feat(ExTop): allow users to interactively select a Node to connect to

This commit also removes the "-noinput" argument to escript emu_args so
that IO.gets/1 (to choose a Node) works. This might result in a warning
like:

    Port<0.2105> stealing control of fd=0 from input driver fd (0/1) #Port<0.351>

I'll fix this once I find a good workaround.

Closes #3.

lib/ex_top.ex

@@ -37,7 +37,18 @@ defmodule ExTop do
     end
 
     node = case args do
-             [] -> Node.self
+             [] ->
+               IO.puts "Select a Node to connect to:"
+               {:ok, names} = :net_adm.names
+               [_, host] = Node.self |> Atom.to_string |> String.split("@")
+               nodes = for {name, _} <- names do
+                 String.to_atom "#{name}@#{host}"
+               end
+               for {node, index} <- nodes |> Enum.with_index do
+                 IO.puts "#{index}: #{node}"
+               end
+               which = IO.gets("") |> String.rstrip |> String.to_integer
+               Enum.fetch!(nodes, which)
              [node] -> String.to_atom(node)
            end
 

mix.exs

@@ -33,6 +33,6 @@ defmodule ExTop.Mixfile do
 
   defp escript do
     [main_module: ExTop,
-     emu_args: "-noinput -elixir ansi_enabled true"]
+     emu_args: "-elixir ansi_enabled true"]
   end
 end