Re: x bit for dirs: misfeature?

[vda <vda@port.imtp.ilyichevsk.odessa.ua>]

On Monday 19 November 2001 14:36, James A Sutherland wrote:
> On Monday 19 November 2001 4:22 pm, vda wrote:
> > Everytime I do 'chmod -R a+rX dir' and wonder are there
> > any executables which I don't want to become world executable,
> > I think "Whatta hell with this x bit meaning 'can browse'
> > for dirs?! Who was that clever guy who invented that? Grrrr"
> >
> > Isn't r sufficient? Can we deprecate x for dirs?
> > I.e. make it a mirror of r: you set r, you see x set,
> > you clear r, you see x cleared, set/clear x = nop?
> >
> > Benefits:
> > chmod -R go-x dir (ensure there is no executables)
> > chmod -R a+r dir (make tree world readable)
> > mount -t vfat -o umask=644 /dev/xxx dir
> > 	(I don't want all files to be flagged as executables there)
> >
> > These commands will do what I want without (sometimes ugly) tricks.
> > For mount, I can't even see how to do it with current implementation.
> >
> > What standards will be broken?
> > Any real loss of functionality apart from compat issues?

> The R and X bits on directories have different meanings. Watch:

I know. I'd like to hear anybody who have a directory with r!=x
on purpose (and quite curious on that purpose). UNIX gugus, anybody?

> $ mkdir test
> $ echo content > test/file
> $ chmod a-r test
> $ ls test
> ls: test: permission denied
> $ cat test/file
> content
> $ chmod a=r test
> $ ls test
> ls: test/file: Permission denied

Hmm... I do actually tested this and last command succeeds
(shows dir contents). You probably meant cat test/file, not ls...

> In short, the X bit allows you to access the contents of the directory,
> while R allows you to LIST those contents. There are valid uses for X only
> directories (i.e. users are not allowed to list the contents, only to
> access them directly by name). R-only directories make little sense, as you
> can see from the transcript above :)