"Jacob Sparre Andersen" <sparre@nbi.dk> wrote in message 
news:87sj67r941.fsf@adaheads.sparre-andersen.dk...
> Yannick Duch�ne wrote:
>
>> I disagree a bit, and this case may suggest to use locks.
>
> Which file systems/operationg systems allow an application to take a
> lock on a directory?

Don't know of any! And *assuming* that only your application can 
create/modify a file is looking for trouble, as such an assumption could be 
violated by accident (some other program using a similar file naming scheme) 
or maliciousness.

In the real world, there are lots of things that you can't know in 
advance -- you are always going to need a way to propagate run-time errors, 
which is what exceptions excel at (much better than error codes, IMHO).

                               Randy.