Author: Mike Cardwell Date: To: exim-users Subject: Re: [exim] Undefined variable in eval: (string expansion)
Mike Cardwell wrote:
>> What do I get if I do something like
>>
>> ${eval:$some_variable+1}
>>
>> when "some_variable" is not actually defined?
>
> Looks like it treats some_variable as 0:
>
> root@clayman:~# /usr/sbin/exim -be
> > ${eval:$acl_m9+1}
> 1
> >
Hmmm. More accurately, it expands to the empty string so your eval becomes:
${eval:+1}
Which evaluates to 1
root@clayman:~# /usr/sbin/exim -be > ${eval:$acl_m9+1} 1 > ${eval:1+$acl_m9} Failed: error in expression evaluation: expecting number or opening
parenthesis (after processing "1+") >