Implemented getopt option support

3 files changed, 366 insertions, 5 deletions

diff --git a/ebin/rebar.app b/ebin/rebar.app
index 9598e8e..c2f7967 100644
--- a/ebin/rebar.app
+++ b/ebin/rebar.app
@@ -21,7 +21,8 @@
               rebar_rel_utils,
               rebar_reltool,
               rebar_subdirs,
-              rebar_utils ]},
+              rebar_utils,
+              getopt ]},
   {registered, []},
   {applications, [kernel, 
                   stdlib, 
diff --git a/src/getopt.erl b/src/getopt.erl
new file mode 100644
index 0000000..b335f0c
--- /dev/null
+++ b/src/getopt.erl
@@ -0,0 +1,314 @@
+%%%-------------------------------------------------------------------
+%%% @author Juan Jose Comellas <juanjo@comellas.org>
+%%% @copyright (C) 2009 Juan Jose Comellas
+%%% @doc Parses command line options with a format similar to that of GNU getopt.
+%%% @end
+%%%
+%%% This source file is subject to the New BSD License. You should have received
+%%% a copy of the New BSD license with this software. If not, it can be
+%%% retrieved from: http://www.opensource.org/licenses/bsd-license.php
+%%%-------------------------------------------------------------------
+-module(getopt).
+-author('juanjo@comellas.org').
+
+-define(TAB_LENGTH, 8).
+%% Indentation of the help messages in number of tabs.
+-define(INDENTATION, 3).
+
+-define(OPT_NAME, 1).
+-define(OPT_SHORT, 2).
+-define(OPT_LONG, 3).
+-define(OPT_ARG, 4).
+-define(OPT_HELP, 5).
+
+-define(IS_OPT_SPEC(Opt), (is_tuple(Opt) andalso (size(Opt) =:= ?OPT_HELP))).
+
+
+%% @type arg_type() = 'atom' | 'binary' | 'bool' | 'float' | 'integer' | 'string'.
+%% Atom indicating the data type that an argument can be converted to.
+-type arg_type() :: 'atom' | 'binary' | 'boolean' | 'float' | 'integer' | 'string'.
+%% @type arg_value() = atom() | binary() | bool() | float() | integer() | string().
+%% Data type that an argument can be converted to.
+-type arg_value() :: atom() | binary() | boolean() | float() | integer() | string().
+%% @type arg_spec() = arg_type() | {arg_type(), arg_value()} | undefined.
+%% Argument specification.
+-type arg_spec() :: arg_type() | {arg_type(), arg_value()} | undefined.
+%% @type option() = atom() | {atom(), arg_value()}. Option type and optional default argument.
+-type option() :: atom() | {atom(), arg_value()}.
+%% @type option_spec() = #option{}. Command line option specification.
+-type option_spec() :: {
+                   Name    :: atom(),
+                   Short   :: char() | undefined,
+                   Long    :: string() | undefined,
+                   ArgSpec :: arg_spec(),
+                   Help    :: string() | undefined
+                  }.
+
+-export([parse/2, usage/2]).
+
+
+-spec parse([option_spec()], string() | [string()]) -> {ok, {[option()], [string()]}} | {error, {Reason :: atom(), Data :: any()}}.
+%%--------------------------------------------------------------------
+%% @spec parse(OptSpecList::[option_spec()], Args::string() | [string()]) -> [option()].
+%% @doc  Parse the command line options and arguments returning a list of tuples
+%%       and/or atoms using the Erlang convention for sending options to a
+%%       function.
+%%--------------------------------------------------------------------
+parse(OptSpecList, CmdLine) ->
+    try
+        Args = if
+                   is_integer(hd(CmdLine)) ->
+                       string:tokens(CmdLine, " \t\n");
+                   true ->
+                       CmdLine
+               end,
+        parse(OptSpecList, [], [], 0, Args)
+    catch
+        throw: {error, {_Reason, _Data}} = Error ->
+            Error
+    end.
+
+-spec parse([option_spec()], [option()], [string()], integer(), [string()]) ->
+    {ok, {[option()], [string()]}} | {error, {Reason :: atom(), Data:: any()}}.
+%% Process long options.
+parse(OptSpecList, OptAcc, ArgAcc, ArgPos, [[$-, $- | LongName] = OptStr | Tail]) ->
+    {Option, Tail1} = get_option(OptSpecList, OptStr, LongName, ?OPT_LONG, Tail),
+    parse(OptSpecList, [Option | OptAcc], ArgAcc, ArgPos, Tail1);
+%% Process short options.
+parse(OptSpecList, OptAcc, ArgAcc, ArgPos, [[$-, ShortName] = OptStr | Tail]) ->
+    {Option, Tail1} = get_option(OptSpecList, OptStr, ShortName, ?OPT_SHORT, Tail),
+    parse(OptSpecList, [Option | OptAcc], ArgAcc, ArgPos, Tail1);
+%% Process multiple short options with no argument.
+parse(OptSpecList, OptAcc, ArgAcc, ArgPos, [[$- | ShortNameList] = OptStr | Tail]) ->
+    NewOptAcc =
+        lists:foldl(
+          fun (ShortName, OptAcc1) ->
+                  [get_option_no_arg(OptSpecList, OptStr, ShortName, ?OPT_SHORT) | OptAcc1]
+          end, OptAcc, ShortNameList),
+    parse(OptSpecList, NewOptAcc, ArgAcc, ArgPos, Tail);
+%% Process non-option arguments.
+parse(OptSpecList, OptAcc, ArgAcc, ArgPos, [Arg | Tail]) ->
