pbmtomacp --version (return code: 0)
pbmtomacp: Using libpbm from Netpbm Version: Netpbm 10.0
pbmtomacp: BSD defined
pbmtomacp: RGB_ENV='RGBDEF'
pbmtomacp: RGBENV= 'RGBDEF' (env vbl is unset)
pbmtomacp -h (return code: 1)
usage: pbmtomacp [-l left] [-r right] [-b bottom] [-t top] [pbmfile]