-int rrd_update_r(char *filename, char *tmplt, int argc, char **argv);
-int _rrd_update(char *filename, char *tmplt, int argc, char **argv,
+int rrd_update_r(const char *filename, const char *tmplt, int argc, const char **argv);
+int _rrd_update(const char *filename, const char *tmplt, int argc, const char **argv,