NamePros.Com - A whois class (sort of)

This isn't actually a whois class, it's a class that selects a whois server for a domain. If multiple whois servers are available, it chooses a random one.
The script uses this XML file to get the servers (human-readable version here).
As per their request, by default the class keeps a local cache of the XML file and updates once a day. To enable caching, make the directory the cache will be in writable. To disable caching change

PHP Code:

    var $use_cache = true;

PHP Code:

    var $use_cache = false;

Here is the class

PHP Code:

    class whoisserver{

 
    var $url = "http://serverlist.domaininformation.de/";

    var $cache = "whois.xml";

    var $use_cache = true;

 
    function parsexml($file){

        $parser = xml_parser_create('');

        xml_parser_set_option($parser, XML_OPTION_CASE_FOLDING, 0);

        xml_parser_set_option($parser, XML_OPTION_SKIP_WHITE, 1);

        xml_parse_into_struct($parser, file_get_contents($file), $tags);

        xml_parser_free($parser);

    

        $elements = array();

        $stack = array();

        foreach($tags as $tag){

            $index = count($elements);

            if($tag['type'] == "complete" || $tag['type'] == "open"){

                $elements[$index] = array();

                $elements[$index]['name'] = $tag['tag'];

                $elements[$index]['attributes'] = empty($tag['attributes']) ? "" : $tag['attributes'];

                $elements[$index]['content']    = empty($tag['value']) ? "" : $tag['value'];

            

                if($tag['type'] == "open"){    # push

                    $elements[$index]['children'] = array();

                    $stack[count($stack)] = &$elements;

                    $elements = &$elements[$index]['children'];

                }

            }

        

            if($tag['type'] == "close"){    # pop

                $elements = &$stack[count($stack) - 1];

                unset($stack[count($stack) - 1]);

            }

        }

        return $elements[0];

    }

 
    function cachecheck(){

        if(!file_exists($this->cache) || filemtime($this->cache) < time() - 86400 && $this->use_cache == true){

            $xml = file_get_contents($this->url);

            

            unlink($this->cache);

            

            $fp = fopen($this->cache, "w+");

            fwrite($fp, $xml);

            fclose($fp);

            

            return true;

        }else{

            return false;

        }

    }

 
    function getxml(){

        $file = ($this->use_cache == true) ? $this->cache : $this->url;

        $xml = $this->parsexml($file);

        

        return $xml;

    }

    

    function getservers(){

        $xml = $this->getxml();

        $servers = array();

 
        foreach($xml['children'] as $child){

            if(!empty($child['children'])){

                foreach($child['children'] as $baby){

                    if($baby['name'] == 'domain'){

                        if(empty($servers["{$baby['attributes']['name']}"])){

                            $servers["{$baby['attributes']['name']}"] = array("{$child['attributes']['host']}");

                        }else{

                            $servers["{$baby['attributes']['name']}"][] = "{$child['attributes']['host']}";

                        }

                    }

                }

            }

        }

        

        return $servers;

    }

    

    function pickserver($tld){

        $servers = $this->getservers();

        

        if(!empty($servers["{$tld}"])){

            $server = $servers["{$tld}"];

            if(count($server) != 1){

                return $server[array_rand($server)];

            }else{

                return $server[0];

            }

        }else{

            return false;

        }

    }

    

    function go($domain){

        $this->cachecheck();

        

        $domain = str_replace('www.', '', $domain);

        $domain = strrev($domain);

        $domain = explode('.', $domain);

        

        if(count($domain) == 3){

            $tld = strrev($domain[1]) . '.' . strrev($domain[0]);

        }else{

            $tld = strrev($domain[0]);

        }

        

        $server = $this->pickserver($tld);

        return $server;

    }

}

I wrote the whole class except the parsexml() function which I found on php.net. Do what you want with the code.

Here are two examples:

PHP Code:

    $ws = new whoisserver;

echo $ws->go("http://www.yarrt.com")."\n"; // should return "whois.crsnic.net"

echo $ws->go("http://hello.uyp")."\n"; // should return false