Finding part of a string that a user has sent via POST - php

Question

My users can send links from popular file hosts like Rapidshare, Megaupload, Hotfile and FileFactory. I need to somehow find out what filehost they sent the link from and use the correct class for it appropriately.
For example, if I sent a Rapidshare link in a form on my web page, I need to somehow cycle through each file host that I allow until I find the text rapidshare.com, then I know the user has posted a Rapidshare link.
Perhaps a PHP example:
switch($_POST['link'])
{
case strstr($_POST['link'], 'rapidshare.com'):
// the link is a Rapidshare one
break;
case strstr($_POST['link'], 'megaupload.com'):
// the link is a Megaupload one
break;
case strstr($_POST['link'], 'hotfile.com'):
// the link is a Hotfile one
break;
case strstr($_POST['link'], 'filefactory.com'):
// the link is a Filefactory one
break;
}
However, I know for a fact this isn't correct and I'd rather not use a huge IF statement if I can help it.
Does anyone have any solution to this problem?
If you need me to explain more I can try, English isn't my native language so it's kinda hard.
Thanks all.

Answer 1

Nevermind guys, I used this:
$sentLink = trim($_POST['link']);
$host = parse_url($sentLink, PHP_URL_HOST);
switch($host)
{
case 'rapidshare.com':
echo "RS";
break;
case 'megaupload.com':
echo "MU";
break;
case 'hotfile.com':
echo "HF";
break;
case 'filefactory.com':
echo "FF";
break;
default:
echo "WTF! D:";
}
First time I've heard of parse_url :)

Answer 2

According to php - regex hostname extraction you want to make sure you check for the www. portion of th eurl as parse_url can sometimes return that as well.
$sentLink = trim($_POST['link']);
$host = array_shift( explode( '.', str_replace('www.', '', parse_url( $sentLink , PHP_URL_HOST )) ) );
switch($host)
{
case 'rapidshare.com':
echo "RS";
break;
case 'megaupload.com':
echo "MU";
break;
case 'hotfile.com':
echo "HF";
break;
case 'filefactory.com':
echo "FF";
break;
default:
echo "WTF! D:";
}