Telnet server: Detecting CTRL-<key>, as happends with CTRL-C
Hello, I have an application, with Python 2.4 and Twisted 8.2.0. Can I somehow detect e.g. CTRL-J key presses in: class Telnet_simulation(telnet.Telnet) --> def dataReceived(self, data): (or elsewhere in code)? When sending CTRL-C, the dataReceived() is called immeaditely, but when sending some other combinations, the data can be seen only after Enter is pressed? (telnet_Command is called then) But the CTRL-J is not a telnet command, it should act same way as CTRL-C. Thank you, Teuvo
On Wed, 4 Feb 2009 13:35:23 +0200, "Eloranta, Teuvo \(NSN - FI/Tampere\)"
Hello,
I have an application, with Python 2.4 and Twisted 8.2.0.
Can I somehow detect e.g. CTRL-J key presses in:
class Telnet_simulation(telnet.Telnet) --> def dataReceived(self, data):
(or elsewhere in code)?
If the `telnet´ above is twisted.protocols.telnet, then you should switch to twisted.conch.telnet. If it's twisted.conch.telnet, then you should override `applicationDataReceived´, not `dataReceived´ (or use one of the other mechanisms for hooking into it - subclass and override is one approach, but there are others which you can find examples of in doc/conch/ examples).
When sending CTRL-C, the dataReceived() is called immeaditely, but when sending some other combinations, the data can be seen only after Enter is pressed? (telnet_Command is called then) But the CTRL-J is not a telnet command, it should act same way as CTRL-C.
Ah, telnet_Command, I guess you are using twisted.protocols.telnet. :) Most likely your telnet client is in line editing mode. This means it isn't sending data typed in until enter is pressed, so of course you can't receive it until then. There are telnet negotiation options which you can use from the server to ask the client to go into character mode. You can see some code which negotiates about linemode in twisted/conch/telnet.py (search for LINEMODE). I'm not sure if LINEMODE is the preferred option for controlling this behavior (I seem to recall there being another one, but I forget which obsoleted which). Also, twisted-python@twistedmatrix.com might be a more appropriate list for this topic, since this is a web-oriented list. Jean-Paul
Hi Jean-Paul! Ok, that's exactly what I was after, the character mode. I'll try make the telnet client switch to character mode with IAC + WONT + LINEMODE Br. Teuvo
I have an application, with Python 2.4 and Twisted 8.2.0.
Can I somehow detect e.g. CTRL-J key presses in:
class Telnet_simulation(telnet.Telnet) --> def dataReceived(self, data):
(or elsewhere in code)?
If the `telnet´ above is twisted.protocols.telnet, then you should switch to twisted.conch.telnet. If it's twisted.conch.telnet, then you should override `applicationDataReceived´, not `dataReceived´ (or use one of the other mechanisms for hooking into it - subclass and override is one approach, but there are others which you can find examples of in doc/conch/ examples).
When sending CTRL-C, the dataReceived() is called
immeaditely, but when
sending some other combinations, the data can be seen only after Enter is pressed? (telnet_Command is called then) But the CTRL-J is not a telnet command, it should act same way as CTRL-C.
Ah, telnet_Command, I guess you are using twisted.protocols.telnet. :)
Most likely your telnet client is in line editing mode. This means it isn't sending data typed in until enter is pressed, so of course you can't receive it until then. There are telnet negotiation options which you can use from the server to ask the client to go into character mode. You can see some code which negotiates about linemode in twisted/conch/telnet.py (search for LINEMODE). I'm not sure if LINEMODE is the preferred option for controlling this behavior (I seem to recall there being another one, but I forget which obsoleted which).
Also, twisted-python@twistedmatrix.com might be a more appropriate list for this topic, since this is a web-oriented list.
Jean-Paul
participants (2)
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Eloranta, Teuvo (NSN - FI/Tampere) -
Jean-Paul Calderone