Re: Newcomer's CAsyncSocket example: trouble connecting with other clients

stephen park wrote:

Wow, I really hate turning this into a .net discussion in an mfc
group, but I built a CLR console app and this just doesn't send
anything to the Newcomer server: (code in its entirety)

#include "stdafx.h"

using namespace System;
using namespace System::Net::Sockets;


int main(array<System::String ^> ^args)
{
TcpClient^ c = gcnew TcpClient( server,port );
String^ msg = "hello, world!";
array<Byte>^data = Text::Encoding::ASCII->GetBytes( msg );
c->Client->Send( data );

Console::ReadKey();

c->Close();

return 0;
}

The server says its connected, but when I hit a key the server says
?.?.?.? [?] Closed

with the "Last Received Message" edit box empty.

Doing the same thing with csocket and an mfc console app does the same
thing. Just what the heck am I missing in both?


I don't know what Joe's program is, but the above is correct when you
are talking to a telnet-like like server. I have no reason to question Joe's CAsyncServer, but I have not try it to see what it suppose to do for you.

What part are you trying to make work? What are you looking for?

What I would do is begin with the basics of writing a TTY client. If you are just learning sockets, you need to begin with the
basics, which comes with "mistakes" and trial and error process.

Try this TTY() function:

void tty(String ^hostname, int port)
{

Console::WriteLine("* Connecting");

TcpClient^ c;

try {
c = gcnew TcpClient(hostname,port);
} catch(SocketException ^e) {
Console::WriteLine(L"- Connect Error {0}",e->ErrorCode);
Console::ReadKey();
return;
}

// use 100ms timeout for reader
c->Client->ReceiveTimeout = 100;

array<Byte>^ bytes = gcnew array<Byte>(1024);
NetworkStream ^cio = c->GetStream();

while (1) {
if (Console::KeyAvailable) {
ConsoleKeyInfo^ key = Console::ReadKey(true);
if (key->Key == ConsoleKey::Escape) break;
try {
cio->WriteByte(key->KeyChar);
} catch( Exception ^e) {
break;
}
}
try {
int nBytes = c->Client->Receive( bytes );
for (int i=0; i < nBytes; i++) {
Console::Write("{0}",(wchar_t)bytes[i]);
}
} catch( SocketException ^e) {
if (e->ErrorCode == 10054) {
Console::WriteLine(L"! Disconnect");
break;
}
}
}
c->Close();
Console::WriteLine("* Closed");
Console::ReadKey();
}


You can try this against any TELNET like server, including any TELNET, SMTP, FTP, NNTP, POP3, IMAP server, etc.

Here are a few telnet servers:

bbs.winserver.com port=23
beta.winserver.com port=23

Even SMTP, FTP or NNTP servers, try these:

msforums.winserver.com port=119
news.microsoft.com port119

You know, you can make the tty() function a SERVER by changing the connect() which you are implicitly doing with the constructor

gcnew TcpClient(hostname,port)

above and replacing it with SOCKET functional calls equivalent in C/C++.NET for:

Listen()
Bind()
Accept()

Anyway, if your question is about your code, it is fine. I don't know Joe's code but I'm sure it works. :)

--
.

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