After an input file is completed, it has to be processed by the
preprocessor before it can be fed to TEX or LaTeX. The
preprocessor is called devnag. To process an input file, type:
devnag <inputfile> <outputfile>
The default file extension for an input file is .DN and for an
output file .TEX. If no output filename is specified then the
name of the output file will be the same as that of the input file.
Example: devnag hindi will cause devnag to read from the
file hindi.dn and write to the file hindi.tex. If you
just type: devnag then you will be prompted for the names of
the input and output file.