Summary of usage of php external execution command function
This article mainly introduces the usage of PHP external execution command function, and analyzes the related usage skills of exec and system to execute external commands in the form of examples. Friends in need can refer to it
First of all, self-examination Yes, I have been studying and using PHP for more than a year, and I have been studying and using the Linux system for almost a year. I didn’t know that an interpreted language like PHP can directly call operating commands to control the system...
Let’s first summarize the operations of Linux. I won’t mention the commonly used cd, cp, mv, rm and the like. The first point worth summarizing is that ordinary users need to add before the command when extracting root permissions. Enter sudo, and then the command to output the line number in the vi editor is: set nu.
PHP’s built-in functions exec and system can call system commands (shell commands). However, if you want to use these two functions, the safe mode in php.ini must be turned off, otherwise PHP will not allow calling the system for security reasons. commanded.
Let’s first look at the explanation of these two functions in the PHP manual:
1. exec --- Execute external programs
Syntax: string exec (string command [, array &output [, int &return_var]] )
Description:
exec() executes the given command command, but It does not output anything, it simply returns the last line from the result of the command. If you need to execute a command and get all the data from the command, you can use the passthru() function.
If the parameter array is given, the specified array will be filled with each line output by the command. Note: If the array already contains some elements, exec() will append it to the array. later, if you don't want this function to append elements, you can call unset() before passing the array to exec().
2. system --- Execute the external program and display the output
Syntax: string system (string command [, int &return_var] )
Description:
system() executes the given command command and outputs the result. If the parameter return_var is given, the status code of the executed command will be written to this variable.
If PHP is running as a server module, system() will try to automatically clear the web server's output buffer after outputting each line. Returns the last line of the command on success, false on failure.
If you need to execute a command and obtain all information from the command, you can use the passthru() function.
Both of these are used to call system shell commands.
The difference:
exec can return all execution results to $output In the function (array), $status is the status of execution. 0 is success and 1 is failure.
systerm does not need to provide the $output function. It returns the result directly. Similarly, $return_var is the status code of execution. 0 is failure. Success 1 means failure
exec example:
The following is the quoted content:
<?php
$a = exec("dir",$out,$status);
print_r($a);
print_r($out);
print_r($status);
?>system example:
The following is the quoted content:
<?php
$a = system("dir",$out);
print_r($a);
print_r($out);
?>Summary: The above is the entire content of this article, I hope it can be helpful to everyone Learning helps.
Related recommendations:
phpEncapsulation form validation class
PHP uses the preg_split function to split the content Line breaks and semicolon strings
Write a PHP program to implement the following functions
The above is the detailed content of Summary of usage of php external execution command function. 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
1666
14
1425
52
1325
25
1272
29
1252
24
PHP and Python: Comparing Two Popular Programming Languages
Apr 14, 2025 am 12:13 AM
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 in Action: Real-World Examples and Applications
Apr 14, 2025 am 12:19 AM
PHP is widely used in e-commerce, content management systems and API development. 1) E-commerce: used for shopping cart function and payment processing. 2) Content management system: used for dynamic content generation and user management. 3) API development: used for RESTful API development and API security. Through performance optimization and best practices, the efficiency and maintainability of PHP applications are improved.
PHP: A Key Language for Web Development
Apr 13, 2025 am 12:08 AM
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
PHP vs. Python: Understanding the Differences
Apr 11, 2025 am 12:15 AM
PHP and Python each have their own advantages, and the choice should be based on project requirements. 1.PHP is suitable for web development, with simple syntax and high execution efficiency. 2. Python is suitable for data science and machine learning, with concise syntax and rich libraries.
The Enduring Relevance of PHP: Is It Still Alive?
Apr 14, 2025 am 12:12 AM
PHP is still dynamic and still occupies an important position in the field of modern programming. 1) PHP's simplicity and powerful community support make it widely used in web development; 2) Its flexibility and stability make it outstanding in handling web forms, database operations and file processing; 3) PHP is constantly evolving and optimizing, suitable for beginners and experienced developers.
PHP and Python: Code Examples and Comparison
Apr 15, 2025 am 12:07 AM
PHP and Python have their own advantages and disadvantages, and the choice depends on project needs and personal preferences. 1.PHP is suitable for rapid development and maintenance of large-scale web applications. 2. Python dominates the field of data science and machine learning.
PHP vs. Other Languages: A Comparison
Apr 13, 2025 am 12:19 AM
PHP is suitable for web development, especially in rapid development and processing dynamic content, but is not good at data science and enterprise-level applications. Compared with Python, PHP has more advantages in web development, but is not as good as Python in the field of data science; compared with Java, PHP performs worse in enterprise-level applications, but is more flexible in web development; compared with JavaScript, PHP is more concise in back-end development, but is not as good as JavaScript in front-end development.
PHP and Python: Different Paradigms Explained
Apr 18, 2025 am 12:26 AM
PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.
