ppmtopj --version (return code: 0)
ppmtopj: Using libpbm from Netpbm Version: Netpbm 10.0
ppmtopj: BSD defined
ppmtopj: RGB_ENV='RGBDEF'
ppmtopj: RGBENV= 'RGBDEF' (env vbl is unset)
ppmtopj -h (return code: 1)
usage: ppmtopj [-center] [-xpos <pos>] [-ypos <pos>] [-gamma <val>] [-back <dark|lite>] [-rle] [-render <none|snap|bw|dither|diffuse|monodither|monodiffuse|clusterdither|monoclusterdither>] [ppmfile]