Byte Proxy

A proxy server acts as an intermediary between client and server parts of distributed network applications. The role of a transit node provides a logical break in the direct connection between the server and the client. A proxy server can also act as a firewall if the traffic it controls does not go through a workaround.

Qt primarily focuses on providing tools and libraries for GUI development, networking, and other application-level features. While it includes facilities for working with XML through classes like QXmlStreamReader and QXmlStreamWriter, these are more geared toward parsing XML rather than HTML.

For HTML parsing, especially when using XPath expressions, you might need to consider additional libraries or tools. One common choice is to use a third-party library like Gumbo or htmlcxx. These libraries are not part of the Qt framework, but they can be used alongside Qt to handle HTML parsing.

Here's a basic example using htmlcxx for HTML parsing:

#include 
#include 
#include 

int main(int argc, char *argv[]) {
    QCoreApplication a(argc, argv);

    std::string htmlData = "
Hello, world!
";

    htmlcxx::HTML::ParserDom parser;
    tree dom = parser.parseTree(htmlData);

    // Example XPath query
    std::string xpathExpression = "//p/span";
    std::vector::iterator> result;
    htmlcxx::XPath::NodeSet nodeSet;
    htmlcxx::XPath::Parser xpathParser;
    xpathParser.compile(xpathExpression.c_str(), &nodeSet);

    for (tree::iterator it = dom.begin(); it != dom.end(); ++it) {
        nodeSet.evaluate(*it);
        if (nodeSet.size() > 0) {
            result.push_back(it);
        }
    }

    // Output the result
    for (auto &it : result) {
        std::cout << "Match found: " << htmlcxx::HTML::toPlainText(it->begin(), it->end()) << std::endl;
    }

    return a.exec();
}

In this example, I've used htmlcxx for HTML parsing and XPath queries. Note that you need to include the htmlcxx library in your project.

Incoming and outgoing Internet speeds are important indicators of proxy performance because they directly influence the speed of downloading the required information. The value of the ping is important for estimating the speed - the lower the value, the better. You can find out the real speed of your proxy server with the help of proxy checker.

Technically, ISP can block only some intermediary servers by IP-addresses. But it's impossible to block absolutely all VPN-servers, because there are so many of them and their addresses are constantly changing. Accordingly, in this case, you just need to use another VPN-server.

Yes, it is possible to access blocked YouTube or channels unavailable in a certain country using a proxy.