+#define property(name, fmt, ...) \
+ do { \
+ if (arg_value) \
+ printf(fmt "\n", __VA_ARGS__); \
+ else \
+ printf("%s=" fmt "\n", name, __VA_ARGS__); \
+ } while(0)
+
+static int print_property(const char *name, sd_bus_message *m, const char *contents) {
+ int r;
+
+ assert(name);
+ assert(m);
+ assert(contents);
+
+ if (arg_property && !strv_find(arg_property, name))
+ /* skip what we didn't read */
+ return sd_bus_message_skip(m, contents);
+
+ switch (contents[0]) {
+
+ case SD_BUS_TYPE_STRUCT_BEGIN:
+
+ if (contents[1] == SD_BUS_TYPE_STRING && STR_IN_SET(name, "Display", "Seat", "ActiveSession")) {
+ const char *s;
+
+ r = sd_bus_message_read(m, "(so)", &s, NULL);
+ if (r < 0)
+ return bus_log_parse_error(r);
+
+ if (arg_all || !isempty(s))
+ property(name, "%s", s);
+
+ return 0;
+
+ } else if (contents[1] == SD_BUS_TYPE_UINT32 && streq(name, "User")) {
+ uint32_t uid;
+
+ r = sd_bus_message_read(m, "(uo)", &uid, NULL);
+ if (r < 0)
+ return bus_log_parse_error(r);
+
+ if (!uid_is_valid(uid)) {
+ log_error("Invalid user ID: " UID_FMT, uid);
+ return -EINVAL;
+ }
+
+ property(name, UID_FMT, uid);
+ return 0;
+ }
+
+ break;
+
+ case SD_BUS_TYPE_ARRAY:
+
+ if (contents[1] == SD_BUS_TYPE_STRUCT_BEGIN && streq(name, "Sessions")) {
+ const char *s;
+ bool space = false;
+
+ r = sd_bus_message_enter_container(m, SD_BUS_TYPE_ARRAY, "(so)");
+ if (r < 0)
+ return bus_log_parse_error(r);
+
+ if (!arg_value)
+ printf("%s=", name);
+
+ while ((r = sd_bus_message_read(m, "(so)", &s, NULL)) > 0) {
+ printf("%s%s", space ? " " : "", s);
+ space = true;
+ }
+
+ if (space || !arg_value)
+ printf("\n");
+
+ if (r < 0)
+ return bus_log_parse_error(r);
+
+ r = sd_bus_message_exit_container(m);
+ if (r < 0)
+ return bus_log_parse_error(r);
+
+ return 0;
+ }
+
+ break;
+ }
+
+ r = bus_print_property(name, m, arg_value, arg_all);
+ if (r < 0)
+ return bus_log_parse_error(r);
+
+ if (r == 0) {
+ r = sd_bus_message_skip(m, contents);
+ if (r < 0)
+ return bus_log_parse_error(r);
+
+ if (arg_all)
+ printf("%s=[unprintable]\n", name);
+ }
+
+ return 0;