Macro 32 Ramblings

How to display the current Ubuntu hostname

Simply type the following command:
$ hostnamectl

Ubuntu 18.04 LTS change hostname permanently

The procedure to change the computer name on Ubuntu 18.04 LTS:

1. Type the hostnamectl command :
   sudo hostnamectl set-hostname newNameHere
   Delete the old name and setup new name.
2. Next Edit the /etc/hosts file:
   sudo nano /etc/hosts
   Replace any occurrence of the existing computer name with your new one.
3. Reboot the system to changes take effect:
   sudo reboot

How to change hostname on Ubuntu 18.04 without a system restart

Let us see current setting just type the following command:
$ hostnamectl
Next change hostname from localhost to u1804-nixcraft, enter:
$ hostnamectl set-hostname u1804-nixcraft
Verify new changes:
$ hostnamectl

Find your public or private IP address by running the ip command:
$ ip a
$ ip a s eth0

2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 40:9f:38:28:f6:b5 brd ff:ff:ff:ff:ff:ff
    inet 192.168.2.24/24 brd 192.168.2.255 scope global noprefixroute enp6s0
       valid_lft forever preferred_lft forever
    inet6 fe80::429f:38ff:fe28:f6b5/64 scope link 
       valid_lft forever preferred_lft forever

Update /etc/hosts file with that IP address such as 192.168.2.24 using a text editor such as vim command/nano command:
$ sudo vi /etc/hosts