


There are several commonly used functions for executing system commands in PHP_PHP Tutorial
PHP has several commonly used functions for executing system commands, such as: system function, exec function, popen function, passthru, shell_exec function. They can all execute system commands, but the prerequisite is that the system has given permission.
system function
Description: Execute external program and display output data.
Syntax: string system(string command, int [return_var]);
Return value: string
Detailed introduction:
This function is like the function system() in C language, which is used to execute instructions and output the results. If the return_var parameter exists, the status after executing the command will be filled in return_var. It is also worth noting that if you need to process the data entered by the user, but want to prevent the user from playing tricks to crack the system, you can use EscapeShellCmd(). If PHP is executed in a modular fashion, this function will automatically update the output buffer buffer of the web server after each line of output. If you need to return a complete string and don't want to go through unnecessary other intermediate output interfaces, you can use PassThru().
Example code:
The code is as follows | Copy code | ||||
$last_line = system("ls", $retval); Return value: " . $retval; ?> |
exec function
Description: Execute external program.
Return value: string
Detailed introduction:
This function executes the external program or external instruction input command. Its return string is only the last line returned after the external program is executed; if you need a complete return string, you can use the PassThru() function.If the parameter array exists, the command will add the array to the parameter for execution. If you do not want the array to be processed, you can call unset() before executing exec(). If both return_var and array parameters exist, the status after executing the command will be filled in return_var.
代码如下 | 复制代码 |
< ?php |
It is worth noting that if you need to process the data entered by the user and prevent the user from playing tricks to crack the system, you can use EscapeShellCmd().
Example code:
The code is as follows | Copy code |
< ?php
echo exec("whoami"); |
popen function
Description: Open the file.
代码如下 | 复制代码 |
< ? |
The code is as follows | Copy code |
< ?<🎜> $fp = popen( "/bin/ls", "r" );<🎜> ?> |
Use function passthru to execute external system commands
Prototype: function passthru(string $command,int[optional] $return_value)
Knowledge point: The difference between passthru and system. passthru directly outputs the results to the browser without returning any value, and it can output binary, such as image data.
Method 4: Backtick` (in the same key as ~) executes external system commands
Safety Instructions The code is as follows
|
Copy code
|
||||
echo `dir`; ?>
|

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

Visual Studio Code, also known as VS Code, is a free source code editor — or integrated development environment (IDE) — available for all major operating systems. With a large collection of extensions for many programming languages, VS Code can be c

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,

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

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

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.

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.
