[root@telematic standalone]# su - postgres
-bash-4.1$ psql truck_company
psql (8.4.12)
Type "help" for help.

truck_company=# SELECT * FROM "pg_user";
 usename  | usesysid | usecreatedb | usesuper | usecatupd |  passwd  | valuntil | useconfig
----------+----------+-------------+----------+-----------+----------+----------+-----------
 postgres |       10 | t           | t        | t         | ******** |          |
(1 row)