Make a unique filesystem path, without creating the file

[Jon Ribbens]

On 2016-02-22, Chris Angelico <rosuav at gmail.com> wrote:
> On Tue, Feb 23, 2016 at 5:17 AM, Jon Ribbens
><jon+usenet at unequivocal.co.uk> wrote:
>> Weeeeeell, I have a lot of sympathy for that point, but on the other
>> hand the whole concept of UUIDs ("import uuid") is predicated on the
>> opposite assumption.
>
> Not quite opposite. Ethan is asserting that you cannot be *certain*
> without actually checking the FS; the point of UUIDs is that you can
> be fairly *confident* that there won't be a collision. There is a
> nonzero probability of accidental collisions, and if an attacker is
> deliberately trying to _force_ a collision, it's most definitely
> possible. So both views are correct.

I was under the impression that the point of UUIDs is that you can be
*so* confident that there won't be a collision that for all practical
purposes it's indistinguishable from being certain.