Subject: Re: Known inconsistencies or bugs in CLHS?
From: Erik Naggum <erik@naggum.net>
Date: Sat, 13 Apr 2002 12:41:14 GMT
Newsgroups: comp.lang.lisp
Message-ID: <3227690474302303@naggum.net>

* Daniel Pittman <daniel@rimspace.net>
| I don't know about the underlying reason, but a good many filesystems
| out there in Unix-land today suffer this effect. It's still popular to
| store a '..' record in a directory, pointing to it's parent directory.

  Whether you store it or not, it is part of the file system semantics that
  "." and ".." exist.  If the requirement is also popular, that is great.

| This means that you have a doubly-linked tree of directories, something
| which can be useful for fsck to verify that things still make sense
| internally.

  It is used to find the pathname of the current working directory, and
  hence the physical truename of a file.  It is used to find sibling
  directories.  It is, surprisingly, used to find the parent directory.

| Also, hard links can make this a nightmare...

  Modern Unix/Linux kernels do not allow user code to hardlink directories.

///
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