How to print duplex when using lpr

["Kevin O'Gorman" <kogorman@gmail.com>]

I sometimes use lpr in a pipeline getting postscript from groff.  My printer (HP CP2025dn) has a duplexer and I'd like to use it.  I could look up the Postscript for that, but I'm wondering if there's a way to force either of groff or lpr to do it for me.

--

Kevin O'Gorman

#define QUESTION ((bb) || (!bb))   /* Shakespeare */

Please consider the environment before printing this email.