> > Date: Fri, 11 Aug 2000 12:56:20 -0700 (PDT)
> > From: Paul Eggert <[EMAIL PROTECTED]>
> >
> > Most likely, seds that don't support ? and \| also don't support
> > \{m,n\}, as I recall that those features were introduced to USG Unix
> > at about the same time.
>
> My references indicate otherwise. For example, SunOS 4.x man page
> for ed(1) clearly says that \{m,n\} is supported, while ? and \| are
> not. This is consistent with the latter two not being part of BRE.
>
> Ken, could you comment on this?
I just proved that my memory is faulty --- by checking the v7 manuals
I see that the \{ \} notation does not date back that far. But even
given that experience, I still stick to my memory's claim that \{ \}
is older and more widespread than \| and \?; at any rate, POSIX.2
mandates \{ \} for BREs, but only implicitly allows \? and \|.
--Ken Pizzini
