How to get the file-path of the currently executing javascript code

Question

I'm trying to do something like a C #include "filename.c", or PHP include(dirname(__FILE__)."filename.php") but in javascript. I know I can do this if I can get the URL a js file was loaded from (e.g. the URL given in the src attribute of the tag). Is there any way for the javascript to know that?

Alternatively, is there any good way to load javascript dynamically from the same domain (without knowing the domain specifically)? For example, lets say we have two identical servers (QA and production) but they clearly have different URL domains. Is there a way to do something like include("myLib.js"); where myLib.js will load from the domain of the file loading it?

Sorry if thats worded a little confusingly.

Answer 1

Within the script:

var scripts = document.getElementsByTagName("script"),
    src = scripts[scripts.length-1].src;

This works because the browser loads and executes scripts in order, so while your script is executing, the document it was included in is sure to have your script element as the last one on the page. This code of course must be 'global' to the script, so save src somewhere where you can use it later. Avoid leaking global variables by wrapping it in:

(function() { ... })();