How to Use hostname Command in Linux: Syntax and Examples

Use the hostname command in Linux to display or set the system's hostname. Running hostname alone shows the current hostname, while hostname newname changes it temporarily.

Syntax

The basic syntax of the hostname command is:

• hostname: Displays the current hostname.
• hostname [newname]: Sets the hostname temporarily to newname.
• hostname -I: Shows the IP addresses assigned to the host.
• hostname -f: Displays the fully qualified domain name (FQDN).

bash

hostname [options] [new_hostname]

Example

This example shows how to display the current hostname and how to change it temporarily.

bash

hostname
hostname new-hostname
hostname

Output

my-computer
new-hostname
new-hostname

Common Pitfalls

One common mistake is expecting the hostname change to persist after reboot. The hostname command changes the hostname only temporarily until the system restarts.

To make the change permanent, you must edit system files like /etc/hostname or use system tools like hostnamectl.

bash

hostname permanent-hostname
# This changes hostname only until reboot

# Correct way to set permanent hostname (example for systemd systems):
hostnamectl set-hostname permanent-hostname

Quick Reference

Option	Description
hostname	Show current hostname
hostname newname	Set temporary hostname to newname
hostname -I	Show all IP addresses
hostname -f	Show fully qualified domain name
hostnamectl set-hostname name	Set permanent hostname (systemd)

Key Takeaways

Use hostname alone to see your current system hostname.

Use hostname newname to change the hostname temporarily until reboot.

To make hostname changes permanent, edit system files or use hostnamectl.

Options like -I and -f help show IP addresses and full domain names.

Remember hostname changes via hostname command do not survive system restarts.