$responseStatusCode < 0} then {
    puts [CkRest_lastErrorText $rest]
    delete_CkRest $rest
    delete_CkAuthAws $authAws
    exit
}

puts "Response status code = $responseStatusCode"

# We expect a 200 response status if the JPG data is coming.
# Otherwise, we'll get a string response body with an error message(or no response body).
if {$responseStatusCode == 200} then {

    set bodyStream [new_CkStream]

    # The stream's sink will be a file.
    CkStream_put_SinkFile $bodyStream "qa_output/starfish.jpg"

    # Read the response body to the stream.  Given that we've
    # set the stream's sink to a file, it will stream directly
    # to the file.
    set success [CkRest_ReadRespBodyStream $rest $bodyStream 1]
    if {$success != 1} then {
        puts [CkRest_lastErrorText $rest]
        delete_CkRest $rest
        delete_CkAuthAws $authAws
        delete_CkStream $bodyStream
        exit
    }

    puts "Successfully received the JPG file."

} else {
    set errResponse [CkRest_readRespBodyString $rest]
    if {[CkRest_get_LastMethodSuccess $rest] != 1} then {
        puts [CkRest_lastErrorText $rest]
    }     else {
        puts "$errResponse"
    }

}


delete_CkRest $rest
delete_CkAuthAws $authAws
delete_CkStream $bodyStream