CUPS, USB printers & "Permission Denied"

[Micah]

Anthony Agelastos wrote:
> 
> On Jun 25, 2006, at 9:05 PM, Micah wrote:
> 
>> Anthony Agelastos wrote:
>>> Hello and thank you for the very quick reply.
>>> On Jun 25, 2006, at 7:34 PM, albi wrote:
>>>> On Sun, 25 Jun 2006 19:28:35 -0400
>>>> "Anthony Agelastos" <iqgrande at gmail.com> wrote:
>>>>
>>>>> I updated CUPS and I cannot print to my USB laser printer. The web
>>>>> interface shows the following:
>>>>>
>>>>> hp_LaserJet_1160Le (Default Printer) "Unable to open USB device
>>>>> "usb:/dev/ulpt0": Permission denied"
>>>>>     Description: Hewlett-Packard LaserJet 1160Le
>>>>> Location: Den
>>>>> Make and Model: HP LaserJet 1160 Foomatic/hpijs (recommended)
>>>>> Printer State: stopped, accepting jobs, published.
>>>>> Device URI: usb:/dev/ulpt0
>>>>
>>>> are the permissions on /dev/ulpt0 correct ?
>>> I have no idea what it is supposed to be.
>>> %ls -l /dev/ulpt0
>>> crw-r--r--  1 root  operator    0,  68 Jun 25 19:01 /dev/ulpt0
>>>>
>>>> if the printer runs fine as root you know it's likely a
>>>> permission-problem
>>>>
>>> What's the best way to run it as root? When I log into the CUPS web 
>>> interface as root and try to print a test page, it gives me the 
>>> message I posted above. If, as root, I try to print a Postscript file 
>>> via lp, it does nothing.
>>> Thank you all again for your 
>>> assistance._______________________________________________
>>
>> I had the same problem. chown ulpt0 to group cups and add group write. 
>> That will fix it. I added the following to /etc/devfs.rules to make 
>> the fix permanent:
> I did
> 
> chgrp cups /dev/ulpt0
> chmod g+w /dev/ulpt0
> 
>>
>> [system=10]
>> add path 'unlpt*' mode 0660 group cups
>> add path 'ulpt*' mode 0660 group cups
> I did not have a /etc/devfs.rules file, so I copied 
> /etc/defaults/devfs.rules to /etc/devfs.rules and added what you 
> suggested at the bottom of it.
> 
>>
>> Don't forget to restart devfs.
> When I do
> /etc/rc.d/devfs restart
> it seems like nothing happens. So, I rebooted my machine and the group 
> was back to operator. What am I doing wrong? Thank you so much for your 
> assistance with this.

Oops, I've had a custom devfs.rules for so long that I forgot that you 
need the following in rc.conf:

devfs_system_ruleset="system"

I would also create a new /etc/devfs.rules that only has the three lines 
as shown above since that's pretty close to what mine has. I'm not sure 
what all the hide/unhide stuff in the default rules does. Issuing a 
/etc/rc.d/devfs restart /should/ cause ownership and permissions to 
change - at least it did for me. You can always unplug the USB cable or 
power-cycle the printer to test it.

HTH,
Micah