server_send_file.cpp

#include <iostream>
#include <fstream>
#include <boost/asio.hpp>

using boost::asio::ip::tcp;

void start_sending(tcp::socket& socket, const std::string& file_name) {
    std::ifstream file(file_name, std::ios::binary);
    if (!file.is_open()) {
        std::cerr << "Failed to open the file.\n";
        return;
    }

    
    file.seekg(0, std::ios::end);
    size_t file_size = file.tellg();
    file.seekg(0, std::ios::beg);

    boost::asio::streambuf buf;
    std::ostream out_stream(&buf);
    out_stream << file.rdbuf();
    
    boost::asio::write(socket, buf);
}

int main() {
    try {
        boost::asio::io_service io_service;
        tcp::acceptor acceptor(io_service, tcp::endpoint(tcp::v4(), 1234));
        for (;;) {
            tcp::socket socket(io_service);
            acceptor.accept(socket);
            start_sending(socket, "file_to_send.txt");  
        }
    } catch (std::exception& e) {
        std::cerr << "Exception: " << e.what() << "\n";
    }

    return 0;
}