Re: [RFC][PATCH] cmd: test: Add bitwise AND, document the feature

[Brad Mouring <brad.mouring@ni.com>]

On Thu, Apr 13, 2017 at 06:20:24AM +0300, Andrei Borzenkov wrote:
> 12.04.2017 21:10, Brad Mouring пишет:
> > Currently, there is not a good way to control script flow based on
> > bitwise values. This initially led to NI adding the ability to read
> > a specific bit from a port-mapped register to control bootflow.
> > 
> > Here, we add a more generic ability to test the bitwise AND of a
> > value available to the grub scripting environment. This obviates the
> > need for the inbit command (which is currently OOT).
> > 
> 
> See recent discussion about arithmetic operations. This could also be
> 
> if $((a&b)); then
>  ...
> fi
> 
> I think it is more generic than single specific test.

I can appreciate the sentiment, but are you asking me to implement
some/all of the functionality of the double-paren arith expansion,
partially duplicating the functionality of the test/[ command, simply
because (( a & b )) is more bash-ful than [ a -bwa b ]?

I'm not trying to bake-in any sort of assumption here, in fact, I'm
just trying to get clarification.

Thanks,
Brad