On Jul 3, 2009, at 6:06 PM, Greg Willits wrote:
> So, my question is about those zeros. Does advancing the seek position
> (do we still call that the "cursor"?) intentionally and proactively  
> fill
> the unsed bytes with what apparently equates to zero?

I don't think anyone has answered this question directly but on POSIX- 
like file systems a seek past the end of the file and a subsequent  
write will cause the intervening bytes (which have never been written)  
to read as zeros. Whether those 'holes' occupy disk space or not is  
implementation dependent.

Gary Wright