Symlink UTF-7 directory name into an UTF-8 version

maildir_utf7_symlink.rb

#!/usr/bin/env ruby
# Maildir folder: create an UTF-8 symlink to original UTF-7 maildir.
# For example, it will create a symlink named '所有邮件' to a directory
# named '&YkBnCZCuTvY-'

utf7_dirs = Dir.entries(Dir.pwd).select do |dir|
  dir.start_with?("&")
end

utf7_dirs.each do |dir|
  utf7 = dir.gsub('&', '+').gsub(',', '/')
  utf8 = (`echo '#{utf7}' | iconv -f UTF-7 -t UTF-8`).chomp
  unless File.exists?(utf8)
    File.symlink(dir, utf8)
    puts "#{dir} => #{utf8}"
  end
end