今天一個數據庫的監聽器日志出了點問題，用set log_file命令重新定位一個日志文件得以解決。

發現以下兩個命令很有用:

LSNRCTL> set current_listener <listener name>
LSNRCTL> set log_file <sid name>.log

使用set current_listener可以訪問非缺省監聽器，使用set log_file更改名稱后，原來有問題的日志文件可以清除或實現日志重定位:
[oracle@jumper admin]$ lsnrctl

LSNRCTL for Linux: Version 9.2.0.4.0 - Production on 10-NOV-2006 16:54:16

Copyright (c) 1991, 2002, Oracle Corporation.  All rights reserved.

Welcome to LSNRCTL, type "help" for information.

LSNRCTL> set current_listener LISTENER1
Current Listener is LISTENER1
LSNRCTL> set log_file
Parameter Value: a.log
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC)))
LISTENER1 parameter "log_file" set to a.log
The command completed successfully
LSNRCTL> status
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER1
Version                   TNSLSNR for Linux: Version 9.2.0.4.0 - Production
Start Date                10-NOV-2006 16:54:12
Uptime                    0 days 0 hr. 2 min. 6 sec
Trace Level               off
Security                  OFF
SNMP                      OFF
Listener Parameter File   /opt/oracle/product/9.2.0/network/admin/listener.ora
Listener Log File         /opt/oracle/product/9.2.0/network/log/a.log
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=172.16.33.11)(PORT=1521)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "conner" has 1 instance(s).
  Instance "conner", status UNKNOWN, has 1 handler(s) for this service...
Service "eygle" has 1 instance(s).
  Instance "eygle", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully
LSNRCTL> 小蟲網絡技術http://www.chinaccna.com

如果需要將這個修改永久化，需要使用save_config命令保存一下：
LSNRCTL> save_config
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC)))
Saved LISTENER1 configuration parameters.
Listener Parameter File /opt/oracle/product/9.2.0/network/admin/listener.ora
Old Parameter File /opt/oracle/product/9.2.0/network/admin/listener.bak
The command completed successfully

此時listener.ora文件會被增加如下記錄：
[oracle@jumper oracle]$ tail -5 /opt/oracle/product/9.2.0/network/admin/listener.ora
#----ADDED BY TNSLSNR 14-NOV-2006 16:39:12---
LOG_FILE_LISTENER1 = a.log
#--------------------------------------------

記錄一下。