OpenURI

 OpenURI is an easy-to-use wrapper for net/http, net/https and net/ftp.

Example

 It is possible to open http/https/ftp URL as usual like opening a file:

   open("http://www.ruby-lang.org/") {|f|
     f.each_line {|line| p line}
   }

 The opened file has several methods for meta information as follows since
 it is extended by OpenURI::Meta.

   open("http://www.ruby-lang.org/en") {|f|
     f.each_line {|line| p line}
     p f.base_uri         # <URI::HTTP:0x40e6ef2 URL:http://www.ruby-lang.org/en/>
     p f.content_type     # "text/html"
     p f.charset          # "iso-8859-1"
     p f.content_encoding # []
     p f.last_modified    # Thu Dec 05 02:45:02 UTC 2002
   }

 Additional header fields can be specified by an optional hash argument.

   open("http://www.ruby-lang.org/en/",
     "User-Agent" => "Ruby/#{RUBY_VERSION}",
     "From" => "foo@bar.invalid",
     "Referer" => "http://www.ruby-lang.org/") {|f|
     # ...
   }

 The environment variables such as http_proxy, https_proxy and ftp_proxy
 are in effect by default.  :proxy => nil disables proxy.

   open("http://www.ruby-lang.org/en/raa.html", :proxy => nil) {|f|
     # ...
   }

 URI objects can be opened in a similar way.

   uri = URI.parse("http://www.ruby-lang.org/en/")
   uri.open {|f|
     # ...
   }

 URI objects can be read directly. The returned string is also extended by
 OpenURI::Meta.

   str = uri.read
   p str.base_uri

 Author:: Tanaka Akira <akr@m17n.org>