Make a unique filesystem path, without creating the file

[Paul Rubin]

Chris Angelico <rosuav at gmail.com> writes:
>> 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.
> Maybe, if everyone's cooperating. I'm not sure how they fare in the
> face of malice though.

There are different UUID algorithms, some of which have useful syntax
but are easy to spoof.  Uuid4 is random and implemented properly, should
be hard to spoof.