[Fwd: Re: [BusyBox] Re: ash bug]

[Vladimir N. Oleynik]

I wrote:

 >> dash have expr == let aliased.
 >> Result: let is command for reduce $(()) syntax.
 >> You should change your example to
 >> x=`let 1`


New dash variant for busybox placed to my ftp:
ftp://ftp.simtreas.ru/pub/my/bb/new

News:

- rewroted let syntax as bash:

from bash man:

       let arg [arg ...]
               Each  arg  is  an arithmetic expression to be evaluated (see ARITH-
               METIC EVALUATION).  If the last arg evaluates to 0, let returns  1;
               0 is returned otherwise.


- rewroted arith:

  * - allow access to variable, 

  *   used recursive find value indirection (c=1; a="c"; $((a+=2)) produce 3) 

  * - realize assign syntax (VAR=expr, +=, *= etc) 

  * - realize exponentiation (** operator) 

  * - realize comma separated - expr, expr 

  * - realise ++expr --expr expr++ expr-- 

  * - realise expr ? expr : expr (but, second expr calculate always) 

  * - allow hexdecimal and octal numbers 

  * - restore loses XOR operator 

  * - remove one goto label, added two ;-) 

  * - protect $((num num)) as true zero expr (Manuel`s error) 

  * - always use special isspace(), see comment from bash ;-) 


Test:

unset a b c d 

echo 'rez=$((cond = a=1+2*3 ? (1+2*3,b=2**3) : (c=2|1^5), 0x20-010+d++))' 

rez=$((cond = a=1+2*3 ? (1+2*3,b=2**3) : (c=2|1^5), 0x20-010+d++)) 

echo 'a='$a 'b='$b 'c='$c 'cond='$cond 'rez='$rez 'd='$d 

echo "compare with harcoded:" 

echo 'a=7' 'b=8' 'c=6' 'cond=8' 'rez=24' 'd=1' 



But arith code must remove from libbb, only dash used this functions and require
builtins dash *var*  function now.



Manuel,
I wrote this 30 hours, but result size ~ + 900 bytes. I can`t found reduce size 
presently. :-(


Herbert,
This arith code FULL realised bash expression, but less 1k size. I recomended 
replace your
arith.y to this.


--w
vodz