Remove Inactive Wordpress Themes

remove-themes.php

<?php  define('WP_USE_THEMES', false); require('./wp-blog-header.php');
remove_inactive_themes();
function remove_inactive_themes()
{
    echo '<h1>Removing Inactive Themes</h1><ul>';
    $theme_dir = get_theme_root();
    $template_dir = get_template_directory();

    foreach (scandir($theme_dir) as $res) {
        if (is_dir($theme_dir . '/' . $res)&&($res!='.')&($res!='..')) {
            if($template_dir==$theme_dir . '/' . $res) {
                echo "<li><em>" . $res . "</em></li>";
            } else {
                echo "<li><s>" . $res . "</s>...deleted</li>";

            }

        }
    }
}
function deleteDirectory($dir) {
    if (!file_exists($dir)) return true;
    if (!is_dir($dir) || is_link($dir)) return unlink($dir);
    foreach (scandir($dir) as $item) {
        if ($item == '.' || $item == '..') continue;
        if (!deleteDirectory($dir . "/" . $item)) {
            chmod($dir . "/" . $item, 0777);
            if (!deleteDirectory($dir . "/" . $item)) return false;
        };
    }
    return rmdir($dir);
}