[En-Nut-Discussion] rs232d_example_question

[Dave]

On Thu, 2005-07-21 at 14:10 +0200, Kersten Voigtsberger wrote:
> Please, can somebody help me to change the example in such 
> a way that the echos to the telnet client are prevented?
> Only the inputs with the rs232 client should be transferred 
> to the telnet client and not its own inputs (and vice versa).

Hi Kersten,

The echo you are getting is from your telnet client, not Nut/OS. Based
on your questions, I think this will be a lot more complex than you
would have guessed. In short, you need to send the right command to the
telnet client, to make it operate a character at a time, instead of a
line at a time, which is the default. I had to deal with the same
problems when I wrote my own telnet server for Nut/OS. Unfortunately
there is no small snippet of code that will solve your problems.

Look at http://www.scit.wlv.ac.uk/~jphb/comms/telnet.html for a nice
little intoduction to the telnet protocol. You might also want to look
at RFC 1143. And if you want to see some C code that will handle the
telnet protocol, then google for "Telnet option processing state
machine" (with the double quotes).

The telnet server I wrote does work, but I'm not finished with it yet.
Based on what you said you're trying to do, I don't think you can easily
rip out my code and drop it into your program and make it work, but
you're welcome to try. If you, or anyone else on the list, would like to
see my telnet server code before I release it, then please see my page
at http://wormfood.net/contact_me.php for the best way to contact me.

-Dave