CRYPTOGRAPHIC ANALYSE HELPER (LETTER COUNTER)

require 'jcode'
module CRA
    def self.decrypt(str)
        $text = str
        $chars = {
            'a' => 0,
            'b' => 0,
            'c' => 0,
            'd' => 0,
            'e' => 0,
            'f' => 0,
            'g' => 0,
            'h' => 0,
            'i' => 0,
            'j' => 0,
            'k' => 0,
            'l' => 0,
            'm' => 0,
            'n' => 0,
            'o' => 0,
            'p' => 0,
            'q' => 0,
            'r' => 0,
            's' => 0,
            't' => 0,
            'u' => 0,
            'v' => 0,
            'w' => 0,
            'x' => 0,
            'y' => 0,
            'z' => 0,
            '_SPACE_' => 0
        }
        $text.each_char{|x|
            case x.to_s.downcase
                when 'a' then $chars['a'] = $chars['a'] += 1
                when 'b' then $chars['b'] = $chars['b'] += 1
                when 'c' then $chars['c'] = $chars['c'] += 1
                when 'd' then $chars['d'] = $chars['d'] += 1
                when 'e' then $chars['e'] = $chars['e'] += 1
                when 'f' then $chars['f'] = $chars['f'] += 1
                when 'g' then $chars['g'] = $chars['g'] += 1
                when 'h' then $chars['h'] = $chars['h'] += 1
                when 'i' then $chars['i'] = $chars['i'] += 1
                when 'j' then $chars['j'] = $chars['j'] += 1
                when 'k' then $chars['k'] = $chars['k'] += 1
                when 'l' then $chars['l'] = $chars['l'] += 1
                when 'm' then $chars['m'] = $chars['m'] += 1
                when 'n' then $chars['n'] = $chars['n'] += 1
                when 'o' then $chars['o'] = $chars['o'] += 1
                when 'p' then $chars['p'] = $chars['p'] += 1
                when 'q' then $chars['q'] = $chars['q'] += 1
                when 'r' then $chars['r'] = $chars['r'] += 1
                when 's' then $chars['s'] = $chars['s'] += 1
                when 't' then $chars['t'] = $chars['t'] += 1
                when 'u' then $chars['u'] = $chars['u'] += 1
                when 'v' then $chars['v'] = $chars['v'] += 1
                when 'w' then $chars['w'] = $chars['w'] += 1
                when 'x' then $chars['x'] = $chars['x'] += 1
                when 'y' then $chars['y'] = $chars['y'] += 1
                when 'z' then $chars['z'] = $chars['z'] += 1
                when ' ' then $chars['_SPACE_'] = $chars['_SPACE_'] += 1
            end
        }
        $sorted = {}
        $c = $chars.sort
        file = File.open('result.txt', 'wb')
        $c.each{|x,k|
            puts "#{x.upcase} => #{k}"
            file.write("#{x.upcase} => #{k}")
            file.write("\n")
        }
        file.close
    end
end