[GRASS5] GRASS variables and environment variables

GRASS GIS GRASS GIS developer
1

Hi,

Sorry for my ignorance, but I have been wondering why we have two kinds of
variables, GRASS and environment things, and when one should be used over
another one. It can be confusing to new users, I think. If there is a reason,
it would be great to document it in lib/init/variables.html.

Thank you.
Huidae Cho

2

Huidae Cho wrote:

Sorry for my ignorance, but I have been wondering why we have two kinds of
variables, GRASS and environment things, and when one should be used over
another one. It can be confusing to new users, I think. If there is a reason,
it would be great to document it in lib/init/variables.html.

Any setting which needs to be modifiable by a program (e.g. MONITOR)
has to be a GRASS variable.

OTOH, the shell makes it easy to override environment variables for
individual commands, e.g.:

  GRASS_TRANSPARENT=TRUE d.mon start=PNG

Most of the existing GRASS variables need to be GRASS variables.

OTOH, many of the existing environment variables could be changed to
GRASS variables without problems (except for those which aren't
specific to GRASS, e.g. PAGER).

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