(Perl) Streaming Download Large File to the Local Filesystem

Downloads a large file in a streaming fashion to the local filesystem.

Chilkat Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

# Azure File Service Example: Downloads a large file to the local filesystem using a Chilkat stream.
# See:  https://docs.microsoft.com/en-us/rest/api/storageservices/get-file

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

$rest = chilkat::CkRest->new();

# Connect to the Azure Storage Blob Service
$bTls = 1;
$port = 443;
$bAutoReconnect = 1;
# In this example, the storage account name is "chilkat".
$success = $rest->Connect("chilkat.file.core.windows.net",$port,$bTls,$bAutoReconnect);
if ($success != 1) {
    print $rest->lastErrorText() . "\r\n";
    exit;
}

# Provide Azure Cloud credentials for the REST calls.
$azAuth = chilkat::CkAuthAzureStorage->new();
$azAuth->put_AccessKey("AZURE_ACCESS_KEY");
# The account name used here should match the 1st part of the domain passed in the call to Connect (above).
$azAuth->put_Account("chilkat");
$azAuth->put_Scheme("SharedKey");
$azAuth->put_Service("File");
# This causes the "x-ms-version: 2020-08-04" header to be automatically added.
$azAuth->put_XMsVersion("2020-08-04");
$success = $rest->SetAuthAzureStorage($azAuth);

# Note: The application does not need to explicitly set the following
# headers: x-ms-date, Authorization.  These headers
# are automatically set by Chilkat.

# When streaming a download to the local filesystem or directed elsewhere,
# the complete HTTP GET operation must be broken into parts.
# For example, an HTTP GET consists of sending the request, followed by reading the response header,
# and then finally the response body.  We'll want to read the response header, and then based
# on the information received (such as success or failure), either read the response body
# as an error message, or as the file data.

# Send the HTTP GET request to download the file.
# The share is named "pip".
$success = $rest->SendReqNoBody("GET","/pip/somethingBig.zip");
if ($success != 1) {
    print $rest->lastErrorText() . "\r\n";
    exit;
}

# Read the response header.
$responseStatusCode = $rest->ReadResponseHeader();
if ($responseStatusCode < 0) {
    print $rest->lastErrorText() . "\r\n";
    exit;
}

print "Response status code = " . $responseStatusCode . "\r\n";

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

    $bodyStream = chilkat::CkStream->new();

    # The stream's sink will be a file.
    $bodyStream->put_SinkFile("qa_output/somethingBig.zip");

    # 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.
    $success = $rest->ReadRespBodyStream($bodyStream,1);
    if ($success != 1) {
        print $rest->lastErrorText() . "\r\n";
        exit;
    }

    print "Successfully received the large file." . "\r\n";

}
else {
    $errResponse = $rest->readRespBodyString();
    if ($rest->get_LastMethodSuccess() != 1) {
        print $rest->lastErrorText() . "\r\n";
    }
    else {
        print $errResponse . "\r\n";
    }

}