Add a simple lua mod

.luacheckrc

@@ -1,3 +1,3 @@
-globals = {"minetest", "ItemStack", "VoxelArea", "vector", "nodecore", "include", "SecureRandom"}
+globals = {"minetest", "ItemStack", "VoxelArea", "vector", "nodecore", "include", "SecureRandom", "dump"}
 color = false
 quiet = 1

.lualocals

@@ -2,3 +2,4 @@
 minetest
 ItemStack
 VoxelArea
+dump

szutil_lua/README.md

@@ -0,0 +1,5 @@
+Adds a `/lua` command to allow an admin to execute any arbitrary lua in the server context that they want.
+
+This is comparable to the //lua command functionality present in worldedit, but can be enabled without all the other worldedit stuff.
+
+The code is run inside a synchronous protected call, with no input parameters.  The result (return or error) is sent to the user.

szutil_lua/init.lua

@@ -0,0 +1,31 @@
+-- LUALOCALS < ---------------------------------------------------------
+local dump, loadstring, minetest, pcall, table, tostring
+    = dump, loadstring, minetest, pcall, table, tostring
+local table_remove
+    = table.remove
+-- LUALOCALS > ---------------------------------------------------------
+
+local modname = minetest.get_current_modname()
+
+minetest.register_privilege(modname, {
+		description = "Can run arbitrary lua code",
+		give_to_singleplayer = false,
+		give_to_admin = false,
+	})
+
+minetest.register_chatcommand("lua", {
+		privs = {[modname] = true},
+		description = "Run arbitrary lua code",
+		func = function(_, param)
+			local func, synerr = loadstring(param)
+			if not func then
+				return false, "parse error: " .. tostring(synerr)
+			end
+			local result = {pcall(func)}
+			if not result[1] then
+				return false, "runtime error: " .. tostring(result[2])
+			end
+			table_remove(result, 1)
+			return true, "returned: " .. dump(result)
+		end
+	})

szutil_lua/mod.conf

@@ -0,0 +1,3 @@
+name = szutil_lua
+description = Arbitrary lua code chat command
+supported_games = *