PHP’s parse_url function makes it easy to extract the domain, path and other useful bits of information from a full URL. This can be useful for a variety of purposes, such as when spidering content from a website and needing to extract particular pieces of information from the links in the page.
Returning an associative array
The parse_url function takes the url as the first argument and an optional component value as the second argument. If the second argument is omitted then it returns the found values as an associative array.
This post is at https://www.electrictoolbox.com/php-extract-domain-from-full-url/ and getting the associative array of information from it is done like this:
$url = "https://www.electrictoolbox.com/php-extract-domain-from-full-url/"; $parts = parse_url($url);
Then doing print_r($parts) will output this:
Array ( [scheme] => http [host] => www.electrictoolbox.com [path] => /php-extract-domain-from-full-url/ )
If they are present, the array will also contain values for port, user, pass (i.e. password), query (the query string component of the URL) and fragment (the part after the #).
Returning a string
If all you are after is a single component from the array as a single string, pass the second "component" parameter from the following constants: PHP_URL_SCHEME, PHP_URL_HOST, PHP_URL_PORT, PHP_URL_USER, PHP_URL_PASS, PHP_URL_PATH, PHP_URL_QUERY or PHP_URL_FRAGMENT.
To just get the domain from this blog post’s URL, do this:
$url = "https://www.electrictoolbox.com/php-extract-domain-from-full-url/"; $domain = parse_url($url, PHP_URL_HOST);
For more information read the PHP manual page for this function.
Follow up posts
Have a read of my post titled "PHP: get keywords from search engine referer url" to find out how to use the parse_url function in conjunction with the parse_str function to see what query string visitors have entered into a search engine.