+    case find_non_option_arg(OptSpecList, ArgPos) of
+        {value, OptSpec} when ?IS_OPT_SPEC(OptSpec) ->
+            parse(OptSpecList, [convert_option_arg(OptSpec, Arg) | OptAcc], ArgAcc, ArgPos + 1, Tail);
+        false ->
+            parse(OptSpecList, OptAcc, [Arg | ArgAcc], ArgPos, Tail)
+    end;
+parse(OptSpecList, OptAcc, ArgAcc, _ArgPos, []) ->
+    %% Once we have completed gathering the options we add the ones that were
+    %% not present but had default arguments in the specification.
+    {ok, {lists:reverse(append_default_args(OptSpecList, OptAcc)), lists:reverse(ArgAcc)}}.
+
+
+-spec get_option([option_spec()], string(), string() | char(), integer(), [string()]) ->
+    {option(), [string()]}.
+%% @doc Retrieve the specification corresponding to an option matching a string
+%%      received on the command line.
+get_option(OptSpecList, OptStr, OptName, FieldPos, Tail) ->
+    case lists:keysearch(OptName, FieldPos, OptSpecList) of
+        {value, {Name, _Short, _Long, ArgSpec, _Help} = OptSpec} ->
+            case ArgSpec of
+                undefined ->
+                    {Name, Tail};
+                _ ->
+                    case Tail of
+                        [Arg | Tail1] ->
+                            {convert_option_arg(OptSpec, Arg), Tail1};
+                                    [] ->
+                            throw({error, {missing_option_arg, Name}})
+                    end
+            end;
+        false ->
+            throw({error, {invalid_option, OptStr}})
+    end.
+
+-spec get_option_no_arg([option_spec()], string(), string() | char(), integer()) -> option().
+%% @doc Retrieve the specification corresponding to an option that has no
+%%      argument and matches a string received on the command line.
+get_option_no_arg(OptSpecList, OptStr, OptName, FieldPos) ->
+    case lists:keysearch(OptName, FieldPos, OptSpecList) of
+        {value, {Name, _Short, _Long, undefined, _Help}} ->
+            Name;
+        {value, {Name, _Short, _Long, _ArgSpec, _Help}} ->
+            throw({error, {missing_option_arg, Name}});
+        false ->
+            throw({error, {invalid_option, OptStr}})
+    end.
+
+-spec find_non_option_arg([option_spec()], integer()) -> {value, option_spec()} | false.
+%% @doc Find the option for the discrete argument in position specified in the
+%%      Pos argument.
+find_non_option_arg([{_Name, undefined, undefined, _ArgSpec, _Help} = OptSpec | _Tail], 0) ->
+     {value, OptSpec};
+find_non_option_arg([{_Name, undefined, undefined, _ArgSpec, _Help} | Tail], Pos) ->
+    find_non_option_arg(Tail, Pos - 1);
+find_non_option_arg([_Head | Tail], Pos) ->
+    find_non_option_arg(Tail, Pos);
+find_non_option_arg([], _Pos) ->
+    false.
+
+
+-spec append_default_args([option_spec()], [option()]) -> [option()].
+%% @doc Appends the default values of the options that are not present.
+append_default_args([{Name, _Short, _Long, {_Type, DefaultArg}, _Help} | Tail], OptAcc) ->
+    append_default_args(Tail,
+               case lists:keymember(Name, 1, OptAcc) of
+                   false ->
+                       [{Name, DefaultArg} | OptAcc];
+                   _ ->
+                       OptAcc
+               end);
+%% For options with no default argument.
+append_default_args([_Head | Tail], OptAcc) ->
+    append_default_args(Tail, OptAcc);
+append_default_args([], OptAcc) ->
+    OptAcc.
+
+
+-spec convert_option_arg(option_spec(), string()) -> [option()].
+%% @doc Convert the argument passed in the command line to the data type
+%%      indicated byt the argument specification.
+convert_option_arg({Name, _Short, _Long, ArgSpec, _Help}, Arg) ->
+    try
+        Converted = case ArgSpec of
+                        {Type, _DefaultArg} ->
+                            to_type(Type, Arg);
+                        Type when is_atom(Type) ->
+                            to_type(Type, Arg)
+                    end,
+        {Name, Converted}
+    catch
+        error:_ ->
+            throw({error, {invalid_option_arg, {Name, Arg}}})
+    end.
+
+-spec to_type(atom(), string()) -> arg_value().
+to_type(binary, Arg) ->
+    list_to_binary(Arg);
+to_type(atom, Arg) ->
+    list_to_atom(Arg);
+to_type(integer, Arg) ->
+    list_to_integer(Arg);
+to_type(float, Arg) ->
+    list_to_float(Arg);
+to_type(boolean, Arg) ->
+    LowerArg = string:to_lower(Arg),
+    (LowerArg =:= "true") orelse (LowerArg =:= "t") orelse
+    (LowerArg =:= "yes") orelse (LowerArg =:= "y") orelse
+    (LowerArg =:= "on") orelse (LowerArg =:= "enabled");
+to_type(_Type, Arg) ->
+    Arg.
+
+
+-spec usage([option_spec()], string()) -> ok.
+%%--------------------------------------------------------------------
+%% @spec usage(OptSpecList :: option_spec_list(), ProgramName :: string()) -> ok.
+%% @doc  Show a message on stdout indicating the command line options and
