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Remove all HTML but keep <p> tags
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Rob
Feb 10, 2012, 4:24:57 PM2/10/12
to
I am looking for a perl REGEX statement to remove all the HTML from a
string except for the <p> tags. It would have to leave the <p> (and
the </p>) tags but also longer ones such as <p style=...> etc. I
haven't been able to find anything similar online for this.
Can anyone help with a suitable REGEX for this? I have tried a few
things but had no success.
Any help would be much appreciated.
Rob
string except for the <p> tags. It would have to leave the <p> (and
the </p>) tags but also longer ones such as <p style=...> etc. I
haven't been able to find anything similar online for this.
Can anyone help with a suitable REGEX for this? I have tried a few
things but had no success.
Any help would be much appreciated.
Rob
J. Gleixner
Feb 10, 2012, 5:02:55 PM2/10/12
to
avoid a regular expression solution and use a parser.e.g.
HTML::Parser.
Read the documentation and take a look a some of the examples
in the distribution, like hstrip and htext.
Jürgen Exner
Feb 10, 2012, 7:41:32 PM2/10/12
to
Rob <rdw...@gmail.com> wrote:
>I am looking for a perl REGEX statement to remove all the HTML from a
Please see the FAQ and the many, many archived posts why HTML and REGEX
>I am looking for a perl REGEX statement to remove all the HTML from a
is not a viable combination.
>string except for the <p> tags. It would have to leave the <p> (and
>the </p>) tags but also longer ones such as <p style=...> etc. I
>haven't been able to find anything similar online for this.
>
>Can anyone help with a suitable REGEX for this? I have tried a few
>things but had no success.
further details please read up on the Chomsky hierarchy of languages.
jue
Peter J. Holzer
Feb 11, 2012, 4:06:50 AM2/11/12
to
[As J. Gleixner has already pointed out, there are HTML parsers
available for perl - doing this with a regexp is almost certainly not
the best way to do this]
On 2012-02-11 00:41, Jürgen Exner <jurg...@hotmail.com> wrote:
> Rob <rdw...@gmail.com> wrote:
>>I am looking for a perl REGEX statement to remove all the HTML from a
>
> Please see the FAQ and the many, many archived posts why HTML and REGEX
> is not a viable combination.
>
>>string except for the <p> tags. It would have to leave the <p> (and
>>the </p>) tags but also longer ones such as <p style=...> etc. I
>>haven't been able to find anything similar online for this.
What exactly do you mean by "remove all html except <p> tags"?
What would the result of processing the following (simple) file be?
<html>
<head>
<title>
A test
</title>
</head>
<body>
<h1> A test </h1> <h2> for Robs script </h2>
<p>
The quick brown fox jumps over the lazy dog.
</p>
<table>
<tr>
<td>
<p>
upper left
</p>
<p>
lower left
</p>
</td>
<td>
<p>
right
</p>
</td>
</tr>
</table>
<!--
<p>
This is not a paragraph
</p>
-->
<p>
Over & out!
</p>
</body>
</html>
>>Can anyone help with a suitable REGEX for this? I have tried a few
>>things but had no success.
Well, what have you tried?
Some tips:
* Start with a formal grammar of what you want to match.
I usually use some form of BNF.
* Don't try to write the whole Regexp at once. Use one Regexp
for every production in your grammar and use variable substitution
to build more complex regexps (there is a parallel thread about
matching RFC5322 headers with some examples).
* Use /x and comments.
> That is not surprising because it cannot be done for arbitrary HTML. For
> further details please read up on the Chomsky hierarchy of languages.
Care to explain how the difference between regular and context-free
grammars is relevant to the task at hand? And you know of course that
Perl regexps are a superset of regular expressions, so that even if the
task is impossible with a regular expression, it may still be possible
with a regexp (has anyone tried to prove that regexps are/are not
equivalent to context-free grammars lately?).
hp
--
_ | Peter J. Holzer | Deprecating human carelessness and
|_|_) | Sysadmin WSR | ignorance has no successful track record.
| | | h...@hjp.at |
__/ | http://www.hjp.at/ | -- Bill Code on as...@irtf.org
available for perl - doing this with a regexp is almost certainly not
the best way to do this]
On 2012-02-11 00:41, Jürgen Exner <jurg...@hotmail.com> wrote:
> Rob <rdw...@gmail.com> wrote:
>>I am looking for a perl REGEX statement to remove all the HTML from a
>
> Please see the FAQ and the many, many archived posts why HTML and REGEX
> is not a viable combination.
