How to Use the hostname Command in Linux

Introduction

The Linux hostname command is used to view or change a system’s domain and hostname. It can also check a computer’s IP address.

In this tutorial, we will cover all the ways you can use the hostname command on Linux and how to change your computer’s hostname on a Linux system.

Prerequisites

• A system running Linux
• Access to the command line / terminal window

hostname Command Syntax

The hostname command uses the following format:

hostname [options] [new_hostname]

Use the [options] parameter to add more specific instructions to the hostname command. Without it, the default output shows your computer’s hostname:

Use the [new_hostname] parameter when you want to change your computer’s hostname.

hostname Command Examples

The hostname command has a number of options you can use for more specific outputs:

• -a, --alias: Displays the alias name of the host.
• -A, --all-fqdns: Displays every FQDN (Fully Qualified Domain Name) of the computer.
• -b, --boot: Always set a hostname.
• -d, --domain: Display DNS domain name.
• -f, --fqdn, --long: Display the FQDN.
• -F, --file: Check a file to recover and display the hostname.
• -h, --help: Print the help message as the output.
• -i, --ip-address: Display the computer’s IP address.
• -I, --all-ip-addresses: Display all of the computer’s network addresses.
• -s, --short: Display the short version of the hostname.
• -v, --verbose: Expand all output to verbose.
• -y, --yp, --nis: Display the NIS domain name.

Display Hostname

Using the hostname command without any additional options displays the computer’s hostname:

hostname

Display Short Hostname

Use the -s or --short option to display the short version of the hostname, which is cut off at the first dot:

hostname -s
hostname --short

Display Alias

Use the -a or --alias option to display the alias (substitute hostname) of the host if one is set. There are very few cases where this option is useful, and its use is no longer recommended.

hostname -a
hostname --alias

Search for Hostnames

Use the -F or --file option to search a specific file (such as hostname or hosts) and change your computer’s hostname to match the content of the file:

sudo hostname -F [file path]
sudo hostname --file [file path]

Force Default Hostname

If you don’t want to have a specific file containing the hostname, or want to leave that file empty, use the -b or --boot option. This makes your computer use the default hostname (localhost) until you set a different one:

hostname -b
hostname --boot

Display Domain Name

Use the -d or --domain option to display the name of your DNS domain:

hostname -d
hostname –domain

Display FQDN

If you want to display a system’s FQDN, use the -f, --fqdn, or --long option:

hostname -f
hostname --fqdn
hostname --long

A FQDN contains the short hostname and the DNS domain name.

Display All FQDNs

To display each FQDN of your machine, use the -A or --all-fqdns option:

hostname -A
hostname --all-fqdns

This option lists out all of your network addresses and their DNS domain names. It skips any addresses that it can’t translate.

Display NIS Domain

If you’re using NIS (Network Information Service), you can check your NIS domain name with the -y, --yp, or --nis option:

hostname -y
hostname --yp
hostname --nis

Change NIS Domain Name

Use this command with the following format to change your NIS domain name:

sudo hostname -y [NIS hostname]
sudo hostname --yp [NIS hostname]
sudo hostname --nis [NIS hostname]

Display Related Network Addresses

The hostname command also lets your display network addresses tied to a hostname. To do this, use the -i or --ip-address option:

hostname -i
hostname --ip-address

This command only works if the hostname can be resolved.

Display All Network Addresses

Use the -I or --all-ip-addresses option to display all of the host’s network addresses. Unlike -i, this option doesn’t depend on hostname resolution:

hostname -I
hostname --all-ip-addresses

Change Hostname Until Reboot

You can change your computer’s hostname with the hostname command. To do this, use the following format:

sudo hostname [new hostname]

Any changes to the hostname you make using this command will only last until the next reboot.

Change Hostname Permanently

To change the hostname permanently, use a text editor like Nano to make changes to the hostname and hosts files:

sudo nano /etc/hostname
sudo nano /etc/hosts

You can also use the hostnamectl command to permanently change the hostname:

sudo hostnamectl set-hostname [new hostname]

Additional hostname Options

Use the -V or --version option to print out the version of the hostname software package on your Linux system:

hostname -V
hostname --version

If you need help with any of the commands, use the -h or --help option to print out a help message:

hostname -h
hostname --help

Conclusion

After following this guide, you now know how to use the hostname command in Linux and all the options that can extend its use.

For more Linux commands, check out our Linux Commands Cheat Sheet.