po4a(1) update both the PO files and translated documents in one shot


po4a [options] config_file


The po4a (PO for anything) project goal is to ease translations (and more interestingly, the maintenance of translations) using gettext tools on areas where they were not expected like documentation.

The po4a program is useful if you want to avoid calling po4a-gettextize(1), po4a-updatepo(1), and po4a-translate(1) in complex Makefiles when you have multiple files to translate, different format, or need to specify different options for different documents.

Table of content

This document is organized as follow:




Specifying the template languages

Specifying the paths to translator inputs

Autodetection of the paths and languages

Specifying the documents to translate

Specifying options for the modules

Specifying aliases

Split mode







The po4a program is in charge of updating both the PO files (to sync them to the original documents) and the translated documents (to sync them to the PO files). The main point is to make the use of po4a easier without having to remember of the command line options.

It also allows you to mix documents having different formats into the same POT file so that you can have only one such file per project.

This behaviour can be mimicked by the other tools of the po4a suite (for example with Makefiles), but it is rather difficult to do, and exhausting to redo the same complicated Makefiles for each project using po4a.

The dataflow can be summarized as follow. Any changes to the master document will be reflected in the PO files, and all changes to the PO files (either manual or caused by previous step) will be reflected in translation documents.

 master document --> PO files --> translations

The dataflow cannot be inversed in this tool, and changes in translations are overwritten by the content of the PO files. As a matter of fact, this tool cannot be used to convert existing translations to the po4a system. For that task, please refer to po4a-gettextize(1).


The (mandatory) argument is the path to the configuration file to use. Its syntax aims at being simple and close to the configuration files used by the intl-tools projects.

Comments in this files are noted by the char '#'. It comments everything until the end of the line. Lines can be continued by escaping the end of line. All non blank lines must begin with a [] command, followed by its arguments. (sound difficult said that way, but it is rather easy, I hope ;)

Specifying the template languages

Note: It is recommended to use [po_directory] rather than [po4a_langs] and [po4a_paths]. See section Autodetection of the paths and languages below.

This is an optional command that can simplify the whole config file, and will make it more scalable. You have to specify a list of the languages in which you want to translate the documents. This is as simple as:

 [po4a_langs] fr de

This will enable you to expand $lang to all the specified languages in the rest of the config file.

Specifying the paths to translator inputs

Note: It is recommended to use [po_directory] rather than [po4a_langs] and [po4a_paths]. See section Autodetection of the paths and languages below.

First, you have to specify where the translator input files (i.e. the files used by translators to do their job) are located. It can be done by such a line:

 [po4a_paths] doc/l10n/project.doc.pot \
              fr:doc/l10n/fr.po de:doc/l10n/de.po

The command is thus [po4a_paths]. The first argument is the path to the POT file to use. All subsequent arguments are of the self-explanatory form:

    <lang>:<path to the PO file for this lang>

If you've defined the template languages, you can rewrite the line above this way:

 [po4a_paths] doc/l10n/project.doc.pot $lang:doc/l10n/$lang.po

You can also use $master to refer to the document basename. In this case, po4a will use a split mode: one POT and one PO (for each language) will be created for each document specified in the po4a configuration file. See the Split mode section.

 [po4a_paths] doc/$master/$master.pot $lang:doc/$master/$lang.po

Autodetection of the paths and languages

Another command can be used to specify the name of a directory where the PO and POT files are located. When it is used, po4a will detect the POT file as the only *.pot file from the specified directory. po4a will also use the list of *.po files to define the list of languages (by stripping out the extension). These languages will be used for the substitution of the $lang variable in the rest of the configuration file.

This command should not be used together with the [po4a_langs] or [po4a_paths] commands.

When using this command, you have to create an empty POT file on the first invocation of po4a to let it know the name of the POT file.

 [po_directory] po4a/po/

Specifying the documents to translate

You now naturally have to specify which documents are translated, their format, and where to put the translations. It can be made by such lines:

 [type: sgml] doc/my_stuff.sgml fr:doc/fr/mon_truc.sgml \
 [type: pod] script fr:doc/fr/script.1 de:doc/de/script.1 \

This should be rather self-explanatory also. Note that in the second case, doc/l10n/script.fr.add is an addendum to add to the French version of this document. Please refer to po4a(7) for more information about the addenda.

