homemade opt parser

It's either this or ~400 lines of code from github under a
non-standard license.

The idea here is that you specify options with tuples like:
  - {flag, <flag string>}, or
  - {option, <option string>, <default value>}.

Then, you let get_options separate the flags and options from the
arguments.

The spec for get_options is:

get_options/2 :: ([{flag, string()} | {option, string(), any()}],
                  [string()])
                 -> {[string()], [{string(), any()}]}

For instance:
   get_options([{flag, "-q"}, {option, "-p", "/"}],
               ["set_permissions","-p","/","guest", "-q",".*",".*",".*"])
== {["set_permissions","guest",".*",".*",".*"],
     [{"-q",true},{"-p","/"}]}

1 files changed, 100 insertions, 76 deletions

diff --git a/src/rabbit_control.erl b/src/rabbit_control.erl
index 21d88bbc73..cb19485efc 100644
--- a/src/rabbit_control.erl
+++ b/src/rabbit_control.erl
@@ -32,20 +32,25 @@
 -module(rabbit_control).
 -include("rabbit.hrl").
 
--export([start/0, stop/0, action/4]).
-
--record(params, {quiet, node, command, args}).
+-export([start/0, stop/0, action/5]).
 
 -define(RPC_TIMEOUT, infinity).
 
+-define(QUIET_OPT, "-q").
+-define(NODE_OPT, "-n").
+-define(VHOST_OPT, "-p").
+-define(SCOPE_OPT, "-s").
+
 %%----------------------------------------------------------------------------
 
 -ifdef(use_specs).
 
 -spec(start/0 :: () -> no_return()).
 -spec(stop/0 :: () -> 'ok').
--spec(action/4 :: (atom(), node(), [string()],
-                   fun ((string(), [any()]) -> 'ok')) -> 'ok').
+-spec(action/5 ::
+        (atom(), node(), [string()], [{string(), any()}],
+         fun ((string(), [any()]) -> 'ok'))
+        -> 'ok').
 -spec(usage/0 :: () -> no_return()).
 
 -endif.
@@ -55,18 +60,30 @@
 start() ->
     {ok, [[NodeStr|_]|_]} = init:get_argument(nodename),
     FullCommand = init:get_plain_arguments(),
-    #params{quiet = Quiet, node = Node, command = Command, args = Args} =
-        parse_args(FullCommand, #params{quiet = false,
-                                        node = rabbit_misc:makenode(NodeStr)}),
+    {[Command0 | Args], Opts} =
+        get_options([{flag, ?QUIET_OPT}, {option, ?NODE_OPT, NodeStr},
+                     {option, ?VHOST_OPT, "/"}, {option, ?SCOPE_OPT, "client"}],
+                    FullCommand),
+    Opts1 = lists:map(fun({K, V}) ->
+                              case K of
+                                  ?NODE_OPT -> {?NODE_OPT, rabbit_misc:makenode(V)};
+                                  _    -> {K, V}
+                              end
+                      end, Opts),
+    io:format("~p~n", [Opts1]),
+    Command = list_to_atom(Command0),
+    io:format("~p~n", [[Command | Args]]),
+    Quiet = proplists:get_bool(?QUIET_OPT, Opts1),
+    Node = proplists:get_value(?NODE_OPT, Opts1),
     Inform = case Quiet of
                  true  -> fun (_Format, _Args1) -> ok end;
                  false -> fun (Format, Args1) ->
                                   io:format(Format ++ " ...~n", Args1)
-                         end
+                          end
              end,
     %% The reason we don't use a try/catch here is that rpc:call turns
     %% thrown errors into normal return values
-    case catch action(Command, Node, Args, Inform) of
+    case catch action(Command, Node, Args, Opts, Inform) of
         ok ->
             case Quiet of
                 true  -> ok;
@@ -118,15 +135,6 @@ print_badrpc_diagnostics(Node) ->
     fmt_stderr("- current node cookie hash: ~s", [rabbit_misc:cookie_hash()]),
     ok.
 
-parse_args(["-n", NodeS | Args], Params) ->
-    parse_args(Args, Params#params{node = rabbit_misc:makenode(NodeS)});
-parse_args(["-q" | Args], Params) ->
-    parse_args(Args, Params#params{quiet = true});
-parse_args([Command | Args], Params) ->
-    Params#params{command = list_to_atom(Command), args = Args};
-parse_args([], _) ->
-    usage().
-
 stop() ->
     ok.
 
