I don't know if unix is the most ahem "specific" specification ever given. What specification of unix do you think the author was referring to? In any case, they have corrected themselves in the blogpost.

well, if he was referring to 'unix' as specified in the Single Unix Specification (which incorporates IEEE Std 1003.1)

then all unix systems have 'ed'

http://pubs.opengroup.org/onlinepubs/009695399/utilities/ed....

If arch linux doesn't include it, it's not a 'unix'; it's not even a good "not unix". So the author wouldn't have needed to correct his article but Arch would need to include 'ed' :)

I get where you're coming from but I just want to raise two quibbles:

> If arch linux doesn't include it, it's not a 'unix'

...but according to that version of SUS, I'm sure the original unix isn't unix either. In any case, I don't think you can just assume any particular spec when someone says the word 'unix', most people usually just mean *nix-family (and if the spec is relevant they'll probably cite it).

> it's not even a good "not unix". I imagine arch is much closer to compliance if you install everything in the 'core' repository (which is recommended and includes ed). In any case, if lacking ed makes something a "bad not unix", I'm not sure most people mind being wrong ;)