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