New example for the running_os command

examples/running_os.lua

@@ -0,0 +1,34 @@
+--[[
+    This file is part of darktable,
+    copyright (c) 2017 Tobias Jakobs
+
+    darktable is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    darktable 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 General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with darktable.  If not, see <http://www.gnu.org/licenses/>.
+]]
+--[[
+
+USAGE
+* require this script from your main lua file
+  To do this add this line to the file .config/darktable/luarc: 
+require "running_os"
+
+prints the operating system
+
+]]
+local dt = require "darktable"
+dt.configuration.check_version(...,{5,0,0})
+
+dt.print("You are running: "..dt.configuration.running_os)
+
+--
+-- vim: shiftwidth=2 expandtab tabstop=2 cindent syntax=lua