Passwords in UNIX process list

I'm trying to keep database passwords out of the 'ps' listing on a UNIX system.

I've use simple redirect scripts in the past, with Sybase and Informix. These would just feed the password to the database login process rather than including it on the command line ( login/password ).

sqlplus dblogin <<!
dbpassword
select ......;
quit
!

I get errors from Oracle (8.1.6) when trying this froma ksh script - SP2-0306 Invalid option. and a usage message .

I can drag something like 'expect' into the mix, but I would like to use a simpler solution, if it exists. The system I'm working on does not use the operating system credentials for the database access.

I'm more of a UNIX admin than a DBA, so please pardon my ignorance if this is a stupid question. I have looked through some Oracle 7 course material from about 4 years ago, and a couple of O'reilly books I've got, but haven't come across a solution yet.

Thanks for any help or direction you can provide.

-Craig