A symbolic link is similar to a shortcut in Windows or a soft link in Unix/Linux. It's a special type of file that points to another file or directory. Symbolic links help manage files and directories more flexibly, especially when files are renamed or moved, ensuring path validity.

The crypt() function is usually used to hash the password, and its original intention is to verify the password, not for data encryption or signature. But in some practical projects, developers may try to use crypt() for other purposes, such as encrypting or signing URLs. This article will analyze whether the crypt() function is suitable for URL encryption or signatures, and its security and effectiveness in this regard.

The str_split() function is a very useful string processing function that can split strings into small pieces. This function will be very convenient if you want to analyze and disassemble a URL string and split it at a certain length.

It is a common requirement to process URLs and their parameters in PHP, especially in scenarios such as jump judgment, record source or security verification. stripos() is a very practical function that can be used to determine whether a string contains another string, and yes.

In PHP development, routing processing is an important part of building modern web applications. Through routing, we can parse parameters based on the requested URL and decide how to respond to user requests. This article will introduce how to use PHP's preg_replace_callback_array function, combine regular expressions, extract URL parameters and implement link rewriting, and replace all URL domain names with m66.net in the sample code.