Re: _AS_DETECT_BETTER_SHELL speedup

[Ralf Wildenhues]

* Alexandre Duret-Lutz wrote on Sat, Jan 29, 2005 at 02:07:53PM CET:
> It seems to me that replacing
> 
>    (foo) 2>/dev/null
> 
> by
> 
>    (exec foo) 2>/dev/null
> 
> would also replace two forks by one, and it looks a lot less
> risky.  
> 
> However my understanding is that modern shells already detect
> these cases and perform the optimization by themselves.  I know
> for sure that Zsh has the machinery for this (along with some
> other hairy tricks to limit forks at other places), and, from
> what I can observe from the command line, so does Bash.  

Yes, after testing around a little, that is also my observation.
I should have done that before (grumble).  The only noticeable
difference I found was when foo was a shell builtin (old shells
and new shells alike).

Sorry, I did not mean to generate so much noise,
Ralf