#!/usr/bin/env ruby
# encoding:UTF-8

if ARGV.include?('--help')
  puts <<USAGE
wu-clean-encoding cleans malformed characters from stdin.

If a character is malformed, as defined by valid_encoding?,
it is replaced with a '�'.

wu-clean-encoding was built to work with UTF-8, and no 
guarantees are provided for other encodings.
USAGE
  exit(0)
end

ARGF.each do |line|
  if line.valid_encoding?
    $stdout.write line
  else 
    repaired_line = []
    line.each_char do |char|
      if char.valid_encoding?
        repaired_line << char
      else
        repaired_line << "�"
      end
    end
    $stdout.write repaired_line.join
  end
end