I ended up using posix_access() which is what is_writeable() should be. is_writeable() is virtually
useless.

Al wrote:
> I need to determine if a file is truly deletable by a php script,
> Deleting permissions seem to be the same as writing, they probably have
> the same criteria.
>
> is_writable() seems to virtually useless in most cases. It doesn't take
> into account the directory ownership/permissions; which, best I can
> tell, is the real determining factor.
>
> I've resorted to having to determine the directory's ownership and then
> compare the directory's rights with the owner's and then the other
> ['world'].
>
> E.g., Assume my script was loaded with ftp, so it's ownership is the
> site-name, and I want the scrip to be able to determine if it can delete
> a file. Thus, the file in question must have its "other" permissions
> include write.
>
> Surely, there must be an easier way.
>
> Thanks, Al........