[cups.development] Re: [RFE] STR #1382: Please pre-process next document while printing current document

[Till Kamppeter]

[STR New]

This can even be done without modifying CUPS:

Define 2 queues:

1. A first queue with the driver/PPD for your printer selected, but the
backend is a simple script which pipes the data to be printed into an
"lpr" command pointing to the second queue. See the CUPS Software
Programmers Manual (http://localhost:631/spm.html) for how to write simple
backends.

2. A second queue which is a raw queue with a backend which points to the
actual printer.

As the two queues are independent, the first queue can process without the
second being working, the second only needs to be set for accepting jobs.
Then in case of printer failure the processed jobs simply stack up in the
second queue.

Configuration tips:

1. If you use CUPS 1.2, make only the first queue being broadcasted into
the network and not the second queue.

2. Restrict the second queue to only the "lp" or the "root" user being
allowed to print into it (the user as which backends are executed). This
way no normal user can print directly into the raw queue and get garbage.

It would be nice if this could be a standard feature of CUPS or if at
least such a configuration could be done automatically (option in web
interface or so).

Link: http://www.cups.org/str.php?L1382
Version:  -feature