More formally, the format is:

 [type: <format>] <master_doc> (<lang>:<localized_doc>)* \

If there is no modifier, addendum_path is a path to an addendum. Modifiers are

Include addendum_path if this file does exist, otherwise do nothing.
addendum_path is not a regular addendum but a file containg a list of addenda, one by line. Each addendum may be preceded by modifiers.
addendum_path is discarded, it is not loaded and will not be loaded by any further addendum specification.

If you've defined the template languages, you can rewrite the line above this way:

 [type: pod] script $lang:doc/$lang/script.1 \

If all the languages had addenda with similar paths, you could also write something like:

 [type: pod] script $lang:doc/$lang/script.1 \

Specifying options for the modules

po4a accepts options that will be passed to the module. These options are module specific and are specified with the -o switch.

If you need a specific option for one of the document you want to translate, you can also specify it in the configuration file. Options are introduced by the opt keyword. The argument of the opt keyword must be quoted with double quotes if it contains a space (e.g. if you specify multiple options, or an option with an argument). You can also specify options that will only apply to a specific language by using the opt_lang keyword.

Here is an example:
 [type:man] data-05/test2_man.1 $lang:tmp/test2_man.$lang.1 \
            opt:``-k 75'' opt_it:``-L UTF-8'' opt_fr:-v

Arguments may contain spaces if you use single quotes or escaped double quotes:
 [po4a_alias:man] man opt:``-o \''mdoc=NAME,SEE ALSO\`` -k 20''

If you want to specify the same options for many documents, you may want to use an alias (see the Specifying aliases section below).

You can also set options for all the documents specified in the configuration file:
 [options] opt:``...'' opt_fr:``...''

Specifying aliases

If you must specify the same options for multiple files, you may be interested in defining a module alias. This can be done this way:

[po4a_alias:test] man opt:``-k 21'' opt_es:``-o debug=splitargs''

This defines a module alias named test, based on the man module, with the -k 21 applied to all the languages and with -o debug=splitargs applied to the Spanish translation.

This module alias can then be use like a regular module:

[type:test] data-05/test2_man.1 $lang:tmp/test2_man.$lang.1 \
            opt_it:``-L UTF-8'' opt_fr:-v

Note that you can specify additional options on a per file basis.

Split mode

The split mode is used when $master is used in the [po4a_paths] line.

When the split mode is used, a temporary big POT and temporary big POs are used. This permits to share the translations between all the POs.

If two POs have different translations for the same string, po4a will mark this string as fuzzy and will submit both translations in all the POs which contain this string. Then, when a translator updates the translation and removes the fuzzy tag in one PO, the translation of this string will be updated in every POs automatically.


-k, --keep
Minimal threshold for translation percentage to keep (i.e. write) the resulting file (default: 80). I.e. by default, files have to be translated at at least 80% to get written.
-h, --help
Show a short help message.
-M, --master-charset
Charset of the files containing the documents to translate. Note that all master documents must use the same charset for now. This is a known limitation, and we are working on solving this.
-L, --localized-charset
Charset of the files containing the localized documents. Note that all translated documents will use the same charset for now. This is a known limitation, and we are working on solving this.
-A, --addendum-charset
Charset of the addenda. Note that all the addenda should be in the same charset.
-V, --version
Display the version of the script and exit.
-v, --verbose
Increase the verbosity of the program.
-q, --quiet
Decrease the verbosity of the program.
-d, --debug
Output some debugging information.
-o, --option
Extra option(s) to pass to the format plugin. Specify each option in the 'name=value' format. See the documentation of each plugin for more information about the valid options and their meanings.
-f, --force
Always generate the POT and PO files, even if po4a considers it is not necessary.

The default behavior (when --force is not specified) is the following:

If the POT file already exists, it is regenerated if a master document or the configuration file is more recent. The POT file is also written in a temporary document and po4a verifies that the changes are really needed.

Also, a translation is regenerated only if its master document, the PO file, one of its addenda or the configuration file is more recent. To avoid trying to regenerate translations which do not pass the threshold test (see --keep), a file with the .po4a-stamp extension can be created (see --stamp).

