[sane-devel] libsane udev rule

[m. allan noah]

I'm not sure why libusb would be so noisy by default. Can you check
your environment vars to see if there is some libusb debugging turned
on?

allan

On Wed, Jun 11, 2014 at 9:17 AM, gobo <gobo770 at gmail.com> wrote:
> 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"
>>
>
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-- 
"The truth is an offense, but not a sin"