OT: linux vs vt100 termcap problems + screen - help!

[Brian K. White]

On 12/7/2010 7:13 PM, Fairlight wrote:
> Okay, this is driving me NUTS!  Someone, please, for the love of all that's
> good and holy, save my sanity.
>
> I have screen(1) in play.  It's 8-bit clean, and will do UTF-8.
>
> My setup:
>
> PuTTY or Anzio (doesn't matter which) ->
> OpenSuSE 11.1 TERM=linux ->
> screen ->
> ssh->
> any system TERM=linux ->
> mutt, yast, any ncurses-based program
>
> Okay...On the box to which I ssh from inside screen, if I have TERM=linux,
> then colours draw incompletely, and some graphics characters are wrong
> (notably the arrows in thread mode in mutt.  The screens draw incompletely.
> Notably, what I mean by this is that colour is entirely absent wherever
> there's not a character drawn (even a space will force colour painting).
>
> If I change that box to which I ssh to read TERM=vt100, vt220,
> vt320...anything in the vtxxx series, I lose colour, but at least the
> screen draws solidly in yast, and the arrows are correctly drawn in mutt.
>
> Problem:  I want my termcap to be linux on the target ssh'd box at all
> times, so that I can use -one- terminal setting across multiple emulators
> and locations.
>
> Please tell me what the key difference between the vtxxx and linux entries
> actually is that's causing this bloody nightmare that I've wasted hours on?
> The linux entry is -supposed- to be an extended vt220.  It doesn't act like
> it.  And it's driving me mad.  I literally am using the same encodings, the
> same font...and it's soley the termcap setting that's causing my headaches.
>
> Problem 2:  I also don't want to have to modify the core /etc/termcap file
> for the linux entry.  I need a way to set TERM=linux, yet fix the actual
> problem that accounts for the difference.  I thought there was a way around
> that...memory is hazy, but I think you can shove an entire termcap entry
> into $TERMCAP and that does it.  So I could copy the core entry and just
> modify what needs changing and stuff it in the environment.  But I need to
> know what the critical difference is that's causing these mis-draws.
>
> Retaining colour would be ideal, but if I absolutely have to suffer
> monochrome, so be it--grudgingly.
>
> I know we have some termcap gods here...please, save what's left of my
> sanity.
>
> mark->

I've been using screen a lot lately, but only for sysadmin tasks that 
don't really care much how well the terminal works. Like a long rsync or 
a one-off script that I know will have to chug a long time doing 
something to a zillion scanned image files. And as the "console" for 
virtual servers running in lxc containers.

I have seen similar problems though not as bad. I can't get fp working 
perfectly, but yast and midnight commander work ok.

I have not looked deeply into it since I haven't cared yet, but trying 
to help someone else here the other day I saw that screen sets TERM to 
"screen.${TERM}", and in /etc/termcap there are screen.linux, 
screen.rxvt etc...

Copying screen.linux to fp termcap and copying the fp-specific fields 
from fp's regular linux entry did NOT make filepro work in a 
screen-in-linux terminal.

Neither did copying the "screen" entry.

At that point I cut my losses spending time on it because I was really 
busy and _I_ didn't need this to work perfectly, neither did they 
really. There are several cooks in that pot and it would be a tedious 
chore to plod through the process of elimination, so I just gave the 
person involved the hints and background necessary to hunt down the 
glitch themselves at their leisure.

-- 
bkw