pnmrotate --version (return code: 0)
pnmrotate: Using libpbm from Netpbm Version: Netpbm 10.0
pnmrotate: BSD defined
pnmrotate: RGB_ENV='RGBDEF'
pnmrotate: RGBENV= 'RGBDEF' (env vbl is unset)
pnmrotate -h (return code: 1)
usage: pnmrotate [-noantialias] <angle> [pnmfile]