[clue-tech] help with: "fifo: Permission denied" when using acpi_fakekey as non-root

[Jim Ockers]

Hi Mike,

You are going to have to do a bit of detective work.  The brute force 
way might be to just do "find / -type p" as root and see what comes up.

[root]# find / -type p -exec ls -l {} \;
prw-------    1 root     root            0 Nov 18 15:20 /dev/initctl
...

There will be more, I don't know how long the find command will take, 
but it may take a long time depending on your system.  As for which 
process is using it, try 'lsof -n" to see what filehandles each process 
has open.

Hope this helps,
Jim

Mike Jensen wrote:
> That is VERY helpful.  I did not know that previously.
>
> But that does beg the question, how can I find out which file 
> acpi_fakekey is trying to use and does not have the proper permissions 
> for?
>
> Jim Ockers wrote:
>> Hi Mike,
>>
>> FIFOs are usually unix pipe special files. Here is an example:
>>
>> [root at agadez tmp]# touch this_is_a_normal_file
>> [root at agadez tmp]# mknod this_is_a_fifo p
>> [root at agadez tmp]# ls -al this*
>> prw-r--r-- 1 root root 0 Feb 11 07:16 this_is_a_fifo
>> -rw-r--r-- 1 root root 0 Feb 11 07:16 this_is_a_normal_file
>>
>> As you can see the FIFO has permissions associated with it just like any 
>> other file. Please check the permissions on your FIFO using ls -al and 
>> see who has permission to write to it and read from it. Here is an 
>> example of me changing the permissions on my FIFO file:
>>
>> [root at agadez tmp]# chmod 666 this_is_a_fifo
>> [root at agadez tmp]# ls -al this_is_a_fifo
>> prw-rw-rw- 1 root root 0 Feb 11 07:16 this_is_a_fifo
>>
>> I hope this helps,
>> Jim
>>
>> Mike Jensen wrote:
>>   
>>> Been lurking around for a while, but never posted before.  Sorry to have 
>>> my first post be a help request.
>>>
>>> I am trying to get the volume up/down/mute key to work on my Lenovo 
>>> T400.  The distro is Debian Squeeze, fully updated, amd64.  My volume 
>>> keys don't seem to work, so I traced down /etc/acpi/volupbtn.sh (and 
>>> others), and noticed that it was using acpi_fakekey....when I run it as 
>>> such in root, there is no problems, it returns fine.  But when I run the 
>>> same thing as a normal user I get: fifo: Permission denied
>>>
>>> Let me know if there is any more information I can provide.  I have 
>>> searched around but have not seen this percise problem before.  Thanks 
>>> in advanced.
>>> _______________________________________________
>>> clue-tech mailing list
>>> clue-tech at cluedenver.org
>>> http://cluedenver.org/mailman/listinfo/clue-tech
>>>   
>>>     
>>
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>
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