How to get the file extension from a url?

Question

New to ruby, how would I get the file extension from a url like:

http://www.example.com/asdf123.gif 

Also, how would I format this string, in c# I would do:

string.format("http://www.example.com/{0}.{1}", filename, extension); 

Answer 1

Use File.extname

File.extname("test.rb")         #=> ".rb" File.extname("a/b/d/test.rb")   #=> ".rb" File.extname("test")            #=> "" File.extname(".profile")        #=> "" 

To format the string

"http://www.example.com/%s.%s" % [filename, extension]