Magnus Holmgren wrote:
> On Saturday 16 December 2006 17:01, W B Hacker wrote:
>> Jeremy Harris wrote:
>>> http://exim.org/exim-html-4.63/doc/html/spec_html/ch11.html#SECTexpvar
>>>
>>> Is $domain already lower-cased? The docs don't say one way or the other.
>>> What about $original_domain and $parent_domain?
>>> $sender_address?
>>>
>>> Note that $local_part is specified for this.
>> IIRC, the internet specifications are that <domain>.<tld> *must* be
>> lower-case.
>
> No, the "internet specifications" (in general, and DNS in particular) say that
> domain labels are *case-insensitive*.
>
> For that reason some applications *might* require domain names to be all
> lowercase on input (but that's stupid), or they may convert them to all
> lowercase without penalty.
>
>
ACK. But given that bytes are NOT 'case insensitive', that implies folding
applied 'just in case' (pun intended), 'penalty' or otherwise [1]. Else multiple
sets of comparisons, which might require more work.
Bill
[1] ASCII alpha character 'folding' can be done with an XOR and two NAND gates,
applied to just two bits in hardware.
Or the equivalent in software - probably a lib function in C et al?
