module Rails module Rack class LogTailer def initialize(app, log = nil) @app = app path = Pathname.new(log || "#{File.expand_path(Rails.root)}/log/#{Rails.env}.log").cleanpath @cursor = ::File.size(path) @last_checked = Time.now.to_f @file = ::File.open(path, 'r') end def call(env) response = @app.call(env) tail_log response end def tail_log @file.seek @cursor mod = @file.mtime.to_f if mod > @last_checked contents = @file.read @last_checked = mod @cursor += contents.size $stdout.print contents end end end end end