[GRASS-dev] select issue with wingrass

[Glynn Clements]

Moritz Lennert wrote:

> > We received an error with the following simple mapcalc statements
> > 
> > r.mapcalc 'frict=1'
> > r.mapcalc 'test=pendiente*2'
> > 
> > It turns out that you cannot use single quotes in this context. You need to
> > use regular quotes. So the way to specify the same mapcalc statements from
> > the GUI command console is...
> > 
> > r.mapcalc "frict=1"
> > r.mapcalc "test=pendiente*2"
> > 
> > I thought we had tried double quotes too, but maybe we didn't. I'll wait for
> > Javi to check email and test. The worrisome thing is that we initially used
> > the GUI map calculator from the menu and got an error. I tried it this
> > morning on my Mac and did not get an error.
> 
> In windows you don't need any quotation marks, so
> 
> r.mapcalc frict=1 also works, as does r.mapcalc x=frict/3.
> 
> The only issue might be special characters which you would have to 
> escape somehow.

Those examples will work without quotes on any platform. Also, the
expression can be split over multiple arguments; r.mapcalc just
concatenates its arguments with spaces between them.

You only need quotes if there are any shell metacharacters; Bourne
shells have more of those than cmd.exe, so it's more of an issue for
Unix.

I don't recall whether cmd.exe expands * and ?, or whether that's up
to the individual program.

-- 
Glynn Clements <glynn at gclements.plus.com>