On Tue, Jul 5, 2011 at 11:13 AM, Prashant Shah [off-list ref] wrote:

Hi,

On Tue, Jul 5, 2011 at 9:45 AM, Bond [off-list ref] wrote:

quoted

This is an interview question.
My answer was
In unix it simply opens the device node as a file and sends/receives
data and commands from it.

A little more detailed method :

Userland read/write to the file -> Calls C Library read/write
functions -> Makes System Calls for read/write -> (now inside kernel)
-> Process the system calls (check parameter, etc) -> Refer the
file_operations structure for that file -> Call the corresponding
read/write function.

This is not correct.If you answer this in interview which I faced as I
did not get that job even you will not.
The answers on this mailing list did not helped.If you would have been
in the interview and given these answers it will not work.
Initially I posted the question on list I was expecting I missed some
thing or interviewer was blabbering more.But I gave 2-3 more
interviews
and all of them asked me same and I gave the answers which I learned
in this thread but I was not selected.

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