From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham autolearn_force=no version=3.4.2 Received: from minnie.tuhs.org (minnie.tuhs.org [45.79.103.53]) by inbox.vuxu.org (OpenSMTPD) with ESMTP id 752defea for ; Fri, 2 Aug 2019 11:42:24 +0000 (UTC) Received: by minnie.tuhs.org (Postfix, from userid 112) id DA4AF9BAB6; Fri, 2 Aug 2019 21:42:22 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id B8D809BA7E; Fri, 2 Aug 2019 21:41:49 +1000 (AEST) Received: by minnie.tuhs.org (Postfix, from userid 112) id 026199BA7E; Fri, 2 Aug 2019 21:41:47 +1000 (AEST) X-Greylist: delayed 1389 seconds by postgrey-1.36 at minnie.tuhs.org; Fri, 02 Aug 2019 21:41:45 AEST Received: from ppsw-31.csi.cam.ac.uk (ppsw-31.csi.cam.ac.uk [131.111.8.131]) by minnie.tuhs.org (Postfix) with ESMTPS id A4BF19B84E for ; Fri, 2 Aug 2019 21:41:45 +1000 (AEST) X-Cam-AntiVirus: no malware found X-Cam-ScannerInfo: http://help.uis.cam.ac.uk/email-scanner-virus Received: from grey.csi.cam.ac.uk ([131.111.57.57]:48186) by ppsw-31.csi.cam.ac.uk (ppsw.cam.ac.uk [131.111.8.137]:25) with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) id 1htVZv-000Pxw-Kr (Exim 4.92.1) (return-path ); Fri, 02 Aug 2019 12:18:31 +0100 Date: Fri, 2 Aug 2019 12:18:30 +0100 From: Tony Finch To: arnold@skeeve.com In-Reply-To: <201908020835.x728ZUal026532@freefriends.org> Message-ID: References: <201908011235.x71CZP2B035023@tahoe.cs.Dartmouth.EDU> <201908020835.x728ZUal026532@freefriends.org> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Subject: Re: [TUHS] Additional groups and additional directory permissions X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: tuhs@tuhs.org, doug@cs.dartmouth.edu Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" arnold@skeeve.com wrote: > Arthur Krewat : > > There's also the setgid bit on directories, that when files are created, > > they will be in the group that the parent directory has on it. > > IIRC this was a Sun invention. It was in SunOS 4.x, and may even have > been in SunOS 3.x. When Bill Joy added the "multi-group stuff" to BSD all directories became implicitly set-gid: https://svnweb.freebsd.org/csrg/sys/ufs/ffs/ffs_inode.c?r1=4818&r2=5855 This is in SCCS revision 4.8 so I think it appeared in 4.2BSD As I understand it, when group support was improved in System V they did not change creat() to match BSD but instead used the directory set-gid bit to provide opt-in BSD semantics. I don't know if this was in Solaris or earlier? > > Also, I don't think it's been mentioned, but there's the setuid bit on > > directories - otherwise known as the sticky bit. When set, even if you > > have rights to "write" the directory (meaning, delete files), you can't > > delete those owned by other users. Useful for /tmp > > Also a SunOS invention, IIRC. BSD again :-) SCCS revision 6.6 so I think it appeared in 4.3BSD https://svnweb.freebsd.org/csrg/sys/ufs/ffs/ufs_lookup.c?r1=15809&r2=16046 Tony. -- f.anthony.n.finch http://dotat.at/ Mull of Galloway to Mull of Kintyre including the Firth of Clyde and North Channel: Variable 1 to 3, becoming easterly or southeasterly 2 to 4 later. Smooth, occasionally slight at first in North Channel. Showers for a time near shore. Good.