Sqlplus not exiting w/ error code

Question

When I run sqlplus like the following I would have expected it to return a status 1 instead of a 0:
sqlplus /nolog
SQL*Plus: Release 10.2.0.2.0 - Production on Mon Jan 8 08:41:39 2007
Copyright (c) 1982, 2005, Oracle. All Rights Reserved.
SQL> whenever SQLERROR EXIT 1 rollback;
SQL> select * from dual;
SP2-0640: Not connected
SQL>
SQL>exit
echo $?
0
Why wouldn't sqlplus return me a 1 return code, and exit the script automatically?

Answer 1

WHENEVER SQLERROR EXIT forces SQL*Plus to exit whenever SQL exception occurs. SP2-XXXX errors are internal SQL*Plus errors (not SQL errors) and they don't force SQL*Plus to exit regardless of WHENEVER SQLERROR setting.
Consider:
C:\>sqlplus /NOLOG
SQL*Plus: Release 10.1.0.2.0 - Production on Mon Jan 8 17:41:41 2007
Copyright (c) 1982, 2004, Oracle.  All rights reserved.
SQL> connect max
Enter password:
Connected.
SQL>
SQL> whenever sqlerror exit
SQL>
SQL> set echo on
SQL>
SQL> -- I won't exit on SP2-errors...
SQL> set some_illegal_setting off
SP2-0735: unknown SET option beginning "some_illeg..."
SQL>
SQL> totally_illegal_command
SP2-0734: unknown command beginning "totally_il..." - rest of line ignored.
SQL>
SQL> select dummy from dual;
D
X
SQL> -- I am gonna make SQL error, I will exit...
SQL> select illegal_column from dual;
select illegal_column from dual
ERROR at line 1:
ORA-00904: "ILLEGAL_COLUMN": invalid identifier
Disconnected from Oracle9i Enterprise Edition Release 9.2.0.6.0 - Production
With the Partitioning, Oracle Label Security, OLAP and Oracle Data Mining options
JServer Release 9.2.0.6.0 - Production
C:\>Regards.