Oracle Listener 11g

Listener Commands
LSNRCTL> help
LSNRCTL> change_password
LSNRCTL> save_config #Create new updated listner.ora file
LSNRCTL> quit
LSNRCTL> reload #reread the listener.ora file

Set the configuration
LSNRCTL> set current_listener uwlistener
LSNRCTL> set inound_connect_timeout 0
LSNRCTL> set password
LSNRCTL> set inbound_connect_timeout
LSNRCTL> set trc_level 0 #Set Trace Level
Value Description
0 - 1 off
2 - 3 err
4 - 5 user
6 - 14 admin
15 dev
16 - 99 support

Show the configuration
LSNRCTL> show current_listener
LSNRCTL> show inbound_connect_timeout
LSNRCTL> show startup_waittime
LSNRCTL> show trc_level #Shows the Trace Level
LSNRCTL> show log_status

==>To Prevent remote modification of listener.ora using lsnrctl commands
ADMIN_RESTRICTIONS_[listener_name]=

==>Force the database to register, or reregister, with the listener
ALTER SYSTEM REGISTER;

for more: http://psoug.org/reference/listener.html