Hard links to directories: why not?

[Guy Harris]

>  Older versions of mv couldn't move files between partitions at all,
>since rename() doesn't work between partitions.  Newer versions first
>attempt to use rename() to change the name of a file, and if that
>fails because the rename() attempted to rename a file to a different
>partition, than it uses the same method as cp to copy the file.

I've used versions of "mv" that existed before "rename()" existed,
and they did what you describe the "newer versions" as doing; they were
standard "mv"s from standard distribution tapes.  I seem to remember
*all* versions of "mv" doing the latter, at least as far back as V7....