Sql*plus always returns exit code 0?

Question

You have to explicitly tell sqlplus to do that, in your script. Basically, there are two statements that you can use:

For example:

WHENEVER SQLERROR EXIT SQL.SQLCODE
begin
  SELECT COLUMN_DOES_NOT_EXIST FROM DUAL;
END;
/

And for OS errors:

WHENEVER OSERROR EXIT FAILURE
START no_such_file

For more information, see this and that.

Hope it helps. Good Luck!