Re: Pcre Binding

[Patrick Donnelly <batrick () batbytes com>]

Hi nnposter,

On Fri, Jul 11, 2014 at 2:51 PM,  <nnposter () users sourceforge net> wrote:
> devin bjelland wrote:
> > Since no scripts are still using the Pcre binding, and Lpeg does everything
> > it does, I propose removing the NSE binding for Pcre. I'm interested to
> > know what people think of this (i.e. do you have some secret super awesome
> > thing that you use the Pcre binding for).
>
> The PCRE/lpeg conversion broke telnet-brute.nse. A cursory look at the
> script code shows that some unwarranted liberties were taken when
> re-inventing the match patterns.

I'm responsible for most of the conversions from PCRE to LPeg.
telnet-brute was the only difficult script to convert. This is largely
because it uses some peculiar patterns like \b (word boundary) and
some unnecessary/obscure capture options (?). I had to make a fix in
r33180 because I botched the patterns. I'm pretty sure they are
correct now and we have some simple asserts to verify subjects that
should match.

> IMHO it is not appropriate to do so
> unless the person can in fact validate that the patterns are still
> working as expected. Put differently, either the new patterns should be
> functionally equal or the legacy PCRE bindings should not be messed
> with for the time being.

I would normally agree with this philosophy but because we have so
many scripts which are non-trivial to confirm actually work, I don't
feel this is a sensible way to think. If we weren't willing to make
some changes, we'd be stuck with a lot of legacy code and be hamstrung
in efforts to improve things.

-- 
Patrick Donnelly
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