Prettyprint to file??

[Robert Elton Maas <REM at MIT-AI>]

To LISP hackers -- Does anybody know of a clean way in NEWIO to
prettyprint or grindef to a file other than the TTY?  I looked
at GFN and GFILE, but GFN (the usual pretty printer) is
hardwired to use the TTY and would seem to need total rewriting
to use a general file (all TYO/PRIN1/PRIN2 etc. would have to
be changed to use another argument...) while GFILE is specially
written to read one file and write another rather than write
arbitrary stuff from memory to a file. (At least that's how it
looked to me when I perused those files.) -- What I'm doing now
is writing to a file with PRIN1 and later using EMACS to MM
Grind Sexpr.  Anybody have a better way programmed in LISP?