PHP遍历文件夹下的所有文件和文件夹

<?php
function tree($dir)
{
    $mydir = dir($dir);
    echo "<ul>\n";
    while ($file = $mydir->read()) {
        if (is_dir("$dir/$file") AND $file != "." AND $file != "..") {
            echo "<li><font color=\"#ff00cc\"><b>$file</b></font></li>";
            tree("$dir/$file");
        } else {
            echo "<li>$file</li>\n";
        }
    }
    echo "</ul>\n";
    $mydir->close();
}

echo "<h2>目录为粉红色</h2><br>\n";
tree("e:/www");

function tree($dir)
{
    if (is_dir($dir)) {
        if ($dh = opendir($dir)) {
            while (($file = readdir($dh)) !== false) {
                if ((is_dir($dir . "/" . $file)) && $file != "." && $file != "..") {
                    echo "<b><font color='red'>文件名：</font></b>", $file, "<br><hr>";
                    tree($dir . "/" . $file . "/");
                } else {
                    if ($file != "." && $file != "..") {
                        echo $file . "<br>";
                    }
                }
            }
            closedir($dh);
        }
    }
}