1 files changed, 87 insertions, 0 deletions
diff --git a/ctl-lib/ctl-lua-utils.c b/ctl-lib/ctl-lua-utils.c
new file mode 100644
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+++ b/ctl-lib/ctl-lua-utils.c
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2016 \"IoT.bzh\"
+ * Author Fulup Ar Foll <fulup@iot.bzh>
+ *
+  Licensed under the Apache License, Version 2.0 (the \"License\");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an \"AS IS\" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ref:
+ *  (manual) https://www.lua.org/manual/5.3/manual.html
+ *  (lua->C) http://www.troubleshooters.com/codecorn/lua/lua_c_calls_lua.htm#_Anatomy_of_a_Lua_Call
+ *  (lua/C Var) http://acamara.es/blog/2012/08/passing-variables-from-lua-5-2-to-c-and-vice-versa/
+ *  (Lua/C Lib)https://john.nachtimwald.com/2014/07/12/wrapping-a-c-library-in-lua/
+ *  (Lua/C Table) https://gist.github.com/SONIC3D/10388137
+ *  (Lua/C Nested table) https://stackoverflow.com/questions/45699144/lua-nested-table-from-lua-to-c
+ *  (Lua/C Wrapper) https://stackoverflow.com/questions/45699950/lua-passing-handle-to-function-created-with-newlib
+ *
+ */
+
+const char *lua_utils = "--===================================================\n\
+--=  Niklas Frykholm\n\
+-- basically if user tries to create global variable\n\
+-- the system will not let them!!\n\
+-- call GLOBAL_lock(_G)\n\
+-- \n\
+--===================================================\n\
+function GLOBAL_lock(t)\n\
+  local mt = getmetatable(t) or {}\n\
+  mt.__newindex = lock_new_index\n\
+  setmetatable(t, mt)\n\
+end\n\
+\n\
+--===================================================\n\
+-- call GLOBAL_unlock(_G)\n\
+-- to change things back to normal.\n\
+--===================================================\n\
+function GLOBAL_unlock(t)\n\
+  local mt = getmetatable(t) or {}\n\
+  mt.__newindex = unlock_new_index\n\
+  setmetatable(t, mt)\n\
+end\n\
+\n\
+function lock_new_index(t, k, v)\n\
+  if (string.sub(k,1,1) ~= \"_\") then\n\
+    GLOBAL_unlock(_G)\n\
+    error(\"GLOBALS are locked -- \" .. k ..\n\
+          \" must be declared local or prefix with '_' for globals.\", 2)\n\
+  else\n\
+    rawset(t, k, v)\n\
+  end\n\
+end\n\
+\n\
+function unlock_new_index(t, k, v)\n\
+  rawset(t, k, v)\n\
+end\n\
+\n\
+-- return serialised version of printable table\n\
+function Dump_Table(o)\n\
+   if type(o) == 'table' then\n\
+      local s = '{ '\n\
+      for k,v in pairs(o) do\n\
+         if type(k) ~= 'number' then k = '\"'..k..'\"' end\n\
+         s = s .. '['..k..'] = ' .. Dump_Table(v) .. ','\
+      end\n\
+      return s .. '} '\n\
+   else\n\
+      return tostring(o)\n\
+   end\n\
+end\n\
+\n\
+-- simulate C prinf function\n\
+printf = function(s,...)\n\
+    io.write(s:format(...))\n\
+    io.write(\"\")\n\
+    return\n\
+end\n\
+\n\
+-- lock global variable\n\
+GLOBAL_lock(_G)\n\
+";