create or replace function get_rowid
(l_rowid in varchar2)
return varchar2
is
ls_my_rowid  varchar2(200);          
rowid_type  number;          
object_number  number;          
relative_fno  number;          
block_number  number;          
row_number  number;  
begin
dbms_rowid.rowid_info(l_rowid,rowid_type,
object_number,relative_fno, block_number, row_number);          
ls_my_rowid := 'Object# is      :'||to_char(object_number)||chr(10)||
'Relative_fno is :'||to_char(relative_fno)||chr(10)||
'Block number is :'||to_char(block_number)||chr(10)||
'Row number is   :'||to_char(row_number);
return ls_my_rowid ;
end;          
/

[oracle@jumper tools]$ sqlplus scott/tiger

SQL*Plus: Release 9.2.0.4.0 - Production on Sun Nov 7 12:30:19 2004

Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.


Connected to:
Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production
With the Partitioning option
JServer Release 9.2.0.4.0 - Production

SQL> set echo on
SQL> @f_get_rowid
SQL> create or replace function get_rowid
2  (l_rowid in varchar2)
3  return varchar2
4  is
5  ls_my_rowid        varchar2(200);
6  rowid_type number;
7  object_number      number;
8  relative_fno       number;
9  block_number       number;
10  row_number number;
11  begin
12   dbms_rowid.rowid_info(l_rowid,rowid_type,

object_number,relative_fno, block_number, row_number);

13   ls_my_rowid := 'Object# is :'||to_char(object_number)||chr(10)||

14   'Relative_fno is :'||to_char(relative_fno)||chr(10)||

15    'Block number is :'||to_char(block_number)||chr(10)||
16    'Row number is   :'||to_char(row_number);
17   return ls_my_rowid ;
18  end;
19  /

Function created.

SQL> 
SQL> select * from dept;

    DEPTNO DNAME          LOC
---------- -------------- -------------
10 ACCOUNTING     NEW YORK
20 RESEARCH       DALLAS
30 SALES          CHICAGO
40 OPERATIONS     BOSTON

SQL> select rowid,a.* from dept a;

ROWID                  DEPTNO DNAME          LOC
------------------ ---------- -------------- -------------
AAABiPAABAAAFRSAAA         10 ACCOUNTING     NEW YORK
AAABiPAABAAAFRSAAB         20 RESEARCH       DALLAS
AAABiPAABAAAFRSAAC         30 SALES          CHICAGO
AAABiPAABAAAFRSAAD         40 OPERATIONS     BOSTON


SQL> col row_id for a60
SQL> select get_rowid('AAABiPAABAAAFRSAAA') row_id from dual;

ROW_ID
------------------------------------------------------------
Object# is      :6287
Relative_fno is :1
Block number is :21586
Row number is   :0


SQL> select get_rowid('AAABiPAABAAAFRSAAB') row_id from dual;

ROW_ID
------------------------------------------------------------
Object# is      :6287
Relative_fno is :1
Block number is :21586
Row number is   :1
SQL>