WordPress博客中添加博客描述(description)和关键字(keywords)

开博有几个月了，博客描述(description)和博客关键字(keywords)一直没有添加，今天，抽出点时间，终于添加上了，效果可以通过(右键->查看源代码)查看。 在header.php(一般是该文件)的<title></title>标签对下方添加的代码如下：

$desc = "六度外博|歪博/6duweb.com,记录平时生活和工作中的点滴,主要侧重于IT技术,注重积累与分享";
$key = "六度外博,六度歪博,外博,歪博,博客,Blog,电脑,IT,技术,Java,Javascript,积累,分享,代码,Wordpress,WP,生活,学习,经验,教程,日志,日记,文章,随笔";
if (is_home()){ 
    $description = $desc;
    $keywords = $key;
} elseif (is_single()){
    if ($post->post_excerpt) {
        $description = $post->post_excerpt;
    } else {
        $description = substr(strip_tags($post->post_content),0,220);
    }
    $keywords = "";        
    $tags = wp_get_post_tags($post->ID);
    foreach ($tags as $tag ) {
        $keywords = $keywords.$tag->name.",";
    }
} elseif (is_category())
{
    $description = category_description();
    $keywords = single_cat_title(”, false);
} elseif (is_tag())
{
    $description = tag_description();
    $keywords = single_tag_title(”, false);
} else {
    $description = $desc;
    $keywords = $key;
}
$description = trim(strip_tags($description));
$keywords = trim(strip_tags($keywords));