If a master document includes files, you should use the --force flag because the modification time of these included files are not taken into account.

The PO files are always re-generated based on the POT with msgmerge -U.

Tells po4a to create stamp files when a translation is not generated because it does not reach the threshold. These stamp files are named according to the expected translated document, with the .po4a-stamp extension.

Note: This only activates the creation of the .po4a-stamp files. The stamp files are always used if they exist, and they are removed with --rm-translations or when the file is finally translated.

Do not generate the translated documents, only update the POT and PO files.
Remove the translated files (implies --no-translations).
This flag does nothing since 0.41, and may be removed in later releases.
This flag does nothing since 0.41, and may be removed in later releases.
--translate-only translated-file
Translate only the specified file. It may be useful to speed up processing if a configuration file contains a lot of files. Note that this option does not update PO and POT files. This option can be used multiple times.
--variable var=value
Define a variable that will be expanded in the po4a configuration file. Every occurrence of $(var) will be replaced by value. This option can be used multiple times.
--msgid-bugs-address email@address
Set the report address for msgid bugs. By default, the created POT files have no Report-Msgid-Bugs-To fields.
--copyright-holder string
Set the copyright holder in the POT header. The default value is ``Free Software Foundation, Inc.''
--package-name string
Set the package name for the POT header. The default is ``PACKAGE''.
--package-version string
Set the package version for the POT header. The default is ``VERSION''.
--msgmerge-opt options
Extra options for msgmerge.

Note: $lang will be extended to the current language.

This option removes --previous from the options passed to msgmerge. This permits to support versions of gettext earlier than 0.16.
This option adds --previous to the options passed to msgmerge. It requires gettext 0.16 or later, and is activated by default.
--srcdir SRCDIR
Set the base directory for all input documents specified in the po4a configuration file.
--destdir DESTDIR
Set the base directory for all the output documents specified in the po4a configuration file.


Let's assume you maintain a program named foo which has a man page man/foo.1 which naturally is maintained in English only. Now you as the upstream or downstream maintainer want to create and maintain the translation. First you need to create the POT file necessary to send to translators using po4a-gettextize(1).

So for our case we would call

 cd man && po4a-gettextize -f man -m foo.1 -p foo.pot

You would then send this file to the appropriate language lists or offer it for download somewhere on your website.

Now let's assume you received three translations before your next release: de.po (including an addendum de.add), sv.po and pt.po. Since you don't want to change your Makefile(s) whenever a new translation arrives you can use po4a with an appropriate configuration file in your Makefile. Let's call it po4a.cfg. In our example it would look like the following:

 [po_directory] man/po4a/po/
 [type: man] man/foo.1 $lang:man/translated/$lang/foo.1 \
            add_$lang:?man/po4a/add_$lang/$lang.add opt:"-k 80"

In this example we assume that your generated man pages (and all PO and addenda files) should be stored in man/translated/$lang/ (respectively in man/po4a/po/ and man/po4a/add_$lang/) below the current directory. In our example the man/po4a/po/ directory would include de.po, pt.po and sv.po, and the man/po4a/add_de/ directory would include de.add.

Note the use of the modifier ? as only the German translation (de.po) is accompanied by an addendum.

To actually build the translated man pages you would then (once!) add the following line in the build target of the appropriate Makefile:

        po4a po4a.cfg

Once this is set up you don't need to touch the Makefile when a new translation arrives, i.e. if the French team sends you fr.po and fr.add then you simply drop them respectively in man/po4a/po/ and man/po4a/add_fr/ and the next time the programm is build the French translation is automatically build as well in man/translated/fr/.

Note that you still need an appropriate target to install localized manual pages with English ones.

Finally if you do not store generated files into your version control system, you will need a line in your clean target as well:
        -rm -rf man/translated


  • Duplicates some code with the po4a-* programs.

Patch welcome ;)


 Denis Barbier <[email protected]>
 Nicolas Francois <[email protected]>
 Martin Quinson (mquinson#debian.org)


Copyright 2002-2012 by SPI, inc.

This program is free software; you may redistribute it and/or modify it under the terms of GPL (see the COPYING file).