How to extract the first few sentences from a body of text on web page

We are building some sort of digg site and want to automatically fetch limited text (2-3 sentences). It can be last 3 sentences of article.if that would be easier. At the momemt we fetch web page content without the problem but want to make universal script to get few sentences. We want to avoid making custom scripts for each web site from which we want to get content.

I was thinking to find the text block by dots. To find dots in a close range and than to get words around dots. That is raw idea. Does so开发者_如何学运维meone has some other idea how to extract just par of the text.

We don't want to scrape full content.

Thank you.

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You could look for large portions of the document that have less markup and less vertical whitespace. Download the page's source and strip out any markup using strip_tags(). Then you can search for, say, five consecutive sentences using regular expressions.

Here's an example script. It uses a class not included (an abstraction of curl_multi functions), but that class isn't really relevant for your question.

<?php

require_once("./../MultipleRequester.php");

$requester = new MultipleRequester();

$requester->addGetRequest( 'test', 'http://www.businessweek.com/news/2011-08-24/gold-tumbles-most-since-march-2008-as-demand-for-haven-wanes.html');
$requester->execute();
$content = $requester->getContent('test');

$plainText = strip_tags( $content );

$search = preg_match('/(\h{0,2}\v{0,2}\h{0,2}[A-Z]{1}[A-z0-9 ,\'")(.$]{10,1000}\.){2,5}/', $plainText, $matches);

if( $search )
    print trim($matches[0]);
else
    print "Could not extract anything.";

print "\n\n";
?>

This prints:

The dollar rose against a basket of six major currencies amid speculation about whether Federal Reserve Chairman Ben S. Bernanke will say this week that the central bank is willing to provide more stimulus to the economy. Central bankers meet this week in Jackson Hole, Wyoming, to address the U.S. recovery.

You may still have trouble with sites that mark up their content a lot. You might want to make the regular expression more lenient, particularly towards whitespace.

The regexp is a little messy, but you can tune it or write your own.