Proxy Chip

The main task of these two popular technologies is to provide security for the Internet user. Despite a certain similarity of tasks, they are performed absolutely differently. Proxy, although it allows you to remain anonymous and bypass blocked sites, it is still quite vulnerable, especially when it comes to untested services. VPN in this regard looks preferable, because thanks to end-to-end encryption it reliably protects information from the entry point to the exit point.

CefSharp is a .NET wrapper for the Chromium Embedded Framework (CEF) that allows you to embed a Chromium browser in your .NET applications. While CefSharp doesn't have a direct replacement for Selenium functions, you can use its own methods to interact with the browser and perform similar actions.

To find elements using XPath in CefSharp, you can use the GetElementById(), GetElementsByClassName(), GetElementsByTagName(), and GetElementsByAttribute() methods provided by the CEFBrowser and CefV8Handler classes.

Here's an example of how you can find elements using XPath in CefSharp:

First, install the CefSharp NuGet package in your project:

Install-Package CefSharp.Minimal

Use the following code to create a CefSharp browser and load a webpage:

using CefSharp.WinForms;
using System;
using System.Drawing;
using System.Windows.Forms;

namespace CefSharpExample
{
    public class Program
    {
        [STAThread]
        public static void Main(string[] args)
        {
            CefSettings settings = new CefSettings();
            settings.BrowserSubprocessPath = "path/to/cef/browser_win32_x64.exe";
            settings.CefCommandLineArgs.Add("--disable-gpu");
            settings.CefCommandLineArgs.Add("--headless");
            Cef.Initialize(settings);

            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);

            using (Form mainForm = new Form())
            {
                ChromiumWebBrowser browser = new ChromiumWebBrowser("https://www.example.com");
                mainForm.Controls.Add(browser);
                mainForm.Show();

                // Wait for the browser to initialize
                Application.DoEvents();

                // Load the JavaScript needed to interact with the browser
                browser.EvaluateScriptAsync("document.body.style.behavior = 'url(#default#homepage)'; document.body.style.expression = 'ieUseLinkHover=true';");

                // Wait for the page to load
                Application.DoEvents();

                // Add event handlers for navigation, loading, and error events
                browser.LoadingStateChanged += (sender, args) => { };
                browser.NavigationStateChanged += (sender, args) => { };
                browser.ErrorOccurred += (sender, args) => { };

                // Perform actions on the webpage using the browser object
                // ...

                // Close the browser when done
                browser.Dispose();
            }

            Cef.Shutdown();
        }
    }
}

To find elements using XPath, you can use the CefV8Handler class to execute JavaScript code that locates elements based on the XPath expression. Here's an example of how to find elements using XPath:

using System;
using CefSharp.WinForms;

namespace CefSharpXPathExample
{
    public class Program
    {
        [STAThread]
        public static void Main(string[] args)
        {
            CefSettings settings = new CefSettings();
            settings.BrowserSubprocessPath = "path/to/cef/browser_win32_x64.exe";
            settings.CefCommandLineArgs.Add("--disable-gpu");
            settings.CefCommandLineArgs.Add("--headless");
            Cef.Initialize(settings);

            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);

            using (Form mainForm = new Form())
            {
                ChromiumWebBrowser browser = new ChromiumWebBrowser("https://www.example.com");
                mainForm.Controls.Add(browser);
                mainForm.Show();

                // Wait for the browser to initialize
                Application.DoEvents();

                // Load the JavaScript needed to interact with the browser
                browser.EvaluateScriptAsync("document.body.style.behavior = 'url(#default#homepage)'; document.body.style.expression = 'ieUseLinkHover=true';");

                // Wait for the page to load
                Application.DoEvents();

                // Execute JavaScript code to find elements using XPath
                browser.ExecuteScriptAsync("var xpath = arguments[0];" +
                                           "var result = document.evaluate(xpath, document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null);" +
                                           "return result.singleNodeValue;", "//*[@id='element-id']");

                // Perform actions on the webpage using the browser object
                // ...