@@ -134,39 +142,39 @@ usage() ->
     io:format("~s", [rabbit_ctl_usage:usage()]),
     halt(1).
 
-action(stop, Node, [], Inform) ->
+action(stop, Node, [], _Opts, Inform) ->
     Inform("Stopping and halting node ~p", [Node]),
     call(Node, {rabbit, stop_and_halt, []});
 
-action(stop_app, Node, [], Inform) ->
+action(stop_app, Node, [], _Opts, Inform) ->
     Inform("Stopping node ~p", [Node]),
     call(Node, {rabbit, stop, []});
 
-action(start_app, Node, [], Inform) ->
+action(start_app, Node, [], _Opts, Inform) ->
     Inform("Starting node ~p", [Node]),
     call(Node, {rabbit, start, []});
 
-action(reset, Node, [], Inform) ->
+action(reset, Node, [], _Opts, Inform) ->
     Inform("Resetting node ~p", [Node]),
     call(Node, {rabbit_mnesia, reset, []});
 
-action(force_reset, Node, [], Inform) ->
+action(force_reset, Node, [], _Opts, Inform) ->
     Inform("Forcefully resetting node ~p", [Node]),
     call(Node, {rabbit_mnesia, force_reset, []});
 
-action(cluster, Node, ClusterNodeSs, Inform) ->
+action(cluster, Node, ClusterNodeSs, _Opts, Inform) ->
     ClusterNodes = lists:map(fun list_to_atom/1, ClusterNodeSs),
     Inform("Clustering node ~p with ~p",
               [Node, ClusterNodes]),
     rpc_call(Node, rabbit_mnesia, cluster, [ClusterNodes]);
 
-action(force_cluster, Node, ClusterNodeSs, Inform) ->
+action(force_cluster, Node, ClusterNodeSs, _Opts, Inform) ->
     ClusterNodes = lists:map(fun list_to_atom/1, ClusterNodeSs),
     Inform("Forcefully clustering node ~p with ~p (ignoring offline nodes)",
               [Node, ClusterNodes]),
     rpc_call(Node, rabbit_mnesia, force_cluster, [ClusterNodes]);
 
-action(status, Node, [], Inform) ->
+action(status, Node, [], _Opts, Inform) ->
     Inform("Status of node ~p", [Node]),
     case call(Node, {rabbit, status, []}) of
         {badrpc, _} = Res -> Res;
@@ -174,136 +182,117 @@ action(status, Node, [], Inform) ->
                              ok
     end;
 
-action(rotate_logs, Node, [], Inform) ->
+action(rotate_logs, Node, [], _Opts, Inform) ->
     Inform("Reopening logs for node ~p", [Node]),
     call(Node, {rabbit, rotate_logs, [""]});
-action(rotate_logs, Node, Args = [Suffix], Inform) ->
+action(rotate_logs, Node, Args = [Suffix], _Opts, Inform) ->
     Inform("Rotating logs to files with suffix ~p", [Suffix]),
     call(Node, {rabbit, rotate_logs, Args});
 
-action(close_connection, Node, [PidStr, Explanation], Inform) ->
+action(close_connection, Node, [PidStr, Explanation], _Opts, Inform) ->
     Inform("Closing connection ~s", [PidStr]),
     rpc_call(Node, rabbit_networking, close_connection,
              [rabbit_misc:string_to_pid(PidStr), Explanation]);
 
-action(add_user, Node, Args = [Username, _Password], Inform) ->
+action(add_user, Node, Args = [Username, _Password], _Opts, Inform) ->
     Inform("Creating user ~p", [Username]),
     call(Node, {rabbit_access_control, add_user, Args});
 
-action(delete_user, Node, Args = [_Username], Inform) ->
+action(delete_user, Node, Args = [_Username], _Opts, Inform) ->
     Inform("Deleting user ~p", Args),
     call(Node, {rabbit_access_control, delete_user, Args});
 
-action(change_password, Node, Args = [Username, _Newpassword], Inform) ->
+action(change_password, Node, Args = [Username, _Newpassword], _Opts, Inform) ->
     Inform("Changing password for user ~p", [Username]),
     call(Node, {rabbit_access_control, change_password, Args});
 
