rilevare e se esiste rinominare un file

[Il_Drugo]

function rename_existing_file($filename, $dir)
{
    $parts = explode('.', $filename);
    $newname = $parts[0].'-.'.$parts[1];
     
    if( file_exists($dir.$newname))
    {
        return rename_existing_file($newname, $dir);
    }
    else
    {
        return $newname;
    }
}

rename_existing_file("file.zip", "./directory/");