WordPress 判断邮箱是否设置了头像

WordPress 判断邮箱是否设置了头像，做一下记录，下面有代码出处。

function validate_gravatar($email) {
     // Craft a potential url and test its headers
     $hash = md5(strtolower(trim($email)));
     $uri = 'http://www.gravatar.com/avatar/' . $hash . '?d=404';
     $headers = @get_headers($uri);
     if (!preg_match("|200|", $headers[0])) {
         $has_valid_avatar = FALSE;
     } else {
         $has_valid_avatar = TRUE;
     }
     return $has_valid_avatar;
 }