-action(list_users, Node, [], Inform) ->
+action(list_users, Node, [], _Opts, Inform) ->
     Inform("Listing users", []),
     display_list(call(Node, {rabbit_access_control, list_users, []}));
 
-action(add_vhost, Node, Args = [_VHostPath], Inform) ->
+action(add_vhost, Node, Args = [_VHostPath], _Opts, Inform) ->
     Inform("Creating vhost ~p", Args),
     call(Node, {rabbit_access_control, add_vhost, Args});
 
-action(delete_vhost, Node, Args = [_VHostPath], Inform) ->
+action(delete_vhost, Node, Args = [_VHostPath], _Opts, Inform) ->
     Inform("Deleting vhost ~p", Args),
     call(Node, {rabbit_access_control, delete_vhost, Args});
 
-action(list_vhosts, Node, [], Inform) ->
+action(list_vhosts, Node, [], _Opts, Inform) ->
     Inform("Listing vhosts", []),
     display_list(call(Node, {rabbit_access_control, list_vhosts, []}));
 
-action(list_user_permissions, Node, Args = [_Username], Inform) ->
+action(list_user_permissions, Node, Args = [_Username], _Opts, Inform) ->
     Inform("Listing permissions for user ~p", Args),
     display_list(call(Node, {rabbit_access_control, list_user_permissions,
                              Args}));
 
-action(list_queues, Node, Args, Inform) ->
+action(list_queues, Node, Args, Opts, Inform) ->
     Inform("Listing queues", []),
-    {VHostArg, RemainingArgs} = parse_vhost_flag_bin(Args),
-    ArgAtoms = default_if_empty(RemainingArgs, [name, messages]),
+    VHostArg = list_to_binary(proplists:get_value(?VHOST_OPT, Opts)),
+    ArgAtoms = default_if_empty(Args, [name, messages]),
     display_info_list(rpc_call(Node, rabbit_amqqueue, info_all,
                                [VHostArg, ArgAtoms]),
                       ArgAtoms);
 
-action(list_exchanges, Node, Args, Inform) ->
+action(list_exchanges, Node, Args, Opts, Inform) ->
     Inform("Listing exchanges", []),
-    {VHostArg, RemainingArgs} = parse_vhost_flag_bin(Args),
-    ArgAtoms = default_if_empty(RemainingArgs, [name, type]),
+    VHostArg = list_to_binary(proplists:get_value(?VHOST_OPT, Opts)),
+    ArgAtoms = default_if_empty(Args, [name, type]),
     display_info_list(rpc_call(Node, rabbit_exchange, info_all,
                                [VHostArg, ArgAtoms]),
                       ArgAtoms);
 
-action(list_bindings, Node, Args, Inform) ->
+action(list_bindings, Node, _Args, Opts, Inform) ->
     Inform("Listing bindings", []),
-    {VHostArg, _} = parse_vhost_flag_bin(Args),
+    VHostArg = list_to_binary(proplists:get_value(?VHOST_OPT, Opts)),
     InfoKeys = [exchange_name, queue_name, routing_key, args],
     display_info_list(
       [lists:zip(InfoKeys, tuple_to_list(X)) ||
           X <- rpc_call(Node, rabbit_exchange, list_bindings, [VHostArg])],
       InfoKeys);
 
-action(list_connections, Node, Args, Inform) ->
+action(list_connections, Node, Args, _Opts, Inform) ->
     Inform("Listing connections", []),
     ArgAtoms = default_if_empty(Args, [user, peer_address, peer_port, state]),
     display_info_list(rpc_call(Node, rabbit_networking, connection_info_all,
                                [ArgAtoms]),
                       ArgAtoms);
 
-action(list_channels, Node, Args, Inform) ->
+action(list_channels, Node, Args, _Opts, Inform) ->
     Inform("Listing channels", []),
     ArgAtoms = default_if_empty(Args, [pid, user, transactional, consumer_count,
                                        messages_unacknowledged]),
     display_info_list(rpc_call(Node, rabbit_channel, info_all, [ArgAtoms]),
                       ArgAtoms);
 
