rxvt and line-drawing characters

[Andrew DeFaria]

Charles Wilson wrote:
> Charles Wilson wrote:
>> Strangely, if I set TERM=rxvt-cygwin-native , use luconP as my font , 
>> it does NOT matter whether my CYGWIN variable has codepage:oem, 
>> codepage:ansi, or neither.  The following behaviors are the same:
>>
>> ascii.exe prints the line draw characters
>> pstree -G prints garbage
>>
>> It *could be* due to the fact that pstree uses ncurses, and ascii 
>> does not.   Checking...
>>
>> Hmmm.  /usr/lib/ncurses/test/ncurses.exe (part of the ncurses-demo 
>> package) turns the screen black-on-black when I try to check the 
>> line-draw characters.  So I can't even tell if ACS chars with ncurses 
>> is broken -- first I gotta figure out why the colors are getting 
>> scrogged by the test program!  Somebody, like the ncurses maintainer, 
>> should fix that.
>>
>> Oh.  That'd be me, then.  Ooops.  I'll try to look into it soon, but 
>> PTC.
>
> Okay, so I've looked into this.
Thanks for looking into this...
>
> (1) the ncurses "problem" is not a problem.  The ncurses.exe test 
> program leaves the decision as to whether to use colorfgbg() defaults 
> up to the user (-a fg,bg to explicitly specify defaults, -d to inherit 
> defaults from rxvt, or '' to use the DEFAULT defaults.  Which is, 
> apparently, black on black -- at least when run in an rxvt shell.)
>
> So, running ncurses.exe with -d, (or, for that matter, the hideous -a 
> 1,4 == red-on-blue, unless you've redefined rxvt's colors) works fine. 
> With
>
>   rxvt -fn 'Lucida ConsoleP-16' -tn rxvt-cygwin-native -e /bin/bash
>
> I get nice line draw characters from the ncurses.exe test program.  With
>
>   rxvt -fn 'Lucida Console-16' -tn rxvt-cygwin-native -e /bin/bash
>
> I get "european" characters where the line drawing ones used to be. 
> Just as expected.  Also, codepage:oem|ansi has no effect -- it only 
> applies when using the windows console, not when using rxvt.
>
> (2) So why does pstree misbehave? Because it's hardcoded to use VT-100 
> control characters for line drawing.  But that's EXACTLY where rxvt 
> differs from VT-100 (and where rxvt-cygwin differs from rxvt, and 
> where rxvt-cygwin-native differs from them all).
>
> pstree SHOULD be using tgetent() calls to dynamically obtain the 
> appropriate line-drawing character codes and escape sequences from 
> ncurses/terminfo.  But it doesn't.
>
> (There's also a similar bug in that it doesn't always calculate 
> accurately the width of strings in which these line-draw chars are 
> embedded...but that's a whole 'nother thing.)
>
> Basically, pstree -G should be rewritten; it's just not going to work 
> on cygwin's rxvt (native or X) very well.
>
> "It's surely evil code"
> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=265552
>
>
> Basically, you're stuck with 'pstree -A'.
Works in Cygwin but not on my Linux box (Fedora Core 3):

Jupiter:pstree -A
pstree: invalid option -- A
usage: pstree [ -a ] [ -c ] [ -h | -H pid ] [ -l ] [ -n ] [ -p ] [ -u ]
              [ -G | -U ] [ pid | user]
       pstree -V

    -a     show command line arguments
    -c     don't compact identical subtrees
    -h     highlight current process and its ancestors
    -H pid highlight process "pid" and its ancestors
    -G     use VT100 line drawing characters
    -l     don't truncate long lines
    -n     sort output by PID
    -p     show PIDs; implies -c
    -u     show uid transitions
    -U     use UTF-8 (Unicode)) line drawing characters
    -V     display version information
    -Z     show SELinux security contexts
    pid    start at pid, default 1 (init))
    user   show only trees rooted at processes of that user

-- 
A waist is a terrible thing to mind.


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