来看看代码:
echo "(1)浏览当前页面的用户的 IP 地址为:";
echo $_SERVER['REMOTE_ADDR'];
echo "
";
echo "(2)浏览当前页面的用户的 IP 地址为:";
echo getenv('REMOTE_ADDR');
echo "
";
echo "主机 www.baidu.com 的 IP 地址为:";
echo gethostbyname(www.baidu.com);
它的输出结果为:
(1)浏览当前页面的用户的 IP 地址为:127.0.0.1
(2)浏览当前页面的用户的 IP 地址为:127.0.0.1
主机 www.baidu.com 的 IP 地址为:61.135.169.105
关于获取客户端的 IP 地址,有俩方法:
第一个是使用:
?$_SERVER['REMOTE_ADDR']
它正在浏览当前页面用户的 IP 地址,这里的输出结果为 127.0.0.1,因为这是在本地测试,输出的是我本地的环路地址。
第俩个是使用:
?getenv('REMOTE_ADDR')
这里使用了函数 getenv : Gets the value of an environment variable(得到各种环境变量的值),返回值:Returns the value of the environment variable varname, or FALSE on an error(失败的话返回 FALSE).
关于获取服务器端的 IP 地址:
?gethostbyname(www.baidu.com)
这里使用了函数 gethostbyname : Get the IP address corresponding to a given Internet host name(通过给定的一个主机名字而得到它的 IP 地址),返回值:Returns the IP address of the Internet host specified by hostname or a string containing the unmodified hostname on failure(失败的话返回原样的输入字符主机名).
注意这里的最后一句,也就是说,如果失败的话,它会将原样输出,例如:
?echo "无效主机 iwilldown 的 IP 地址为:";
echo gethostbyname("iwilldown");
输出:
?无效主机 iwilldown 的 IP 地址为:iwilldown
当然,这个可不是 IP 地址….

PHP is used to build dynamic websites, and its core functions include: 1. Generate dynamic content and generate web pages in real time by connecting with the database; 2. Process user interaction and form submissions, verify inputs and respond to operations; 3. Manage sessions and user authentication to provide a personalized experience; 4. Optimize performance and follow best practices to improve website efficiency and security.

PHP uses MySQLi and PDO extensions to interact in database operations and server-side logic processing, and processes server-side logic through functions such as session management. 1) Use MySQLi or PDO to connect to the database and execute SQL queries. 2) Handle HTTP requests and user status through session management and other functions. 3) Use transactions to ensure the atomicity of database operations. 4) Prevent SQL injection, use exception handling and closing connections for debugging. 5) Optimize performance through indexing and cache, write highly readable code and perform error handling.

Using preprocessing statements and PDO in PHP can effectively prevent SQL injection attacks. 1) Use PDO to connect to the database and set the error mode. 2) Create preprocessing statements through the prepare method and pass data using placeholders and execute methods. 3) Process query results and ensure the security and performance of the code.

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 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 makes it easy to create interactive web content. 1) Dynamically generate content by embedding HTML and display it in real time based on user input or database data. 2) Process form submission and generate dynamic output to ensure that htmlspecialchars is used to prevent XSS. 3) Use MySQL to create a user registration system, and use password_hash and preprocessing statements to enhance security. Mastering these techniques will improve the efficiency of web development.

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 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.


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

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

SublimeText3 Linux new version
SublimeText3 Linux latest version

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.

VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft

Dreamweaver Mac version
Visual web development tools

Atom editor mac version download
The most popular open source editor