SQL & PL/SQL

Hi,
I want to spool the results of a query to a file.
I don't want to see the query or anything else other than the results in the file.

How do I suppress that information.
I've been trying
SET ECHO OFF
SET FEEDBACK OFF
SPOOL /home/abc/file.txt
SELECT user from DUAL;
SPOOL OFF;
SET ECHO ON
SET FEEDBACK ON

But I guess there is some command I am missing.

Any help would be appreciated!