How to use the glogin.sql file to set global sqlplus attributes

The file $ORACLE_HOME/sqlplus/admin/glogin.sql can be used to define global attributes for users of sqlplus on that particular host.

For example:

SET SQLPROMPT "_USER'@'_CONNECT_IDENTIFIER SQL>"
SET LINESIZE 200
SET PAGSEIZE 200

On Production servers, you may consider adding a colored prompt, for example red:

SET SQLPROMPT "'^[[41m'_USER'@'_CONNECT_IDENTIFIER'^[[0m' SQL> "