C++ network 同步读写示例

#include <iostream>
#include <experimental/net>
#include <array>
#include <system_error>

int main()
{
    using namespace std::experimental;
    using net::ip::tcp;

    net::io_context io;

    tcp::acceptor acceptor(io,tcp::endpoint(tcp::v4(), 3954) );

    std::array<char,128> arr;

    std::string s{"please wait"};

    for (;;)
    {
        try
        {
            std::error_code err;

            tcp::socket socket = acceptor.accept(io,err);

            size_t len = socket.read_some(net::buffer(arr), err);

            std::cout << "read " << len << " letters" << std::endl;

            for (size_t i = 0; i < len; ++i)
            {
                std::cout << arr[i];
            }

            socket.write_some(net::buffer(s),err );

            socket.close();
        }
        catch (std::exception &e)
        {
            std::cerr << e.what() << std::endl;
        }
    }

    return 0;
}