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Re: Problem with function keys codes with vt100 emulation


The TERM variable is most certainly _not_ broken. You're misunderstanding what it's for. The TERM variable is how programs that must adapt to different terminal types (emulators or physical hardware) find out how to properly drive the terminal's display and respond to characters sent by it.

Some applications use termcap, others use compiled terminfo. They're conceptually the same thing (hence the possibility for a utility like "captoinfo"). They simply are a way to capture the details of how software should interact with a terminal (or a terminal emulator).

There are many terminals out there (I think--I haven't seen one for years now) and they all use distinct control sequences and produce distinct key sequences. That's why one needs something like termcap or terminfo.

Beyond curiosity, which is fine, there's no need for you to know the details of the design and operation of a terminal emulator (any more than you need to know how a hardware terminal works, as long as it does work...).

I'm not sure you actually have a problem, do you? Any program that uses either termcap or terminfo (correctly) should work under Cygwin as long as the TERM variable is set properly. Why are you trying to change TERM? Just leave it the way Cygwin initializes it and you should be fine.

As I said, I don't know anything about captoinfo, so I can't help you with it. Have you read its man page?

Randall Schulz
Mountain View, CA USA

At 15:06 2002-11-06, you wrote:
Randall, thanks for the quick response.

So the TERM environment variable is somewhat broken, in that setting it to
something else is a no-op.  The first question that comes to mind is whether
this is characterized as a bug or a feature, and if a bug how deep does it
run, and how likely that it will ever be fixed.

On the issue of 3 terminal emulation models (cygwin console, RXVT, and
xterm) I am a bit lost.  Forgive me for being slow here, but if I understand
you correctly the terminal emulation model is hard-coded into these
applications (knowing how would be nice).  Does this mean that /etc/termcap
is not used at all?  For example, if I change the termcap entry for linux
(cygwin inherits from linux) to generate vt100 function key codes then will
I get \EOP for f1 in the cygwin console?

Is there any reference materials I can read to bring myself up to date on
the architectural issues/shortcomings here?

On the problem with captoinfo the issue is that it prints nothing (other
than errors) to stdout.  I have captured the output of "captoinfo
/etc/termcap" and "captoinfo -V /etc/termcap" in the two attached file for
your reference.  As I said before, considering the findings so far, this is
probably unrelated to the topic of the discussion.

Thanks again,


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