centos 7 : oracle listener config & log Hint with /etc/hosts

# vi /home/oracle/app/oracle/product/11.2.0/dbhome_1/network/admin/listener.ora

-----------------------

LISTENER =

(DESCRIPTION_LIST =

(DESCRIPTION =

(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))

(ADDRESS = (PROTOCOL = TCP)(HOST = owl)(PORT = 1521))

)

ADR_BASE_LISTENER = /home/oracle/app/oracle

-----------------------

# vi /etc/hosts

-----------------------

127.0.0.1 owl

-----------------------

# systemctl restart oracle

# tail -f /home/oracle/app/oracle/diag/tnslsnr/owl47/listener/alert/log.xml