First Client and Server

This complete program starts a loopback TCP echo server and a client, verifies a reply, and shuts both down.

Create the application project

Follow installation to install dependencies. Create CMakeLists.txt next to main.cpp, replacing /path/to/arknet with your checkout path:

cmake_minimum_required(VERSION 3.21)
project(arknet_echo LANGUAGES CXX)
add_subdirectory(/path/to/arknet arknet-build)
add_executable(arknet_echo main.cpp)
target_link_libraries(arknet_echo PRIVATE arknet::arknet)

arknet is header-only; the interface target propagates build settings and dependencies.

Add the client and server

Put the complete program below in main.cpp:

#include <chrono>
#include <future>
#include <string>

#include <arknet/arknet.hpp>
using namespace std::chrono_literals;

int main()
{
    arknet::tcp_server server;
    server.bind_recv([](auto& session, std::string_view data)
    {
        session->async_send(data);
    });
    if (!server.start("127.0.0.1", 0, arknet::use_dgram))
        return 1;

    arknet::tcp_client client;
    client.set_auto_reconnect(false);
    std::promise<std::string> reply;
    client.bind_recv([&](std::string_view data)
    {
        reply.set_value(std::string(data));
    });
    if (!client.start("127.0.0.1", server.get_listen_port(), arknet::use_dgram))
        return 2;
    auto result = reply.get_future();
    if (!client.async_send("hello"))
        return 3;
    const bool ready = result.wait_for(5s) == std::future_status::ready;
    const bool correct = ready && result.get() == "hello";
    client.stop();
    server.stop();
    return correct ? 0 : 4;
}

Build and check the echo

cmake -S . -B build
cmake --build build --parallel 3
./build/arknet_echo

Exit status 0 confirms that the client received hello and both endpoints stopped. With Visual Studio, build with --config Release and run build/Release/arknet_echo.exe.

Next Steps

Choose TCP, UDP, WebSocket, HTTP and routing or TLS. Read lifecycle and sends before keeping objects in a service, and IO models before sharing a context.