/**
 * @Author: 小破孩嫩
 * @Email: 3584685883@qq.com
 * @Time: 2020/12/10 20:00
 * @param string $email 邮箱
 * @param int $s 大小
 * @param string $d
 * @param string $g
 * @return string
 * @Description：生成avatar头像
 */
function getAvatar($email='', $s=40, $d='mm', $g='g') {
    $hash = md5($email);
    $avatar = "http://www.gravatar.com/avatar/$hash?s=$s&d=$d&r=$g";
    return $avatar;
}