[GRASS-dev] Re: [GRASS-user] Problems with v.outlier and v.lidar.edgedetection

[Brad Douglas]

On Fri, 2006-11-17 at 14:38 +1300, Hamish wrote:
> Markus Neteler wrote:
> > some minutes ago I have submitted a fix from Roberto Antolin
> > to fix a v.outlier problem. It fixes a crash if qgis=name
> > isn't used (so, maybe use that and it works)?
> 
> C question re that fix:   (vector/lidar/v.outlier/main.c)
> 
>     /* Structs' declarations */
>     struct Map_info In, Out, Outlier, Qgis;
>     struct Option *in_opt, *out_opt, *outlier_opt, *qgis_opt, *passoE_opt, *passoN_opt, \
> 	*lambda_f_opt, *Thres_O_opt;
> 
> 
> is the end of line "\" harmful or treated like whitespace?

It's interpreted as string literal concatenation.  In my experience,
it's useful with strings:

Okay for gcc:
fprintf(stderr, "blah blah"
        "more blah blah");

More appropriate:
fprintf(stderr, "blah blah" \
        "more blah blah");

I'm sure Glynn has details, but that is my understanding.  I don't know
if the same issues apply with variable declaration, but it isn't
necessary at least with gcc.


-- 
Brad Douglas <rez touchofmadness com>                    KB8UYR/6
Address: 37.493,-121.924 / WGS84    National Map Corps #TNMC-3785