David Holland <dholland-tech%netbsd.org@localhost> wrote:
> On Mon, Aug 02, 2021 at 06:42:14PM +0200, Joerg Schilling wrote:
> > Do you believe that POSIX should include a method to control whether $$ is
> > expanded with := or not?
>
> I don't know the history of this (or at least, not without going and
> raking it up) but I'd say that $$ should never be expanded except at
> the final output stage. The purpose of $$ is to produce $ in the
> output, not cater to monstrosities like $$$$$$$$(VAR) that depend on
> knowing exactly how many and which eval stages are going to be applied
> to your text.
OK, from our discussions at the POSIX teleconferences, we came to the
conclusion that using $$ is extremely rare
I find that .... puzzling. If I was Living in the 70's, backtick would be the norm for command substitution. But I'm not. so Instead I use $() which means $$() is common.
(and having combined that with GNU Make's define+eval which relies on $$, yes I've ended up with plenty of monstrosities, mea culpa)