(Perl) Download File (Stream to Local Filesystem)

This example demonstrates how to download the content of a file from Google Drive. The file is streamed to the local filesystem.

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

use chilkat();

$success = 1;

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

# This example uses a previously obtained access token having permission for the 
# Google Drive scope.

$gAuth = chilkat::CkAuthGoogle->new();
$gAuth->put_AccessToken("GOOGLE_DRIVE_ACCESS_TOKEN");

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

# Connect using TLS.
# A single REST object, once connected, can be used for many Google Drive REST API calls.
# The auto-reconnect indicates that if the already-established HTTPS connection is closed,
# then it will be automatically re-established as needed.
$bAutoReconnect = 1;
$success = $rest->Connect("www.googleapis.com",443,1,$bAutoReconnect);

# Provide the authentication credentials (i.e. the access token)
$rest->SetAuthGoogle($gAuth);

# ------------------------------------------------------------------------------
# To download a file, we must know the file ID.
# In a previous example (see Build Local Metadata Cache
# we built a local cache to make it easy to lookup file IDs given a file path.
# Let's say we want to download "testFolder/abc/123/penguins.jpg".
# First we lookup the fileId in the cache.  With the fileId, we can download the file.
$gdCache = chilkat::CkCache->new();
$gdCache->put_Level(0);
$gdCache->AddRoot("C:/ckCache/googleDrive");

$fileId = $gdCache->fetchText("testFolder/abc/123/penguins.jpg");
if ($gdCache->get_LastMethodSuccess() != 1) {
    print "Filepath not found in cache." . "\r\n";
    exit;
}

# We need to send a GET request like this:
# GET https://www.googleapis.com/drive/v3/files/fileId?alt=media
# The fileId is part of the path.
$sbPath = chilkat::CkStringBuilder->new();
$sbPath->Append("/drive/v3/files/");
$sbPath->Append($fileId);
$rest->AddQueryParam("alt","media");

# Create a stream object with a SinkFile set to the path where the downloaded file will go.
$fileStream = chilkat::CkStream->new();
$fileStream->put_SinkFile("qa_output/penguins.jpg");
# Indicate that the response body should stream directly to fileStream,
# but only if the response status is 200.  
$rest->SetResponseBodyStream(200,1,$fileStream);

# Download the file, streaming the content to the SinkFile.
$jsonResponse = $rest->fullRequestNoBody("GET",$sbPath->getAsString());
if ($rest->get_LastMethodSuccess() != 1) {
    print $rest->lastErrorText() . "\r\n";
    exit;
}

# A successful response will have a status code equal to 200.
if ($rest->get_ResponseStatusCode() != 200) {
    print "response status code = " . $rest->get_ResponseStatusCode() . "\r\n";
    print "response status text = " . $rest->responseStatusText() . "\r\n";
    print "response header: " . $rest->responseHeader() . "\r\n";
    exit;
}

print "File downloaded." . "\r\n";