how to check domain from given url in php code example

Example 1: php get domain from url

$url = 'http://google.com/dhasjkdas/sadsdds/sdda/sdads.html';
$parse = parse_url($url);
echo $parse['host']; // prints 'google.com'

Example 2: if browser url is having domain in it check using php

$url = 'http://' . $_SERVER['SERVER_NAME'] . $_SERVER['REQUEST_URI'];

if (!strpos($url,'mysql')) {
echo 'No mysql.'; //swapped with other echo statement
} else {
echo 'Mysql exists.';
}