Linux System Variables

Date, time, language

Locale, Date & Time

Locale

In Linux, a locale is a set of environment variables that defines the language, country, and character encoding settings for a user's environment. Locales affect various aspects of a program's behavior, such as the way dates and times are displayed, the format of numbers, the sort order of strings, and the language used for messages.

------------------------------------------------------------------------------------------------------------------------------------------------

View locale configuration

localectl

and

locale

View specific locale variable option

locale LC_NUMERIC

View available locales

localectl list-locales

------------------------------------------------------------------------------------------------------------------------------------------------

Setting locale
localectl set-locale LANG=fr_FR.utf8

(reboot may be required)

====================================================================================

Time

------------------------------------------------------------------------------------------------------------------------------------------------

Check system time
date

or for more detail

timedatectl

------------------------------------------------------------------------------------------------------------------------------------------------

NTP

View current NTP configuration:
timedatectl show-timesync --all
Enable NTP
timedatectl set-ntp on
Disable NTP
timedatectl set-ntp off
NTP Server selection

Most mainstream Linux distributions come with NTP servers preconfigured, these can be altered however, this is done via the /etc/systemd/timesync.conf file. Simply add a new line to the file formatted as follows:

NTP=NTPSERVERHOSTNAME

------------------------------------------------------------------------------------------------------------------------------------------------

Timezone

Check available timezones
timedatectl list-timezones
Set server timezone
timedatectl set-timezone timezonename

------------------------------------------------------------------------------------------------------------------------------------------------

Hostname

Show current server hostname:
hostname
Show current server hostname, and other useful info:
hostnamectl status

example output:

root@test:~# hostnamectl status
 Static hostname: test
       Icon name: computer-vm
         Chassis: vm
      Machine ID: 8c1d97558b594586af68685af4a049c9
         Boot ID: c2478c600d2b43f0bf58682f1df01013
  Virtualization: kvm
Operating System: Ubuntu 22.04.3 LTS
          Kernel: Linux 5.15.0-106-generic
    Architecture: x86-64
 Hardware Vendor: QEMU
  Hardware Model: Standard PC _i440FX + PIIX, 1996_

Change server hostname: