It uses the get_headers function to verify the existing headers. Doesn`t matter if it`s or no, if exists menas the domain is registered. If doesn`t exist, the domain is free. Atleast in my vision. =)
PHP Code:
<form action="" method="GET">
<label>Domain name (e.g. elitepvpers.com)</label><br /><br />
<input type="text" size="30" name="domain" value="<?php echo @$_GET['domain'] ?>" autofocus />
<input type="submit" value="Check" />
</form>
PHP Code:
<?php
if (isset($_GET['domain']) && $_GET['domain'] != '') {
$headers = @get_headers('http://'.$_GET['domain']);
$file = @file_get_contents('http://who.is/whois/'.$_GET['domain'].'/');
$html = explode("\n", $file);
if (strlen($headers[0]) > 0) {
echo 'Domain <span style="color:#C00;font-weight:bold">registered</span>.';
} else {
echo 'Domain <span style="color:#0C0;font-weight:bold">not registered</span>.';
$file = @file_get_contents('http://who.is/whois/'.$_GET['domain'].'/');
if (!preg_match('/appears to be available/', $file)) {
echo '<br />Although who.is says it is.<br />Just check for any HTTP headers. :/';
}
unset($file);
unset($html);
}
}
?>