can NOT connect telnet

[yanzixiang]

/*******************************************************************************
 * CLI - A simple command line interface.
 * Copyright (C) 2016-2021 Daniele Pallastrelli
 *
 * Boost Software License - Version 1.0 - August 17th, 2003
 *
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 * obtaining a copy of the software and accompanying documentation covered by
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 * must be included in all copies of the Software, in whole or in part, and
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#include <cli/standaloneasioscheduler.h>
#include <cli/cli.h>
#include <cli/clilocalsession.h>
#include <cli/standaloneasioremotecli.h>


using namespace cli;
using namespace std;
namespace cli
{
    using MainScheduler = StandaloneAsioScheduler;
    using CliTelnetServer = StandaloneAsioCliTelnetServer;
    } // namespace cli


#if ASIO_VERSION < 101200
using IoContext = asio::io_service;
#else
using IoContext = asio::io_context;
#endif

class UserInterface
{
public:
    explicit UserInterface(IoContext& iocontext) : scheduler(iocontext)
    {
        auto rootMenu = make_unique< Menu >("cli");
        rootMenu->Insert(
            "hello",
            [](std::ostream& out) { out << "Hello, world\n"; },
            "Print hello world");
        colorCmd = rootMenu->Insert(
            "color",
            [&](std::ostream& out)
            {
                out << "Colors ON\n";
                SetColor();
                colorCmd.Disable();
                nocolorCmd.Enable();
            },
            "Enable colors in the cli");
        nocolorCmd = rootMenu->Insert(
            "nocolor",
            [&](std::ostream& out)
            {
                out << "Colors OFF\n";
                SetNoColor();
                colorCmd.Enable();
                nocolorCmd.Disable();
            },
            "Disable colors in the cli");

        cli = make_unique<Cli>(std::move(rootMenu));
        // global exit action
        cli->ExitAction([](auto& out) { out << "Goodbye and thanks for all the fish.\n"; });
        // std exception custom handler
        cli->StdExceptionHandler(
            [](std::ostream& out, const std::string& cmd, const std::exception& e)
            {
                out << "Exception caught in cli handler: "
                    << e.what()
                    << " handling command: "
                    << cmd
                    << ".\n";
            }
        );

        localSession = make_unique<CliLocalTerminalSession>(*cli, scheduler, std::cout, 200);
        localSession->ExitAction(
            [this](auto& out) // session exit action
            {
                out << "Closing App...\n";
                scheduler.Stop();
            }
        );


        // setup server

        server = make_unique<CliTelnetServer>(*cli, scheduler, 5000);
        // exit action for all the connections
        server->ExitAction([](auto& out) { out << "Terminating this session...\n"; });

    }
private:
    StandaloneAsioScheduler scheduler;
    unique_ptr<Cli> cli;
    unique_ptr<CliLocalTerminalSession> localSession;
    unique_ptr<CliTelnetServer> server;
    CmdHandler colorCmd;
    CmdHandler nocolorCmd;
};

int main()
{
    try
    {
        // main application that creates an asio io_context and uses it
        IoContext iocontext;
        asio::steady_timer timer(iocontext, std::chrono::seconds(5));
        timer.async_wait([](const error_code&) { cout << "Timer expired!\n"; });

        // cli setup
        UserInterface interface(iocontext);

        // start the asio io_context
#if ASIO_VERSION < 101200
        asio::io_service::work work(iocontext);
#else
        auto work = asio::make_work_guard(iocontext);
#endif
        iocontext.run();

        return 0;
    }
    catch (const std::exception& e)
    {
        cerr << "Exception caugth in main: " << e.what() << '\n';
    }
    catch (...)
    {
        cerr << "Unknown exception caugth in main.\n";
    }
    return -1;
}

when connect with windows telnet client

when connect with linux telnet client

and the process exit

the asio lib version is

[daniele77]

I've just tried the same example, with last cli version and asio v. 1.12.2.
Compiled with GCC and running under Linux, it works fine with linux telnet.
I did several test and they always worked.
I guess it's something in your environment.