如何在PHP中的同一路径中创建两个具有相同名称的文件夹

If i want to make a folder with

mkdir('folder');

And there was a folder in the path with same name .. PHP will return me an error but what i want to do is to make the folder's name "folder (2)" .. and when i create another one with the same name it will be "folder (3)" I tried this:

if(is_dir('folder')){
mkdir('folder (2)');
}else{
mkdir('folder');
}

But it works with just two folders .. i want a solution for unlimited folders

Can anybody help me ?

Something like this

if(is_dir('folder')){
    $foldername = '';
    $counter = 2;
    while (!$foldername) {
        if (!is_dir("folder ({$counter})")) {
            $foldername = "folder ({$counter})";
        }
        $counter++;
    }
    mkdir($foldername);
}else{
    mkdir('folder');
}