How to run sql query in more than one database at same time using Shell script

Instead of connecting to each and every db using sqlplus  and run sql query just use below script. It will reduce  manual intervention.

for i in dbname1 dbname2 dbname3 dbname4

do

sqlplus -s /@$i <<EOD>>file.txt

select name from v\$database;

SELECT DISTINCT grantee,granted_role from dba_role_privs where granted_role ='UPDATOR_ROLE';

EOD

done

cat file.txt