How to install/change locale on Debian?

Edit /etc/default/locale and set the contents to:

LANG="nl_NL.UTF-8"

You can check which locales you currently have generated using:

locale -a

You can generate more by editing /etc/locale.gen and uncommenting the lines for the locales that you want to enable. Then you can generate them by running the command:

locale-gen

You can find a list of supported locales in /usr/share/i18n/SUPPORTED

There is more information available on the Debian wiki.

You may need to install the locales package. This will ask you which locales to generate. If it's already installed, then dpkg-reconfigure locales will let you generate more locales.

Answers here are incomplete as with most elsewhere. After piecing together information from a few places, what worked for me was to (1) make sure the locale I wanted was available (generate it if it wasn't) then (2) set locale related environment variables to desired locale.

In my case I needed en_US.UTF-8 programmatically (i.e. non-interactively) installed in a docker container. The ff accomplished what I need but it should work just fine in an interactive shell.

apt-get update

# Install locales package
apt-get install -y locales

# Uncomment en_US.UTF-8 for inclusion in generation
sed -i 's/^# *\(en_US.UTF-8\)/\1/' /etc/locale.gen

# Generate locale
locale-gen

# Export env vars
echo "export LC_ALL=en_US.UTF-8" >> ~/.bashrc
echo "export LANG=en_US.UTF-8" >> ~/.bashrc
echo "export LANGUAGE=en_US.UTF-8" >> ~/.bashrc

On the same shell, you will need to do source ~/.bashrc for the env vars to take effect immediately. You can check that locale has been configured correctly by invoking locale.

LANG=en_US.UTF-8
LANGUAGE=en_US.UTF-8
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_PAPER="en_US.UTF-8"
LC_NAME="en_US.UTF-8"
LC_ADDRESS="en_US.UTF-8"
LC_TELEPHONE="en_US.UTF-8"
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION="en_US.UTF-8"
LC_ALL=en_US.UTF-8

There were a lot of Q&A entries regarding this subject but only a few were actually helpful. Credit where credit is due:

• https://unix.stackexchange.com/a/247019/21289
• https://perlgeek.de/en/article/set-up-a-clean-utf8-environment

None of these answers worked for me, on an LXC container installed with:

lxc-create -n sse-master -t download -n sse-master -- \
    -d debian -r jessie --arch i386

I always got the following output from locale-gen, i.e. not generating any locales (none listed):

$ sudo locale-gen
Generating locales (this might take a while)...
Generation complete.

Running dpkg-reconfigure locales and selecting some locales did not update /etc/locale.gen as I expected it to.

However, when I modified that file manually and uncommented the locales that I wanted, then locale-gen started working properly:

$ sudo locale-gen
Generating locales (this might take a while)...
  en_GB.UTF-8... done
  en_US.UTF-8... done
Generation complete.

I was also able to generate locales manually like this:

sudo localedef -i en_US -f UTF-8 en_US.UTF-8
sudo localedef -i en_GB -f UTF-8 en_GB.UTF-8

But this was not a permanent solution: I found that running locale-gen without the --keep-existing option will delete all such manually-generated locales, i.e. every locale not listed (and uncommented) in /etc/locale.gen.

For a web application, it might be better to use setlocale() inside the program, rather than requiring that the system default locale be set appropriately outside. Less loose ends that way.

For those who, like me, on Ubuntu 14.04 LTS, have, somehow, no /etc/locale.gen file, you can add a new locale in /var/lib/locales/supported.d/local and then run :

sudo dpkg-reconfigure locales

You can also add the french (for example) locale this way (instead of editing /var/lib/locales/supported.d/local) :

sudo locale-gen fr_FR fr_FR.UTF-8

to add and generate the ISO-8859-1 and UTF-8 codesets of the fr_FR locale and finally type :

sudo dpkg-reconfigure locales

to finish the job

Note: Some of the commands below require root privileges, consider the use of sudo.

Basic info

According to man locale-gen, locales are set in several files.

/etc/locale.gen

The main configuration file, which has a simple format: every line that is not empty and does not begin with a # is treated as a locale definition that is to be built.

/var/lib/locales/supported.d/

A directory containing locale.gen snippets provided by language-pack packages. Do not edit these manually, they will be overwritten on package upgrades.

Comprehensive details on locales at the Arch Wiki.

Checking locales and the locale

To check the (already) generated locales, run any of the following commands (with minor output differences).

locale -a
localedef --list-archive
localectl list-locales

To check the currently used locale, run any of the following commands (with minor output differences).

locale
localectl

Setting and generating (new) locales

Locales are typically set by uncommenting lines in /etc/locale.gen, after which running locale-gen is required.

nano /etc/locale.gen # uncomment desired lines (locales)
locale-gen

This will generate locales files for each uncommented line in /etc/locale.gen (and under /var/lib/locales/supported.d/), whether they were previously generated or not.

Alternatively, the command

locale-gen <locale>

will uncomment the corresponding line in locale-gen while generating the desired locale and only this one.

Removing locales

To remove locales in /etc/locale.gen, simply comment the desired lines and regenerate the locales using locale-gen. The command locale-gen --purge <locale> doesn't do what the modifier suggests.

To remove locales under /var/lib/locales/supported.d/ is trickier. Since any file /var/lib/locales/supported.d/<code> depends on the package language-pack-<code>-base, any change on the former will be restored when the latter is updated.

Workaround. To prevent changes under /var/lib/locales/supported.d/, set files in it with the "immutable (i)" attribute. So instead of removing files, empty them. For instance:

cd /var/lib/locales/supported.d/
rm <code> && touch <code> # <code> has been emptied
lsattr <code>    # regular attributes
chattr +i <code> # adding (+) immutable
lsattr <code>    # checking attributes

Setting the locale

Setting and generating locales does not set the system locale. Any of the following commands achieves this.

echo LANG=<code> | sudo tee /etc/locale.conf # reboot (might be ignored in Ubuntu)
localectl set-locale LANG=<code>

But first you need to have needed language pack installed. On my German based VPS there was no english language pack pre-installed. So first you check that you have it installed:

aptitude install language-pack-en