$dir = __DIR__ . '/old';
$upload_dir = '/new' ;
$files = array();
$counterf = 1;
foreach(glob($dir . '/*.jpg') as $key => $file) {
$files[] = basename($file);
rename($dir . '/' . basename($file), $upload_dir . '/' . $counterf++ . '.jpg');
}
print_r($files);