check if run in a GRASS session

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@42909 15284696-431f-4ddb-bdfa-cd5b030d7da7

scripts/v.krige/v.krige.py

@@ -104,6 +104,10 @@ from tempfile import gettempdir
 import time
 import thread
 
+if not os.environ.has_key("GISBASE"):
+    print "You must be in GRASS GIS to run this program."
+    sys.exit(1)
+
 GUIModulesPath = os.path.join(os.getenv("GISBASE"), "etc", "gui", "wxpython", "gui_modules")
 sys.path.append(GUIModulesPath)