[GRASSLIST:7695] Re: g.mapset OR g.gisenv (GUI wishlist discussion)

[Glynn Clements]

Dave Sampson wrote:

> having posted a wish to be able to move between mapsets and locations 
> without closing out of GRASS I was given two options from two people 
> (ref bug#3456).
> 
> One was g.mapset and the other is g.gisenv. Some questions.
> 
> 1. What is the difference between the two

g.gisenv is a general-purpose utility for modifying GRASS parameters.

g.mapset is more specific. It can only modify the GISDBASE,
LOCATION_NAME and MAPSET parameters; however, it does some sanity
checking, handles locking correctly, etc.

With the addition of g.mapset, the g.gisenv approach should be
considered deprecated.

> 2. Can a button be built in to show ALL mapsets and coresponsing 
> locations for either or both of these. This could enhance the gui

It would be possible to make the location and mapset fields into combo
boxes.

> 3. It appears that g.mapset creates only a NEW location. How do you 
> access a created location that is not current.

If so, that's a bug. The code explicitly checks that the selected
database, location or mapset exists.

> 4. for g.gisenv is it possible to provide options of what variables are 
> possible to change? eg dataset, mapset, location and have these 
> accesible through a button.

Not realistically; the set of GRASS variables is open-ended.

g.gisenv is a low-level tool, primarily for use by scripts, or for
quick hacks where a more suitable tool doesn't exist.

> 5. could someone provide an example of how I might COMPLETELY move from 
> one location and mapset to a new location with a mapset of the same name.

Convenient tools for creating a new database, location or mapset are
currently missing. At present, this can only easily be done at
startup.

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