ppmspread --version (return code: 0)
ppmspread: Using libpbm from Netpbm Version: Netpbm 10.0
ppmspread: BSD defined
ppmspread: RGB_ENV='RGBDEF'
ppmspread: RGBENV= 'RGBDEF' (env vbl is unset)
ppmspread -h (return code: 1)
usage: ppmspread amount [ppmfile]
amount: # of pixels to displace a pixel by at most