diff --git a/binding/lua_c/util_test.lua b/binding/lua_c/util_test.lua
index 1748453..6cfb855 100644
--- a/binding/lua_c/util_test.lua
+++ b/binding/lua_c/util_test.lua
@@ -76,8 +76,11 @@ local ip_str = "1.2.3.4"
 searcher, err = xdb.new_with_file_only("../../data/ip2region.xdb")
 local t_start = xdb.now()
 region, err = searcher:search(ip_str)
+local c_time = xdb.now() - t_start
 print(string.format("search(%s): {region=%s, io_count: %d, took: %dμs, err=%s}",
-        ip_str, region, searcher:get_io_count(), xdb.now() - t_start, err))
+        ip_str, region, searcher:get_io_count(), c_time, err))
+print(string.format("searcher.tostring=%s", searcher))
+searcher:close()
 
 
 print("")
diff --git a/binding/lua_c/xdb_searcher.c b/binding/lua_c/xdb_searcher.c
index 2e27d5c..df51fda 100644
--- a/binding/lua_c/xdb_searcher.c
+++ b/binding/lua_c/xdb_searcher.c
@@ -56,7 +56,7 @@ static int lua_xdb_new_with_vector_index(lua_State *L) {
     // check the db path and vector index buffer
     db_path = luaL_checkstring(L, 1);
     if (db_path == NULL) {
-        return luaL_error(L, "ip2region.xdb file path expected");
+        return luaL_error(L, "xdb file path expected");
     }
 
     v_index = luaL_checkstring(L, 2);
@@ -140,7 +140,7 @@ static int lua_xdb_search(lua_State *L) {
     // get the searcher
     searcher = (xdb_searcher_t *) luaL_checkudata(L, 1, XDB_METATABLE_NAME);
     if (searcher == NULL) {
-        return luaL_error(L, "call via ':' or broken xdb searcher instance");
+        return luaL_error(L, "call via ':' or xdb searcher was broken");
     }
 
     // input ip type checking
@@ -174,7 +174,7 @@ static int lua_xdb_get_io_count(lua_State *L) {
 
     searcher = (xdb_searcher_t *) luaL_checkudata(L, 1, XDB_METATABLE_NAME);
     if (searcher == NULL) {
-        return luaL_error(L, "broken xdb searcher instance");
+        return luaL_error(L, "call method via ':' or xdb searcher was broken");
     }
 
     lua_pushinteger(L, xdb_get_io_count(searcher));