an enviroment for quick shell data munging in xml,html or json

datamung.rb

#!/usr/bin/ruby
require "rubygems"
require "nokogiri"
require "json"

format = ARGV[0]
code = ARGV[1]

class Runner
  attr_accessor :doc
end

doc = case format
when "json" then JSON.parse(STDIN.read)
when "xml" then Nokogiri::XML(STDIN.read)
when "html" then Nokogiri::HTML(STDIN.read)
end

run = Runner.new
run.doc = doc
run.instance_eval code