CREATE OR REPLACE FUNCTION view_instr (piv_owner in varchar2, piv_vname IN varchar2, piv_searchfor in varchar2)
  RETURN NUMBER
IS
  v_long long;
  v_return number;
BEGIN
  select text 
    into v_long
    from all_views
    where owner = piv_owner
    and view_name = piv_vname;
    
    v_return := instr(v_long,piv_searchfor);
    return v_return;
EXCEPTION
  WHEN NO_DATA_FOUND
  THEN
    return -1;
  WHEN OTHERS
  THEN
    RAISE;
END view_instr;
/

SELECT _whatever_
  FROM all_views
 WHERE view_instr(owner, view_name, '_search_string_') > 0