From 67d83e15fdee068217df7f14a32fb901d7d4d91b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Wed, 22 May 2013 11:39:13 +0200
Subject: 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
---
 lib/stdlib/doc/src/c.xml    |  4 ++--
 lib/stdlib/src/c.erl        |  6 ++++--
 lib/stdlib/test/c_SUITE.erl | 11 +++++++++--
 3 files changed, 15 insertions(+), 6 deletions(-)

(limited to 'lib/stdlib')

diff --git a/lib/stdlib/doc/src/c.xml b/lib/stdlib/doc/src/c.xml
index ddae388a1b..9cd4581a89 100644
--- a/lib/stdlib/doc/src/c.xml
+++ b/lib/stdlib/doc/src/c.xml
@@ -140,9 +140,9 @@ compile:file(<anno>File</anno>, <anno>Options</anno> ++ [report_errors, report_w
     </func>
     <func>
       <name name="ls" arity="1"/>
-      <fsummary>List files in a directory</fsummary>
+      <fsummary>List files in a directory or a single file</fsummary>
       <desc>
-        <p>Lists files in directory <c><anno>Dir</anno></c>.</p>
+        <p>Lists files in directory <c><anno>Dir</anno></c> or, if Dir is a file, only list it.</p>
       </desc>
     </func>
     <func>
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;
diff --git a/lib/stdlib/test/c_SUITE.erl b/lib/stdlib/test/c_SUITE.erl
index 25281365be..8c55b616b9 100644
--- a/lib/stdlib/test/c_SUITE.erl
+++ b/lib/stdlib/test/c_SUITE.erl
@@ -20,7 +20,7 @@
 -export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1, 
 	 init_per_group/2,end_per_group/2]).
 -export([c_1/1, c_2/1, c_3/1, c_4/1, nc_1/1, nc_2/1, nc_3/1, nc_4/1,
-         memory/1]).
+	 ls/1, memory/1]).
 
 -include_lib("test_server/include/test_server.hrl").
 
@@ -29,7 +29,7 @@
 suite() -> [{ct_hooks,[ts_install_cth]}].
 
 all() -> 
-    [c_1, c_2, c_3, c_4, nc_1, nc_2, nc_3, nc_4, memory].
+    [c_1, c_2, c_3, c_4, nc_1, nc_2, nc_3, nc_4, ls, memory].
 
 groups() -> 
     [].
@@ -147,6 +147,13 @@ nc_4(Config) when is_list(Config) ->
     ?line Result = nc(R,[{outdir,W}]),
     ?line {ok, m} = Result.
 
+ls(Config) when is_list(Config) ->
+    Directory = ?config(data_dir, Config),
+    ok = c:ls(Directory),
+    File = filename:join(Directory, "m.erl"),
+    ok = c:ls(File),
+    ok = c:ls("no_such_file").
+
 memory(doc) ->
     ["Checks that c:memory/[0,1] returns consistent results."];
 memory(suite) ->
-- 
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