Utility module (used in examples)

Author: Garrett Smith

src/erlzmq_util.erl

@@ -0,0 +1,64 @@
+-module(erlzmq_util).
+
+-export([dump/1]).
+
+%%--------------------------------------------------------------------
+%% @doc Reads available messages from Socket, printing them to stdout.
+%% @spec dump(Socket) -> any()
+%% Socket = erlzmq_socket()
+%% @end
+%%--------------------------------------------------------------------
+
+dump(Socket) ->
+    {ok, Msg} = erlzmq:recv(Socket),
+    io:format("----------------------------------------~n"),
+    dump_msg(Msg, Socket).
+
+%%--------------------------------------------------------------------
+%% @doc Print a socket message, including subsequent parts.
+%% @spec dump_msg(Msg, Socket) -> ok
+%% @end
+%%--------------------------------------------------------------------
+
+dump_msg(Msg, Socket) ->
+    io:format("[~3..0B] ", [size(Msg)]),
+    Str = binary_to_list(Msg),
+    case io_lib:printable_list(Str) of
+        true -> io:format(Str);
+        false -> io:format(bin_to_hex(Msg))
+    end,
+    io:format("~n"),
+    case erlzmq:getsockopt(Socket, rcvmore) of
+        {ok, true} ->
+            {ok, Next} = erlzmq:recv(Socket),
+            dump_msg(Next, Socket);
+        {ok, false} ->
+            ok
+    end.
+
+%%--------------------------------------------------------------------
+%% @doc Convert a binary to a hex string.
+%% @spec bin_to_hex(binary()) -> list()
+%% @end
+%%--------------------------------------------------------------------
+
+bin_to_hex(B) when is_binary(B) ->
+    lists:flatten(lists:map(fun int_to_hex/1, binary_to_list(B))).
+
+%%--------------------------------------------------------------------
+%% @doc Convert an int to a two char hex string.
+%% @spec int_to_hex(integer()) -> string()
+%% @end
+%%--------------------------------------------------------------------
+
+int_to_hex(N) when N < 256 ->
+    [hex(N div 16), hex(N rem 16)].
+
+%%--------------------------------------------------------------------
+%% @doc Converts an integer to a hex char.
+%% @spec hex(integer()) -> char()
+%% @end
+%%--------------------------------------------------------------------
+
+hex(N) when N < 10 -> $0 + N;
+hex(N) when N >= 10, N < 16 -> $a + (N - 10).