man sane usb
If sane-find-scanner finds your scanner only as root but not as normal user, the permissions for the device files are not
adjusted correctly.
http://www.linuxquestions.org/questions/linux-hardware-18/epson-n1240u-xsane-and-permissions-85191/"It's also possible to mount the usbfs with the option "devmode=0666", e.g. by using the following line in /etc/fstab:
none /proc/bus/usb usbfs defaults,devmode=0666 00
:my /etc/fstab
usbfs /proc/bus/usb usbfs rw,devmode=0666 0 0
:as normal user
scanimage -L
No scanners were identified. If you were expecting something different,
check that the scanner is plugged in, turned on and detected by the
sane-find-scanner tool (if appropriate). Please read the documentation
which came with this software (README, FAQ, manpages)
:as root
xsane
:/usr/share/doc/sane/README.linux
"So if scanimage -L lists your scanner as root but not as normal user
read on this text. Usually you must just add the users that are allowed to access
the scanner to group "scanner". The device files used by libusb are located in /proc/bus/usb/
(e.g. /proc/bus/usb/001/003) or in /dev/bus/usb/ (e.g. /dev/bus/usb/001/003), if
you use udev. The exact file name can be found out by running sane-find-scanner
which would print "libusb:001:003" in this case. While setting permissions with
e.g. "chmod a+rw /proc/bus/usb/001/003" works, this change is not permanent.
The permissions will be reset when the scanner is replugged or Linux is
rebooted."
"One solution to set permissions on-the-fly is Linux udev which comes with current distributions. SANE comes with a udev rules file in the tools/udev directory which may be used by distributions or can be copied to /etc/udev/rules.d manually."
ls -la /etc/udev/rules.d
total 16
drwxr-xr-x 2 root root 4096 Jul 1 17:16 ./
drwxr-xr-x 3 root root 4096 Jan 5 08:53 ../
-rw-r--r-- 1 root root 789 Jul 1 14:18 70-persistent-cd.rules
-rw-r--r-- 1 root root 442 Jul 1 14:21 70-persistent-net.rules
Has anyone experience in the change of files like in the udev tools directory?