stdlib: Add filename:basedir/2,3

1 files changed, 160 insertions, 0 deletions

diff --git a/lib/stdlib/src/filename.erl b/lib/stdlib/src/filename.erl
index 008beb8b67..d921a69108 100644
--- a/lib/stdlib/src/filename.erl
+++ b/lib/stdlib/src/filename.erl
@@ -36,6 +36,7 @@
 	 extension/1, join/1, join/2, pathtype/1,
 	 rootname/1, rootname/2, split/1, nativename/1]).
 -export([find_src/1, find_src/2, flatten/1]).
+-export([basedir/2, basedir/3]).
 
 %% Undocumented and unsupported exports.
 -export([append/2]).
@@ -139,6 +140,7 @@ absname_join(AbsBase, Name) ->
 
 -spec basename(Filename) -> file:filename_all() when
       Filename :: file:name_all().
+
 basename(Name) when is_binary(Name) ->
     case os:type() of
 	{win32,_} ->
@@ -954,3 +956,161 @@ filename_string_to_binary(List) ->
 	    Bin
     end.
 
+%% Application Base Directories
+%% basedir
+%% http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
+
+-type basedir_type() :: 'user_cache' | 'user_config' | 'user_data'
+                      | 'user_log'
+                      | 'site_config' | 'site_data'.
+
+-spec basedir(Type,Application) -> file:filename_all() when
+      Type :: basedir_type(),
+      Application :: string() | binary().
+
+basedir(Type,Application) when is_atom(Type), is_list(Application) orelse
+                                              is_binary(Application) ->
+    basedir(Type, Application, #{}).
+
+-spec basedir(Type,Application,Opts) -> file:filename_all() when
+      Type :: basedir_type(),
+      Application :: string() | binary(),
+      Opts :: #{author => string() | binary(),
+                os => 'windows' | 'darwin' | 'linux',
+                version => string() | binary()}.
+
+basedir(Type,Application,Opts) when is_atom(Type), is_map(Opts),
+                                    is_list(Application) orelse
+                                    is_binary(Application) ->
+    Os   = basedir_os_from_opts(Opts),
+    Name = basedir_name_from_opts(Os,Application,Opts),
+    Base = basedir_from_os(Type,Os),
+    case {Type,Os} of
+        {user_log,linux} ->
+            filename:join([Base,Name,"log"]);
+        {user_log,windows} ->
+            filename:join([Base,Name,"Logs"]);
+        {user_cache,windows} ->
+            filename:join([Base,Name,"Cache"]);
+        {Type,_} when Type =:= site_config orelse Type =:= site_data ->
+            [filename:join([B,Name]) || B <- Base];
+        _ ->
+            filename:join([Base,Name])
+    end.
+
+basedir_os_from_opts(#{os := linux}) -> linux;
+basedir_os_from_opts(#{os := windows}) -> windows;
+basedir_os_from_opts(#{os := darwin}) -> darwin;
+basedir_os_from_opts(#{}) -> basedir_os_type().
+
+basedir_name_from_opts(windows,App,#{author:=Author,version:=Vsn}) ->
+    filename:join([Author,App,Vsn]);
+basedir_name_from_opts(windows,App,#{author:=Author}) ->
+    filename:join([Author,App]);
+basedir_name_from_opts(_,App,#{version:=Vsn}) ->
+    filename:join([App,Vsn]);
+basedir_name_from_opts(_,App,_) ->
+    App.
+
+basedir_from_os(Type,Os) ->
+    case Os of
+        linux   -> basedir_linux(Type);
+        darwin  -> basedir_darwin(Type);
+        windows -> basedir_windows(Type)
+    end.
+
+-define(basedir_linux_user_data,   ".local/share").
+-define(basedir_linux_user_config, ".config").
+-define(basedir_linux_user_cache,  ".cache").
+-define(basedir_linux_user_log,    ".cache"). %% .cache/App/log
