[sane-devel] libsane udev rule

[gobo]

the scripts i'm "reusing" were written ages ago for use with network
attached hp all-in-ones.  for this machine i could have gone without
specifying the scanner.  i failed to remember that and will make that
change.  thanks for pointing it out.

the libusb messages appear anytime scanimage is executed.

scanimage > t2.png
libusb couldn't open USB device /dev/bus/usb/001/001: Permission denied.
libusb requires write access to USB device nodes.
libusb couldn't open USB device /dev/bus/usb/002/001: Permission denied.
libusb requires write access to USB device nodes.
libusb couldn't open USB device /dev/bus/usb/003/001: Permission denied.
libusb requires write access to USB device nodes.
libusb couldn't open USB device /dev/bus/usb/004/001: Permission denied.
libusb requires write access to USB device nodes.
libusb couldn't open USB device /dev/bus/usb/005/001: Permission denied.
libusb requires write access to USB device nodes.
libusb couldn't open USB device /dev/bus/usb/001/003: Permission denied.
libusb requires write access to USB device nodes.

of course they don't appear when scanimage is run as root.  i can make
them disappear by redirecting stderr to null, but that's not the best
idea.




On 6/10/14, m. allan noah <kitno455 at gmail.com> wrote:
> If you only have one scanner, you don't need to name the device.
> Where do you see those libusb error messages?
>
> allan
>
> On Tue, Jun 10, 2014 at 4:57 PM, gobo <gobo770 at gmail.com> wrote:
>> thanks for the reply.
>>
>> changed my approach and used scanimage -f "%d" to capture the device
>> in my script.  this works well enough since i have only one scanner.
>>
>> is there a way to suppress the
>>
>> libusb couldn't open USB device /dev/bus/usb/001/001: Permission denied.
>> libusb requires write access to USB device nodes.
>>
>> messages libusb puts out?  not a problem, just an annoyance.
>>
>>
>> thanks.
>>
>>
>> On 6/9/14, Olaf Meeuwissen <olaf.meeuwissen at avasys.jp> wrote:
>>> gobo writes:
>>>
>>>> generally, i know how to write udev rules.  but i'm not sure how to
>>>> write one for libsane.
>>>>
>>>> scanimage -L returns something like:
>>>> device `canon_dr:libusb:001:002' is a CANON DR-2580C scanner
>>>>
>>>> where the 001:002 is always changing.  :005, :008, etc.
>>>>
>>>> so in 55-libsane.rules there is:
>>>> # Canon DR-2580C
>>>> ATTR{idVendor}=="04a9", ATTR{idProduct}=="1608", MODE="0664",
>>>> GROUP="lp", ENV{libsane_matched}="yes"
>>>>
>>>> what do i add to the rule to force this device to always have the same
>>>> libusb name?
>>>
>>> In short, you can't.
>>>
>>> You can assign a value to the SYMLINK key in a udev rule.  That will
>>> dutifully create a device with that name no matter what bus and device
>>> number it has.  However, as long as the canon_dr backend (or probably
>>> most any backend) creates device names using the bus and device numbers,
>>> you are out of luck.
>>>
>>> Hope this clarifies,
>>> --
>>> Olaf Meeuwissen, LPIC-2           FLOSS Engineer -- AVASYS CORPORATION
>>> FSF Associate Member #1962               Help support software freedom
>>>                  http://www.fsf.org/jf?referrer=1962
>>>
>>
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>
>
>
> --
> "The truth is an offense, but not a sin"
>