Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uunet!auspex!guy
From: guy@auspex.auspex.com (Guy Harris)
Newsgroups: comp.unix.wizards
Subject: Re: ln -f
Message-ID: <3770@auspex.auspex.com>
Date: 27 Jul 90 18:45:56 GMT
References: <3732@auspex.auspex.com> <1056@undeed.UUCP>
Organization: Auspex Systems, Santa Clara
Lines: 12

>But that doesn't give the same result.  If you remove file2 first, then
>there is a brief window between the 'rm' and the 'ln' during which no
>file named file2 exists.  
>If you use a version of 'ln' that clobbers file2 and replaces it with a
>link to file1 in an atomic operation, there is no such window.

As far as I know, there's no such atomic operation, either; I sure
haven't seen any such operation in any UNIX system I've ever run into.

Given that, every version of "ln" I know of that removes the target
first has to first "unlink()" the target, and then do the "link()".  As
such, the window is still there....