Create and read XML

I'm guessing you probably have this solved by now, but just in case...

     xml = Builder:: => './inf.xml', :indent => 1)

Here you are setting the target of a Build::XmlMarkup object to the string './inf.xml' I'm guessing that's not what you really want. Although, I would guess that Ruby isn't complaining about that since your target is an object that responds to the << method.

Try something like this:

f ="./inf.xml", "w") xml = => f, :indent => 1) xml.instruct! xml.some_tag f.close