Extract display name and email addresses from Maildir

collectmail.rb

# fork of https://gist.github.com/ringe/2593827
# added the following features:
# - filter common social networks
# - only included email if it was found at least 2 times
# - extract display name
# - write to tab seperated file
require 'mail' # uses the mail gem => gem install mail

def sanitize_display_name(name)
  name.gsub!(/["']/, "")
  name
end

class Email
  attr_accessor :count, :display_name, :address
  def initialize(email)
    @address = email.address.downcase
    if email.display_name
      name = sanitize_display_name(email.display_name)
      if name != @address
        @display_name = name
      end
    end
    @count = 1
  end
  def to_s
    "#{display_name}\t#{address}"
  end
end

def find_all_email_addresses_in(base_folder)
  # Bash goodness :P
  a=`find #{base_folder} -type d -name cur`.split("\n") +`find #{base_folder} -type d -name new`.split("\n")
  emails={}
  header_matcher = Regexp.new(/(?:From|^To|Cc): (.+)/)
  a.each do |folder|
    Dir[folder+"/*"].each do |file|
      content = File.read(file).encode('UTF-8', 'binary', invalid: :replace, undef: :replace, replace: '')
      content.scan(header_matcher).each do |line|
        begin
          list = Mail::AddressList.new(line.first)
          list.addresses.each do |email|
            next if email.domain.nil? or email.domain =~ /(facebook|github|unknown\.email|amazon|paypal|twitter|google\.com)/

            address = email.address.downcase
            if emails[address]
              obj = emails[address]
              obj.count += 1
              if email.display_name and
                display_name = sanitize_display_name(email.display_name)
                if display_name.downcase != address and
                  (obj.display_name.nil? or obj.display_name.size < display_name.size)
                  obj.display_name = display_name
                end
              end
            else
              emails[address] = Email.new(email)
            end
          end
        rescue Mail::Field::ParseError
          # ignore invalid emails
        end
      end
    end
  end
  emails = emails.values.select{|e| e.count > 1}.sort_by {|e| e.count }
  file = File.open(ENV['HOME']+"/emails.tsv", 'w')
  emails.each do |email|
    file.write(email)
    file.write("\n")
  end
  file.close
end

t = Thread.new { find_all_email_addresses_in(".") }

chars = %w{ | / - \\ }
while t.alive?
  print chars[0]
  sleep 0.1
  print "\b"
  chars.push chars.shift
end

t.join
puts "Save all emails found to #{ENV['HOME']}/emails.tsv"