Re: autoconf not hard-link safe

[Paul Eggert]

Robert Collins <address@hidden> writes:

> >  Most POSIX utilities are required to leave output files
> > hard-linked, so there's good precedent for Autoconf's behavior.  Even
> > if we altered Autoconf, that still leaves the sh, cp, etc. as tools
> > that won't break the hard links.
> 
> Autoconf is designed to operate on source code - like patch is.

As far as I can see, this is a bug in 'patch', as 'patch' currently
violates POSIX in this respect.
<http://www.opengroup.org/onlinepubs/007904975/utilities/xcu_chap01.html#tag_01_07_01_04>
says that when a standard utility writes an existing regular file, it
should not unlink and then create it; it should simply open it for
writing.

> It needn't be the default, but it certainly should be an option,

Yes, it would be reasonable to add it as an option.