Using a scanner (USB) as user and not as root

[Warren Block]

On Wed, 28 Apr 2010, Marco Beishuizen wrote:

> On Wed, 28 Apr 2010, Roland Smith wrote:
>
>> Are the permissions correct? Check with 'ls -l /dev/usb/ /dev/ugen*'.
>> Is your user-id in the usb group? Check by running 'id' as the normal user.
>> 
>> If all that is in order, remove all lines except the three above from
>> /etc/devfs.rules, and try again.
>
> Running id as user looks ok:
>
> uid=1001(marco) gid=0(wheel) groups=0(wheel),5(operator),1001(usb)
>
> But the permissions are not:
>
> ls -l /dev/usb/ /dev/ugen*
> lrw-rw-r--  1 root  usb  9 Apr 28 19:05 /dev/ugen0.1 -> usb/0.1.0
> lrw-rw-r--  1 root  usb  9 Apr 28 19:05 /dev/ugen1.1 -> usb/1.1.0
> lrw-rw-r--  1 root  usb  9 Apr 28 21:05 /dev/ugen1.2 -> usb/1.2.0
> lrw-rw-r--  1 root  usb  9 Apr 28 21:05 /dev/ugen1.3 -> usb/1.3.0
> lrw-rw-r--  1 root  usb  9 Apr 28 19:05 /dev/ugen2.1 -> usb/2.1.0
>
> /dev/usb/:
> total 0
> crw-------  1 root  operator    0,  87 Apr 28 19:05 0.1.0
> crw-------  1 root  operator    0,  93 Apr 28 19:05 0.1.1
> crw-------  1 root  operator    0,  89 Apr 28 19:05 1.1.0
> crw-------  1 root  operator    0,  94 Apr 28 19:05 1.1.1
> crw-------  1 root  operator    0, 104 Apr 28 21:05 1.2.0
> crw-------  1 root  operator    0, 105 Apr 28 21:05 1.2.1
> crw-------  1 root  operator    0, 117 Apr 28 21:05 1.3.0
> crw-------  1 root  operator    0, 119 Apr 28 21:05 1.3.1
> crw-------  1 root  operator    0,  91 Apr 28 19:05 2.1.0
> crw-------  1 root  operator    0,  95 Apr 28 19:05 2.1.1

You can use devd.conf for this:

attach 100 {
         device-name "ugen[0-9].[0-9]";
         match "vendor" "0x04b8";
         match "product" "0x010a";
         action "usb_devaddr=`echo $device-name | sed 's#^ugen##'` && \
                 chown root:saned /dev/usb/${usb_devaddr}.* && \
                 chmod 0660 /dev/usb/${usb_devaddr}.*

Copied from a post on -current or similar; apologies to the author, who 
I've forgotten.  I thought this was in the default devd.conf as an 
example, but it appears not.

devfs.rules don't apply to devices that are created dynamically after 
boot-up.  Or I guess they might be if you reload the ruleset with 
applyset after the device is created, but devd is a lot more capable.

-Warren Block * Rapid City, South Dakota USA