How to safely get the file extension from a URL?

Question

Consider the following URLs

http://m3u.com/tunein.m3u
http://asxsomeurl.com/listen.asx:8024
http://www.plssomeotherurl.com/station.pls?id=111
http://22.198.133.16:802         


        

Answer 1

File extensions are basically meaningless in URLs. For example, if you go to http://code.google.com/p/unladen-swallow/source/browse/branches/release-2009Q1-maint/Lib/psyco/support.py?r=292 do you want the extension to be ".py" despite the fact that the page is HTML, not Python?

Use the Content-Type header to determine the "type" of a URL.