If you use the traditional output method - output by string, you must have a large number of escape characters to escape special characters such as quotation marks in the string to avoid syntax errors. If it is one or two places, it can be tolerated, but if it is a complete html text or a 200-line js, I think everyone will collapse. This is why PHP introduces a delimiter - at least a large part of the reason.
1. The function of the PHP delimiter is to output what is inside it as it is, including newline format and so on;
2. Any special characters in the PHP delimiter do not need to be escaped;
3.PHP definition PHP variables within delimiters will be replaced with their values normally.
The delimiter format in PHP is like this:
Copy the code The code is as follows:
...
Eof;
Looks very simple, but there are There are many places to pay attention to.
First of all, the character Eof after In the process of using PHP delimiters, the second issue that needs attention is also the most common place where problems occur:
The last line (such as Eof; in the above example) must be started on a new line, and the line must be changed except for Eof ; There cannot be any other characters outside the end of this delimiter, and there cannot be any characters before or after it, including spaces. If spaces or tabs appear at the beginning or end of the line, you will receive an error message like this:
Parse error: parse error, unexpected $end in..., prompting you for a syntax error;
The third one needs attention. The thing is, if there is a PHP variable in the middle of the delimiter, you only need to write it like output in other strings, for example
Copy the code The code is as follows:
hello{$name}
Eof;
The reason why the variable $name is enclosed in {} is to tell the PHP parser that this is a PHP variable. In fact, it is okay not to use it, but it may cause ambiguity. For example, what happens if there is not a letter or special symbol behind your variable? Never write like this
Copy the code The code is as follows:
hello
Eof;
In this case, you You will also receive a syntax error message. The first is the correct way to write the PHP delimiter that has been tested in the field. It contains html and javascript code:
Copy code The code is as follows:
$name = 'kitty';
echo
{$name} <script> <BR>var p='hello world'; <BR>document.writeln(p); <BR>< ;/script> <BR></script> |
Eof;
?>
The above introduces the Windows XP application skills and PHP delimiter usage skills, including the Windows XP application skills. I hope it will be helpful to friends who are interested in PHP tutorials.

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

ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment

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

DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software

SublimeText3 Mac version
God-level code editing software (SublimeText3)

SublimeText3 English version
Recommended: Win version, supports code prompts!
