[sane-devel] Sane only available to Super User - Canon FP330P

Matthew Duggan stauff@guarana.org
Mon, 15 Dec 2003 08:56:43 +1100

On Sat, Dec 13, 2003 at 08:47:48PM +1300, Kim L. Mantle wrote:
> I have MandrakeLinux 9.2.
> For the past month or so I have had great difficulty trying to find out why Xsane would only recognise 'Super User' and not 'Normal User'.
> I have made sure on each occasion I have re-installed 9.2 that there is only one installation of Sane. I have then installed/upgraded (Sane Backends 1.0.12-5mdk) - also used the version on the Distro's CDs - and then Xsane and also tried it the other way around. But each time I get the message 'No Device found' when using 'Normal User' - yet when I use 'Super User' - bang... in comes Xsane and I am also then able to use Gimp.


There are two options to fix this:

1. You can set up saned as Till suggested (this may also yield speed 
improvements) however, by default the canon_pp backend saves data in 
the home directory of the user running the program, and saned runs as 
root, so you may wish to consider changing this line from canon_pp.conf:
calibrate ~/.sane/canon_pp-calibration-pp0 parport0
to something like this:
calibrate /var/sane/canon_pp-calibration
Leave off the port name too, because there's a bug with the way the
canon_pp backend handles port names from saned.

2. The canon_pp backend uses the correct kernel methods to access the
parallel port, however you still need to give your non-super-user
account access.  To do this, check the permissions on 
/dev/parport0 with "ls -l /dev/parport0".  On a Debian system it 
will be something like:
crw-rw----    1 root     lp        99,   0 Jun 15  2002 /dev/parport0
The letters at the front means that it's a character device, readable
and writable by the owner user, and readable and writable by the owner
group.  In this case the owner user is "root" (aka superuser) and owner 
group is "lp".  I assume Mandrake is similar in this respect..

To give your regular user access to this port, you can add yourself to
the "lp" group by typing this at the root (superuser) prompt:
adduser my_normal_username lp

Then if you log out and back in, you will be part of the lp group and
should be able to access the parallel port.


- Matthew Duggan