Thanks much for the explanation. I'll try this out with the wxPython georectifier I'm working on now.
Michael On 9/4/07 3:32 AM, "Glynn Clements" <[EMAIL PROTECTED]> wrote: > > Michael Barton wrote: > >>> I'm not questioning whether it's necessary to switch mapsets. I'm >>> questioning whether modifying the existing $GISRC is the right >>> approach, or whether gis.m should create a new $GISRC solely for use >>> by the georectifier. >>> >>> Personally, I'd suggest the latter. >> >> OK. I see what you're getting at now. I'm not sure how to accomplish it. >> >> The active GISRC is a tempfile ( /tmp/grass6-cmbarton-6824/gisrc on my >> machine). >> >> Will simply creating a new temporary file with different values for >> LOCATION_NAME and MAPSET have the effect of 'switching' to a different >> working location/mapset? > > You also need to change $GISRC to refer to the new file. > >> If so, how to get the current GRASS session to >> recognize this? > > You don't want the "current GRASS session" to recognise it. What you > want is for the commands run from the georectifier (and nothing else) > to recognise it. > > In gis.m, "set env(GISRC) $tmp_gisrc" before calling such commands, > then set it back afterwards. > > In Python, change GISRC in the environment passed to Popen() for such > commands, e.g.: > > env = os.environ.copy() > env["GISRC"] = tmp_gisrc > child = subprocess.Popen(cmd, env = env, ...) > >> Does it even have to be a text file on disk somewhere or can it simply be >> set to a variable (e.g., Python data object) with the appropriate values? > > It needs to be a text file. > >> Can I just make a minimal GISRC with only location and mapset, or is it >> safer to copy whatever is in the currently active one and then modify >> location and mapset. > > I suggest the latter. If creating a new one, you need at least > GISDBASE, LOCATION_NAME and MAPSET for all commands. The others should > be optional. > >> My active one currently contains... >> >> DIGITIZER: none >> GISDBASE: /Users/Shared/grassdata >> GRASS_DB_ENCODING: utf-8 >> GRASS_ADDON_PATH: >> /Applications/Grass/GRASS-6.3.app/Contents/Resources/etc/gm/script >> MONITOR: x0 >> LOCATION_NAME: xy >> MAPSET: test >> GRASS_RENDER_IMMEDIATE: TRUE >> GRASS_GUI: wx > > [I don't know how the GRASS_RENDER_IMMEDIATE setting got there; that's > an environment variable.] > > I have: > > GISDBASE: /opt/grass-data > LOCATION_NAME: spearfish57 > MAPSET: glynn > GRASS_DB_ENCODING: ascii > GRASS_GUI: text > > GRASS_DB_ENCODING is only used by the form library. GRASS_GUI is used > to remember the -text/-gui/etc setting between sessions and to > determine whether --ui uses Tcl/Tk or wxPython. Neither of these are > relevant for non-interactive commands. __________________________________________ Michael Barton, Professor of Anthropology Director of Graduate Studies School of Human Evolution & Social Change Center for Social Dynamics & Complexity Arizona State University phone: 480-965-6213 fax: 480-965-7671 www: http://www.public.asu.edu/~cmbarton _______________________________________________ grass-dev mailing list [email protected] http://grass.itc.it/mailman/listinfo/grass-dev
