[The Real Slim Shady]

afaik you will never find one piece of code that will work for all browsers. Its not like browsers are required to report the current URL to the OS, so why would there be a specific operating system API to get it. Each browser may have its own API but it wont be a standard of some sort.

Youll likely need to either find snippets of code for each browser you want to support, or study the API of each browser you would like to support.

But while i doubt it... I could be wrong too...