Re: Space removal in AE takes place before brace expansion

[Greg Wooledge]

On Sun, Apr 30, 2017 at 08:31:30PM +0200, Florian Mayer wrote:
> I want to add up all numbers from 1 to 10,

sum=0; for ((i=1; i<=10; i++)); do ((sum+=i)); done

> but when I do 
> $ echo $(({1,10}???+??? +0)) # with a space between the first + and the 
> second one

I cannot figure out what you actually typed here, because your UTF-8
characters have been replaced by three question marks in my mail client.

What I see is literally:  echo $(({1,10}???+??? +0))

You should NOT be entering UTF-8 characters into bash commands, unless
they're literal characters that are part of a string that you want to
store or print or pass as an argument.  They should certainly not be
part of an arithmetic expression.

> I get an error:
> bash: ((: 1+ ,3 10+ ,3: syntax error: operand expected (error token is ",3 
> 10+ ,3???)

So you are trying to be CLEVER?  You are trying to trick bash into
executing code that generates code that will then be evaluated?  And you
didn't even explictly call eval?

I really, very strongly, discourage you from pursuing this line of
solutions.  Generating code with the intent to eval it is NOT the way
to go for a simple arithmetic problem.  Just use a loop.