Convert a CSV of email addresses into Google Contacts' import format

converter.rb

#!/usr/bin/env ruby
require 'csv'

# This will convert a CSV with a column of email addresses into a valid Google
# Contacts CSV which can be imported.
# Usage: ./converter.rb <input> <output>

# The constants below can be used to configure this script.

# The column of the input CSV, starting from zero, which contains email
# addresses.
INPUT_CSV_EMAIL_COLUMN = 1

# Whether the input CSV has headers. If this is true, the first line of input is
# skipped.
INPUT_CSV_HAS_HEADERS = true

# -----------------------

def die(msg)
  puts msg
  exit 1
end

if ARGV.length != 2
  die 'Usage: ./converter.rb <input> <output>'
end
INPUT_FILE, OUTPUT_FILE = ARGV

# Read the input file and extract the email addresses
input_csv = CSV.new(File.read(INPUT_FILE))
relevant_rows = INPUT_CSV_HAS_HEADERS ? input_csv.read[1..-1] : input_csv.read
email_addresses = relevant_rows.map do |row|
  row[INPUT_CSV_EMAIL_COLUMN] or die "Missing column value on row: #{row}"
end

# Generate the output CSV
# We'll use the email address as the contact name
output_csv = CSV.generate do |csv|
  # This is a lot of fields, and the Google Contacts CSV needs all of them!
  csv << ["Name", "Given Name", "Additional Name", "Family Name", "Yomi Name", "Given Name Yomi", "Additional Name Yomi", "Family Name Yomi", "Name Prefix", "Name Suffix", "Initials", "Nickname", "Short Name", "Maiden Name", "Birthday", "Gender", "Location", "Billing Information", "Directory Server", "Mileage", "Occupation", "Hobby", "Sensitivity", "Priority", "Subject", "Notes", "Language", "Photo", "Group Membership", "E-mail 1 - Type", "E-mail 1 - Value"]
  email_addresses.each do |email_address|    
    # Fields:   name                                                                                                                         group     type      email
    csv << [email_address, "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "* myContacts", "* ", email_address]
  end
end

# Write output
File.write(OUTPUT_FILE, output_csv)