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diff --git a/.gitignore b/.gitignore
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+.eunit/
+ebin/
+*~
diff --git a/COPYING b/COPYING
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--- /dev/null
+++ b/COPYING
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+                   GNU LESSER GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+
+  This version of the GNU Lesser General Public License incorporates
+the terms and conditions of version 3 of the GNU General Public
+License, supplemented by the additional permissions listed below.
+
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diff --git a/README b/README
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+Some function to generate v4 uuids
+==================================
+
+Generate a random uuid:
+
+	1> UUID = guid:v4().
+	<<254,194,254,188,1,12,79,173,84,118,109,153,143,115,228,127>>
+
+Convert to text representation:
+
+	2> guid:unparse(UUID).       
+ 	"0ee31c01-26cc-43f1-a0f9-b52c6de7fcf7"
+
+Check it's version:
+
+	3> guid:version(UUID).
+	4
+
+Generate text representation drectly:
+
+	4> guid:v4string().
+	"68718f41-06ff-49a8-8283-00582b2d5269"
+
+
diff --git a/rebar b/rebar
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--- /dev/null
+++ b/rebar
diff --git a/rebar.config b/rebar.config
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--- /dev/null
+++ b/rebar.config
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+%%-*- mode: erlang -*-
+
+{deps, []}.
diff --git a/src/guid.app.src b/src/guid.app.src
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+++ b/src/guid.app.src
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+%%-*- mode: erlang -*-
+{application, guid,
+ [
+  {description, "Simple v4 uuid generator"},
+  {vsn, git},
+  {registered, []},
+  {applications, []},
+  {env, []}
+ ]}.
diff --git a/src/guid.erl b/src/guid.erl
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+++ b/src/guid.erl
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+%% @author Guido Günther <agx@sigxcpu.org>
+%% @copyright 2013 godiug.net
+%%
+%%  This library is free software; you can redistribute it and/or
+%%  modify it under the terms of the GNU Lesser General Public
+%%  License as published by the Free Software Foundation; either
+%%  version 3 of the License, or (at your option) any later version.
+%%
+%%  This library is distributed in the hope that it will be useful,
+%%  but WITHOUT ANY WARRANTY; without even the implied warranty of
+%%  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+%%  Lesser General Public License for more details.
+%%
+%%  You should have received a copy of the GNU Lesser General Public
+%%  License along with this library.  If not, see
+%%  <http://www.gnu.org/licenses/>.
+%%
+%% @doc Simple v4 uuid generator
+
+-module(guid).
+-export([v4/0,
+	 v4string/0,
+	 unparse/1,
+	 version/1]).
+
+%% @doc generate a version 4 uuid as bin
+v4() ->
+    << D1:32, D2:16, D3:16, D4:64 >> = crypto:rand_bytes(16),
+    << D1:32, D2:16, 4:4, D3:12, D4:64 >>.
+
+%% @doc generate a version 4 uuid as string
+v4string() ->
+    unparse(v4()).
+
+%% @doc convert a uuid from bin to string
+unparse(UUID) ->
+    lists:flatten(
+      io_lib:format("~8.16.0b-"
+                    "~4.16.0b-"
+                    "~4.16.0b-"
+                    "~2.16.0b~2.16.0b-"
+                    "~12.16.0b", parts(UUID))).
+
+%% @doc get a uuid's version number
+version(<< _:48, Version:4, _:76 >>) ->
+    Version.
+
+%% @private
+% Return the parts of the uuid as per rfc4122:
+% time_low (32), time_mid (16), time_hi_and_version (16)
+% clock_seq_hi_and_reseved (8), clock_seq_low(8), node (48)
+parts(<< TL:32, TM:16, THV:16, CSHR:8, CSL:8, N:48 >>) ->
+    [TL, TM, THV, CSHR, CSL, N].
+
+
diff --git a/test/guid_test.erl b/test/guid_test.erl
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+-module(guid_test).
+-include_lib("eunit/include/eunit.hrl").
+
+% Test descriptions
+v4_test_() ->
+    [{"A v4 uuid must have version 4",
+      check_v4_version()},
+     {"A uuid must be 16 bytes",
+      check_v4_length()}
+    ].
+
+text_test_() ->
+    [{"The text representation must be 38 characters long",
+      check_v4_string_length()}
+    ].
+
+% Tests
+check_v4_version() ->
+    Uuid = guid:v4(),
+    [?_assertEqual(guid:version(Uuid), 4)].
+
+
+check_v4_length() ->
+    Uuid = guid:v4(),
+    [?_assertEqual(byte_size(Uuid), 16)].
+
+check_v4_string_length() ->
+    String = guid:v4string(),
+    [?_assertEqual(length(String), 36)].