a simple tail script which can detect file change of symbol link

tail.scala

import scala.sys.process._

def someProcessing(line: String): Unit = {
  print("[just read this line] ")
  println(line)
}

val file = "1.txt"

val tail = Seq("tail", "-F", file)
tail.lineStream.foreach(someProcessing)  

tail.scala.README

#####Usage######
# 
#   in shell one, start the script, and in another shell, do the file operation in such order:
#   1. echo "1" >> 2.txt
#   2. ln -s 2.txt 1.txt
#   3. echo "2" >> 2.txt
#   4. echo "3" >> 1.txt
#   5. ln -snf 3.txt 1.txt
#   6. echo "4" >> 3.txt
#   7. echo "5" >> 1.txt
#########
$ scala tail.scala