Path: utzoo!utgpu!utstat!jarvis.csri.toronto.edu!mailrus!cornell!rochester!rutgers!att!whuts!homxb!opus!jgy
From: jgy@opus.ATT.COM (John Young)
Newsgroups: comp.unix.questions
Subject: Re: File Write Permission Rules
Keywords: file write permission rules
Message-ID: <85@opus.ATT.COM>
Date: 20 Feb 89 18:08:52 GMT
References: <306@wubios.wustl.edu> <249@ibd.BRL.MIL> <1995@lindy.Stanford.EDU> <23095@conexch.UUCP>
Organization: AT&T BL Red Hill NJ USA
Lines: 24

In article <23095@conexch.UUCP>, root@conexch.UUCP (Larry Dighera) writes:
> In article <630@jonlab.UUCP> jon@jonlab.UUCP (Jon H. LaBadie) writes:
> <This is a future direction of UNIX question.
> <I stumbled upon a system with /tmp directory permissions as follows:
> <
> <	drwsrwxrwx ......
> <
> <Note the "s". 
> <[...] namely a meaning for the set user id bit on directories.
> <The meaning?  Anyone could create files in the directory,
> <but only the owner of the directory, OR the owner of the individual
> <files could remove them.
> <So, the questions:
> <	1. Anyone know of the future fate of this useful tweak?
> 
> At a presentation to the Orange County Unix Users Group last month the
> AT&T speaker mentioned that Release 4 will support use of the suid bit
> on directories.  He didn't elaberate on its use, but I'll bet this is it.
> 
> Larry Dighera

Release 3.2 already supports this feature (only file owner & directory owner
(and root)) may remove a file.  This is implemented using the 't', sticky
bit on the directory.