Notes on National Language Support (NLS)

This package is internationalized with libintl-perl, a free
internationalization library for Perl, you will need to install a copy of
libintl-perl in order to use the package.  You can get libintl-perl from the
Comprehensive Perl Archive Network CPAN at

The following notes are meant to be a quick start guide for somewhat
experienced users and system administrators and many important details had to
be omitted for brevity.  If you have any difficulties with the
internationalization features of this package, no matter if you are a
programmer, a translator, or an end user, feel free to ask at the mailing list
for libintl-perl.  To do so, send an e-mail to the address 
<libintl-perl AT imperia DOT net> (please replace "AT" with a "@", and "DOT"
with a dot ".").

You can subscribe to this list at

A searchable archive of earlier postings is located at

You may already find an answer to your question there.

Feel free to include this document in your own Perl packages internationalized
with libintl-perl, no severe copyright restrictions apply.  You should send
corrections or improvements to the author Guido Flohr <guido AT imperia DOT
net>, so that others can benefit from your changes.

The End User's View

The installation routine for this package will automatically take care that
your system has a sufficient version of libintl-perl installed.  This is
basically sufficient for proper operation, but - especially if
internationalized software is new to you - you should read on carefully in
order to fully benefit from the internationalization (I18N) features of this

Perl Setup

The I18N library libintl-perl will run with a wide range of Perl versions (at
least from Perl version 5.005_03 to Perl 5.8.0) but you will experience slight
difference in features and performance depending on the version of Perl you

With Perl versions prior to 5.7.3 you can use the package for all European
scripts (including those with Greek or Cyrillic scripts), and also for many
scripts used outside Europe, like Arabic, Hebrew, Georgian, Vietnamese or
Thai, more general all scripts using 8 bit charsets.  Other scripts are only
available if the translations in this package are provided in Unicode and they
can only be output in Unicode.

Beginning with Perl 5.7.3 the module Encode became part of the Perl core, and
it offers you a much wider range of possible scripts.  If you plan to use some
of the lesser used scripts for Chinese, Japanese, and Korean, you should also
install the module Encode::HanExtra.

Setting Your Language

Most modern systems are already prepared and configured for
internationalization, and the user interface of the software you have
installed will already be configured for your preferred language.  Packages
internationalized with libintl-perl will honor these configuration settings
and will also operate in your preferred language if the necessary translations
are available.

The environment variable "LANGUAGE" has the highest precedence for
translations.  The most common format for this environment variable is a
(lowercase) two-letter language code and an (uppercase) two-letter country
code separated by an underscore "_", for example:

     export LANGUAGE

This will set your language preferences to French ("fr") for Belgium ("BE").
Other examples are French for France ("fr_FR"), German for Austria ("de_AT"),
and so on.  You can also omit the country part ("FR", "DE", "IT", "RU", ...)
in which case a default setting for the country will be assumed.

If there are no translations available for your selected languages, the
original message (normally in English) will be displayed.

You can also define a chain of languages to be tried separated by a colon:


Read this as: "I want translations in French for Belgium.  If they are not
available try French for France, then any French translation, and finally
Italian".  Please note that this chain notation is only allowed for the
environment variable "LANGUAGE", it is not valid for any of the following

If "LANGUAGE" is not set, the library checks the variable "LANG".  It has the
same syntax as "LANGUAGE" but does not allow the preferences chain with the
colon syntax.  After "LANG" the variable "LC_MESSAGES" (think "locale category
messages") is tried, and finally "LC_ALL".

Note for Microsoft Windows users: The locale preferences you have configured
for your system cannot yet be evaluated by libintl-perl.  This may change for
future versions of libintl-perl but for the moment you have to make do with
the instructions given above.  In order to set environment variables, you have
to right-click on the icon "My Computer" on your desktop, select "Properties"
in the context menu, and then click the tab labelled "Environment variables".

Setting the Output Charset

Even if you have managed to properly select your preferred language, you may
still have difficulties reading the program languages, because libintl-perl
was unable to determine the correct charset to use for messages.  For example,
it may assume Unicode ("UTF-8") but you really need ISO-Latin-1 (also known as
"Latin-1" or "ISO-8859-1").  If this is the case, please set the environment
variable "OUTPUT_CHARSET" to the appropriate value, for example:

     export OUTPUT_CHARSET

Charset names are case-insensitive, i. e. "LATIN-1" is the equivalent to
"Latin-1" or even "lAtIn-1".

Note: The output charset "utf8" is NOT recognized.  Please use the correct
abbreviation "utf-8" (with a hyphen) instead.

The Translator's View

If you want to contribute a new translation to this package, please contact
the author first.  Somebody may have already started this translation, and
furthermore the package author will be able to give you detailled instructions
and help.

Translating a Perl package is not much work and it does not require any
technical skills.  If you are able to use the software itself, you will also
be able to contribute a translation for your language.  But why should you do
that? You are able to read and understand this text and you will also be able
to understand the English messages that the software spits out by default.

Computers are an integral part of today's society.  Computers are used to
explore new sources of information, forbidding computers would be a modern
form of censorship.  Computers may also improve social life, the internet
helps people to find contacts in their area and all over the world, even if
they would otherwise be deprived from that because of a handicap, lack of money
for traveling, or other reasons.  In many societies, the ability to use and 
handle a computer also has a strong impact on your perspectives in life, you 
may not be able to find an adequate job because of your lack of computer 
experience, or you may even lose your job because of that.

Everybody should benefit from computers, regardless of cultural
background. Computers are expansive goods, and their price is already a high
barrier to cross.  If computers speak in a foreign language, the learning
curve gets steeper and the barrier gets even higher.  You can help the people
that share your native language by contributing a translation.  The author of
this package has already prepared everything, the rest is up to you!

The Programmer's View

You have downloaded this package because you want to use it in your own
project(s).  The fact that the package is internationalized with libintl-perl
does not affect its usability in any way.  But you should keep in mind that
textual messages produced by the package may change according to the locale
settings at run-time.  This can lead to errors.  For example, if you parse
error messages produced by the package, you will most probably fail to detect
what you are looking for, if these error messages are suddenly presented in
another language or another output charset.

It is probably needless to say that this is bad practice and an indicator for
a poorly written interface.  Either you have missed the correct method for
determining the substance of the message in a locale-independent manner, or
the author of the package has mis-designed the package interface.  In any
case, this is a technical problem that should be solved by technicians.  You
should not put that burden on the shoulders of your users but rather solve the
problem in cooperation with the author of the module that causes it.

If this is absolutely impossible, as a temporary workaround you can completely
switch off the native language support of the package by setting the
environment variable "LANGUAGE" to the special value "C":

     BEGIN {
         $ENV{LANGUAGE} = $ENV{LANG} = "C";

The value "C" instructs libintl-perl to leave all messages untouched, and you
can use the package as if it was not internationalized at all.

If the project you are working on is not yet internationalized, you should
consider to prepare it for internationalization now.  Doing so is only little 
work for yourself, but results in a large benefit for the users of your 
software.  The package "libintl-perl" ships with exhaustive documentation for
programmers and a sample package that you can use as a skeleton for your own
project(s).  Internationalizing Perl software with libintl-perl is easy, the
package that this file is a part of, prooves that.

Guido Flohr