pnmtoxwd --version (return code: 0)
pnmtoxwd: Using libpbm from Netpbm Version: Netpbm 10.0
pnmtoxwd: BSD defined
pnmtoxwd: RGB_ENV='RGBDEF'
pnmtoxwd: RGBENV= 'RGBDEF' (env vbl is unset)
pnmtoxwd -h (return code: 1)
usage: pnmtoxwd [-pseudodepth n] [-directcolor] [pnmfile]