Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!lll-tis!ames!mailrus!rutgers!iuvax!bsu-cs!dhesi
From: dhesi@bsu-cs.UUCP (Rahul Dhesi)
Newsgroups: comp.unix.wizards
Subject: Re: A suggestion: .... == ../../..
Message-ID: <2653@bsu-cs.UUCP>
Date: 19 Apr 88 22:05:55 GMT
References: <75@vertical.oz> <1934@bgsuvax.UUCP>
Reply-To: dhesi@bsu-cs.UUCP (Rahul Dhesi)
Organization: CS Dept, Ball St U, Muncie, Indiana
Lines: 14
Summary: . and .. are SPECIAL

In article <1934@bgsuvax.UUCP> kutz@bgsuvax.UUCP (Kenneth Kutz) writes:
>This would seem to be only a matter of creating a third link (in addition
>to the 2 that get created now "." and "..") which would be "..." for
>grandparent etc....
>There's nothing special about . and ..  There just directory entries
>with the same inode number (links) to another directory entry.

There is something very special about "." and "..".  Programs that
traverse directory trees know not to get into infinite loops by
traversing "." and ".." also.  If there were a third hard link called
"...", such programs would loop endlessly unless they were modified.

Consider "rm -r subdir", for example.
-- 
Rahul Dhesi         UUCP:  <backbones>!{iuvax,pur-ee,uunet}!bsu-cs!dhesi