read_file

# File lib/rdoc/encoding.rb, line 31
  def self.read_file filename, encoding, force_transcode = false
    content = File.open filename, "rb" do |f| f.read end
    content.gsub!("\r\n", "\n") if RUBY_PLATFORM =~ /mswin|mingw/

    utf8 = content.sub!(/\A\xef\xbb\xbf/, '')

    enc = RDoc::Encoding.detect_encoding content
    content = RDoc::Encoding.change_encoding content, enc if enc

    begin
      encoding ||= Encoding.default_external
      orig_encoding = content.encoding

      if not orig_encoding.ascii_compatible? then
        content = content.encode encoding
      elsif utf8 then
        content = RDoc::Encoding.change_encoding content, Encoding::UTF_8
        content = content.encode encoding
      else
        # assume the content is in our output encoding
        content = RDoc::Encoding.change_encoding content, encoding
      end

      unless content.valid_encoding? then
        # revert and try to transcode
        content = RDoc::Encoding.change_encoding content, orig_encoding
        content = content.encode encoding
      end

      unless content.valid_encoding? then
        warn "unable to convert #{filename} to #{encoding}, skipping"
        content = nil
      end
    rescue Encoding::InvalidByteSequenceError,
           Encoding::UndefinedConversionError => e
      if force_transcode then
        content = RDoc::Encoding.change_encoding content, orig_encoding
        content = content.encode(encoding,
                                 :invalid => :replace,
                                 :undef => :replace,
                                 :replace => '?')
        return content
      else
        warn "unable to convert #{e.message} for #{filename}, skipping"
        return nil
      end
    end

    content
  rescue ArgumentError => e
    raise unless e.message =~ /unknown encoding name - (.*)/
    warn "unknown encoding name \"#{$1}\" for #{filename}, skipping"
    nil
  rescue Errno::EISDIR, Errno::ENOENT
    nil
  end