Print a buffer with “M-x print-buffer”

Place the following in your .emacs file:
(setq printer-name “MY-PRINTER-NAME”)

Your printer name “MY-PRINTER-NAME” will be found with the device driver for your printer. I have an Hewlett-Packard (HP) printer and I find the printer name listed in the HP Device Manager dialog.

If you want to print in landscape mode, add the following: (setq lpr-switches ‘(“-o -o orientation-requested=4”))

More options can be specified in the list. Lots of options are at this link:
U Texas Computer Science Lab

The essential reference is GNU Emacs printing