Teach c:ls/1 to show non-directory files

In an email to erlang-questions, Bengt Kleberg wrote:

    When I use c:ls/1 it reminds me so much of Unix "ls" that I
    expect c:ls("filename") to work. The resulting error surprises
    me every time (not the same day).

While teaching c:ls/1 to show non-directory files, update the
error handling to make use of the POSIX error codes from
file:list_dir/1 and file:format_error/1 (which had not been
invented when the c module was first implemented).

Suggested-by: Bengt Kleberg
Test-suite-by: Bengt Kleberg

1 files changed, 4 insertions, 2 deletions

diff --git a/lib/stdlib/src/c.erl b/lib/stdlib/src/c.erl
index 91d317489c..6e96e3d564 100644
--- a/lib/stdlib/src/c.erl
+++ b/lib/stdlib/src/c.erl
@@ -713,8 +713,10 @@ ls(Dir) ->
     case file:list_dir(Dir) of
 	{ok, Entries} ->
 	    ls_print(sort(Entries));
-	{error,_E} ->
-	    format("Invalid directory\n")
+	{error, enotdir} ->
+	    ls_print([Dir]);
+	{error, Error} ->
+	    format("~s\n", [file:format_error(Error)])
     end.
 
 ls_print([]) -> ok;