//
// program to sum integers from file, where filename is a command-line argument
//
// version that "catches" exceptions
//
import scala.io.Source

if (args.length < 1) {
  println("need command-line argument (name of file)")
  sys.exit(1)
}
try {
  val source = Source.fromFile(args(0))
  val sum = source.getLines.map(_.toInt).sum
  source.close
  println("sum is " + sum)
}
catch {
  case e:java.io.FileNotFoundException => {
    println("could not open file:  " + e.getMessage)
  }
  case e:java.lang.NumberFormatException => {
    println("invalid input:  " + e.getMessage)
  }
}