https://www.bnl.gov/phobos/Detectors/Computing/Orant/doc/network.804/a48385/ch5.htm

Using the Listener Control Utility
The network listener establishes listen endpoints on a machine. These listen endpoints are well-known addresses that clients and servers use to connect to a database. The Listener Control Utility, LSNRCTL, is a tool that you run from the operating system prompt to start and control the listener. For SQL*Net use, the general form of the Listener Control Utility is:

LSNRCTL command [listener_name]

LSNRCTL
Specifies the name of the tool that controls the listener. In some operating systems, this fixed parameter is case sensitive. If the operating system is case sensitive, enter LSNRCTL in lowercase.

command    
Specifies the action to be performed.

listener_name    
Specifies the listener name defined in LISTENER.ORA. If listener_name is not included, the default value LISTENER is used.

Commands for LSNRCTL Information
The Listener Control Utility has three commands that provide information about LSNRCTL itself. These commands are HELP, SET, and SHOW.

HELP : HELP provides a list of all the LSNRCTL commands available. An example follows:

LSNRCTL> help
The following operations are available
An asterisk (*) denotes a modifier or extended command:
 
start               stop                status
services            version             reload
trace               spawn               dbsnmp_start
dbsnmp_stop         dbsnmp_status       change_password
quit                exit                set*
show*  

SET: This command lists the operations that can be set using the SET command.

LSNRCTL> set
The following operations are available after set
An asterisk (*) denotes a modifier or extended command:

password             trc_file             trc_directory
trc_level            log_file             log_directory
log_status           current_listener     connect_timeout
startup_waittime     use_plugandplay

SHOW: This command lists the operations that can be set using the SHOW command.

LSNRCTL> show
The following operations are available after show
An asterisk (*) denotes a modifier or extended command:

trc_file             trc_directory        trc_level
log_file             log_directory        log_status
current_listener     connect_timeout      startup_waittime
snmp_visible         use_ckpfile          use_plugandplay

Stopping the Listener
To stop the default listener, use the command:
LSNRCTL STOP

To stop a running listener defined in LISTENER .ORA as TCP_LSNR, use the command:
LSNRCTL STOP TCP_LSNR

You can then stop the listener from the command line by entering:
LSNRSTOP

Start the Listener
to start a default listener (which is a listener defined in a LISTENER.ORA file with the alias LISTENER):
LSNRCTL START

To start a non-default listener:
LSNRCTL START listener_name

Checking Listener Status
LSNRCTL STATUS

Retrieving Listener Services
LSNRCTL> SERVICES