Afisarea unei structuri de date recursive

gistfile1.php

<?php

function get_directory_structure($dirpath){
	$ar = array();
	
	$dh = opendir($dirpath);
	
    while($entry = readdir($dh)){
        if($entry != "." && $entry != ".."){
            if(is_dir($dirpath.DIRECTORY_SEPARATOR.$entry)) {
                $ar[$entry] = get_directory_structure($dirpath.DIRECTORY_SEPARATOR.$entry);
            }
            else{
			    $ar[] = $entry;
            }
        }
	}
	
	closedir($dh);
	return $ar;	
}


function render_recursive_array_to_ul($array){
    $str = "<ul>";

    foreach($array as $k => $v){ 
        if(is_array($v)){
            $str .= "<li><b>$k</b>";
            $str .= render_recursive_array_to_ul($v);
            $str .= "</li>";
        }
        else{
            $str .= "<li>$v</li>";
        }
    }

    $str .= "</ul>";

    return $str;
}

$str = render_recursive_array_to_ul(get_directory_structure("./dir"));
echo $str;