QQ 自定义头像+Gravatar 头像缓存

add_filter('get_avatar', 'cache', 10, 3);
function cache($avatar, $comment, $size){
$t = 604800; //設定7天, 單位:秒
$d = get_bloginfo('wpurl').'/wp-content/cache/img/default.jpg';//默认图片
$face_size = false;//单独指定头像的大小, false or integer
$qq_face_url = 'http://qun.qq.com/cgi/svr/face/getface?type=1&uin=%s';     
//QQ头像地址, %s表示QQ号    
if ( isset($comment->comment_author_url) && preg_match
('/^(http:\/\/)?[1-9][0-9]*$/i', $comment->comment_author_url) ) {
        $qq = preg_replace('|\D*|', '', $comment->comment_author_url);
        $avatar = preg_replace('/src=\'[^\']*\'/',
                'src=\'' . str_replace('%s', $qq, $qq_face_url) . '\'',
                $avatar);
        if( $face_size )
$avatar = str_replace('\'' . $size . '\'', '\'' . $face_size . '\'', $avatar);
                return $avatar;
                        }
        else{
        $f = md5(strtolower($comment->comment_author_email));
        $r = get_option('avatar_rating');
        $g = 'http://www.gravatar.com/avatar/'.$f.'?s=50&d='.$d.'&r='.$r;
        $a = get_bloginfo('wpurl').'/wp-content/cache/img/'.$f.'.jpg';
        $e = ABSPATH .'/wp-content/cache/img/'.$f.'.jpg';
        if ( !is_file($e) || (time() - filemtime($e)) > $t ){
                                copy($g, $e);
                                @chmod($e,0777);
                        if (filesize($e) < 500) {
                                copy($d, $e);
                                }
                        }
                        if( $face_size )
                        $size = $face_size;
                        $avatar = "<img  src='{$a}' class='avatar avatar-{$size} photo' height='{$size}' width='{$size}' />";
                return $avatar;
        }
        return $avatar;
}