Debes saber que las arañas no están bien vistas por los webmasters, ya que su misión es rastrear, capturar, robar ya sea documentos, textos, imágenes, etc... Pero si tantas inquietudes tienes te pongo un simple ejemplo en el cual captaríamos la documentación de la pagina php.net.
Código PHP:
Ver original<?php
// It may take a whils to crawl a site ...
// Inculde the phpcrawl-mainclass
include("libs/PHPCrawler.class.php");
// Extend the class and override the handleDocumentInfo()-method
class MyCrawler extends PHPCrawler
{
function handleDocumentInfo($DocInfo)
{
// Just detect linebreak for output ("\n" in CLI-mode, otherwise "<br>").
if (PHP_SAPI == "cli") $lb = "\n";
else $lb = "<br />";
// Print the URL and the HTTP-status-Code
echo "Page requested: ".$DocInfo->url." (".$DocInfo->http_status_code.")".$lb;
// Print the refering URL
echo "Referer-page: ".$DocInfo->referer_url.$lb;
// Print if the content of the document was be recieved or not
if ($DocInfo->received == true)
echo "Content received: ".$DocInfo->bytes_received." bytes".$lb;
else
echo "Content not received".$lb;
// Now you should do something with the content of the actual
// received page or file ($DocInfo->source), we skip it in this example
echo $lb;
}
}
// Now, create a instance of your class, define the behaviour
// of the crawler (see class-reference for more options and details)
// and start the crawling-process.
$crawler = new MyCrawler();
// URL to crawl
$crawler->setURL("www.php.net");
// Only receive content of files with content-type "text/html"
$crawler->addContentTypeReceiveRule("#text/html#");
// Ignore links to pictures, dont even request pictures
$crawler->addURLFilterRule("#\.(jpg|jpeg|gif|png)$# i");
// Store and send cookie-data like a browser does
$crawler->enableCookieHandling(true);
// Set the traffic-limit to 1 MB (in bytes,
// for testing we dont want to "suck" the whole site)
$crawler->setTrafficLimit(1000 * 1024);
// Thats enough, now here we go
$crawler->go();
// At the end, after the process is finished, we print a short
// report (see method getProcessReport() for more information)
$report = $crawler->getProcessReport();
if (PHP_SAPI == "cli") $lb = "\n";
else $lb = "<br />";
echo "Summary:".$lb;
echo "Links followed: ".$report->links_followed.$lb;
echo "Documents received: ".$report->files_received.$lb;
echo "Bytes received: ".$report->bytes_received." bytes".$lb;
echo "Process runtime: ".$report->process_runtime." sec".$lb;
?>