Hello, On Tue, 26 Sep 2006 05:28:15 +0900, Frank Reiff <reiff / publicspace.net> wrote: > My problem: "How can I write (append) to the same log file from multiple > interpreter instances at least potentially simultaneously?" Take advantage of your operating system and use File's flock features. For example this code snippet should do what you are asking for: File.open("foo.txt", "w") do |f| f.flock(File::LOCK_EX) f.puts "Hello from #{Process.pid}" f.flock(File::LOCK_UN) end Try running the above code with multiple instances of ruby and loop. You should notice that each entry is on a new line with no data being clipped. I hope that helps, Zev