Usually when you install Ubuntu, it will ask you for your username and assign a hostname to you, such as damien@damien-laptop. This is also what you will see in your terminal. If you don’t like the hostname shown in the terminal, or for some reason that you want to change the hostname, here’re the exact steps in Ubuntu. It is very easy. Just follow along and you will be done in a minute.
1. First, open a terminal and type:
gksu gedit /etc/hostname
You should see a line stating your current hostname. For eg. damien-desktop
2. Change the hostname to something you desired. Save and close the file.
3. Back in your terminal, type:
gksu gedit /etc/hosts
4. Change the line:
Save and close the file.
Restart the computer. Your new hostname should appear in the terminal now.