Re: regarding file synchronization

There is no way to get any notification that someone else has changed the
file. There is
no mechanism at all for this, none whatsoever. No editor provides this
capability, in
fact, I've never heard of ANY editor that can do this. Note that editors
do not hold the
file open. They open the file, read it in, and at some later point they
write it back.
From time to time, they can check to see if the file has changed, and this
done by reading
the timestamps of the file; if the file has changed, the timestamp will
change, and you
can detect this.

You are probably confusing this rather simple method with some way of
"receiving a
notification", but there is no such mechanism to receive notifications.
Note that no
editor I am aware of that opens a file allowing concurrent write access.
Word, for
example, opens allow read-sharing but not write-sharing. Therefore, it is
not possible to
make any changes to a Word document that is being held open in a copy of
Word.