my_logger.rb

require 'logger'

class MyFormatter < Logger::Formatter
  def call(severity, timestamp, progname, msg)
    if String === msg then
      if msg.nil? or msg.empty? then
        return "\n"
      else
        return "%s %s\n" % [timestamp.strftime("%H:%M:%S"), msg]
      end
    else
      return msg.inspect + "\n"
    end
  end
end

class MyLogger < Logger
  def initialize(file, level = Logger::DEBUG, log_dir = $log_dir)
    if file.class.to_s == 'IO' then
      super(file, 2)
    else
      super(log_dir + file, 5, 10*1024*1024)
    end
    self.formatter = MyFormatter.new
    self.level = level
  end
end