# Cheatsheet & Examples: hostname

The `hostname` command is a utility used to display or set the system's hostname. The hostname is a name assigned to a computer on a network, used to identify it.

## Displaying the Current Hostname

Example Usage:
`hostname`

What it does:
Displays the current hostname of the system.

Command-line Arguments Explained:
- (None)
## Setting the Hostname (Permanently)

Example Usage:
`sudo hostnamectl set-hostname newhostname.example.com`

What it does:
Sets the system's hostname to the specified value. This change is often persistent across reboots, depending on the system configuration and init system (systemd, sysvinit, etc.)

Command-line Arguments Explained:
- `sudo`:  Executes the command with elevated privileges, necessary to modify system settings.
- `hostnamectl`: A command used to control the system hostname.
- `set-hostname`: The option of the `hostnamectl` command that modifies the hostname.
- `newhostname.example.com`: The new hostname to be set. This example uses a fully qualified domain name (FQDN).
## Setting the Hostname (Temporarily)

Example Usage:
`sudo hostname newhostname`

What it does:
Sets the system's hostname to the specified value. This change is typically only effective until the next system reboot or network configuration change.

Command-line Arguments Explained:
- `sudo`: Executes the command with elevated privileges, necessary to modify system settings.
- `hostname`: The command used to manipulate the hostname.
- `newhostname`: The new hostname to be set (e.g., a simple hostname or a short form of an FQDN).
## Viewing Related Hostname Information (using hostnamectl)

Example Usage:
`hostnamectl`

What it does:
Displays information about the system's hostname, including the static, transient, and pretty hostnames. This provides a comprehensive view of how the hostname is configured.

Command-line Arguments Explained:
- `hostnamectl`: The command to display hostname-related information using `systemd`.
- (No arguments) When no arguments are given, `hostnamectl` displays the system's current hostname configuration.
## Getting the FQDN (Fully Qualified Domain Name)

Example Usage:
`hostname -f`

What it does:
Displays the fully qualified domain name (FQDN) of the system, if one is configured.

Command-line Arguments Explained:
- `-f`: Option for the `hostname` command that specifies the retrieval of the FQDN.
## Getting the Short Hostname

Example Usage:
`hostname -s`

What it does:
Displays the short hostname (the part of the hostname before the first dot).

Command-line Arguments Explained:
- `-s`: Option for the `hostname` command to display the short hostname.
## Checking the Kernel's Hostname

Example Usage:
`hostname -k`

What it does:
Displays the kernel's hostname. This is usually the same as the current hostname but can differ in certain situations.

Command-line Arguments Explained:
- `-k`: Option for the `hostname` command to display the kernel's hostname.
## Displaying Hostname Information (Alternative Format)

Example Usage:
`hostname -i`

What it does:
Displays the IP address(es) associated with the hostname. This is useful for quickly determining a server's IP.

Command-line Arguments Explained:
- `-i`: Option for `hostname` command to display the IP addresses associated with the hostname.