[GRASS5] nviz problem

[Huidae Cho]

Hi Bob,

Do you have any progress on this nviz background issue?

Thank you.
Huidae Cho



On Thu, Jan 06, 2005 at 10:29:33PM +0000, Glynn Clements wrote:
> 
> Bob Covill wrote:
> 
> > The original reason I had changed nviz to run directly as nvwish was the 
> > error handling. All errors seemed to generate the same unhelpful output 
> > when passed through the original script. Somthing along the line of ...
> > 
> > .............
> > child killed: segmentation violation
> >      while executing
> > "exec /usr/local/grass5/etc/nviz2.2/NVWISH2.2 -f
> > /usr/local/grass5/etc/nviz2.2/scripts/nviz2.2_script -q -name NVIZ
> >  >&@stdout"
> >      ("eval" body line 1)
> 
> Right. The easiest solution to that issue is to rewrite the "nviz"
> script as a Bourne-shell script instead of a Tcl script.
> 
> Bourne shell doesn't print anything if an external command fails.
> 
> > Interestingly, when I started looking into this I notice that v.digit is 
> > written as a modified wish (I think?).
> 
> v.digit uses the "form" library (as does d.what.vect). Most of the
> functions in that library just send data to an external program, which
> is a modified wish (sort of; it tries to do too much in C, which is
> probably why it isn't particularly reliable).
> 
> > What would be the best front-end to nviz? It needs to satisfy G_gui(), 
> > allow errors to handled more cleanly, and allow by-passing G_parser when 
> > in script mode.
> 
> The error messages can be fixed by using /bin/sh instead of Tcl.
> 
> The G_gui() issues can be fixed by either:
> 
> a) having NVWISH2.2 force the program name to "nviz" (this may require
> the addition of e.g. G_set_program_name() to parser.c, but that's
> trivial), or
> 
> b) making the "nviz" script use g.parser (so, in the G_gui() case, the
> re-execution is performed before NVWISH2.2 gets involved).
> 
> -- 
> Glynn Clements <glynn at gclements.plus.com>