Detailed explanation of php setting session (expiration, invalidation, validity period)_PHP tutorial

There are many aspects of setting up sessions in php, including setting values ​​for sessions or directly setting expiration, expiration and validity periods. The following editor will introduce to you how to use them.

Let’s first take a look at how to set up session in php.ini

Open php.ini and look for the following item in the Session Settings section:

The code is as follows

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代码如下	复制代码
session.save_path = "N;/path" session.save_path = "C:/Temp"　　#此处以你自己设定的路径为准

session.save_path = "N;/path"

session.save_path = "C:/Temp"　#The path you set here shall prevail

代码如下	复制代码
session.save_path = "2;C:/Temp"

This setting allows us to perform multi-level hashing on the session storage directory, where "N" represents the directory level to be set, and the following "/path" represents the root directory path where the session file is stored. For example, we set it to the following Format

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session.save_path = "2;C:/Temp"

The above settings mean that we store PHP session files in two-level directories. Each level of directory is 0-9 and a-z, with a total of 36 alphanumeric names as directory names. In this way, the directory where sessions can be stored can reach 36*36 , a total of 1332 folders, which I believe is enough for a single server. If your system architecture is designed to share session data with multiple servers, you can increase the directory level to 3 or more.

Session expiration time setting

代码如下	复制代码
ini_set('session.gc_maxlifetime', 3600); //设置时间 ini_get('session.gc_maxlifetime');//得到ini中设定值 ?>

Continuing with the topic of Session in PHP, the life cycle of Session is mainly set in PHP by setting session.gc_maxlifetime. For example:

The code is as follows

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代码如下

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function start_session($expire = 0) {     if ($expire == 0) {         $expire = ini_get('session.gc_maxlifetime');     } else {         ini_set('session.gc_maxlifetime', $expire);     }     if (empty($_COOKIE['PHPSESSID'])) {         session_set_cookie_params($expire);         session_start();     } else {         session_start();         setcookie('PHPSESSID', session_id(), time() + $expire);     } } ?>

ini_set('session.gc_maxlifetime', 3600); //Set time ini_get('session.gc_maxlifetime');//Get the value set in ini ?>

The following is a function packaged by others, but I have not tested it. It is for reference only:

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function start_session($expire = 0) { If ($expire == 0) {           $expire = ini_get('session.gc_maxlifetime'); } else {         ini_set('session.gc_maxlifetime', $expire); } if (empty($_COOKIE['PHPSESSID'])) { Session_set_cookie_params($expire); session_start(); } else { session_start();           setcookie('PHPSESSID', session_id(), time() + $expire); } } ?>

How to use:

Add start_session(600); //Expires after 600 seconds.

How session never expires

Open the php.ini settings file

Change three lines as follows:

1. session.use_cookies
Set the value of this to 1 and use cookies to pass sessionid

2. session.cookie_lifetime
This represents the time that the SessionID is stored in the client cookie. The default is 0, which means that the SessionID will be invalidated as soon as the browser closes it... It is because of this that the PHP session cannot be used permanently! So let's set it to a number we think is big, how about 999999999, that's ok! that's all.

3. session.gc_maxlifetime
This is the time that Session data is stored on the server side. If this time is exceeded, the Session data will be automatically deleted! So let's also set it to 99999999.

That's it, everything is ok. Of course, if you don't believe it, just test it and see - set up a session and come back after 10 days and a half. If your computer does not have a power outage or downtime, you will still be able to see it. You can see this sessionid.

Of course, it is also possible that you do not have the authority to control the server and are not as lucky as me to be able to modify the php.ini settings. We have a way to rely on ourselves. Of course, we must use the client to store cookies, and get the sessionID Store it in the client's cookie, set the value of this cookie, and then pass this value to the session_id() function. The specific method is as follows:

The code is as follows

代码如下	复制代码
session_start(); // 启动Session $_SESSION['count']; // 注册Session变量Count isset($PHPSESSID)?session_id($PHPSESSID):$PHPSESSID = session_id(); // 如果设置了$PHPSESSID，就将SessionID赋值为$PHPSESSID，否则生成SessionID $_SESSION['count']++; // 变量count加1 setcookie('PHPSESSID', $PHPSESSID, time()+3156000); // 储存SessionID到Cookie中 echo $count; // 显示Session变量count的值 ?>

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session_start(); // Start Session $_SESSION['count']; // Register Session variable Count

isset($PHPSESSID)?session_id($PHPSESSID):$PHPSESSID = session_id();

// If $PHPSESSID is set, assign SessionID to $PHPSESSID, otherwise generate SessionID $_SESSION['count']++; // Add 1 to variable count setcookie('PHPSESSID', $PHPSESSID, time()+3156000); // Store SessionID in Cookie echo $count; // Display the value of Session variable count ?>

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www.bkjia.comtruehttp: //www.bkjia.com/PHPjc/632659.htmlTechArticleThere are many aspects of setting up session in php, including setting value for session or directly setting expiration, expiration and validity period, as follows The editor is here to introduce to you how to use it. Let’s take a look first...