In scenario one: the oracle environment will not be set up properly - the oracle user will inherit the root environment - so variables like ORACLE_HOME will be undefined.

In the second scenario, your command will be executed properly. The reason you are getting the message, I believe, is that you have a "stty" command in the oracle ".cshrc" file - move this command to the oracle user ".login" file and the error message should go away.

Hope this helps - let me know the result please!

-amar