                // Close the browser when done
                browser.Dispose();
            }

            Cef.Shutdown();
        }
    }
}

In this example, we use the ExecuteScriptAsync() method to execute JavaScript code that finds elements using the provided XPath expression. The JavaScript code uses the document.evaluate() method to find the first matched node based on the provided XPath expression.

Keep in mind that the CefSharp library is actively maintained and provides a wide range of features for interacting with the browser. You can find more information and examples in the CefSharp GitHub repository.

In Qt, you can use the QUdpSocket class to handle incoming UDP packets and the QDataStream class to parse the QByteArray into a bitfield structure. Here's an example of how to accept and parse a UDP QByteArray into a bitfield structure in Qt:

1. First, create a structure to represent the bitfield:

struct Bitfield {
    unsigned int field1 : 8;
    unsigned int field2 : 8;
    unsigned int field3 : 8;
    unsigned int field4 : 8;
};

2. Next, create a QUdpSocket object and bind it to a specific port:

QUdpSocket udpSocket;
if (!udpSocket.bind(QHostAddress::Any, 12345)) {
    qDebug() << "Failed to bind UDP socket:" << udpSocket.errorString();
    return;
}

3. In the readyRead() slot, accept incoming UDP packets and parse the QByteArray:

void MyClass::handleIncomingDatagram() {
    QByteArray datagram = udpSocket.receiveDatagram();
    QDataStream dataStream(&datagram, QIODevice::ReadOnly);

    Bitfield bitfield;
    dataStream >> bitfield;

    // Process the bitfield structure as needed
    qDebug() << "Received bitfield:" << bitfield.field1 << "," << bitfield.field2 << "," << bitfield.field3 << "," << bitfield.field4;
}

4. Finally, connect the readyRead() signal to the handleIncomingDatagram() slot:

connect(&udpSocket, &QUdpSocket::readyRead, this, &MyClass::handleIncomingDatagram);

In this example, the handleIncomingDatagram() slot is called whenever a new UDP packet is received. The slot accepts the incoming datagram, parses it into a bitfield structure using QDataStream, and processes the bitfield as needed.

Make sure to include the necessary headers in your code:

#include 
#include 
#include 
#include 

This example assumes that the incoming UDP packet contains exactly 4 bytes, which is enough to store the bitfield structure. If the packet contains more data, you'll need to handle it accordingly.

In Scrapy, you can control the caching behavior of requests made by rules in your spider by adjusting the dont_cache attribute in the Rule object. The dont_cache attribute, when set to True, indicates that the requests matched by the rule should not be cached.

Here's an example of how you can use dont_cache in a CrawlSpider:

from scrapy.linkextractors import LinkExtractor
from scrapy.spiders import CrawlSpider, Rule

class MySpider(CrawlSpider):
    name = 'my_spider'
    allowed_domains = ['example.com']
    start_urls = ['http://example.com']

    rules = (
        # Example Rule with dont_cache set to True
        Rule(LinkExtractor(allow=('/page/')), callback='parse_page', follow=True, dont_cache=True),
    )

    def parse_page(self, response):
        # Your parsing logic for individual pages goes here
        pass

- The spider is defined as a CrawlSpider.
- The Rule is created with LinkExtractor to match URLs that contain '/page/' in them.
- The dont_cache=True attribute is set to True in the Rule, indicating that requests matched by this rule should not be cached.

By setting dont_cache to True, Scrapy will make sure that requests matched by this rule will be fetched without considering the cache. This is useful when you want to ensure that each request to the specified URLs results in a fresh response, bypassing any cached data.

Open the "Data and memory" item in the settings, and then, under "Proxy", click "Proxy settings". In the "Connection" window that opens, select "Add proxy" and then check the SOCKS5 proxy. Next, in the "Server" field, you must enter the IP of the proxy, and in the "Port" field enter the port SOCKS5. The next step is to enter the login from the proxy and the password from the proxy. Now, all you have to do is click "Done".