vi is a screen-oriented text editor originally created for the Unix operating system.
Tempororay define editor in session level
SQL> define_editor=vi
SQL> select * from duall;
select * from duall
*
ERROR at line 1:
ORA-00942: table or view does not exist
SQL> ed
Wrote file afiedt.buf
1* select * from dual
SQL> /
D
-
X
SQL>
To make permanent above settings for SQLPLUS utility you need to define it in $ORACLE_HOME/sqlplus/admin/glogin.sql and it will be effective for all session with sqlplus.
vi $ORACLE_HOME/sqlplus/admin/glogin.sql define _editor='vi'