```ruby
require 'nokogiri'
class XMLHandler < Nokogiri::XML::SAX::Document
def start_element(name, attrs = [])
puts "start: #{name}"
end
def end_element(name)
puts "end: #{name}"
end
end
parser = Nokogiri::XML::SAX::Parser.new(XMLHandler.new)
parser.parse_file(ARGV[0])
# don't try to use
#parser.parse(File.read(ARGV[0]))
```
See the [documentation for Sax::Document for details](http://nokogiri.org/Nokogiri/XML/SAX/Document.html)