protected $client_id = '<CLIENT_ID>';
protected $client_secret = '<CLIENT_SECRET>';
protected $redirect_uri = '<REDIRECTED_URI>';

require_once 'google.php'; // Include Class File
session_start(); //Start the session
$google = new GoogleClient(); //Create GoogleClient Object

// Check if the user is logged in
if(!$google->isLoggedIn()){ 
    // Go to Google Login Page
	header('Location: '.$google->getAuthURL());
	exit;
}

// If the page is redirected from google authentication
if(isset($_GET['code'])){
    // Authenticate and start the session
	$google->authenticate($_GET['code']);
	# your code ..
}

$google->initDriveService();

/**
 *  Create folder at google drive
 *  @param string $parentId folder id in which folder will be created
 *  @param string $folderName folder name to create
 *  @return string id of created folder
 */
$folderId = $google->createFolder($parentFolderId,$folderName);

 /**
  *  Upload file to given folder
  *  @param string $parentId parent folder in which folder will be upload
  *  @param string $filePath file local path of file which will be upload
  *  @param string $fileName file name of the uploaded copy at google drive
  *  @return string id of uploaded file
 */
    $fileId uploadFile($parentId,$filePath,$fileName="none");

/**
 *  Get the list of files or folders or both from given folder or root
 *  @param string $search complete or partial name of file or folder to search
 *  @param string $parentId parent folder id or root from which the list of files or folders or both will be generated
 *  @param string $type='all' file or folder (files,folders or all)
 *  @return array list of files or folders or both from given parent directory
 */
$list = listFilesFolders($search,$parentId,$type='all');