+-define(basedir_linux_site_data,   "/usr/local/share/:/usr/share/").
+-define(basedir_linux_site_config, "/etc/xdg").
+
+basedir_linux(Type) ->
+    case Type of
+        user_data   -> getenv("XDG_DATA_HOME",  ?basedir_linux_user_data,  true);
+        user_config -> getenv("XDG_CONFIG_HOME",?basedir_linux_user_config,true);
+        user_cache  -> getenv("XDG_CACHE_HOME", ?basedir_linux_user_cache, true);
+        user_log    -> getenv("XDG_CACHE_HOME", ?basedir_linux_user_log,   true);
+        site_data   ->
+            Base = getenv("XDG_DATA_DIRS",?basedir_linux_site_data,false),
+            string:tokens(Base,":");
+        site_config ->
+            Base = getenv("XDG_CONFIG_DIRS",?basedir_linux_site_config,false),
+            string:tokens(Base,":")
+    end.
+
+-define(basedir_darwin_user_data,   "Library/Application Support").
+-define(basedir_darwin_user_config, "Library/Application Support").
+-define(basedir_darwin_user_cache,  "Library/Caches").
+-define(basedir_darwin_user_log,    "Library/Logs").
+-define(basedir_darwin_site_data,   "/Library/Application Support").
+-define(basedir_darwin_site_config, "/Library/Application Support").
+
+basedir_darwin(Type) ->
+    case Type of
+        user_data   -> basedir_join_home(?basedir_darwin_user_data);
+        user_config -> basedir_join_home(?basedir_darwin_user_config);
+        user_cache  -> basedir_join_home(?basedir_darwin_user_cache);
+        user_log    -> basedir_join_home(?basedir_darwin_user_log);
+        site_data   -> [?basedir_darwin_site_data];
+        site_config -> [?basedir_darwin_site_config]
+    end.
+
+%% On Windows:
+%% ex. C:\Users\egil\AppData\Local\Ericsson\Erlang
+%% %LOCALAPPDATA% is defined on Windows 7 and onwards
+%% %APPDATA% is used instead of %LOCALAPPDATA% if it's not defined.
+%% %APPDATA% is used for roaming, i.e. for user_config on Windows 7 and beyond.
+%%
+%% user_data    %LOCALAPPDATA%[/$author]/$appname[/$version]
+%% user_config  %APPDATA%[/$author]/$appname[/$version]
+%% user_cache   %LOCALAPPDATA%[/$author]/$appname[/$version]/Cache
+%% user_log     %LOCALAPPDATA%[/$author]/$appname[/$version]/Logs
+
+basedir_windows(Type) ->
+    %% If LOCALAPPDATA is not defined we are likely on an
+    %% XP machine. Use APPDATA instead.
+    AppData = basedir_windows_appdata(),
+    case Type of
+        user_data   -> getenv("LOCALAPPDATA", AppData);
+        user_config -> AppData;
+        user_cache  -> getenv("LOCALAPPDATA", AppData);
+        user_log    -> getenv("LOCALAPPDATA", AppData);
+        site_data   -> [];
+        site_config -> []
+    end.
+
+basedir_windows_appdata() ->
+    case os:getenv("APPDATA") of
+        Invalid when Invalid =:= false orelse Invalid =:= [] ->
+            erlang:error(noappdata);
+        Val   -> Val
+    end.
+
+%% basedir aux
+
+getenv(K,Def,false) -> getenv(K,Def);
+getenv(K,Def,true)  -> getenv(K,basedir_join_home(Def)).
+
+getenv(K,Def) ->
+    case os:getenv(K) of
+        []    -> Def;
+        false -> Def;
+        Val   -> Val
+    end.
+
+basedir_join_home(Dir) ->
+    case os:getenv("HOME") of
+        false ->
+            {ok,[[Home]]} = init:get_argument(home),
+            filename:join(Home,Dir);
+        Home  -> filename:join(Home,Dir)
+    end.
+
+basedir_os_type() ->
+    case os:type() of
+        {unix,darwin} -> darwin;
+        {win32,_}     -> windows;
+        _             -> linux
+    end.