Get First Para from Wikipedia

wiki.php

<?php

$query = $_GET['query'];

$url = "http://en.wikipedia.org/w/api.php?action=parse&page=$query&format=json&prop=text&section=0";
$ch = curl_init($url);
curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt ($ch, CURLOPT_USERAGENT, "TestScript"); // required by wikipedia.org server; use YOUR user agent with YOUR contact information. (otherwise your IP might get blocked)
$c = curl_exec($ch);

$json = json_decode($c);

$content = $json->{'parse'}->{'text'}->{'*'}; // get the main text content of the query (it's parsed HTML)

// pattern for first match of a paragraph
$pattern = '#<p>(.*)</p>#Us'; // http://www.phpbuilder.com/board/showthread.php?t=10352690
if(preg_match($pattern, $content, $matches))
{
    // print $matches[0]; // content of the first paragraph (including wrapping <p> tag)
    $cont = strip_tags($matches[1]); // Content of the first paragraph without the HTML tags.
}


$pattern = '/\[([^\[\]]|(?R))*]|\(([^()]|(?R))*\)/';
echo $my = preg_replace($pattern, '', $cont);

?>

Credit: http://stackoverflow.com/questions/8555320/is-there-a-clean-wikipedia-api-just-for-retrieve-content-summary