test@9i > show user
USER is "TEST"

test@9i > select synonym_name,table_owner,table_name from user_synonyms;

SYNONYM_NAME                   TABLE_OWNER                    TABLE_NAME
------------------------------ ------------------------------ ------------------------------
SYN_EMP                        SCOTT                          EMP

test@9i > get get_ddl_synonym.sql
  1  set long 500000
  2  set linesize 1000
  3  SET HEAD off
  4  set trimspool on
  5  set verify off
  6  column XXXX format a300
  7  SELECT
  8  replace(replace((DBMS_METADATA.GET_DDL('SYNONYM',D.SYNONYM_NAME))||';','"TEST".','"TEST2".'),'"SCOTT".','"ANOTHER_SCOTT".')
  9  FROM user_synonyms D;
 10* set head on;
test@9i > @get_ddl_synonym.sql


  CREATE SYNONYM "TEST2"."SYN_EMP" FOR "ANOTHER_SCOTT"."EMP"
 ;

--THIS SCRIPS IS USED TO CREATE OR REPLACE ALL THE SYNONYMS IN THE CURRENT SCHEMA

--GIVE THE USERNAME AT THE PROMPT


DECLARE

 v_syn_name VARCHAR2(50);

 v_table_name VARCHAR2(50);

 v_table_owner VARCHAR2(10);

 v_sql VARCHAR2(200);

CURSOR c1 IS
 SELECT synonym_name, table_name, table_owner

 FROM user_synonyms;

 c2 c1%ROWTYPE;

BEGIN

 OPEN c1;

 LOOP FETCH c1 INTO c2;

     EXIT WHEN c1%NOTFOUND;

 v_syn_name := c2.synonym_name;

 v_table_name := c2.table_name;

 v_table_owner := C2.table_owner;

 v_sql := 'CREATE OR REPLACE SYNONYM '||v_syn_name||' FOR '||&user_name||'.'||v_table_name;
 
 EXECUTE IMMEDIATE(v_sql);

 END LOOP;

 DBMS_OUTPUT.PUT_LINE('Records processed : '||C1%ROWCOUNT);

 CLOSE c1;

END;