bug-bash
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Space removal in AE takes place before brace expansion


From: Florian Mayer
Subject: Re: Space removal in AE takes place before brace expansion
Date: Mon, 01 May 2017 15:29:43 +0200

> sum=0; for ((i=1; i<=10; i++)); do ((sum+=i)); done
You can actually omit ‚sum=0;‘, because bash dereferences unset variables to 0
(according to the holy manual of course).

> I cannot figure out what you actually typed here, because your UTF-8

I don’t know what caused that, but it was not intentionally.
https://lists.gnu.org/archive/html/bug-bash/2017-04/msg00152.html
correctly shows what I’ve submitted.

> You should NOT be entering UTF-8 characters into bash commands, unless
I know. I did not.

> I really, very strongly, discourage you from pursuing this line of
I’d rather like you to save your recommendations regarding how I am supposed to
do things.

> Am 01.05.2017 um 15:10 schrieb Greg Wooledge <address@hidden>:
> 
> 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 characters have been replaced by three question marks in my mail client.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.




reply via email to

[Prev in Thread] Current Thread [Next in Thread]