example-io-parse.rb

#!/usr/bin/env ruby

require 'net/http'
require 'pp'

string_output = StringIO.new
http = Net::HTTP.new('www.iana.org')
http.set_debug_output string_output
http.start do |http|
  request = Net::HTTP::Get.new('/domains/example')
  response = http.request request
end

lines = string_output.string.split("\n")
request_headers = Hash[lines.select{|line| line =~ /-> "[\w\-]*:/ }.map{|line| line.gsub(/-> \"(.*) *: *(.*)\"$/, '\1:\2').split(':', 2) }]

pp reqest_headers

# {"Date"=>" Mon, 25 Mar 2013 00:15:05 GMT\\r\\n",
#  "Server"=>"Apache/2.2.3 (CentOS)\\r\\n",
#  "Last-Modified"=>" Fri, 04 Jan 2013 01:17:22 GMT\\r\\n",
#  "Vary"=>"Accept-Encoding\\r\\n",
#  "Connection"=>"close\\r\\n",
#  "Transfer-Encoding"=>"chunked\\r\\n",
#  "Content-Type"=>"text/html; charset=UTF-8\\r\\n"}