Thomas Abeel

To print from the command line with Firefox, you need to install an extension. One such extension is
Command Line Print by torisugari.

This extension allows you to print URLs immediately, without user interaction. This can be useful to convert html pages to PDF for example.

You first have to install the extension from http://torisugari.googlepages.com/commandlineprint2

After you've properly installed the extension, you can start using Firefox as command line printer.

Usage:

$>firefox -print http://www.example.com/index.html
$>firefox -print http://www.example.com/index.html -printmode pdf -printfile foobar.pdf
$>firefox -print http://www.example.com/index.html -printmode PNG

Documentation from the author:
-print @required. If not set, a normal browser launches.

-printmode mode @optional. mode is either {0, 1, 2, printer, pdf, png}. Case-insensitive. If not set, this application behaves according to pref settings. See also: Tools -> Add-ons -> Extensions -> Command Line Print -> Options. Note that PNG requires Firefox version is equal to or more than 2.0, and PDF requires Firefox version is => 3.0, while PRINTER should work with Firefox 1.5.

-printfile filepath @optional. filepath is an absolute, or a relative path from the current directory, like other CLI applications. Any local path will do, as long as Gecko understands where. This option will be ignored, if mode is PRINTER. If not set, the file will be saved at default location: download directory, where you can set Tools -> Options -> Main -> Downloads.

Source: http://torisugari.googlepages.com/commandlineprint2