Home Backend Development PHP Tutorial Common anti-crawling strategies for PHP web crawlers

Common anti-crawling strategies for PHP web crawlers

Jun 14, 2023 pm 03:29 PM
php crawler Network anti-crawling strategic response

A web crawler is a program that automatically crawls Internet information. It can obtain a large amount of data in a short period of time. However, due to the scalability and efficiency of web crawlers, many websites are worried that they may be attacked by crawlers, so they have adopted various anti-crawling strategies.

Among them, common anti-crawling strategies for PHP web crawlers mainly include the following:

  1. IP restriction
    IP restriction is the most common anti-crawling technology. By restricting IP Access can effectively prevent malicious crawler attacks. In order to deal with this anti-crawling strategy, PHP web crawlers can use proxy servers and change IPs in turns to bypass IP restrictions. In addition, distributed crawlers can also be used to distribute tasks to multiple computers, thereby increasing the number and diversity of IPs accessing the target site.
  2. Verification code identification
    Verification code is a commonly used anti-crawler technology. By adding verification code to the request, it prevents crawlers from automatically obtaining website information. For PHP web crawlers, automated verification code recognition tools can be used to solve this problem, thereby avoiding the time wasted of manually entering verification codes.
  3. Frequency Limitation
    Frequency limitation is an anti-crawling technology that limits the number of visits to a certain website by each IP address within a unit time. Generally speaking, if the crawler requests too frequently, the target website will trigger the frequency limit, resulting in the inability to obtain data. In order to deal with this anti-crawler technology, PHP web crawlers can choose to reduce the request frequency, spread the access tasks to multiple IPs, or use randomly spaced access methods to avoid risks.
  4. JavaScript Detection
    Some websites will use JavaScript to detect the visitor's browser and device information to determine whether it is a crawler. In order to solve this problem, PHP web crawlers can simulate browser behavior, such as real request header information, cookies, etc., or use header information pooling and other technologies to deceive JavaScript detection.
  5. Simulated login
    Some websites will require users to log in to obtain information. At this time, the PHP web crawler needs to simulate login to obtain the required data. For websites that require login, you can use simulated user login to obtain data, thereby bypassing anti-crawler restrictions.

In short, in the process of crawling data, PHP web crawlers need to follow the rules of the website, respect the privacy of the website, and avoid unnecessary trouble and losses. At the same time, it is also necessary to understand the anti-crawler strategy of the website in a timely manner so as to take effective countermeasures to ensure the stability and long-term operation of the crawler program.

The above is the detailed content of Common anti-crawling strategies for PHP web crawlers. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

How to use PHP crawler to crawl big data How to use PHP crawler to crawl big data Jun 14, 2023 pm 12:52 PM

With the advent of the data era and the diversification of data volume and data types, more and more companies and individuals need to obtain and process massive amounts of data. At this time, crawler technology becomes a very effective method. This article will introduce how to use PHP crawler to crawl big data. 1. Introduction to crawlers Crawlers are a technology that automatically obtains Internet information. The principle is to automatically obtain and parse website content on the Internet by writing programs, and capture the required data for processing or storage. In the evolution of crawler programs, many mature

Implementation method of high-performance PHP crawler Implementation method of high-performance PHP crawler Jun 13, 2023 pm 03:22 PM

With the development of the Internet, the amount of information in web pages is getting larger and deeper, and many people need to quickly extract the information they need from massive amounts of data. At this time, crawlers have become one of the important tools. This article will introduce how to use PHP to write a high-performance crawler to quickly and accurately obtain the required information from the network. 1. Understand the basic principles of crawlers. The basic function of a crawler is to simulate a browser to access web pages and obtain specific information. It can simulate a series of operations performed by users in a web browser, such as sending requests to the server.

Getting started with PHP crawlers: How to choose the right class library? Getting started with PHP crawlers: How to choose the right class library? Aug 09, 2023 pm 02:52 PM

Getting started with PHP crawlers: How to choose the right class library? With the rapid development of the Internet, a large amount of data is scattered across various websites. In order to obtain this data, we often need to use crawlers to extract information from web pages. As a commonly used web development language, PHP also has many class libraries suitable for crawlers to choose from. However, there are some key factors to consider when choosing a library that suits your project needs. Functional richness: Different crawler libraries provide different functions. Some libraries can only be used for simple web scraping, while others

Common anti-crawling strategies for PHP web crawlers Common anti-crawling strategies for PHP web crawlers Jun 14, 2023 pm 03:29 PM

A web crawler is a program that automatically crawls Internet information. It can obtain a large amount of data in a short period of time. However, due to the scalability and efficiency of web crawlers, many websites are worried that they may be attacked by crawlers, so they have adopted various anti-crawling strategies. Among them, common anti-crawling strategies for PHP web crawlers mainly include the following: IP restriction IP restriction is the most common anti-crawling technology. By restricting IP access, malicious crawler attacks can be effectively prevented. To deal with this anti-crawling strategy, PHP web crawlers can

Concurrency and multi-threading techniques for PHP crawlers Concurrency and multi-threading techniques for PHP crawlers Aug 08, 2023 pm 02:31 PM

Introduction to concurrency and multi-thread processing skills of PHP crawlers: With the rapid development of the Internet, a large amount of data information is stored on various websites, and obtaining this data has become a requirement in many business scenarios. As a tool for automatically obtaining network information, crawlers are widely used in data collection, search engines, public opinion analysis and other fields. This article will introduce a concurrency and multi-threading processing technique for a PHP-based crawler class, and illustrate its implementation through code examples. 1. The basic structure of the reptile class is used to realize the concurrency and multi-threading of the reptile class.

PHP-based crawler implementation methods and precautions PHP-based crawler implementation methods and precautions Jun 13, 2023 pm 06:21 PM

With the rapid development and popularization of the Internet, more and more data need to be collected and processed. Crawler, as a commonly used web crawling tool, can help quickly access, collect and organize web data. According to different needs, there will be multiple languages ​​​​to implement crawlers, among which PHP is also a popular one. Today, we will talk about the implementation methods and precautions of crawlers based on PHP. 1. PHP crawler implementation method Beginners are advised to use ready-made libraries. For beginners, you may need to accumulate certain coding experience and network

How to use PHP to implement a crawler and capture data How to use PHP to implement a crawler and capture data Jun 27, 2023 am 10:56 AM

With the continuous development of the Internet, a large amount of data is stored on various websites, which has important value for business and scientific research. However, these data are not necessarily easy to obtain. At this point, the crawler becomes a very important and effective tool, which can automatically access the website and capture data. PHP is a popular interpreted programming language. It is easy to learn and has efficient code, making it suitable for implementing crawlers. This article will introduce how to use PHP to implement crawlers and capture data from the following aspects. 1. Working principle of crawler

How to use PHP crawler to automatically fill forms and submit data? How to use PHP crawler to automatically fill forms and submit data? Aug 08, 2023 pm 12:49 PM

How to use PHP crawler to automatically fill forms and submit data? With the development of the Internet, we increasingly need to obtain data from web pages, or automatically fill in forms and submit data. As a powerful server-side language, PHP provides numerous tools and class libraries to implement these functions. In this article, we will explain how to use crawlers in PHP to automatically fill forms and submit data. First, we need to use the curl library in PHP to obtain and submit web page data. The curl library is a powerful

See all articles