[root@localhost ~]# hostnamectl 
   Static hostname: localhost.localdomain
         Icon name: computer-desktop
           Chassis: desktop
        Machine ID: b4f65cfce3a24bdea03ec5b8ee0a0260
           Boot ID: f6e5e776b7cf47f882f4fcc0c70be2e9
  Operating System: CentOS Linux 7 (Core)
       CPE OS Name: cpe:/o:centos:centos:7
            Kernel: Linux 3.10.0-229.el7.x86_64
      Architecture: x86_64	
	

unzip linuxamd64_12c_database_1of2.zip
unzip linuxamd64_12c_database_2of2.zip

cd  database/
./runInstaller
		

[root@localhost ~]# /opt/oraInventory/orainstRoot.sh
Changing permissions of /opt/oraInventory.
Adding read,write permissions for group.
Removing read,write,execute permissions for world.

Changing groupname of /opt/oraInventory to oinstall.
The execution of the script is complete.
		

[root@localhost ~]# /opt/oracle/product/12.1.0/dbhome_1/root.sh
Performing root user operation.

The following environment variables are set as:
    ORACLE_OWNER= oracle
    ORACLE_HOME=  /opt/oracle/product/12.1.0/dbhome_1

Enter the full pathname of the local bin directory: [/usr/local/bin]:
   Copying dbhome to /usr/local/bin ...
   Copying oraenv to /usr/local/bin ...
   Copying coraenv to /usr/local/bin ...


Creating /etc/oratab file...
Entries will be added to the /etc/oratab file as needed by
Database Configuration Assistant when a database is created
Finished running generic part of root script.
Now product-specific root actions will be performed.