[GRASS-user] r.fillnulls constrained to single cell nulls

Hi,

After reading the documentation for r.fillnulls, and relevant pages from
the Neteler and Mitasova's GRASS book, I am not sure whether it's
possible to constrain r.fillnulls to single cell nulls. Is this
accomplished by constructing a specialized mask with values 0 for areas
with multicell nulls? If so, is there an example of how to build such a
mask?

Thanks,

--
Seb