+%%       arguments that are supported by the program.
+%%--------------------------------------------------------------------
+usage(OptSpecList, ProgramName) ->
+    io:format("Usage: ~s~s~n~n~s~n",
+              [ProgramName, usage_cmd_line(OptSpecList), usage_options(OptSpecList)]).
+
+
+-spec usage_cmd_line([option_spec()]) -> string().
+%% @doc Return a string with the syntax for the command line options and
+%%      arguments.
+usage_cmd_line(OptSpecList) ->
+    usage_cmd_line(OptSpecList, []).
+
+usage_cmd_line([{Name, Short, Long, ArgSpec, _Help} | Tail], Acc) ->
+    CmdLine =
+        case ArgSpec of
+            undefined ->
+                if
+                    %% For options with short form and no argument.
+                    Short =/= undefined ->
+                        [$\s, $[, $-, Short, $]];
+                    %% For options with only long form and no argument.
+                    Long =/= undefined ->
+                        [$\s, $[, $-, $-, Long, $]];
+                    true ->
+                        []
+                end;
+            _ ->
+                if
+                    %% For options with short form and argument.
+                    Short =/= undefined ->
+                        [$\s, $[, $-, Short, $\s, $<, atom_to_list(Name), $>, $]];
+                    %% For options with only long form and argument.
+                    Long =/= undefined ->
+                        [$\s, $[, $-, $-, Long, $\s, $<, atom_to_list(Name), $>, $]];
+                    %% For options with neither short nor long form and argument.
+                    true ->
+                        [$\s, $<, atom_to_list(Name), $>]
+                end
+        end,
+    usage_cmd_line(Tail, [CmdLine | Acc]);
+usage_cmd_line([], Acc) ->
+    lists:flatten(lists:reverse(Acc)).
+
+
+-spec usage_options([option_spec()]) -> string().
+%% @doc Return a string with the help message for each of the options and
+%%      arguments.
+usage_options(OptSpecList) ->
+    usage_options(OptSpecList, []).
+
+usage_options([{Name, Short, Long, _ArgSpec, _Help} = OptSpec | Tail], Acc) ->
+    Prefix = 
+        case Long of 
+            undefined ->
+                case Short of
+                    %% Neither short nor long form (non-option argument).
+                    undefined ->
+                        [$<, atom_to_list(Name), $>];
+                    %% Only short form.
+                    _ ->
+                        [$-, Short]
+                end;
+            _ ->
+                case Short of
+                    %% Only long form.
+                    undefined ->
+                        [$-, $-, Long];
+                    %% Both short and long form.
+                    _ ->
+                        [$-, Short, $,, $\s, $-, $-, Long]
+                end
+        end,
+    usage_options(Tail, add_option_help(OptSpec, Prefix, Acc));
+usage_options([], Acc) ->
+    lists:flatten(lists:reverse(Acc)).
+
+-spec add_option_help(option_spec(), Prefix :: string(), Acc :: string()) -> string().
+%% @doc Add the help message corresponding to an option specification to a list
+%%      with the correct indentation.
+add_option_help({_Name, _Short, _Long, _ArgSpec, Help}, Prefix, Acc) when is_list(Help), Help =/= [] ->
+    FlatPrefix = lists:flatten(Prefix),
+    case ((?INDENTATION * ?TAB_LENGTH) - 2 - length(FlatPrefix)) of
+        TabSize when TabSize > 0 ->
+            Tab = lists:duplicate(ceiling(TabSize / ?TAB_LENGTH), $\t),
+            [[$\s, $\s, FlatPrefix, Tab, Help, $\n] | Acc];
+        _ ->
+            %% The indentation for the option description is 3 tabs (i.e. 24 characters)
+            %% IMPORTANT: Change the number of tabs below if you change the
+            %%            value of the INDENTATION macro.
+            [[$\t, $\t, $\t, Help, $\n], [$\s, $\s, FlatPrefix, $\n] | Acc]
+    end;
+add_option_help(_Opt, _Prefix, Acc) ->
+    Acc.
+
+
+-spec ceiling(float()) -> integer().
+%% @doc Return the smallest integral valur not less than the argument.
+ceiling(X) ->
+    T = erlang:trunc(X),
+    case (X - T) of
+        %% Neg when Neg < 0 ->
+        %%    T;
+        Pos when Pos > 0 ->
+            T + 1;
+        _ ->
+            T
+    end.
diff --git a/src/rebar_core.erl b/src/rebar_core.erl
index 06afc7f..e6cfa73 100644
--- a/src/rebar_core.erl
+++ b/src/rebar_core.erl
@@ -46,19 +46,41 @@ run(["version"]) ->
     ?CONSOLE("Version ~s built ~s\n", [Vsn, ?BUILD_TIME]),
     ok;
 run(Args) ->
-    %% Filter all the flags (i.e. string of form key=value) from the
-    %% command line arguments. What's left will be the commands to run.
-    Commands = filter_flags(Args, []),
-    
     %% Pre-load the rebar app so that we get default configuration
     ok = application:load(rebar),
 
