`hostname` “hostname” command

Overview

The hostname command displays or sets the system hostname. When called without arguments, it prints the current hostname. When called with a hostname argument, it sets the system hostname to the specified value.

The hostname is stored in the kernel and can be retrieved by applications using the gethostname() system call. It is typically used to identify the system on a network and in shell prompts.

Configuration

Enable the command with CONFIG_SYSTEM_HOSTNAME. This option has no additional dependencies.

Usage

hostname

Display the current system hostname.

hostname <hostname>

Set the system hostname to <hostname>.

hostname -F <file>

Read the hostname from the specified file and set it as the system hostname.

Options

-F <file>: Read the hostname from the specified file. The first line of the file is used as the hostname. Trailing newlines are stripped.
-h: Display usage information and exit.

Examples

Display the current hostname:

nsh> hostname
nuttx

Set a new hostname:

nsh> hostname mydevice
nsh> hostname
mydevice

Read hostname from a file:

nsh> cat /etc/hostname
embedded-device
nsh> hostname -F /etc/hostname
nsh> hostname
embedded-device

Display usage information:

nsh> hostname -h
Usage: hostname [<hostname>|-F <file>]

Notes

The hostname must be between 1 and HOST_NAME_MAX characters long.
Setting an empty hostname or a hostname longer than HOST_NAME_MAX will result in an error.
The hostname is stored in the kernel and persists until the system is rebooted or the hostname is changed again.
The -F option reads only the first line of the specified file and strips any trailing newline characters.
If both a hostname argument and the -F option are provided, the -F option takes precedence.

hostname “hostname” command