Arguments.rb

class Arguments < Hash
  def initialize (input)
    if input.is_a? String
      quote = false
      escape = false
      buffer = ''
      key = ''

      input.each_char do |char|

        # Handle escape sequences roughly
        if escape
          case char
          when 'n'
            buffer << "\n"
          else
            buffer << char
          end
          escape = false
        end

        case char
        when '"', '\''
          unless quote = !quote
            if haskey
              self[key.downcase] = buffer
              haskey = false
              key = ''
            buffer = ''
            else
              raise 'Parse error'
            end
          end
        when ' '
          unless quote
            if not key.empty?
              self[key.downcase] = buffer
              key = ''
            else
              self[buffer.downcase] = true
            end
            buffer = ''
          end
        when '='
          key = buffer
          buffer = ''
        when '\\'
          escape = true
        else
          buffer << char
        end
      end
    elsif input.is_a? Hash
      self.merge! input
    end
  end
  def to_s
    out = []
    self.each do |key, value|
      if value == true
        out.push key
      elsif value.include? ' '
        out.push ""
        out.last << key
        out.last << '="'
        out.last << '"' + value.to_s.gsub('"', '\\"') + '"'
      else
        out.push key + '=' + value.to_s.gsub('"', '\\\"')
      end
    end
    return out.join ' '
  end
end