本文实例讲述了php防止网站被刷新的方法。分享给大家供大家参考。具体方法如下:
对于像采用WP建设的站来说,频繁的刷新会导致数据库吃紧。下面附上一段代码,防止频繁的刷新造成的死机情况。
方法一,代码如下:
代码如下:
session_start();
$k=$_GET['k'];
$t=$_GET['t'];
$allowTime = 1800;//防刷新时间
$ip = get_client_ip();
$allowT = md5($ip.$k.$t);
if(!isset($_SESSION[$allowT]))
{
$refresh = true;
$_SESSION[$allowT] = time();
}elseif(time() - $_SESSION[$allowT]>$allowTime){
$refresh = true;
$_SESSION[$allowT] = time();
}else{
$refresh = false;
}
?>
方法二,代码如下:
代码如下:
session_start();
$allow_sep = "2";
if (isset($_SESSION["post_sep"]))
{
if (time() - $_SESSION["post_sep"]
{
exit("请不要频繁刷新,休息2秒再刷新吧");
}
else
{
$_SESSION["post_sep"] = time();
}
}
else
{
$_SESSION["post_sep"] = time();
}
?>
方法三,代码如下:
代码如下:
session_start();
if(!emptyempty($_POST[name])){
$data = $_POST[name];
$tag = $_POST[tag];
if($_SESSION[status]==$tag){
echo $data;
}else{
echo "不允许刷新!";
}
}
$v = mt_rand(1,10000);
?>
echo $v;
$_SESSION[status] = $v;
?>
注意:代码有了,不过要应用到WordPress还要一些其他操作.
因为上面的代码是基于 session的验证,假设你在2秒内刷新了页面,那么他会执行exit() 函数输出一条消息,并退出当前脚本,于是就不会加载下面的内容,所以这段代码最好放在header中,先让代码执行,再加载其他的东西.
如果把代码放在了footer里,结果整个页面都加载了只在最后一行输出了"请不要频繁刷新",放在header中,效果比较好,想看效果的话按两下F5 吧.
当然最好的是采用的是新建一个php文件,然后在header调用.
这样做的好处有两个:
一个是修改功能代码方便,不用每次都打开header文件,也不怕误改了其他地方的代码,二是一旦出错,可以快速修改并检查,甚至可以直接删除文件,代码如下:
代码如下:
include('includes/forbiddenCC.php');
?>
这里要注意下,必须调用在所有页面的最前面.
希望本文所述对大家的PHP程序设计有所帮助。

Effective methods to prevent session fixed attacks include: 1. Regenerate the session ID after the user logs in; 2. Use a secure session ID generation algorithm; 3. Implement the session timeout mechanism; 4. Encrypt session data using HTTPS. These measures can ensure that the application is indestructible when facing session fixed attacks.

Implementing session-free authentication can be achieved by using JSONWebTokens (JWT), a token-based authentication system where all necessary information is stored in the token without server-side session storage. 1) Use JWT to generate and verify tokens, 2) Ensure that HTTPS is used to prevent tokens from being intercepted, 3) Securely store tokens on the client side, 4) Verify tokens on the server side to prevent tampering, 5) Implement token revocation mechanisms, such as using short-term access tokens and long-term refresh tokens.

The security risks of PHP sessions mainly include session hijacking, session fixation, session prediction and session poisoning. 1. Session hijacking can be prevented by using HTTPS and protecting cookies. 2. Session fixation can be avoided by regenerating the session ID before the user logs in. 3. Session prediction needs to ensure the randomness and unpredictability of session IDs. 4. Session poisoning can be prevented by verifying and filtering session data.

To destroy a PHP session, you need to start the session first, then clear the data and destroy the session file. 1. Use session_start() to start the session. 2. Use session_unset() to clear the session data. 3. Finally, use session_destroy() to destroy the session file to ensure data security and resource release.

How to change the default session saving path of PHP? It can be achieved through the following steps: use session_save_path('/var/www/sessions');session_start(); in PHP scripts to set the session saving path. Set session.save_path="/var/www/sessions" in the php.ini file to change the session saving path globally. Use Memcached or Redis to store session data, such as ini_set('session.save_handler','memcached'); ini_set(

TomodifydatainaPHPsession,startthesessionwithsession_start(),thenuse$_SESSIONtoset,modify,orremovevariables.1)Startthesession.2)Setormodifysessionvariablesusing$_SESSION.3)Removevariableswithunset().4)Clearallvariableswithsession_unset().5)Destroythe

Arrays can be stored in PHP sessions. 1. Start the session and use session_start(). 2. Create an array and store it in $_SESSION. 3. Retrieve the array through $_SESSION. 4. Optimize session data to improve performance.

PHP session garbage collection is triggered through a probability mechanism to clean up expired session data. 1) Set the trigger probability and session life cycle in the configuration file; 2) You can use cron tasks to optimize high-load applications; 3) You need to balance the garbage collection frequency and performance to avoid data loss.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.

Atom editor mac version download
The most popular open source editor

VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft

Notepad++7.3.1
Easy-to-use and free code editor

EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function
