[GRASS-user] exporting areas to shapefiles without filling holes

[Moritz Lennert]

On 09/04/09 10:47, Markus Neteler wrote:
> On Thu, Apr 9, 2009 at 10:38 AM, Hamish <hamish_b at yahoo.com> wrote:
>>> Hamish wrote:
>>>> I've got a grass vector map containing some areas with holes.
>> ...
>>>> after exporting with 'v.out.ogr type=area' to a shapefile, when I load
>>>> the shp file into QGIS 0.8.1 I see that all the holes have been filled
>>>> in.
>> ...
>>>> what am I doing wrong?
>> Markus Metz:
>>> Maybe use v.out.ogr -c?
>> yup, that's it. I'd focused on the shapefile example in the man page
>> and totally missed the blinking red letters at the top:
> 
> I am also regularly missing that (and only now understand how to
> solve this island problem).
> 
> Any chance to generate a warning if islands are there and -c not
> given? Only then the problem + solution is obvious...

You already have :

"%d features without category were written" (line 638 of 
v.out.ogr/main.c in trunk), maybe you can just add a hint there about 
using '-c' ?

Moritz