pbmtoascii --version (return code: 0)
pbmtoascii: Using libpbm from Netpbm Version: Netpbm 10.0
pbmtoascii: BSD defined
pbmtoascii: RGB_ENV='RGBDEF'
pbmtoascii: RGBENV= 'RGBDEF' (env vbl is unset)
pbmtoascii -h (return code: 1)
usage: pbmtoascii [-1x2|-2x4] [pbmfile]