Ownership of usb device with udev.

[Patrick Brunschwig]

Guillaume Yziquel wrote:
> Werner Koch a écrit :
>> On Fri, 29 Jun 2007 11:38, guillaume.yziquel at free.fr said:
>>
>>> Visibly, purging pcscd does not solve the problem. Concerning
>>> permissions, I guess I have some work to do:
>> Indeed.  That is your problem.  Use lsusb to figure out where the SCR335
>> is attached and the manually update the ownership for testing.  The
>> HOWTO has hints on how to install the hotplug stuff.
> 
> I read the hotplug stuff was deprecated, and that udev should be used
> instead. The output of lsusb -v concerning the smart card reader follows.
> 
> My main problem is that I do not really understand how udev works. I
> understood there was lots of renaming involved. And with all these
> renamings, I do not really know how to make ownership changes.
> 
> I'd really love to find a good document on how udev works. In particular
> with debian.

The basic idea with udev is that you define rules for defining the group
and permission of devices (and other actions such as launching
applications). Here is a how-to that explains how these things work:
http://reactivated.net/writing_udev_rules.html

In your case you should create a file containing something like the
example below (everything on one line) and place it into
/etc/udev/rules.d. Check the README in /etc/udev/rules.d for the file
naming conventions.

SYSFS{idProduct}=="5115", SYSFS{idVendor}=="04e6", MODE="660",
GROUP="myspecialgroup"

HTH
-Patrick