Re: Autoconf 2.52g is released

[Bob Proulx]

> I hope you don't mind my using this text into the Autoconf doc?

Not at all.  Flattered, in fact.  I might like to improve the prose so
that it flows into the documentation better.  Let me know if there is
any way I can help.

Bob

> --------------------------------------------------
> > Thomas> "cp -p" has some unfortunate side-effects (some versions copy
> > Thomas> the ownership of the original file in addition to the
> > Thomas> protection)
> > 
> > Do you have references for this?  This is typical information that
> > must be double checked and included in autoconf.texi once certified.
> 
> The 'cp -p' command always -tries- to copy ownerships.  But whether it
> actually does copy ownerships or not is a system dependent policy
> decision implemented by the kernel.  If the kernel allows it then it
> happens.  If the kernel does not allow it then it does not happen.  It
> is not something the cp command itself has control over.
> 
> In SysV any user can chown files to any other user, and also had a
> non-sticky /tmp.  That undoubtedly derives from the heritage of SysV
> in a business environment without hostile users.  BSD changed this to
> be a more secure model where only root can chown files, and used a
> sticky /tmp.  That undoubtedly derives from the heritage of BSD in a
> campus environment.
> 
> Linux by default follows BSD, but it can be configured to allow chown.
> HP-UX as an alternate example follows SysV, but it can be configured
> to use the modern security model and disallow chown.  That is how mine
> are configured.  Since it is an administrator configurable parameter
> you can't use the name of the kernel as an indicator of the behavior.
> 
> See the single unix specification for the standards information on
> what cp -p should or should not do.
> 
>   http://www.unix-systems.org/single_unix_specification_v2/xcu/cp.html
> 
> See the GNU fileutils faq here for more details and rational on this
> particular topic.  (Since I wrote it I recommend it.)
> 
>   
> http://www.gnu.org/software/fileutils/doc/faq/core-utils-faq.html#Why%20can%20only%20root%20chown%20files%3f
> 
> Stevens "Advanced Programming in the UNIX Environment" section 4.10 &
> 4.11 has good information.
> 
> HTH
> 
> Bob