[oracle@orcl1 ~]$ . oraenv
ORACLE_SID = [orcl1] ? oracle1
The Oracle base remains unchanged with value /u01/app/oracle
[oracle@orcl1 ~]$ sqlplus / as sysdba
SQL*Plus: Release 19.0.0.0.0 - Production on Fri Apr 7 14:39:41 2023
Version 19.12.0.0.0
Copyright (c) 1982, 2021, Oracle. All rights reserved.
Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.12.0.0.0