buffer a polygon

[Jim Westervelt]

#When you are running a GRASS job in the background with a given region, can
#you change regions interactively using d.rast.zoom, etc., without messing up
#the background job?

For most single grass programs, yes.  That is, while e.g. r.watershed runs
it is safe to change regions, quit GRASS, etc.   Some programs may resample
the region while they are running - though I can't think of any off hand.

Batch jobs containing many GRASS commands will certainly get messed up!  This
is because the region information is read out of a file.  Want to fund an
upgrade to keep all this information in shell variables to avoid this 
problem?