Re: chown: Function not implemented

[Stephen Zander <gibreel@pobox.com>]

>>>>> "Jason" == Jason Gunthorpe <jgg@ualberta.ca> writes:

    Jason> On Sat, 12 Dec 1998, Mike Schmitz wrote:
    >> Some programs act differently according to the name they are
    >> called with.  Theoretically a program when called by a certain
    >> symlink may do something you don't want just anybody doing.

And ownership of the symlink has no effect on that - I can also
*still* do what you're trying to aviod as long as I can create symlinks
*somewhere*.

    Jason> Erm, symlinks don't effect permissions so that's not true.

    Jason> The reason is simple ownership:

    Jason> va{jgg}/tmp#ls -l foo lrwxrwxrwx 1 root root 1 Dec 12 23:42
    Jason> foo -> va{jgg}/tmp#rm foo rm: foo: Operation not permitted

Which fails as you note due to the +t on /tmp, otherwise it's the
relevant write attributes on the directory which control your ability
to delete the link.  Link ownership is irrelevant.

    Jason> Yes this has to do with tmp being +t. Ownership also
    Jason> controls who can change the mtime of a file.

However, link mtimes are only meaningful if you're using lstat.
stat/open et al ignore the link's attributes completely.

-- 
Stephen
---
It should be illegal to yell "Y2K" in a crowded economy.  :-) -- Larry Wall