[juneau-lug] Re: losing permissions

  • From: Jamie <jamie@xxxxxxxxxxxxxxxxx>
  • To: juneau-lug@xxxxxxxxxxxxx
  • Date: Thu, 27 Feb 2014 16:04:39 -0900

Probably my mistake was syntax with the = & ==
> Here is an example rule to illustrate the above:
>
>     KERNEL=="hdb", NAME="my_spare_disk"
>
> The above rule includes one match key (/KERNEL/) and one assignment 
> key (/NAME/). The semantics of these keys and their properties will be 
> detailed later. It is important to note that the match key is related 
> to its value through the equality operator (==), whereas the 
> assignment key is related to its value through the assignment operator 
> (=).
>


On 02/27/2014 03:59 PM, Jamie wrote:
> Success - I think.  Shortened the rule to just:
>
> KERNEL=="ttyUSB0", MODE="0666"
>
> and it survived a re-boot.
>
>
> On 02/27/2014 03:26 PM, Jamie wrote:
>> Thanks for the tip James.   The first run had the lines:
>>> parse_file: reading
>>> '/etc/udev/rules.d/91-persistent-weather-usb.rules' as rules file
>>> add_rule: invalid KERNEL operation
>>> add_rule: invalid rule
>>> '/etc/udev/rules.d/91-persistent-weather-usb.rules:14'
>>> parse_file: reading
>>> '/lib/udev/rules.d/95-keyboard-force-release.rules' as rules file
>> and I noticed an example rule used double equal signs so I changed my
>> rule to:
>> KERNEL=="ttyUSB[0-9]*", GROUP=="dialout", MODE=="0666", ENV{GENERATED}=="1"
>> and tried again.  Eliminating that error:
>>> parse_file: reading
>>> '/etc/udev/rules.d/91-persistent-weather-usb.rules' as rules file
>>> parse_file: reading
>>> '/lib/udev/rules.d/95-keyboard-force-release.rules' as rules file
>> but still not setting my permissions.  Can you help me interpret this
>> (from the udevadm test):
>>> udev_event_execute_rules: no node name set, will use kernel supplied
>>> name 'ttyUSB0'
>>> udev_node_add: creating device node '/dev/ttyUSB0', devnum=188:0,
>>> mode=0660, uid=0, gid=20
>>> udev_node_mknod: preserve file '/dev/ttyUSB0', because it has correct
>>> dev_t
>>> udev_node_mknod: preserve permissions /dev/ttyUSB0, 020660, uid=0, gid=20
>>> node_symlink: preserve already existing symlink '/dev/char/188:0' to
>>> '../ttyUSB0'
>> This seemed to be the pertinent part, but there's lots more - I just
>> don't know what I'm looking for.  Or how to write a udev rule.  BTW this
>> machine is running Ubuntu 12.04.04 LTS server.
>>
>>
>>
>> On 02/27/2014 11:56 AM, James Zuelow wrote:
>>> You say that is a brand new udev rule?  It looks like it should take 
>>> priority as long as it is the last one run on the USB ttys and "lastrule" 
>>> was not included in an earlier rule.
>>>
>>> You can test your udev rules.
>>>
>>> I don't have a USBtty0 on my machine, but here is an example for you to 
>>> follow:
>>>
>>> udevadm info --query=path --name=/dev/ttyUSB0
>>>
>>> (udev will return a string similar to this)
>>> /devices/virtual/tty/ttyUSB0
>>>
>>> (put the string that udevadm returned above at the end of this command):
>>> udevadm test /devices/virtual/tty/ttyUSB0
>>>
>>> At the bottom of the test output should be a list of rules that udev is 
>>> applying, and should give you a clue to which settings are being overridden 
>>> or just not applying.
>>>
>>> James
>>>
>>>
>>>
>>>
>>> ------------------------------------
>>> The Juneau Linux Users Group -- http://www.juneau-lug.org
>>> This is the Juneau-LUG mailing list.
>>> To unsubscribe, send an e-mail to juneau-lug-request@xxxxxxxxxxxxx with the 
>>> word unsubscribe in the subject header.
>> ------------------------------------
>> The Juneau Linux Users Group -- http://www.juneau-lug.org
>> This is the Juneau-LUG mailing list.
>> To unsubscribe, send an e-mail to juneau-lug-request@xxxxxxxxxxxxx with the 
>> word unsubscribe in the subject header.
> ------------------------------------
> The Juneau Linux Users Group -- http://www.juneau-lug.org
> This is the Juneau-LUG mailing list.
> To unsubscribe, send an e-mail to juneau-lug-request@xxxxxxxxxxxxx with the 
> word unsubscribe in the subject header.



------------------------------------
The Juneau Linux Users Group -- http://www.juneau-lug.org
This is the Juneau-LUG mailing list.
To unsubscribe, send an e-mail to juneau-lug-request@xxxxxxxxxxxxx with the 
word unsubscribe in the subject header.

Other related posts:

  1. Home
  2. juneau-lug
  3. Archive
  4. 02-2014