ref: 20bca0c2029c53de3d4149d957240b17d44684a8
dir: /sys/src/cmd/postscript/hardcopy/README/
Redirect output of the print operator to paper. Particularly useful if
you're trying to extract information from a printer, but you don't have
access to the data the printer returns to the host.
For example,
FontDirectory {pop ==} forall
names all the fonts registered in the FontDirectory dictionary. Simple,
but only if you can read the data returned to the host by the printer.