Force telnet client into character mode

Question

I have an application where I accept a socket connection from a telnet client and put up a simple, keyboard driven character GUI.

The telnet client, at least on Linu

Answer 1

Interesting. I had more luck sending

IAC WILL ECHO IAC WILL SUPPRESS_GO_AHEAD IAC WONT LINEMODE
255  251    1 255  251                 3 255  252       34

The IAC WONT LINEMODE seems to be redundant: my telnet client seems to get to the right state without it, but I left it in for completeness.

Answer 2

For what it's worth, solved it myself.

// IAC WONT LINEMODE IAC WILL ECHO

write(s,"\377\375\042\377\373\001",6);

gets the remote (at least telnet from an Xterm on a Linux box) into the right state.

Answer 3

Kevin's solution works great: write(s,"\377\375\042\377\373\001",6);

Although the comment is slightly wrong. It should say "DO LINEMODE", not "WONT LINEMODE", ie: // IAC DO LINEMODE IAC WILL ECHO

(Source: rfc854)