Cs computer science

<?php function read_dir_content($parent_dir, $depth = 0){ $str_result = ""; $str_result .= "<li>". dirname($parent_dir) ."</li>"; $str_result .= "<ul>"; if ($handle = opendir($parent_dir)) { while (false !== ($file = readdir($handle))) { if(in_array($file, array('.', '..'))) continue; if( is_dir($parent_dir . "/" . $file) ){ $str_result .= "<li>" . read_dir_content($parent_dir . "/" . $file, $depth++) . "</li>"; } $str_result .= "<li>{$file}</li>"; } closedir($handle); } $str_result .= "</ul>"; return $str_result; } //echo dirname(__FILE__); echo "<ul>".read_dir_content(dirname(__FILE__))."</ul>"; ?>