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### Simple HTTP Client 💡

Use HTTP to make a GET request to a website and print the response:

File: http_sync_client.cpp

    #include <boost/beast/core.hpp>
    #include <boost/beast/http.hpp>
    #include <boost/beast/version.hpp>
    #include <boost/asio/connect.hpp>
    #include <boost/asio/ip/tcp.hpp>
    #include <cstdlib>
    #include <iostream>
    #include <string>

    namespace beast = boost::beast;     // from <boost/beast.hpp>
    namespace http = beast::http;       // from <boost/beast/http.hpp>
    namespace net = boost::asio;        // from <boost/asio.hpp>
    using tcp = net::ip::tcp;           // from <boost/asio/ip/tcp.hpp>

    // Performs an HTTP GET and prints the response
    int main(int argc, char** argv)
    {
        try
        {
            // Check command line arguments.
            if(argc != 4 && argc != 5)
            {
                std::cerr <<
                    "Usage: http-client-sync <host> <port> <target> [<HTTP version: 1.0 or 1.1(default)>]\n" <<
                    "Example:\n" <<
                    "    http-client-sync www.example.com 80 /\n" <<
                    "    http-client-sync www.example.com 80 / 1.0\n";
                return EXIT_FAILURE;
            }
            auto const host = argv[1];
            auto const port = argv[2];
            auto const target = argv[3];
            int version = argc == 5 && !std::strcmp("1.0", argv[4]) ? 10 : 11;

            // The io_context is required for all I/O
            net::io_context ioc;

            // These objects perform our I/O
            tcp::resolver resolver(ioc);
            beast::tcp_stream stream(ioc);

            // Look up the domain name
            auto const results = resolver.resolve(host, port);

            // Make the connection on the IP address we get from a lookup
            stream.connect(results);

            // Set up an HTTP GET request message
            http::request<http::string_body> req{http::verb::get, target, version};
            req.set(http::field::host, host);
            req.set(http::field::user_agent, BOOST_BEAST_VERSION_STRING);

            // Send the HTTP request to the remote host
            http::write(stream, req);

            // This buffer is used for reading and must be persisted
            beast::flat_buffer buffer;

            // Declare a container to hold the response
            http::response<http::dynamic_body> res;

            // Receive the HTTP response
            http::read(stream, buffer, res);

            // Write the message to standard out
            std::cout << res << std::endl;

            // Gracefully close the socket
            beast::error_code ec;
            stream.socket().shutdown(tcp::socket::shutdown_both, ec);

            // not_connected happens sometimes
            // so don't bother reporting it.
            //
            if(ec && ec != beast::errc::not_connected)
                throw beast::system_error{ec};

            // If we get here then the connection is closed gracefully
        }
        catch(std::exception const& e)
        {
            std::cerr << "Error: " << e.what() << std::endl;
            return EXIT_FAILURE;
        }
        return EXIT_SUCCESS;
    }