Execute TDengine CLI program `taos` directly from the Linux shell to connect to the TDengine service and enter the TDengine CLI interface, as shown in the following example. ```text $ taos
taos> show databases;
name | create_time | vgroups | ntables | replica | strict | duration | keep | buffer | pagesize | pages | minrows | maxrows | comp | precision | status | retention | single_stable | cachemodel | cachesize | wal_level | wal_fsync_period | wal_retention_period | wal_retention_size | wal_roll_period | wal_seg_size | ========================================================================================================================================================================================================================================================================================================================================================================================================================================================================= information_schema | NULL | NULL | 14 | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | ready | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | performance_schema | NULL | NULL | 3 | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | ready | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | db | 2022-08-04 14:14:49.385 | 2 | 4 | 1 | off | 14400m | 5254560m,5254560m,5254560m | 96 | 4 | 256 | 100 | 4096 | 2 | ms | ready | NULL | false | none | 1 | 1 | 3000 | 0 | 0 | 0 | 0 | Query OK, 3 rows in database (0.019154s)
taos> ```
