Date: Sat, 21 Dec 2002 06:00:46 +0100 From: Cliff Sarginson <cls@raggedclown.net> To: freebsd-questions@FreeBSD.ORG Subject: Re: chown broken?? Message-ID: <20021221050046.GA46365@raggedclown.net> In-Reply-To: <20021221034927.GA804@HAL9000.homeunix.com> References: <1040390551.921.36.camel@localhost> <200212201412.GBKECSM91804@asarian-host.net> <20021220141504.GB6893@submonkey.net> <200212201448.GBKEMQM99487@asarian-host.net> <20021221034927.GA804@HAL9000.homeunix.com>
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On Fri, Dec 20, 2002 at 07:49:27PM -0800, David Schultz wrote: > Thus spake Mark <admin@asarian-host.net>: > > ----- Original Message ----- > > From: "Ceri Davies" <setantae@submonkey.net> > > To: "Mark" <admin@asarian-host.net> > > Cc: "Andrew Cutler" <andrew@1stelement.com>; <freebsd-questions@FreeBSD.ORG> > > Sent: Friday, December 20, 2002 3:15 PM > > Subject: Re: chown broken?? > > > > > > > On Fri, Dec 20, 2002 at 03:12:17PM +0100, Mark wrote: > > > > > > > I must say, though, that while I understand this behaviour, one can > > > > argue on what exactly "recursive" is to mean here. Intuitively, > > > > the definition of "the current sub-directory and all sub-directories > > > > below the current directory (and that for each subdirectory)" seems > > > > the correct one. Which would exclude "..", as this is not a > > sub-directory > > > > of the current directory, but the parent. > > > > > > Not really. It recurses through the directories named on the command > > > line, of which '..' happens to be one. > > > > > > Yes, "the directories named on the command line" within the CURRENT > > directory. Technically, "." and ".." are entries within the current > > directory (try: "od -c ."), and they have inode numbers too. But that does > > not deter me from deeming it a bit counter-intuitive to consider ".." a > > directory of the current directory. :) Especially in the context of > > recursion. > > So you want 'chown foo ..' to fail, as a special case? As I > mentioned before, rm gets away with this because you don't want to > remove the parent of the directory you're currently in. > (Actually, some rm implementations *will* let you shoot yourself > in the foot.) But it's perfectly reasonable to chown '..', even > recursively, so chown can't make any assumptions. > > I object to going around and documenting this caveat in the > manpages for every single utility that supports recursion through > a directory tree. It doesn't really belong there, it belongs in a > ``How to use the shell'' tutorial. The way Unix traditionally > does parameter expansion makes it easy to shoot yourself in the > foot in at least a dozen ways, and this is just one of them. > There is a little comfort-factor trick for all of this, that I use a lot on those paranoid days, execute the command first with an "echo" in front of it, then you will see what is going to happen..for example: [admin@willow]:~$ echo chown cls:cls .* chown cls:cls . .. .bash_history .bashrc .cshrc .forward .login .login_conf .mail_aliases .mailcap .mailrc .muttrc .procmailrc .profile .rhosts .shrc .signature .ssh [admin@willow]:~$ Of course this may not be 100% the truth if the program you are echoing makes a special case of "." etc. But it does show you what the shell will expand your command line to. -- Regards Cliff Sarginson The Netherlands [ This mail has been checked as virus-free ] To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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