Can the actual index page be determined when requesting a directory?

When requesting http://example.com (using something like cURL), is there anyway to de开发者_StackOverflow中文版termine what the actual page server side is? Is it /index.php /index.html /index.asp?

This is a completely client side question.

Definitely no guaranteed way, there may not even be a default page at all on the server. Although there's usually some sort of page, script, or template associated with a given URL, it can be buried under several layers framework that make it not useful information anyway. You might be able to glean some extra info from the http response headers. But that's pretty much all you get on the client side.