1 files changed, 25 insertions, 0 deletions
diff --git a/deps/gsms/src/gsms_lib.erl b/deps/gsms/src/gsms_lib.erl
new file mode 100644
index 0000000..187aefd
--- /dev/null
+++ b/deps/gsms/src/gsms_lib.erl
@@ -0,0 +1,25 @@
+-module(gsms_lib).
+
+-export([get_opt/2,
+	 get_opt/3]).
+
+get_opt(K, Opts) when is_atom(K) ->
+    case lists:keyfind(K, 1, Opts) of
+	false  -> erlang:error({mandatory, K});
+	{_, V} -> V
+    end;
+get_opt({K, Def}, Opts) ->
+    get_opt(K, Opts, Def).
+
+get_opt(K, Opts, Def) ->
+    case lists:keyfind(K, 1, Opts) of
+	false when is_function(Def, 0) ->
+	    Def();
+	false when Def == '$mandatory' ->
+	    error({mandatory, K});
+	false ->
+	    Def;
+	{_, V} ->
+	    V
+    end.
+