hostname Command in Linux: View and Set Hostname

Quick take: The hostname command shows or sets the system's hostname. hostname prints it, hostname -f shows the fully qualified name, and hostname -I lists IP addresses. To change it permanently, use sudo hostnamectl set-hostname newname.

Introduction

The hostname command displays and temporarily sets the name that identifies a machine on a network. It is useful for quick checks and scripts, but because changes made with it do not survive a reboot, permanent changes are made with hostnamectl on modern systemd-based distributions.

Syntax

The basic syntax of the hostname command is:

hostname [OPTIONS] [NEW_NAME]

Common Options and Parameters

The most useful options and parameters for the hostname command:

Option	Description
(default)	Print the current short hostname.
-f	Print the fully qualified domain name (FQDN).
-i / -I	Print the IP address(es) of the host.
-d	Print the DNS domain name.
-s	Print the short hostname (up to the first dot).
hostnamectl set-hostname NAME	Set the hostname permanently (systemd).

Practical Examples

Real hostname commands you can run today:

# Show the hostname
hostname
# Show the fully qualified name
hostname -f
# Show the machine's IP addresses
hostname -I
# Set the hostname for this session only
sudo hostname temp-name
# Set it permanently
sudo hostnamectl set-hostname web01
# View full host details
hostnamectl

Tips and Best Practices

Changes made with hostname name are temporary; use hostnamectl set-hostname for a permanent change that persists across reboots.
hostname -I is a quick way to list the machine's IP addresses without parsing ip a.
After changing the hostname, update /etc/hosts so the new name resolves locally and tools do not complain.

Final Thoughts

hostname shows and temporarily sets a machine's network name, with handy flags for the FQDN (-f) and IP addresses (-I). For changes that stick, use hostnamectl set-hostname on systemd systems and update /etc/hosts to match. It is a small but frequently used tool for identifying and configuring servers.

FAQ: hostname Command in Linux

How do I check my hostname in Linux?+

Run hostname to print the short name, hostname -f for the fully qualified domain name, or hostnamectl for full details including the OS and kernel.

How do I change the hostname permanently?+

Use sudo hostnamectl set-hostname newname on systemd-based systems. This updates the configuration so the change survives reboots, unlike the temporary hostname command.

How do I find my IP address with hostname?+

Use hostname -I, which prints all of the machine's IP addresses on one line — a quick alternative to reading ip a.

Why does my hostname change revert after reboot?+

Setting it with hostname name is temporary and lives only in memory. Use hostnamectl set-hostname to write it to configuration so it persists.

What is the difference between hostname and FQDN?+

The hostname is the short name (like web01), while the fully qualified domain name (FQDN) includes the domain (web01.example.com). hostname -f shows the FQDN.

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