Re: "q"s and "x"s as line graphics on Linux console

[Thomas Dickey]

On Mon, Jan 11, 2021 at 11:29:53AM -0500, Patrick McDermott wrote:
> Hello,
> 
> I'm using ncurses 6.2-20210109 and dialog 1.3-20201126.  It works fine
> on VTE, but on the Linux framebuffer console the line graphics are drawn
> with characters like "q" and "x".  For example:
> 
>     $ dialog --msgbox 'Hello, world!' 5 17
>     lqqqqqqqqqqqqqqqk
>     x Hello, world! x
>     tqqqqqqqqqqqqqqqu
>     x   <  OK  >    t
>     mqqqqqqqqqqqqqqqj
> 
> My environment is `TERM=linux LC_ALL=C` (I also tried `LC_ALL=en_US` and
> variants of the "linux" terminal found in terminfo).  I'm using 8-bit
> ncurses, but I've also tried a wide-character build.  I've tried setting
> `NCURSES_NO_UTF8_ACS=1`, and a glance at the ncurses source shows that
> `TERM=linux` already disables ACS.  I'm not using a UTF-8 locale
> encoding because I'm using Linux's built-in (8-bit) fbcon fonts.
> 
> I've read the FAQ on this issue [1] (and similar discussions online),
> but it doesn't seem to offer a solution in this case (unless there's
> some other $TERM I should try).  Any suggestions?

As far as I know, only rather old Linux kernels don't handle the
VT100-style ^N/^O used in smacs/rmacs.  That came in when 2.6/3.0
became generally prevalent -- sometime between 2006:

http://lkml.iu.edu/hypermail/linux/kernel/0602.2/0738.html

and 2011:

# 2011-07-16
...
#       * add SI/SO change to linux2.6 entry (Debian #515609) -TD

I just checked Debian testing, for example, which has 5.10
(and works as expected).

If you actually have an older kernel (I was discussing a problem
with someone a couple weeks ago who _did_ have an old system), I'd
try

        TERM=linux2.2

(noting that you tried "variants", that might be redundant).

If it's a newer kernel, I might be able to reproduce this,
given the version and distribution, and offer better advice.

-- 
Thomas E. Dickey <dickey@invisible-island.net>
https://invisible-island.net
ftp://ftp.invisible-island.net

signature.asc
Description: PGP signature