Regex to get hostname from referer

I'm pretty new to regex, and this is the first time I've tried to use them in php. I'm just trying to take $_SERVER['HTTP_REFERER'] and produce a host string such as http://forums.digitalpoint.com. I'm not even sure if I'm using the best function p;

eregi('^(.*//[a-z0-9.-:]+)',$_SERVER['HTTP_REFERER'],$adcustom['referring_host']);
var_dump($adcustom['referring_host']);

PHP:

It seems like this would work as I didn't didn't ask for more slashes within the [] brackets, but it still returns the rest of the referer string that includes the filename.

 

This is the example of php.net

<?php
// get host name from URL
preg_match('@^(?:[url]http://)?([/url][^/]+)@i',
   "http://www.php.net/index.html", $matches);
$host = $matches[1];

// get last two segments of host name
preg_match('/[^.]+\.[^.]+$/', $host, $matches);
echo "domain name is: {$matches[0]}\n";
?> 

PHP:

Put the referrer variable in place and you will get referring host in return.

Wish you good luck.

Ref. http://au3.php.net/preg-match

 

var_dump(preg_match('@^(?:[url]http://)?([/url][^/]+)@i',$_SERVER['HTTP_REFERER'], $matches));

Code (markup):

prints int(0) when $_SERVER['HTTP_REFERER']==='http://localhost:82/labs/test.php'

But I am still trying to figure it out

Thanks coolsaint

 

This is the code I used for a different project where I wanted to get the root domain

$url = preg_replace("/^http:\/\//", "", $_GET['url']);
	
$url_tokens = explode("/", $url);
$url = $url_tokens[0];

PHP:

First I stripped off the http://, then seperated out the root and each folder and then just selected the root. It's not pure regex but it works and it was easy to create.

 

extract(parse_url($_SERVER['HTTP_REFERER']));

echo $scheme .'://'. $host;

PHP:

 

Also, if you want to block a certain referer, you should remove the www. when checking.

extract(parse_url($_SERVER['HTTP_REFERER']));

$referer = $scheme .'://'. str_replace('www.', null, $host);

echo $referer;

PHP:

 

Thanks. I'm gonna put off this regex until after I launch this project. p;

 

Old post - but I see the regex solution to this problem everywhere.
Just use explode with / as the delimiter.

$foo = @$_SERVER['HTTP_REFERER'];
if ( strlen($foo) > 0 ) {
  $bar = explode("/",$foo);
  $host = $bar[2];
  } else {
  $host = "";
  }

Code (markup):

 

why regex when php has the parse_url function?

 

heh - even easier