ppmtolj --version (return code: 0)
ppmtolj: Using libpbm from Netpbm Version: Netpbm 10.0
ppmtolj: BSD defined
ppmtolj: RGB_ENV='RGBDEF'
ppmtolj: RGBENV= 'RGBDEF' (env vbl is unset)
ppmtolj -h (return code: 1)
usage: ppmtolj [-noreset][-float][-delta][-gamma <val>] [-resolution N] [ppmfile]
resolution = [75|100|150|300|600] (dpi)