Boost C++ Libraries

libs/beast/example/websocket/client/async-local/websocket_client_async_local.cpp

//
// Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
// Copyright (c) 2025 Mohammad Nejati
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// Official repository: https://github.com/boostorg/beast
//

//------------------------------------------------------------------------------
//
// Example: WebSocket client, asynchronous Unix domain sockets
//
//------------------------------------------------------------------------------

#include <boost/asio/local/stream_protocol.hpp>
#include <boost/asio/strand.hpp>
#include <boost/beast/core.hpp>
#include <boost/beast/websocket.hpp>

#include <cstdlib>
#include <iostream>
#include <memory>
#include <string>

#if defined(BOOST_ASIO_HAS_LOCAL_SOCKETS)

namespace beast = boost::beast;                      // from <boost/beast.hpp>
namespace http = beast::http;                        // from <boost/beast/http.hpp>
namespace websocket = beast::websocket;              // from <boost/beast/websocket.hpp>
namespace net = boost::asio;                         // from <boost/asio.hpp>
using stream_protocol = net::local::stream_protocol; // from <boost/asio/local/stream_protocol.hpp>

//------------------------------------------------------------------------------

// Report a failure
void
fail(beast::error_code ec, char const* what)
{
    std::cerr << what << ": " << ec.message() << "\n";
}

// Sends a WebSocket message and prints the response
class session : public std::enable_shared_from_this<session>
{
    websocket::stream<stream_protocol::socket> ws_;
    beast::flat_buffer buffer_;
    std::string host_;
    std::string text_;

public:
    // Resolver and socket require an io_context
    explicit
    session(net::io_context& ioc)
        : ws_(net::make_strand(ioc))
    {
    }

    // Start the asynchronous operation
    void
    run(
        char const* path,
        char const* host,
        char const* port,
        char const* text)
    {
        // Save for later
        host_ = std::string{host} + ":" + port;
        text_ = text;

        // Make the connection
        beast::get_lowest_layer(ws_).async_connect(
            stream_protocol::endpoint{path},
            beast::bind_front_handler(
                &session::on_connect,
                shared_from_this()));
    }

    void
    on_connect(beast::error_code ec)
    {
        if(ec)
            return fail(ec, "connect");

        // Set suggested timeout settings for the websocket
        ws_.set_option(
            websocket::stream_base::timeout::suggested(
                beast::role_type::client));

        // Set a decorator to change the User-Agent of the handshake
        ws_.set_option(websocket::stream_base::decorator(
            [](websocket::request_type& req)
            {
                req.set(http::field::user_agent,
                    std::string(BOOST_BEAST_VERSION_STRING) +
                        " websocket-client-async-local");
            }));

        // Perform the websocket handshake
        ws_.async_handshake(host_, "/",
            beast::bind_front_handler(
                &session::on_handshake,
                shared_from_this()));
    }

    void
    on_handshake(beast::error_code ec)
    {
        if(ec)
            return fail(ec, "handshake");
        
        // Send the message
        ws_.async_write(
            net::buffer(text_),
            beast::bind_front_handler(
                &session::on_write,
                shared_from_this()));
    }

    void
    on_write(
        beast::error_code ec,
        std::size_t bytes_transferred)
    {
        boost::ignore_unused(bytes_transferred);

        if(ec)
            return fail(ec, "write");
        
        // Read a message into our buffer
        ws_.async_read(
            buffer_,
            beast::bind_front_handler(
                &session::on_read,
                shared_from_this()));
    }

    void
    on_read(
        beast::error_code ec,
        std::size_t bytes_transferred)
    {
        boost::ignore_unused(bytes_transferred);

        if(ec)
            return fail(ec, "read");

        // Close the WebSocket connection
        ws_.async_close(websocket::close_code::normal,
            beast::bind_front_handler(
                &session::on_close,
                shared_from_this()));
    }

    void
    on_close(beast::error_code ec)
    {
        if(ec)
            return fail(ec, "close");

        // If we get here then the connection is closed gracefully

        // The make_printable() function helps print a ConstBufferSequence
        std::cout << beast::make_printable(buffer_.data()) << std::endl;
    }
};

//------------------------------------------------------------------------------

int main(int argc, char** argv)
{
    // Check command line arguments.
    if(argc != 5)
    {
        std::cerr <<
            "Usage: websocket-client-async-local <path> <host> <port> <text>\n" <<
            "Example:\n" <<
            "    websocket-client-async-local /tmp/ws.sock localhost 80 \"Hello, world!\"\n";
        return EXIT_FAILURE;
    }
    auto const path = argv[1];
    auto const host = argv[2];
    auto const port = argv[3];
    auto const text = argv[4];

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

    // Launch the asynchronous operation
    std::make_shared<session>(ioc)->run(path, host, port, text);

    // Run the I/O service. The call will return when
    // the socket is closed.
    ioc.run();

    return EXIT_SUCCESS;
}

#else

int
main(int, char*[])
{
std::cerr <<
    "Local sockets not available on this platform" << std::endl;
return EXIT_FAILURE;
}

#endif