escape in sqlplus

set colsep ',' #used to generate csv file

set escape \ #used to escape substitution charactor in sql, not for sql processing.

for example select '\&1' from dual;

if you want to escape character in like clause

use .... like '\_sss' escape '\'

reference:
http://asktom.oracle.com/pls/apex/f?p=100:11:0::::P11_QUESTION_ID:12520384680605