Re: "conformance" vs. compatibility

[Paul Eggert]

ari <address@hidden> writes:

> address@hidden said this stuff:
> 
> > After 10 years of being merely `obsolescent', head -N has finally
> > been officially declared to be `obsolete'.
> 
> I have yet to see a pointer to where the historic usage has been
> declared "obsolete", outside of personal declarations that it has been
> "officially declared obsolete" elsewhere.

"head -10" was marked as obsolescent in the 1992 edition of the POSIX
standard, and POSIX withdrew the requirement to support "head -10" in
the 2001 edition of the standard.  If you don't think that makes "head
-10" obsolete then I guess we'll just have to agree to disagree about
what the word "obsolete" means.

People can reasonably disagree about whether it was wise for POSIX to
make "head -10" obsolete, and about whether it was wise of coreutils
to give the coreutils installer and/or the user the ability to disable
support for "head -10".  But those are different issues.  There's no
real dispute that "head -10" is obsolete.

If this really bugs you, then the proper way to change things back to
the way they used to be is to change POSIX.  You can start this
process by filing a defect report with the Austin Common Standards
Revision Group; see <http://www.opengroup.org/austin/>.

Features become obsolete all the time in the GNU world.  For example,
GCC 3.3 removed support for unescaped newlines in C strings.  This
broke a few programs, but it's not really a big deal in the overall
scheme of things, and there are some real advantages to sticking with
the standard usage.