[GRASS-dev] use of WIND_OVERRIDE in GRASS

[Ivan Shmakov]

>>>>> Glynn Clements <glynn at gclements.plus.com> writes:

 >> exec `g.region rast="$RAST"`

 > This is bogus on two counts. First, g.region doesn't output a shell
 > command, so the use of exec and backticks makes no sense. Second,
 > shell scripts shouldn't change the current region; they should create
 > a temporary region with "g.region ... save=..."  and use
 > WIND_OVERRIDE.

	Apparently, there're a couple of scripts to be fixed in GRASS
	itself.  An (untested) patch follows.

diff --git a/scripts/i.fusion.brovey/i.fusion.brovey b/scripts/i.fusion.brovey/i.fusion.brovey
index ce0be15..8cde5ea 100755
--- a/scripts/i.fusion.brovey/i.fusion.brovey
+++ b/scripts/i.fusion.brovey/i.fusion.brovey
@@ -118,8 +118,6 @@ export LC_NUMERIC
 
 cleanup()
 {
- #restore settings:
- g.region region=i.fusion.brovey.$TMP
  g.remove region=i.fusion.brovey.$TMP > /dev/null
 }
 
@@ -137,10 +135,12 @@ if [ $? -ne 0 ] ; then
  exit 1
 fi
 
-#save current settings:
+# clone current region
 g.region save=i.fusion.brovey.$TMP > /dev/null
+WIND_OVERRIDE=i.fusion.brovey.$TMP
+export WIND_OVERRIDE
 
-g.message message="Temporarily setting raster resolution to PAN resolution: $PANRES"
+# set the resolution
 g.region res=$PANRES -ap > /dev/null
 
 g.message "Performing Brovey transformation..."
diff --git a/scripts/i.in.spotvgt/i.in.spotvgt b/scripts/i.in.spotvgt/i.in.spotvgt
index 826b307..25cbab1 100755
--- a/scripts/i.in.spotvgt/i.in.spotvgt
+++ b/scripts/i.in.spotvgt/i.in.spotvgt
@@ -200,8 +200,10 @@ g.message message="Imported SPOT VEGETATION NDVI map <$NAME>."
 # Coefficient a = 0.004
 # Coefficient b = -0.1
 
-#save region before zoom to SPOT image
-g.region save=spot_$PID 2>&1 >/dev/null
+# switch to a temporary region
+WIND_OVERRIDE=spot_$PID
+export WIND_OVERRIDE
+g.region -d 2>&1 >/dev/null
 g.region rast=$NAME 2>&1 >/dev/null
 
 g.message "Remapping digital numbers to NDVI..."
@@ -276,8 +278,7 @@ EOF
   g.message message="Filtered SPOT VEGETATION NDVI map <${NAME}_filt>."
 fi
 
-# restore user settings:
-g.region region=spot_$PID 2>&1 >/dev/null
+# remove the temporary region
 g.remove region=spot_$PID 2>&1 >/dev/null
 
 #### clean up the mess