Barattalo

I’ve found this nice small bot on the www.php.net site, thanks to the author of the script on the preg_replace page.
This bot returns the text content of a url and it could be used to take text from a site and find relevant words to search.

It’s nice because it uses CURL and let us see some nice stuff that CURL does:

1. hide himself presenting with a specific user agent, to seem a browser and not a spider
2. follows redirect (this means that you can call this function with a tiny url to retrieve the text in the real page!)
3. use very powerful regular expression to remove html tags, but also javascript and styles (they remain if you simply do a strip_tags)

This script will be included in the next version of the Mini Bots PHP Class.

function webpage2txt($url) {
	$user_agent = "Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)";

	$ch = curl_init();    // initialize curl handle
	curl_setopt($ch, CURLOPT_URL, $url); // set url to post to
	curl_setopt($ch, CURLOPT_FAILONERROR, 1);              // Fail on errors
	curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);    // allow redirects
	curl_setopt($ch, CURLOPT_RETURNTRANSFER,1); // return into a variable
	curl_setopt($ch, CURLOPT_PORT, 80);            //Set the port number
	curl_setopt($ch, CURLOPT_TIMEOUT, 15); // times out after 15s

	curl_setopt($ch, CURLOPT_USERAGENT, $user_agent);

	$document = curl_exec($ch);

	$search = array('@<script[^>]*?>.*?</script>@si',  // Strip out javascript
		'@<style[^>]*?>.*?</style>@siU',    // Strip style tags properly
		'@<[\/\!]*?[^<>]*?>@si',            // Strip out HTML tags
		'@<![\s\S]*?–[ \t\n\r]*>@',         // Strip multi-line comments including CDATA
		'/\s{2,}/',
	);

	$text = preg_replace($search, "\n", html_entity_decode($document));

	$pat[0] = "/^\s+/";
	$pat[2] = "/\s+\$/";
	$rep[0] = "";
	$rep[2] = " ";

	$text = preg_replace($pat, $rep, trim($text));

	return $text;
}

echo webpage2txt("http://www.rockit.it");

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4. New version of Mini Bots PHP Class (v.1.4)
5. How to write a text description into html input type password

Tags: curl, Regular expression, Spider, spiders, Web bot