php초보입니다 ㅜㅜ s3 upload 연습중인데요. 하나는 들어가지만

다중업로드를 하려는데 잘안되네요 ,, 어디가 잘못되었는지 부탁드립니다! 

require 'vendor/autoload.php';

		$error = $_FILES['userfile[]']['error'];
		$name = $_FILES['userfile[]']['name'];
		$type = $_FILES['userfile[]']['type'];
    	$ext = array_pop(explode('.', $name));

    	$bucket = 'test';
    	$keyname = 'testup';
					
		$filepath = 'testup/';

    	$s3Client = new Aws\S3\S3Client([
    		'version' => 'latest',
    		'region'  => 'ap-northeast-2',
    		'credentials' => [
    		'key'    => '**************',
        	'secret' => '*****************************',
        	 ],
		]);

		$params = [
  			'Bucket' =>	$bucket,
    		'Key'    => $name,
    		'Body'   => $ext,
    		'ACL'	 => 'public-read',
    		'ContentType' => $type
		];

		$result = $s3Client->putObject($params);

		$command = $s3Client->getCommand('PutObject', $params);
		header('Location:/upload');

		
    }