The doc directory contains a manual page for this program, which is 
automatically copied to the proper GRASS location (for reference by
g.manual) when this program is compiled.

r.in.hdf uses the NCSA Hierarchical Data Format (HDF) library: BEFORE
compiling this program, you must compile the library (see the README
file in src.garden/grass.hdf for instructions on compiling the HDF
library).

Once the library is compilied:

To compile r.in.hdf you must EDIT THE GMAKEFILE by un-commenting
the line that describes the platform on which you are compiling.
Then use the gmake4.1 command as usual.
