I posted how to get the keywords from a search engine referer url a while back (here) and from a number of useful comments on that post have completely revised the function which now also supports the query string when it is sent as part of a URL fragment.
This post shows how to use PHP to extract the keywords searched on by a user when they found your website using a seach engine. Bing, Google and Yahoo are covered here and you can easily add your own to the PHP code supplied.
A little while back I posted how to extract the domain, path, etc from a url with PHP and in this follow up post show how to extract the query string into an associative array using the parse_str function.
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.
When a web browser moves from one website to another and between pages of a website, it can optionally pass the URL it came from. This is called the HTTP_REFERER, and this post looks at how to use this variable with PHP.