recursive function to find all files in subdirectories and push them into a flat array

flatten files in folder to array

$files = array();
function returnFiles($dir) {
	global $files;
	$dh = opendir($dir);
	while(false !== ($filename = readdir($dh))) {
		if($filename == '.' || $filename == '..') {
			continue;
		}
		echo $dir.DIRECTORY_SEPARATOR.$filename . "\n";
		if(is_file($dir.DIRECTORY_SEPARATOR.$filename)) {
			array_push($files, $dir.DIRECTORY_SEPARATOR.$filename);
		} else if(is_dir($dir.DIRECTORY_SEPARATOR.$filename)) {
			returnFiles($dir.DIRECTORY_SEPARATOR.$filename);
		}
	}
	closedir($dh);
}