Allow ** in filelib:wildcard

Two adjacent * used as a single pattern will match
all files and zero or more directories and subdirectories.

3 files changed, 78 insertions, 1 deletions

diff --git a/lib/stdlib/doc/src/filelib.xml b/lib/stdlib/doc/src/filelib.xml
index f3079c7337..cec20aee8e 100644
--- a/lib/stdlib/doc/src/filelib.xml
+++ b/lib/stdlib/doc/src/filelib.xml
@@ -150,6 +150,11 @@
             <p>Matches any number of characters up to the end of
               the filename, the next dot, or the next slash.</p>
           </item>
+          <tag>**</tag>
+          <item>
+            <p>Two adjacent <c>*</c>'s used as a single pattern will
+        match all files and zero or more directories and subdirectories.</p>
+          </item>
           <tag>[Character1,Character2,...]</tag>
           <item>
             <p>Matches any of the characters listed. Two characters
@@ -192,6 +197,10 @@
           <c>src</c> or <c>include</c> directories, use:</p>
         <code type="none">
     filelib:wildcard("lib/*/{src,include}/*.{erl,hrl}")        </code>
+        <p>To find all <c>.erl</c> or <c>.hrl</c> files in any
+          subdirectory, use:</p>
+        <code type="none">
+    filelib:wildcard("lib/**/*.{erl,hrl}")        </code>
       </desc>
     </func>
     <func>
diff --git a/lib/stdlib/src/filelib.erl b/lib/stdlib/src/filelib.erl
index 6b19713609..318f3b87b8 100644
--- a/lib/stdlib/src/filelib.erl
+++ b/lib/stdlib/src/filelib.erl
@@ -301,6 +301,8 @@ do_wildcard_2([File|Rest], Pattern, Result, Mod) ->
 do_wildcard_2([], _, Result, _Mod) ->
     Result.
 
+do_wildcard_3(Base, [[double_star]|Rest], Result, Mod) ->
+    lists:sort(do_double_star(current, [Base], Rest, Result, Mod, true));
 do_wildcard_3(Base, [Pattern|Rest], Result, Mod) ->
     case do_list_dir(Base, Mod) of
 	{ok, Files0} ->
@@ -334,6 +336,8 @@ wildcard_5([question|Rest1], [_|Rest2]) ->
     wildcard_5(Rest1, Rest2);
 wildcard_5([accept], _) ->
     true;
+wildcard_5([double_star], _) ->
+    true;
 wildcard_5([star|Rest], File) ->
     do_star(Rest, File);
 wildcard_5([{one_of, Ordset}|Rest], [C|File]) ->
@@ -354,6 +358,21 @@ wildcard_5([], [_|_]) ->
 wildcard_5([_|_], []) ->
     false.
 
+do_double_star(Base, [H|T], Rest, Result, Mod, Root) ->
+    Full = join(Base, H),
+    Result1 = case do_list_dir(Full, Mod) of
+        {ok, Files} ->
+            do_double_star(Full, Files, Rest, Result, Mod, false);
+        _ -> Result
+    end,
+    Result2 = case Root andalso Rest == [] of
+        true  -> Result1;
+        false -> do_wildcard_3(Full, Rest, Result1, Mod)
+    end,
+    do_double_star(Base, T, Rest, Result2, Mod, Root);
+do_double_star(_Base, [], _Rest, Result, _Mod, _Root) ->
+    Result.
+
 do_star(Pattern, [X|Rest]) ->
     case wildcard_5(Pattern, [X|Rest]) of
 	true  -> true;
@@ -425,6 +444,10 @@ compile_part([$}|Rest], true, Result) ->
     {ok, $}, lists:reverse(Result), Rest};
 compile_part([$?|Rest], Upto, Result) ->
     compile_part(Rest, Upto, [question|Result]);
+compile_part([$*,$*], Upto, Result) ->
+    compile_part([], Upto, [double_star|Result]);
+compile_part([$*,$*|Rest], Upto, Result) ->
+    compile_part(Rest, Upto, [star|Result]);
 compile_part([$*], Upto, Result) ->
     compile_part([], Upto, [accept|Result]);
 compile_part([$*|Rest], Upto, Result) ->
diff --git a/lib/stdlib/test/filelib_SUITE.erl b/lib/stdlib/test/filelib_SUITE.erl
index 94da355f36..1fd7518519 100644
--- a/lib/stdlib/test/filelib_SUITE.erl
+++ b/lib/stdlib/test/filelib_SUITE.erl
@@ -188,7 +188,52 @@ do_wildcard_6(Dir, Wcf) ->
     ["xbin"] = Wcf("*"),
     All = Wcf("*/*"),
     del(Files),
-    ok = file:del_dir(filename:join(Dir, "xbin")).
+    ok = file:del_dir(filename:join(Dir, "xbin")),
+    do_wildcard_7(Dir, Wcf).
+
+do_wildcard_7(Dir, Wcf) ->
+    Dirs = ["blurf","xa","yyy"],
+    SubDirs = ["blurf/nisse"],
+    foreach(fun(D) ->
+		    ok = file:make_dir(filename:join(Dir, D))
+	    end, Dirs ++ SubDirs),
+    All = ["blurf/nisse/baz","xa/arne","xa/kalle","yyy/arne"],
+    Files = mkfiles(lists:reverse(All), Dir),
+
+    %% Test.
+    Listing = Wcf("**"),
+    ["blurf","blurf/nisse","blurf/nisse/baz",
+     "xa","xa/arne","xa/kalle","yyy","yyy/arne"] = Listing,
+    Listing = Wcf("**/*"),
+    ["xa/arne","yyy/arne"] = Wcf("**/arne"),
+    ["blurf/nisse"] = Wcf("**/nisse"),
+    [] = Wcf("mountain/**"),
+
+    %% Cleanup
+    del(Files),
+    foreach(fun(D) ->
+		    ok = file:del_dir(filename:join(Dir, D))
+	    end, SubDirs ++ Dirs),
+    do_wildcard_8(Dir, Wcf).
+
+do_wildcard_8(Dir, Wcf) ->
+    Dirs0 = ["blurf"],
+    Dirs1 = ["blurf/nisse"],
+    Dirs2 = ["blurf/nisse/a", "blurf/nisse/b"],
+    foreach(fun(D) ->
+		    ok = file:make_dir(filename:join(Dir, D))
+	    end, Dirs0 ++ Dirs1 ++ Dirs2),
+    All = ["blurf/nisse/a/1.txt", "blurf/nisse/b/2.txt", "blurf/nisse/b/3.txt"],
+    Files = mkfiles(lists:reverse(All), Dir),
+
+    %% Test.
+    All = Wcf("**/blurf/**/*.txt"),
+
+    %% Cleanup
+    del(Files),
+    foreach(fun(D) ->
+		    ok = file:del_dir(filename:join(Dir, D))
+	    end, Dirs2 ++ Dirs1 ++ Dirs0).
 
 fold_files(Config) when is_list(Config) ->
     ?line Dir = filename:join(?config(priv_dir, Config), "fold_files"),