Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!henry From: henry@utzoo.UUCP (Henry Spencer) Newsgroups: net.unix-wizards Subject: Re: inode number -> pathname? (4.2BSD) Message-ID: <5786@utzoo.UUCP> Date: Fri, 12-Jul-85 13:09:19 EDT Article-I.D.: utzoo.5786 Posted: Fri Jul 12 13:09:19 1985 Date-Received: Fri, 12-Jul-85 13:09:19 EDT References: <11465@brl-tgr.ARPA> Organization: U of Toronto Zoology Lines: 18 > ... If it were possible to set the current working directory > to a given inode and device, then pwd would give you the answer. All > the permission information, and even the bit denoting whether or not > this inode refers to a directory is stored in the inode, and can easily > be checked in such a call... This proposal has the side effect of making a significant change to the semantics of Unix file protection. The permission bits on a Unix directory are *not* sufficient for permission checking, because the permissions of the directories above it in the tree also matter. It can be done the other way, where parent permissions don't matter -- I think Multics did it that way -- but this would require changes to both programs (notably mkdir, which would have to tighten up directory permissions) and user habits (making your home directory private no longer suffices to make everything under it private). -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry