Detailed explanation of PHP's file permission function chmod
chmod() function changes the file mode. chmod — Changes file mode Returns TRUE if successful, FALSE otherwise.
Syntax
chmod(file,mode) Parameter Description
file Required. Specifies the documents to be checked.
mode Optional. Specify new permissions.
The mode parameter consists of 4 numbers:
The first number is always 0
The second number specifies the permissions of the owner
The second number specifies the permissions of the user group to which the owner belongs
The fourth number specifies the permissions of everyone else
Possible values (to set multiple permissions, please total the numbers below):
1 - Execute permissions
2 - Write permissions
4 - Read permissions
Let’s see a simple example
1 2 3 4 5 |
|
Improved recursive file mode@infosoft...., This is a small shortcut that should handle all file types of the Linux file system. This can change the permissions of files or directories in batches
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 |
|
If you have too many directories, you can use
1 2 3 4 5 6 |
|
This code to modify the permissions of the directory
Haha, we are not just talking about simple chmod syntax, and also made complex examples of chmod usage
Explanation
bool chmod (string $filename, int $mode)
Try to change the mode of the file specified by filename to that given by mode.
Note that mode will not be automatically treated as an octal value, and strings (such as "g+w") cannot be used. To ensure correct operation, you need to add 0 in front of mode:
The mode parameter contains three octal numbers that specify the owner, the owner's group, and everyone's access restrictions in order. Each part can be calculated by adding the required permissions. The number 1 makes the file executable, the number 2 makes the file writable, and the number 4 makes the file readable. Add these numbers to specify the required permissions. For information about file permissions on UNIX systems, read the manuals "man 1 chmod" and "man 2 chmod".
1 2 3 4 5 6 7 8 9 10 |
|
Returns TRUE if successful and FALSE if failed.
Note: The current user refers to the user executing PHP. Most likely not the same as the usual shell or FTP user. On most systems a file's mode can only be changed by the user who owns the file.
Note: This function cannot be used on remote files. The files being checked must be accessed through the server's file system.
Note: When safe mode is turned on, PHP will check whether the file being operated on has the same UID (owner) as the script being executed. It should be noted that SUID, SGID and sticky bits cannot be modified.
The above is the detailed content of Detailed explanation of PHP's file permission function chmod. For more information, please follow other related articles on the PHP Chinese website!

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

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

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

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

Hot Topics











PHP 8.4 brings several new features, security improvements, and performance improvements with healthy amounts of feature deprecations and removals. This guide explains how to install PHP 8.4 or upgrade to PHP 8.4 on Ubuntu, Debian, or their derivati

This tutorial demonstrates how to efficiently process XML documents using PHP. XML (eXtensible Markup Language) is a versatile text-based markup language designed for both human readability and machine parsing. It's commonly used for data storage an

JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,

Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.

A string is a sequence of characters, including letters, numbers, and symbols. This tutorial will learn how to calculate the number of vowels in a given string in PHP using different methods. The vowels in English are a, e, i, o, u, and they can be uppercase or lowercase. What is a vowel? Vowels are alphabetic characters that represent a specific pronunciation. There are five vowels in English, including uppercase and lowercase: a, e, i, o, u Example 1 Input: String = "Tutorialspoint" Output: 6 explain The vowels in the string "Tutorialspoint" are u, o, i, a, o, i. There are 6 yuan in total

What are the magic methods of PHP? PHP's magic methods include: 1.\_\_construct, used to initialize objects; 2.\_\_destruct, used to clean up resources; 3.\_\_call, handle non-existent method calls; 4.\_\_get, implement dynamic attribute access; 5.\_\_set, implement dynamic attribute settings. These methods are automatically called in certain situations, improving code flexibility and efficiency.

PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.

PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7