+    %% Parse getopt options
+    case getopt:parse(option_spec_list(), Args) of
+        {ok, {Options, NonOptArgs}} ->
+            case proplists:get_bool(help, Options) of
+                true ->
+                    %% display usage info
+                    getopt:usage(option_spec_list(), "rebar");
+                false ->
+                    %% Set global variables based on getopt options
+                    set_global_flag(Options, verbose),
+                    set_global_flag(Options, quiet),
+                    set_global_flag(Options, force),
+
+                    %% run rebar with supplied options
+                    run2(NonOptArgs)
+            end;
+        {error, {Reason, Data}} ->
+            ?ERROR("Error: ~s ~p~n~n", [Reason, Data]),
+            getopt:usage(option_spec_list(), "rebar")
+    end.
+
+run2(Args) ->
     %% Make sure crypto is running
     crypto:start(),
 
     %% Initialize logging system
     rebar_log:init(),
 
+    %% Filter all the flags (i.e. string of form key=value) from the
+    %% command line arguments. What's left will be the commands to run.
+    Commands = filter_flags(Args, []),
+
     %% Convert command strings to atoms
     CommandAtoms = [list_to_atom(C) || C <- Commands],
 
@@ -71,6 +93,30 @@ run(Args) ->
 %% ===================================================================
 
 %%
+%% set global flag based on getopt option boolean value
+%%
+set_global_flag(Options, Flag) ->
+    Value = case proplists:get_bool(Flag, Options) of
+                true ->
+                    "1";
+                false ->
+                    "0"
+            end,
+    rebar_config:set_global(Flag, Value).
+
+%%
+%% options accepted via getopt
+%%
+option_spec_list() ->
+    [
+     %% {Name, ShortOpt, LongOpt, ArgSpec, HelpMsg}
+     {help,    $h, "help",    undefined, "Show the program options"},
+     {verbose, $v, "verbose", undefined, "Be verbose about what gets done"},
+     {quiet,   $q, "quiet",   undefined, "Be quiet about what gets done"},
+     {force,   $f, "force",   undefined, "Force"}
+    ].
+
+%%
 %% Seperate all commands (single-words) from flags (key=value) and store
 %% values into the rebar_config global storage.
 %%