2016 Update

Task/Remove-lines-from-a-file/Elixir/remove-lines-from-a-file.elixir

@@ -0,0 +1,29 @@
+defmodule RC do
+  def remove_lines(filename, start, number) do
+    File.open!(filename, [:read], fn file ->
+      remove_lines(file, start, number, IO.read(file, :line))
+    end)
+  end
+
+  defp remove_lines(_file, 0, 0, :eof), do: :ok
+  defp remove_lines(_file, _, _, :eof) do
+    IO.puts(:stderr, "Warning: End of file encountered before all lines removed")
+  end
+  defp remove_lines(file, 0, 0, line) do
+    IO.write line
+    remove_lines(file, 0, 0, IO.read(file, :line))
+  end
+  defp remove_lines(file, 0, number, _line) do
+    remove_lines(file, 0, number-1, IO.read(file, :line))
+  end
+  defp remove_lines(file, start, number, line) do
+    IO.write line
+    remove_lines(file, start-1, number, IO.read(file, :line))
+  end
+end
+
+[filename, start, number] = System.argv
+IO.puts "before:"
+IO.puts File.read!(filename)
+IO.puts "after:"
+RC.remove_lines(filename, String.to_integer(start), String.to_integer(number)