how to list only all directories and subdirectories in a certain folder

Question

For a treeview i use this function which gives me a complete summary of all the files and folders inside the main directory:

/* FUNCTION TREEVIEW directories & files */
function listFolderFiles($dir){
$files = preg_grep('/^([^.])/', scandir($dir));

// prevent empty ordered elements
if (count($files) < 1)
    return;

echo '<ul>';
foreach($files as $file){
    echo '<li class="treeview">'.$file;
    if(is_dir($dir.'/'.$file)) listFolderFiles($dir.'/'.$file);
    echo '</li>';
}
echo '</ul>';
}

This works fine! What do i have to change on the code that he only shows me the directories and not the files anymore?

Answer 1

Change

foreach($files as $file){
    echo '<li class="treeview">'.$file;
    if(is_dir($dir.'/'.$file)) listFolderFiles($dir.'/'.$file);
    echo '</li>';
}

To

foreach($files as $file){
    if(is_dir($dir.'/'.$file)) {
        echo '<li class="treeview">'.$file;
        listFolderFiles($dir.'/'.$file);
        echo '</li>';
    }
}