检查php会话到期之前剩余的时间

Question

我需要为我的网站建立一个php会话到期警报/保持登录状态。 我看了几十个示例，但很困惑，回到了基础知识上。

有没有一种方法可以显示默认到期时间的倒计时？

更新1

到目前为止-为了处理这种情况-我有：

echo '<p>This is the $_SESSION[\'expiretime\']: ' . $_SESSION['expiretime'] . '</p>';           
echo '<p>This is the time(): ' . time() . '</p>';           
$timeleft =  time() - $_SESSION['expiretime'];          
echo '<p>This is the time() MINUS the $_SESSION[\'expiretime\'] : ' . $timeleft . '</p>';           

我不确定参数$ _SESSION ['expiretime']是什么，但是我在线程中找到它，看起来很有趣。除了自1970年以来的秒数外，我不确定这一切告诉我什么，但可能对以后的计算有用。

Answer 1

您必须做类似的事情

//Start our session.
session_start();

//Expire the session if user is inactive for 30
//minutes or more.
$expireAfter = 30;

//Check to see if our "last action" session
//variable has been set.
if(isset($_SESSION['last_action'])){

  //Figure out how many seconds have passed
  //since the user was last active.
  $secondsInactive = time() - $_SESSION['last_action'];

  //Convert our minutes into seconds.
  $expireAfterSeconds = $expireAfter * 60;     
  //Check to see if they have been inactive for too long.
  if($secondsInactive >= $expireAfterSeconds){
    //User has been inactive for too long.
    //Kill their session.
    session_unset();
    session_destroy();
  } else {
    echo("Expire in:");
    echo($expireAfterSeconds - $secondsInactive); 
  } 
}
$_SESSION['last_action'] = time();