-action(list_consumers, Node, Args, Inform) ->
+action(list_consumers, Node, _Args, Opts, Inform) ->
     Inform("Listing consumers", []),
-    {VHostArg, _} = parse_vhost_flag_bin(Args),
+    VHostArg = list_to_binary(proplists:get_value(?VHOST_OPT, Opts)),
     InfoKeys = [queue_name, channel_pid, consumer_tag, ack_required],
     display_info_list(
       [lists:zip(InfoKeys, tuple_to_list(X)) ||
           X <- rpc_call(Node, rabbit_amqqueue, consumers_all, [VHostArg])],
       InfoKeys);
 
-action(Command, Node, Args, Inform) ->
-    {VHost, RemainingArgs} = parse_vhost_flag(Args),
-    action(Command, Node, VHost, RemainingArgs, Inform).
-
-action(set_permissions, Node, VHost, Args, Inform) ->
-    {Scope, [Username, CPerm, WPerm, RPerm]} =
-        case Args of
-            ["-s", ScopeArg | RemainingArgs] ->
-                {ScopeArg, RemainingArgs};
-            RemainingArgs ->
-                {"client", RemainingArgs}
-        end,
+action(set_permissions, Node, [Username, CPerm, WPerm, RPerm], Opts, Inform) ->
+    VHost = proplists:get_value(?VHOST_OPT, Opts),
+    Scope = proplists:get_value(?SCOPE_OPT, Opts),
     Inform("Setting permissions for user ~p in vhost ~p", [Username, VHost]),
     call(Node, {rabbit_access_control, set_permissions,
                 [Scope, Username, VHost, CPerm, WPerm, RPerm]});
 
-action(clear_permissions, Node, VHost, [Username], Inform) ->
+action(clear_permissions, Node, [Username], Opts, Inform) ->
+    VHost = proplists:get_value(?VHOST_OPT, Opts),
     Inform("Clearing permissions for user ~p in vhost ~p", [Username, VHost]),
     call(Node, {rabbit_access_control, clear_permissions, [Username, VHost]});
 
-action(list_permissions, Node, VHost, [], Inform) ->
+action(list_permissions, Node, [], Opts, Inform) ->
+    VHost = proplists:get_value(?VHOST_OPT, Opts),
     Inform("Listing permissions in vhost ~p", [VHost]),
     display_list(call(Node, {rabbit_access_control, list_vhost_permissions,
                              [VHost]})).
 
-parse_vhost_flag(Args) when is_list(Args) ->
-    case Args of
-        ["-p", VHost | RemainingArgs] ->
-            {VHost, RemainingArgs};
-        RemainingArgs ->
-            {"/", RemainingArgs}
-    end.
-
-parse_vhost_flag_bin(Args) ->
-    {VHost, RemainingArgs} = parse_vhost_flag(Args),
-    {list_to_binary(VHost), RemainingArgs}.
-
 default_if_empty(List, Default) when is_list(List) ->
     if List == [] ->
         Default;
@@ -391,3 +380,38 @@ prettify_typed_amqp_value(Type, Value) ->
         array   -> [prettify_typed_amqp_value(T, V) || {T, V} <- Value];
         _       -> Value
     end.
+
+
+% Separate flags and options from arguments.
+% get_options([{flag, "-q"}, {option, "-p", "/"}],
+%             ["set_permissions","-p","/","guest",
+%              "-q",".*",".*",".*"])
+% == {["set_permissions","guest",".*",".*",".*"],
+%     [{"-q",true},{"-p","/"}]}
+get_options([{flag, Key} | Defs], As) ->
+    {As1, Value} = get_flag(Key, As),
+    {As2, Rest} = get_options(Defs, As1),
+    {As2, [{Key, Value} | Rest]};
+get_options([{option, Key, Default} | Defs], As) ->
+    {As1, Value} = get_option(Key, Default, As),
+    {As2, Rest} = get_options(Defs, As1),
+    {As2, [{Key, Value} | Rest]};
+get_options([], As) ->
+    {As, []}.
+
+get_option(K, _Default, [K, V | As]) ->
+    {As, V};
+get_option(K, Default, [Nk | As]) ->
+    {As1, V} = get_option(K, Default, As),
+    {[Nk | As1], V};
+get_option(_, Default, As) ->
+    {As, Default}.
+
+get_flag(K, [K | As]) ->
+    {As, true};
+get_flag(K, [Nk | As]) ->
+    {As1, V} = get_flag(K, As),
+    {[Nk | As1], V};
+get_flag(_, []) ->
+    {[], false}.
+