(Perl) Download Binary File to In-Memory Bytes

This example demonstrates how to download the binary content of a file from Google Drive directly into local memory.

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");

# To download to memory, we'll send the request in one call, then receive
# the response header, and then the response body.
# If the response header indicates failure or an unexpected response, then the
# body is not the data we desire.

# First send the HTTP request.
$success = $rest->SendReqNoBody("GET",$sbPath->getAsString());
if ($success != 1) {
    print $rest->lastErrorText() . "\r\n";
    exit;
}

# Get the response header.
$statusCode = $rest->ReadResponseHeader();
if ($statusCode != 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";

    # Read the response body (which should be error text or HTML)
    $errResponseBody = $rest->readRespBodyString();
    if ($rest->get_LastMethodSuccess() == 1) {
        print "response body: " . $errResponseBody . "\r\n";
    }

    exit;
}

# Read the response body, which should contain the file data.
$jpgBytes = chilkat::CkByteData->new();
$success = $rest->ReadRespBodyBinary($jpgBytes);
if ($rest->get_LastMethodSuccess() != 1) {
    print $rest->lastErrorText() . "\r\n";
    exit;
}

# Save jpgBytes to a file so we can examine the file to verify that it worked.
$fac = chilkat::CkFileAccess->new();
$fac->WriteEntireFile("qa_output/penguins_out.jpg",$jpgBytes);

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