php根據隨機數生成6位密鑰

/**
 * 根據隨機數生成6位密鑰
 * author: panzhide
 * @param boolean $num
 * @return string
 * Date: 2020/8/22
 */
function getRandKey ($num = false)
{
    if ($num) {
        $randStr = str_shuffle('1234567890');
        return substr($randStr, 0, 6);
    } else {
        return substr(md5(mt_rand(0, 32) . '0905' . md5(mt_rand(0, 32)) . '0123'), 10, 6);
    }
}