[ SEA-GHOST MINI SHELL]

DO LANGUAGE plpgsql $$
DECLARE
        ver integer;
        res text := 2;
BEGIN
        SELECT current_setting('server_version_num') INTO ver;

        IF (SELECT pg_is_in_recovery()) THEN
                IF (ver >= 90600) THEN
                        SELECT * INTO res from (
                                SELECT COUNT(*) FROM pg_stat_wal_receiver
                                ) T;
                ELSE
                        res := 'ZBX_NOTSUPPORTED: Requires PostgreSQL version 9.6 or higher';
                END IF;
        END IF;

        perform set_config('zbx_tmp.repl_status_res', res, false);
END $$;

SELECT current_setting('zbx_tmp.repl_status_res');