+
+int bus_message_read_strv_extend(sd_bus_message *m, char ***l) {
+ int r;
+
+ assert(m);
+ assert(l);
+
+ r = sd_bus_message_enter_container(m, 'a', "s");
+ if (r < 0)
+ return r;
+
+ for (;;) {
+ const char *s;
+
+ r = sd_bus_message_read_basic(m, 's', &s);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ break;
+
+ r = strv_extend(l, s);
+ if (r < 0)
+ return r;
+ }
+
+ r = sd_bus_message_exit_container(m);
+ if (r < 0)
+ return r;
+
+ return 0;
+}
+
+const char* bus_message_get_arg(sd_bus_message *m, unsigned i) {
+ int r;
+ const char *t;
+ char type;
+
+ assert(m);
+
+ r = sd_bus_message_rewind(m, true);
+ if (r < 0)
+ return NULL;
+
+ while (i > 0) {
+ r = sd_bus_message_peek_type(m, &type, NULL);
+ if (r < 0)
+ return NULL;
+
+ if (type != SD_BUS_TYPE_STRING &&
+ type != SD_BUS_TYPE_OBJECT_PATH &&
+ type != SD_BUS_TYPE_SIGNATURE)
+ return NULL;
+
+ r = sd_bus_message_read_basic(m, type, &t);
+ if (r < 0)
+ return NULL;
+
+ i--;
+ }
+
+ r = sd_bus_message_rewind(m, true);
+ if (r < 0)
+ return NULL;
+
+ return t;
+}