Wikipedia via SMS

Textipedia.php

<?php
header('Content-type: text/xml');
$url = "http://en.wikipedia.org/w/api.php?action=parse&format=xml&prop=sections&page=".$_POST['Body'];

$ch = curl_init($url);
curl_setopt($ch, CURLOPT_USERAGENT, "Textipedia");
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec($ch);
curl_close($ch);

$doc = new SimpleXMLElement($response);
$output = "";

if(count($doc->parse->sections->s) > 0) {
  foreach($doc->parse->sections->s as $section) {
    if($section[toclevel] == 1) {
      $output .= "\n ".$section[line];
    }
  }
}

if ($output == "") {
  $output = "Article not found: Text the title of a Wikipedia article to get an outline. Try 'Universe'.";
}
?>
<Response>
  <Sms><?php echo substr($output, 0, 160); ?></Sms>
</Response>