Re: [Lynx-dev] uxterm vs GNU screen weirdness

[Thomas Dickey]

On Sat, Sep 27, 2008 at 07:11:08PM +0000, Thorsten Glaser wrote:
> Hi!
> 
> In a 60x24 uxterm (version 200 + MirOS patches):
> 
> lynx .<return>v
> 
> <<<                                 Bookmark file (p1 of 21)
> 
> screen lynx .<return>v
> 
> ←←←                                 Bookmark file (p1 of 22)
> 
> Why this difference? I think uxterm is pretty well capable of displaying
> the ←←← left arrows.
> 
> address@hidden:~ $ print $TERM
> xterm-xfree86
> 
> address@hidden:~ $ print $TERM
> screen

There can be differences in the terminal data, but what I have here from
"infocmp xterm-xfree86 screen" shows this comparison for the acsc string:

        acsc: '``aaffggiijjkkllmmnnooppqqrrssttuuvvwwxxyyzz{{||}}~~', 
'++\,\,--..00``aaffgghhiijjkkllmmnnooppqqrrssttuuvvwwxxyyzz{{||}}~~'.

better (xterm-xfree86 on top):

            '``aaffggiijjkkllmmnnooppqqrrssttuuvvwwxxyyzz{{||}}~~'
'++\,\,--..00``aaffgghhiijjkkllmmnnooppqqrrssttuuvvwwxxyyzz{{||}}~~'.

The left-arrows are mapped with

#define ACS_LARROW      NCURSES_ACS(',') /* arrow pointing left */

which means those escaped commas.  If xterm's _not_ in UTF-8 mode, then
none of the different mappings work, because none of them are VT100-compatible.
(screen doesn't care - it'll happily display commas, etc).

ncurses (actually ncursesw) can display either - but the nice arrows are done
only via the wide-character interface (for compatbility).  lynx could be
modified to do that - though it probably would only work with ncurses.

-- 
Thomas E. Dickey <address@hidden>
http://invisible-island.net
ftp://invisible-island.net