an-pnmtofits --version (return code: 0)
an-pnmtofits: invalid option -- '-'
an-pnmtofits [options] [<input-file>, default stdin]
or [<input-file> <output-file>]
[-o <output-file>] (default stdout)
[-v]: verbose
[-q]: quiet
an-pnmtofits --help (return code: 0)
an-pnmtofits: invalid option -- '-'
an-pnmtofits [options] [<input-file>, default stdin]
or [<input-file> <output-file>]
[-o <output-file>] (default stdout)
[-v]: verbose
[-q]: quiet