Oracle: i want to setup some variables for login.sql
Unless you absolutely have to have the platform as part of the alias, I would simply pull the platform from v$database:

select 'You are:          '||upper(user)  "Welcome" from dual union all
select 'Logged into:      '||upper(sys_context('userenv','db_name')) from dual union all
select 'Database Version: '||banner from v$version where rownum &lt;= 2 union all
select 'On Platform:      '||platform_name from v$database;