今天一个数据库的监听器日志出了点问题，用set log_file命令重新定位一个日志文件得以解决。
发现以下两个命令很有用:
LSNRCTL> set current_listener <listener name>
LSNRCTL> set log_file <sid name>.log
使用set current_listener可以访问非缺省监听器，使用set log_file更改名称后，原来有问题的日志文件可以清除或实现日志重定位:
[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>
如果需要将这个修改永久化，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
此时listener.ora文件会被增加如下记录：
[oracle@jumper oracle]$ tail -5 /opt/oracle/product/9.2.0/network/admin/listener.ora
