ppmtoicr --version (return code: 0)
ppmtoicr: Using libpbm from Netpbm Version: Netpbm 10.0
ppmtoicr: BSD defined
ppmtoicr: RGB_ENV='RGBDEF'
ppmtoicr: RGBENV= 'RGBDEF' (env vbl is unset)
ppmtoicr -h (return code: 1)
usage: ppmtoicr [-windowname windowname] [-expand expand] [-display display] [-rle] [ppmfile]