How to test if there are non-ASCII characters in a file.

gistfile1.rb

# Surely there is a better way than this. You can do grep:
#   grep --color='auto' -P -n "[\x80-\xFF]"


def string_has_non_ascii_chars?(string)
  begin
    string.encode("US-ASCII")
    return false
  rescue Encoding::InvalidByteSequenceError => e
    return true
  end
end

# Very, very hackish.
# To identify which line / column the unicode characters are on, in the given file.

def check_for_unicode(filename)
  file = File.read(filename)
  bad_lines = []

  file.lines.each_with_index do |line, line_no|
    next unless string_has_non_ascii_chars?(line)

    line.each_char.with_index do |char, col_no|
      next unless string_has_non_ascii_chars?(char)

      bad_lines << [line_no + 1, col_no + 1]
    end
  end

  bad_lines.map! {|line_col| line_col.join(":") }

  puts "#{filename} has unicode characters on line:col -- #{bad_lines.join(', ')}" if bad_lines.any?
end

# Lulz