[MUD-Dev] Re: Telnet Echo OFF/ON commands and other thingies..

Bruce Mitchener ubmitche at mcs.drexel.edu
Thu Oct 1 09:37:16 New Zealand Daylight Time 1998


> Could someone point me towards some documentation on TELNET
> protocols and perhaps a snippet of example code?  I want to
> at least implement echo-off/on for the passwords...
> 
> Short of that, I'll just dive into someone else's mud source,
> but I'd wrather go straight to the official docs if possible..

This is all in the telnet RFCs.  In this case, you are looking for 

http://www.pmg.lcs.mit.edu/cgi-bin/rfc/view?857

A search for 'telnet' and 'IAC' in the RFCs will yield a number of 
documents that may be of interest:

http://www.pmg.lcs.mit.edu/cgi-bin/rfc/find?pattern=telnet+IAC

We do echo on/off control in Cold by writing a buffer to the connection.  

To turn echo off: `[255, 251, 1, 0, 13]
To turn echo on:  `[255, 252, 1, 0, 13]

Where these buffers are arrays of unsigned 8 bit values for characters.

The process of building a state machine for handling telnet IAC sequences 
is covered in at least one of the books on networking mentioned so often 
on here.  The copies I use are at work, so I can't look to see which one 
it is that has the information right now.

Hope this makes sense,

 - Bruce

--
Bruce Mitchener, Jr.
ubmitche at mcs.drexel.edu

Vote Monarchist!  (licensed from Black Unicorn <unicorn at schloss.li>)
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