What is the Unix command to create a hardlink to a directory in OS X?

Question

How do you create a hardlink (as opposed to a symlink or a Mac OS alias) in OS X that points to a directory? I already know the command \"ln target destination\" but that on

Answer 1

Piffle. On 10.5, it tells you in the man page for ln:

   -d, -F, --directory
          allow the superuser to attempt to hard link  directories  (note:
          will  probably  fail  due  to  system restrictions, even for the
          superuser)

So yes:

    sudo  ln  -d  existing_dir  new_hard_link

Give it your password, and you're not done yet. You didn't document it, did you? You must document hard linked directories; even if it's a single user machine.

Deleting is a different story: if you go about it the usual way to delete directories, you'll delete the contents. So you must "unlink" the directory:

    unlink  new_hard_link

There. Hope you don't wreck your filesystem!