pbmtog3 --version (return code: 0)
pbmtog3: Using libpbm from Netpbm Version: Netpbm 10.0
pbmtog3: BSD defined
pbmtog3: RGB_ENV='RGBDEF'
pbmtog3: RGBENV= 'RGBDEF' (env vbl is unset)
pbmtog3 -h (return code: 1)
usage: pbmtog3 [-reversebits] [pbmfile]