Re: Strange bug in arithmetic function

[Davide Brini]

On Monday 21 Feb 2011 09:13:54 Marcel de Reuver wrote:
> In a bash script I use: $[`date --date='this week' +'%V'`%2] to see if
> the week number is even.
> Only in week 08 the error is: bash: 08: value too great for base
> (error token is "08") the same in week 09, all others are Ok...

It's not a bug. First, you shouldn't use the ancient and deprecated $[ .. ] 
syntax for arithmetic evaluation; use $(( .. )).

Second, bash interprets numbers with leading zeros as octal, thus "08" isn't a 
valid octal number. You can force it to be interpreted as decimal by 
prepending the base, eg see

$ echo $(( 08 + 2 ))
-su: 08: value too great for base (error token is "08")

$ echo $(( 10#08 + 2 ))
10

-- 
D.