Update a spreadsheet of company websites with if they use Google Apps

gistfile1.rb

require "csv"
require "public_suffix"
require "active_support/all"
require "resolv"

def parse_domain(url)
  return url unless url.present?
  domain = url.strip.match(/\A(https?:\/\/(www\.)?)?([^\/]*)\/?/i)[3].downcase
  parsed_domain = PublicSuffix.parse(domain).domain
rescue PublicSuffix::DomainInvalid
  return ""
end

def site_uses_google_apps?(site_url)
  return "" if site_url.blank?
  domain = parse_domain(site_url)
  begin
    !!(Resolv::DNS.new.getresource(domain, Resolv::DNS::Resource::IN::MX).exchange.to_s =~ /google/i)
  rescue => e
    ""
  end
end

CSV.open("companies_out.csv", "wb") do |csv|
  CSV.foreach("companies.csv").each_with_index do |row, i|
    csv << [row, "uses_google_apps"].flatten and next if i == 0
    url = row[2]
    puts url
    uses_google_apps = site_uses_google_apps?(url)
    write_row = [row, uses_google_apps].flatten
    csv << write_row
  end
end