Filter out uniq Chinese characters used in a text file. #ruby

get_uniq_char.rb

#!/usr/bin/env ruby

everything = ""
chars, charcodes = ""
File.open("main.md", "r") do |file|
  while line = file.gets
    everything << line
  end
  chinese_only = everything.gsub(/[\*()%:<>\-\/#\.\+\{\}!\[\]\s\w]+/, '')
  chinese_array = chinese_only.scan(/./)
  chars = chinese_array.uniq.join #=> string
  charcodes = chinese_array.uniq.join
end

File.open("charsfile.txt", "w") do |file|
  file.puts chars
end

File.open("subsetter", "w") do |file|
  #charcodes.each_codepoint { |c| file.print(c.to_s, ' ') }
  file.puts "#!/usr/bin/env fontforge"
  file.puts "Open($1);"
  file.puts "SelectAll();"
  charcodes.each_codepoint { |c| file.print('SelectFewer(0u', c.to_s(16), ");\n") }
  file.puts "DetachAndRemoveGlyphs();"
  file.puts "Save($2);"
  file.puts "Quit(0);"
end