$pathToThemeFolder = $_SERVER["DOCUMENT_ROOT"];
echo '<pre>';
function listFolderFiles($dir=null, $result=array())
{
if (is_dir($dir)) {

    echo '<ol>';
    foreach (new DirectoryIterator($dir) as $fileInfo) {
        if (!$fileInfo->isDot()) {
            echo '<li>' . $fileInfo->getFilename();

            if ($fileInfo->isDir()) {
                listFolderFiles($fileInfo->getPathname(),$result);
                echo 'directory';
            }
            else {
                $tempArr[] = $fileInfo->getFilename();
             $result = array_merge($result, $tempArr);
             //print_r($result);
            echo 'file';
            }
            echo '</li>';
        }
    }
   echo '</ol>';
    } else {
    echo "No such directory";
}
return $result;
}
$temp = array();
$result = listFolderFiles($pathToThemeFolder.'/medianews/wp-content/uploads/2015/02',$temp);

print_r($result);
if(is_array($result))
print_r(array_unique($result));