HTTP download

http-download.rb

require 'socket'
require 'uri'

#TestUrl = 'http://ftp.gnu.org/gnu/autoconf/autoconf-2.56.tar.gz'
TestUrl = 'http://googletest.googlecode.com/files/gtest-1.7.0.zip'

class Response
  attr_reader :content_length
  def initialize(socket)
    parse_header(socket)
    parse_content_length

    parse_body(socket)
  end

  def parse_header(socket)
    @header = ''

    while !@header.match "\r\n\r\n"
      line = socket.readline
      @header << line
    end
  end

  def parse_content_length
    l = @header.lines.select { |l| l.match /content-length/i }.first
    @content_length = l.split(":")[1].strip.to_i
  end

  def parse_body(socket)
    @body = ''
    @body << socket.read(@content_length)
  end

  def header
    @header
  end

  def data
    @body
  end
end

class Request
  UserAgents = ["Mozilla/5.0 (Windows NT 6.1; WOW64; rv:26.0) Gecko/20100101 Firefox/26.0",]

  def initialize(uri)
    @uri = uri
    @http_version = '1.1'
    @request_line = "GET #{@uri.path} HTTP/#{@http_version}\r\n"
    @host = "Host: #{@uri.host}\r\n"
    @end_line = "\r\n"

    @binary = @request_line + @host + @end_line
  end

  def to_binary
    @binary
  end
end

def download(url)
  uri = URI(url)

  sock = TCPSocket.new uri.host, uri.port
  sock.send Request.new(uri).to_binary, 0

  puts 'Read from socket'
  response = Response.new sock
  puts "Content-Length: #{response.content_length} =============="
  puts response.header

  filename = File.basename(uri.path)
  File.open(filename, 'wb') do |f|
    f.write response.data
  end
end