Merge pull request #899 from n1rvana/master

Added File.ls & File.ls!

Author: José Valim

lib/elixir/lib/file.ex

@@ -897,6 +897,45 @@ defmodule File do
     end
   end
 
+
+@doc """
+  Returns list of files in the current working directory. In rare circumstances, this function can
+  fail on Unix. It may happen if read permission does not exist for the parent
+  directories of the current directory. For this reason, returns `{ :ok, [files] }`
+  in case of success, `{ :error, reason }` otherwise.
+  """
+  def ls() do
+    ls(".")
+  end
+
+@doc """
+  Returns list of files in the given directory. In rare circumstances, this function can
+  fail on Unix. It may happen if read permission does not exist for the parent
+  directories of the current directory. For this reason, returns `{ :ok, [files] }`
+  in case of success, `{ :error, reason }` otherwise.
+  """
+  def ls(path) do
+    case F.list_dir(path) do
+      { :ok, file_list } -> { :ok, Enum.map file_list, :unicode.characters_to_binary(&1) }
+      { :error, _ } = error -> error
+    end
+  end
+
+
+  @doc """
+  Get list of files in directories in `dir`.
+ 
+  Raises File.Error in case of an error.
+  """
+  def ls!(dir) do
+    case F.list_dir(dir) do
+      { :ok, file_list } -> Enum.map file_list, :unicode.characters_to_binary(&1)
+      { :error, reason } ->
+        raise File.Error, reason: reason, action: "list directory", path: :unicode.characters_to_binary(dir)
+    end
+  end
+  
+
   @doc """
   Closes the file referenced by `io_device`. It mostly returns `:ok`, except
   for some severe errors such as out of memory.

lib/elixir/test/elixir/file_test.exs

@@ -397,6 +397,33 @@ defmodule FileTest do
     end
   end
 
+  test :ls do
+    {code, value} = File.ls(fixture_path)
+    assert code == :ok
+    refute code == :error
+    assert is_list value
+    assert 0 < Enum.count(value) 
+    assert List.member?(value, "code_sample.exs")
+    assert List.member?(value, "file.txt")
+    {code2, reason} = File.ls(fixture_path("non-existent-subdirectory"))
+    refute code2 == :ok
+    assert code2 == :error
+    assert reason != nil
+  end
+
+  test :ls2 do
+    value = File.ls!(fixture_path)
+    assert is_list value
+    assert 0 < Enum.count(value) 
+    assert List.member?(value, "code_sample.exs")
+    assert List.member?(value, "file.txt")
+    assert_raise File.Error, fn ->
+        File.ls!(fixture_path("non-existent-subdirectory"))
+    end
+  end
+
+
+
   defmodule OpenReadWrite do
     use ExUnit.Case