Getting Started with Internationalization (i18n)

gettext is the GNU internationalization (i18n) library and the standard for open source. Translators understand it and there are a variety of tools available that work with gettext data. This page provides a brief overview of the steps needed to begin internationalizing your project.

Note: If you are starting a new project, you may wish to use Linux Project Generator to help correctly set up the autoconf build files with internationalization support.

Project Code Changes

Step 1: Update header files for main
Add the following to the headers of the C module in which you have your main() function:

Step 2: main function
Add the following to the beginning of your main() function:

Step 3: Update header files
Add the following to each header where internationalized strings are used.

Step 4: String prefixes
When writing a string anywhere in code, use the following format: _( <string> ). For example, instead of:

instead use:

Step 5: Build flags
Either compile your program with -DUSE_GETTEXT or add the following near the top of the main header file:

Step 6: Generating pot and po files
The .pot file contains the list of localizable (translatable) strings. There is often a single .pot file for a project, although multiple .pot files can be generated to avoid overly large files.

Create a single .pot file:

The .pot file that is generated from the above command is the template that contains the English strings and a corresponding empty string field for the translator to add the translation. Once the translations are complete, the file is saved with a .po extension to indicate it is complete. There is one .po file for each language.

Finally, a .mo file must be created for each .po file. The .mo file is the binary version that gets integrated into the parent package.

Step 7: Installing the files
Install the .mo file in the proper directory:

For full details on internationalizing your projects check out the Internationalization Guidelines (PDF, 450KB).