hostname

The hostname command in Linux is used to display or set the system's hostname, which is a unique identifier assigned to a machine in a network. The hostname is used to identify the machine within a network and is essential for network communication and administration tasks.

Basic Usage

hostname [options] [new_hostname]

options: Optional flags to modify the command's behavior.
new_hostname: The new hostname you want to set for the machine.

Common Options and Examples

Display the Current Hostname:
```
hostname
```
This command displays the current hostname of the system.
Set a New Hostname:
```
sudo hostname new_hostname
```
This command sets the system's hostname to new_hostname. Note that you need superuser privileges to change the hostname.
Display the Short Hostname:
```
hostname -s
```
This command displays the short hostname (up to the first dot).
Display the FQDN (Fully Qualified Domain Name):
```
hostname -f
```
This command displays the system's fully qualified domain name (FQDN).
Display the Alias Names:
```
hostname -a
```
This command displays the alias names of the host.
Display the IP Address:
```
hostname -i
```
This command displays the IP address associated with the hostname.
Display the DNS Domain Name:
```
hostname -d
```
This command displays the DNS domain name of the system.
Display All Hostnames:
```
hostname -A
```
This command displays all configured hostnames.

Example Usage

Check the Current Hostname:
```
$ hostname
myhostname
```
Change the Hostname Temporarily:
```
$ sudo hostname newhostname
```
This change will last until the next reboot.
Set the Hostname Permanently: To set the hostname permanently, you need to edit the /etc/hostname file and the /etc/hosts file.
```
$ sudo nano /etc/hostname
```
Change the content to the new hostname and save the file.
```
$ sudo nano /etc/hosts
```
Update the line that starts with 127.0.1.1 to match the new hostname:
```
127.0.1.1   newhostname
```
After making these changes, apply them by running:
```
$ sudo systemctl restart systemd-logind.service
```

Practical Applications

Network Configuration: Setting a hostname is essential for identifying machines in a network, facilitating easier communication and management.
Server Management: Hostnames help in managing multiple servers and services, making it easier to identify and configure them.
Troubleshooting: Knowing the hostname can assist in diagnosing network issues and identifying the source of problems.

Conclusion

The hostname command is a straightforward yet essential tool for managing and configuring the system's network identity. For detailed information, you can refer to the man page:

man hostname

help

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Last updated 3 months ago