[Pkg-cups-devel] Bug#423198: Bug#423198: cupsys: "Unable to open parallel port device file "/dev/lp0": Permission, denied"

[Martin Pitt]

Hi Graham,

Graham M Whittenberg [2008-08-06 22:11 -0400]:
> Ubuntu 8.04 (hardy)
> 2.22.3 (Ubuntu 2008-07-09)
> 2.6.24-19-generic (#1 SMP Fri Jul 11 21:01:46 UTC 2008)
> Linux
> 4.2.3 (x86_64-linux-gnu)
> unknown (13 June 2008  01:10:57AM)
> whitt-desktop

This should actually be an Ubuntu bug report, not a Debian one, but
nevermind now.

> Here is the message that I recieve:
> 
> Aug  6 17:25:20 whitt-desktop kernel: [12507.816239] 
> audit(1218057920.574:9): type=1503 operation="inode_permission" 
> requested_mask="::rw" denied_mask="::rw" name="/dev/tty" pid=16125 
> profile="/usr/sbin/cupsd" namespace="default"
> 
> This problem is pervasive and has been causing a lot a lot of grief.  

I don't believe that. This happens on *every* installation and is
completely harmless. There is no reason why cupsd needs to access the
terminal device (it has log files for that), so that's just a
cosmetical issue.

> Many of the Bug reports have the same complaint;  "Cups cannot print on 
> UBS or Parallel port printers.

So what is your particular problem? Please describe the setup you
have, and send /var/log/cups/error_log after a failed printing
attempt.

> There has to be a better answer that mucking about in Linux to change 
> authorization procedures.  I have a feeling that many of these bug 
> reports will go away if some is smart enough to tell us what values to 
> put into "User Settings" of "User and Groups".  

No, you don't need to change any user setting/group of your's if you
have problems with USB/parallel printing in cups.

> I got this far by checking with a non programmer who has a UBS
> printer running:

That's just a red herring, trust me. We need to fix the problem on the
cups side, not on your user's side. The latter would be a problem if
you cannot administrate your printers, etc.

> I know that I am coming in the back door, but some of this may make 
> sense to people with some experience with Linux.  New desktop user 
> haven't had the time to learn.

I agree, it should Just Work, without fiddling. Indeed it does so for
many people, so I guess it's a hardware specific problem for you. So
please describe your specifics (hardware, log files, problem
description) and we'll see.

Thanks,

Martin

-- 
Martin Pitt                        | http://www.piware.de
Ubuntu Developer (www.ubuntu.com)  | Debian Developer  (www.debian.org)