Converts multiple single person 2.1 vcard files from a Nokia dumb-phone export (".vcf") into one iCloud web contacts importable vcards collection file

vcard_converter.rb

#!/usr/bin/env ruby

require 'vpim'
require 'vcardio'

files = Dir.glob "*.vcf"

vcards = files.map do |f|
  vc_old = Vpim::Vcard.decode(File.read(f))[0]
  # proper vcard 4.0 wasn't accepted by the iCLoud web-interface
  # so we need to set both the FN as well as the N field again
  vc_new = VCardio::VCard.new('3.0') do
    vc_old.fields.each do |field|
      n  field.value if field.name == "N"
      fn  field.value if field.name == "N"
      tel field.value if field.name == "TEL"
    end
  end
  vc_new.to_s
end

export_file = File.new("export.vcf", "w")
export_file.write vcards.join("\n\n") + "\n"
export_file.close