>
>>string except for the <p> tags. It would have to leave the <p> (and
>>the </p>) tags but also longer ones such as <p style=...> etc. I
>>haven't been able to find anything similar online for this.
What would the result of processing the following (simple) file be?
<html>
<head>
<title>
A test
</title>
</head>
<body>
<h1> A test </h1> <h2> for Robs script </h2>
<p>
The quick brown fox jumps over the lazy dog.
</p>
<table>
<tr>
<td>
<p>
upper left
</p>
<p>
lower left
</p>
</td>
<td>
<p>
right
</p>
</td>
</tr>
</table>
<!--
<p>
This is not a paragraph
</p>
-->
<p>
Over & out!
</p>
</body>
</html>
>>Can anyone help with a suitable REGEX for this? I have tried a few
>>things but had no success.
Some tips:
* Start with a formal grammar of what you want to match.
I usually use some form of BNF.
* Don't try to write the whole Regexp at once. Use one Regexp
for every production in your grammar and use variable substitution
to build more complex regexps (there is a parallel thread about
matching RFC5322 headers with some examples).
* Use /x and comments.
> That is not surprising because it cannot be done for arbitrary HTML. For
> further details please read up on the Chomsky hierarchy of languages.
grammars is relevant to the task at hand? And you know of course that
Perl regexps are a superset of regular expressions, so that even if the
task is impossible with a regular expression, it may still be possible
with a regexp (has anyone tried to prove that regexps are/are not
equivalent to context-free grammars lately?).
hp
--
_ | Peter J. Holzer | Deprecating human carelessness and
|_|_) | Sysadmin WSR | ignorance has no successful track record.
| | | h...@hjp.at |
__/ | http://www.hjp.at/ | -- Bill Code on as...@irtf.org
George Mpouras
Feb 14, 2012, 1:14:53 PM2/14/12
to
# try this
use strict;
use warnings;
my $htm=sub{local $/=undef;$_=$_[0];<$_>}->(\*DATA);
while( $htm =~/<p[^>]*?>(.*?)<\/p>/gi ) {
print "*$^N*\n"
}
__DATA__
<p>Earth</p> blah1 <p style=...>Sun</p> blah1
<p style=...>Moon</p> blah2 <p>
Venus
</p><p style=...>Hermes</p>blah2<p>
Jupiter</p>
use strict;
use warnings;
my $htm=sub{local $/=undef;$_=$_[0];<$_>}->(\*DATA);
while( $htm =~/<p[^>]*?>(.*?)<\/p>/gi ) {
print "*$^N*\n"
}
__DATA__
<p>Earth</p> blah1 <p style=...>Sun</p> blah1
<p style=...>Moon</p> blah2 <p>
Venus
</p><p style=...>Hermes</p>blah2<p>
Jupiter</p>
Eli the Bearded
Feb 14, 2012, 7:19:20 PM2/14/12
to
In comp.lang.perl.misc,
George Mpouras <nospam.gravit...@hotmail.com.nospam> wrote:
> # try this
missing </P> tags, if there is markup inside the paragraphs, if
the close paragraph has optional whitespace like "</P >", or if
the paragraph contains newlines.
That's all the errors I can find in a first glance.
Elijah
------
thinks it is html comments that make the original problem tricky
George Mpouras <nospam.gravit...@hotmail.com.nospam> wrote:
> # try this
> while( $htm =~/<p[^>]*?>(.*?)<\/p>/gi ) {
> print "*$^N*\n"
> }
That won't be effective if there are <PRE> (or other <P\w+>) tags,
> print "*$^N*\n"
> }
missing </P> tags, if there is markup inside the paragraphs, if
the close paragraph has optional whitespace like "</P >", or if
the paragraph contains newlines.
That's all the errors I can find in a first glance.
Elijah
------
thinks it is html comments that make the original problem tricky
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