Delivery-Date: Mon Nov 10 09:43:54 2008
Message-Id: <200811101738.mAAHcpbk010604@bourbon.usc.edu>
To: cs551@merlot.usc.edu
Subject: Re: CS551: Final Project 2 : Queries
Date: Mon, 10 Nov 2008 09:38:51 -0800
From: Bill Cheng <william@bourbon.usc.edu>

Someone wrote:

  > I had the following queries about final project part2:
  > 
  > 1. For the store command, if the user enters a file name which is not
  > located in the CWD or the path which he specified, what should be the
  > behavior of the node ?

You should tell the user "file not found" or something equivalent.

  > 2. File ID = A UOID that identifies a file, for getting this file id, do we
  > have to use the getUOID function with filename and other parameters as the
  > input?

You need to make sure that FileID is unique across the network.
Calling GetUOID() is a good way to make sure that it is the case.

  > 3. A random 20-byte long *one-time password* is first generated. How do we
  > generate this password ? Can you please explain a bit about this. Do we have
  > to use the openssl for this?

GetUOID() is a good function to use to get a 20-byte long
random-looking block of data.  In order to make it even *more
random*, you should put something random in the obj_type (2nd
argument to GetUOID()).  You can call gettimeofday() and get
the tv_usec field, format it as a string, and pass it as
obj_type.

  > 4. *FileName* - name of the file. Is this the value which the user enters at
  > the command prompt when the store command is entered ? or say if he entered
  > /home/scf-07/song.mp3 then we have to take only the "song.mp3" part of it
  > and store it in this field ?

Correct!  You can call strrchr() to find the position of the
last '/' character in a string.
--
Bill Cheng // bill.cheng@usc.edu <URL:http://merlot.usc.edu/william/usc/>