You really only need threads if you want to share data between threads in realtime. If not, forking is probably a better choice. Use a fork manager module to fork off a process for each file to be tailed.

If you need to constantly monitor the file tail results, you could use threads, but there are alot of caveats to watch for when using threads. Many times, threads need to be created before any other object code is called(due to non-threadsafe objects), so you may not be able to just use threads any way you want. Threads work well if properly setup for the situation, but you show use the SuperSearch box here and search for all the previous posts on threads. See Why use threads over processes, or why use processes over threads?