no big deal.
you can easily create a custom package by altering the
foloowing sql as ur need.!~

SQL> show user
USER is "SYS"
SQL> desc mag.emp
 Name                                                  Null?    Type
 ----------------------------------------------------- -------- ------------------------------------
 EMPNO                                                 NOT NULL NUMBER(4)
 ENAME                                                          VARCHAR2(10)
 JOB                                                            VARCHAR2(9)
 MGR                                                            NUMBER(4)
 HIREDATE                                                       VARCHAR2(9)
 SAL                                                            NUMBER(7,2)
 COMM                                                           NUMBER(7,2)
 DEPTNO                                                         NUMBER(2)

SQL> ed
Wrote file afiedt.buf

  1  select     column_name "name" ,
  2     decode(nullable,'N','NOT NULL',
  3                          'Y','') "NULL?",
  4     data_type
  5  from dbA_taB_COLUMnS
  6* where owner='MAG' and TABLE_NAME='EMP'
SQL> /

name       NULL?      DATA_TYPE
---------- ---------- ----------
EMPNO      NOT NULL   NUMBER
ENAME                 VARCHAR2
JOB                   VARCHAR2
MGR                   NUMBER
HIREDATE              VARCHAR2
SAL                   NUMBER
COMM                  NUMBER
DEPTNO                NUMBER

8 rows selected.