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Postings from April 2007
On Wed, Apr 11, 2007 at 01:49:08PM +0200, Dr.Ruud wrote:
> Abigail:
>> See `perldoc -q remove.HTML`:
>>
>> <quote>
>> Here's one "simple-minded" approach, that works
>> for most files:
>>
>> #!/usr/bin/perl -p0777
>> s/<(?:[^>'"]*|(['"]).*?\1)*>//gs
>>
>> </quote>
>>
>> That regex has a ** structure, which can make it very slow, for
instance
>> on an "incomplete" string like
>> qq{> <META http-equiv=3DContent-Type content=3D"text/html; =\n>}.
>
> Well, it wasn't called 'simple-minded' without reason.
Yes, but it could use a warning, like "Beware that incorrect HTML can
slow down this regex significantly (it has a double layer of *
quantifiers to try and please the backtracker).".
>> So maybe we should put a "safer" variant in the documentation?
>
> Maybe, but I'd still keep the "simple-minded" regexp there.
Fine.
> Or even (5.10 style + loop-unrolling):
>
> s/< [^>"']++
> (?:
> (?:"[^"]*+")*+
> (?:'[^']*+')*+
> [^>'"]*+
> )*+
> >
> /xg;
Good one for the FAQ.
> None of these actually remove HTML comments correctly, do they?
Yes. :)
The FAQ also mentions Tom Christiansen's striphtml, but that has
problems too.
> My guess is that people would prefer that over fast parsing incorrect
HTML.
That always depends on what it is used for. I use the coarse method to
quickly strip email-messages, just to barely keep the idea of what they
are about. These messages can contain fragments of HTML, even quoted by
inserting '> ' at the start of the lines, etc.
--
Affijn, Ruud
"Gewoon is een tijger."
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