[sane-devel] Re: How to configure sane, xsane, etc.

[Henning Meier-Geinitz]

Hi,

On Wed, Jun 09, 2004 at 10:08:32AM +0200, François Patte wrote:
> I am facing a big problem with xsane from fedora C1. (xsane-0.91-1):
> 
> 1- I have a scanner Nikon LS-2000. The first person who ran xsane was not root
> and it now impossible to change the owner and right of the device /dev/sg0.
> 
> This device has been set with owner didier and group root with permissions 600
> and whatever root can do to change this is destroyed by the next use of xsane:
> ownership, group and permission are reset as previously defined!!!! So nobody
> but didier can use xsane and the scanner!

xsane doesn't change any access permissions. In fact it doesn't even
know which device file to use. The sane libraries ("sane-backends")
themselves also don't touch permissions.

So your problem is most probably caused by some automatic procedure
introduced by Fedora. I remember that there is some stuff to change
permissions based on who logs into the computer locally.

> man sane-scsi :
> 
>  When  using  a  SCSI scanner, ensure that the access permission for the
>        generic SCSI device is set appropriately.  We recommend to add a  group
>        "scanner"  to  /etc/group  which  contains  all  users that should have
>        access to the scanner.  The permission of the device should then be set
>        to  allow  group read and write access.  For example, if the scanner is
>        at generic SCSI device /dev/sg0, then the following two commands  would
>        set the permission correctly:
> 
>               $ chgrp scanner /dev/sg0
>               $ chmod 660 /dev/sg0
> 
> This is now impossible to do! Where are the configuration files responsible for
> this awful behavior?

It works quite fine, I'm doing it on this system. Really looks like a
Fedora problem. Better look at their docs or ask on their mailing
lists for help.

> 2- Even for didier the use of xsane is not easy: every time he asks for xsane he
> has to accept the license 

xsane asks for accepting the liability exclusion only on the first
start (and when xsane is updated to a newer version). So if that
happens more than once, maybe the directoriy ~/.sane/xsane can't be
written?

> and to wait about 10/15 minutes for the research of
> peripherics....

That shouldn't happen. Which version of sane do you use
(scanimage --version)? The scan takes about 1 to5 seconds at least
with newer versions of SANE. As a workaround, you can disable
everything but "coolscan" in /etc/sane.d/dll.conf.

> And, worse, he has to wait also if he wants to use gimp: gimp hangs
> on xsane plug-ins....

If you don't need the xsane gimp plugin, remove the link to xsane.

> I would like to understand how this can happen and how to corrct this windows
> like behavior: unix systems were done for many users, it is more and more
> difficult to use them like this.

The behaviour you describe isn't the normal SANE behaviour. 1) is not
cause by SANE and 2) is caused by the kernel trying to load drivers
for hardware that doesn't exist. That shouldn't happen with current
sane versions anymore.

Bye,
  Henning