Data commit

Task/Remove-lines-from-a-file/Scala/remove-lines-from-a-file.scala

@@ -0,0 +1,18 @@
+object RemoveLinesFromAFile extends App {
+  args match {
+    case Array(filename, start, num) =>
+
+      import java.nio.file.{Files,Paths}
+      val lines = scala.io.Source.fromFile(filename).getLines
+      val keep = start.toInt - 1
+      val top = lines.take(keep).toList
+      val drop = lines.take(num.toInt).toList
+      Files.write(Paths.get(filename), scala.collection.JavaConversions.asJavaIterable(top ++ lines))
+
+      if (top.size < keep || drop.size < num.toInt)
+        println(s"Too few lines: removed only ${drop.size} of $num lines starting at $start")
+
+    case _ =>
+      println("Usage: RemoveLinesFromAFile <filename> <startLine> <numLines>")
+  }
+}