[GRASS-dev] GRASS_RENDER_IMMEDIATE in GRASS7

[Martin Landa]

Hi,

2011/7/8 Glynn Clements <glynn at gclements.plus.com>:
>> AFAIU GRASS_RENDER_IMMEDIATE is used in GRASS7 to set up the display
>> driver, e.g. `cairo` or `ps`. Values TRUE or FALSE are ignored. In
>> this case I would suggest to rename this variable to GRASS_DISPLAY or
>> something similar.
>
> Note that 6.x also understands e.g. "GRASS_RENDER_IMMEDIATE=PS" (the
> only "immediate" drivers available in 6.x are PNG and PS; others
> require the use of a monitor).
>
> IOW, the usage is the same in 6.x and 7.0, except that 7.0 doesn't
> recognise "FALSE" (you'll just get the default driver; cairo if it's
> available, PNG otherwise).

AFAIU all display drivers in G7 are "immediate", monitors as
implemented in G6 has been removed in G7. Right?

>> Similarly GRASS_PNGFILE is used in cairo to set up for e.g. pdf file
>> (GRASS_PNGFILE=map.pdf), `ps` drivers defines GRASS_PSFILE. I would
>> suggest to use only one - generic variable, something like
>> GRASS_MAPFILE, GRASS_OUTFILE or GRASS_FILENAME.
>>
>> Any opinions?
>
> I have no particular opinion on the exact names. However, before
> changing anything, we might want to consider whether these should be
> environment variables or GRASS variables.
>
> Over the years, GRASS has "collected" environment variables like
> people collect stamps or coins, and the collection has become rather
> large.
>
> Some of these environment variables might be better off as GRASS
> variables; this would allow them to be controlled through modules,
> rather than requiring the user to set them on the command line.

That's right, some of them started as shell variables (GRASS_GUI) and
later became GRASS variables (e.g. GRASS_GUI) without changing the
variable name. Manual page variables.html became quite outdated by
time. I would incline to minimalize shell variables if possible. Could
we collect minimal group of shell variable which we need?

> The downside is that scripts (and wxGUI) would need to create a
> temporary $GISRC file rather than just using a modified environment.

That's right. Any opinion from other GRASS devs?

Martin

-- 
Martin Landa <landa.martin gmail.com> * http://geo.fsv.cvut.cz/~landa