Re: Undocumented feature: Unnamed fifo '<(:)'

[felix]

On Fri, Apr 09, 2021 at 01:23:09AM +0200, Léa Gris wrote:
> > You could have a look:
> >    https://f-hauri.ch/vrac/mandelbrot_backgndBc.sh.txt
> >    https://f-hauri.ch/vrac/mandelbrot_backgndBc_4macOs.sh.txt

> Have a look at my POSIX/shell version that is even slightly faster:
> https://gist.github.com/leagris/59e1b7e72462024b278652696f375e71

Faster if run under dash or busybox, not using bash!

But, why did you 
   exec 8<>"$bcin";exec 9<>"$bcout"
then don't use `echo >&8` nor `read <&9`?
As you are re-adressing FS at every read/write, your script is still
something slower! Test and compare my re-modified version of your (dropped
trap exit and addressing FSs, operate few seconds quicker).
  https://f-hauri.ch/vrac/mandelbrot_posix.sh.txt

But there is less to do with [bash].

> There is no need for bash specific features, although coproc and other
> fancynesses can help, these lack portability.

Of course many bashisms could be avoided to stay POSIX portable.
In that way, commands like `coproc` are useless if not counter productive.
My meaning here was to improve coproc in order to by able to drive STDERR too.

-- 
 Félix Hauri  -  <felix@f-hauri.ch>  -  http://www.f-hauri.ch