Mimicking human browsing behavior in a PHP web scraping script is important to avoid detection by anti-scraping mechanisms. Here are several techniques you can use to make your PHP scraper more human-like:
1. User-Agent Rotation
Websites often check the User-Agent string to identify the browser and operating system of the visitor. Using a common browser User-Agent in your scraping requests can help mask your bot as a regular browser.
$userAgents = [
'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3',
'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_5) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.1.1 Safari/605.1.15',
// Add more User-Agent strings here
];
// Randomly select a User-Agent
$userAgent = $userAgents[array_rand($userAgents)];
// Use cURL or any HTTP client to set the User-Agent header
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'https://example.com');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_USERAGENT, $userAgent);
$response = curl_exec($ch);
curl_close($ch);
2. Request Delay
Human users do not send requests at a constant rate. Implementing a delay between requests can help simulate human behavior.
$delayInSeconds = rand(2, 10); // Delay between 2 and 10 seconds
sleep($delayInSeconds);
// Perform the request after the delay
3. Click Simulation
Simulate clicks on the webpage by first scraping the URLs of the links/buttons and then making GET/POST requests to those URLs.
// Use a parser like PHP Simple HTML DOM Parser or similar to find URLs
// $html = str_get_html($response);
// $link = $html->find('a#someLink', 0);
// Perform a GET request to simulate a click
// curl_setopt($ch, CURLOPT_URL, $link->href);
// $response = curl_exec($ch);
4. Referrer Header
Include a referrer header in your requests to simulate navigation from one page to another within the site.
curl_setopt($ch, CURLOPT_REFERER, 'https://example.com/previous-page');
5. Cookie Handling
Websites track session information using cookies. Handle cookies like a browser would.
// Enable cookie handling in cURL
curl_setopt($ch, CURLOPT_COOKIEFILE, ''); // Enable cookie handling
curl_setopt($ch, CURLOPT_COOKIEJAR, 'cookie.txt'); // Store cookies in this file
6. JavaScript Execution
Some websites require JavaScript execution to render content or links. You might need to use a headless browser that can execute JavaScript, such as Puppeteer with Node.js, or a PHP library like PHP Puppeteer.
// Example using Puppeteer with Node.js
const puppeteer = require('puppeteer');
(async () => {
const browser = await puppeteer.launch();
const page = await browser.newPage();
await page.setUserAgent('Your User-Agent string here');
await page.goto('https://example.com');
// Simulate human actions using Puppeteer functions
// await page.click('selector');
// await page.waitForTimeout(1000); // Wait for 1 second
await browser.close();
})();
7. Captcha Handling
If the website uses CAPTCHA, you might need to employ CAPTCHA solving services.
// Integrate a CAPTCHA solving service like 2Captcha, Anti-CAPTCHA
// Use their API to send the CAPTCHA and receive the solution
8. Headless Browser Usage
For complex websites where simple HTTP requests are not enough, consider using a headless browser that can fully render pages, including executing JavaScript.
Conclusion
When scraping websites, always follow the site's robots.txt rules and terms of service. Being respectful of the website's resources by not overloading their servers and obtaining content legally is important to maintain ethical scraping practices.
