[Pdns-users] Exception: unknown escape sequence on NAPTR regex

Peter Fern pdns at obfusc8.org
Tue Aug 5 03:19:01 UTC 2008

Duane wrote:
> Peter Fern wrote:
>> All I'm trying to do is get PDNS to return a record verbatim from the
>> backend (actually, I've just reviewed the RFC, which says a
>> double-backslash in the zone must return a single in the response). 
>> Simply matching '\\' and returning '\' is a low-cost operation, and
>> required for RFC compliance - I can't believe that this will result in a
>> significant load increase.  In any case, load is not an issue for our
>> application - we can through more hardware at it.  And expanding the
>> regex before adding to the backend is entirely impractical since we'd
>> potentially have to insert hundreds of thousands of records to match a
>> single pattern with a backref, depending on the numbering scheme.
> I'm assuming you are talking about consecutive numbering, in which case
> you just use a wildcard.

Correct, however we often have a requirement to match a substring and 
sub it into another pattern to translate one number range to another, 
hence the requirement for regex.  And regardless - it's currently 
impossible to escape characters like '+' since the backslashes are not 
passed correctly.

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