version number and version check added

COPYING.txt

@@ -5,17 +5,17 @@ Copyright (C) 2019 Joachim Stolberg
 License of source code
 ----------------------
 
-This program is free software; you can redistribute and/or
+This mod is free software; you can redistribute and/or
 modify it under the terms of the GNU General Public License version 3 or later
 published by the Free Software Foundation.
 
-This library is distributed in the hope that it will be useful,
+This mod 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 this library; if not, write to the
+License along with this mod; if not, write to the
 Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 Boston, MA  02110-1301, USA.
 

init.lua

@@ -14,6 +14,14 @@
 
 signs_bot = {}
 
+-- Version for compatibility checks, see readme.md/history
+signs_bot.version = 1.01
+
+if minetest.global_exists("techage") and techage.version < 0.06 then
+	minetest.log("error", "[signs_bot] Signs Bot requires techage version 0.06 or newer!")
+	return
+end
+
 signs_bot.S = minetest.get_translator("signs_bot")
 local MP = minetest.get_modpath("signs_bot")
 dofile(MP.."/doc.lua")