po-debconf(7)
NAME
po-debconf - introduction
DESCRIPTION
The goal of "debconf" was to make package configuration user-friendly.
In order to achieve this, it is important to ensure that users will get
the question in their own language. Translators need a framework to
easily work on translations without having to track package
development; "po-debconf" was designed to be able to work with standard
"gettext" tools when translating debconf templates files.
ADDING I18N SUPPORT TO DEBCONF TEMPLATES FILES
If you are adding debconf support to your package, you have written a
templates file containing English text. To add proper i18n support
into your package, you need to:
- Create debian/po/POTFILES.in
This file contains the list of master templates. It typically
contains a single line:
[type: gettext/rfc822deb] templates
Paths are relative to the parent directory.
- Prepend an underscore before translatable fields in each template
Normally "Description", "Choices" and sometimes "Default" fields
can be translated.
- Run debconf-updatepo
This will create the debian/po/templates.pot file that translators
will translate into their language.
- Add a build dependency on "po-debconf" in debian/control
UPDATE TEMPLATES
In order to help translators, PO files in your package should always be
up-to-date, otherwise they may waste their time translating unused
strings. For that, simply call the following command without
arguments:
$ debconf-updatepo
You should run this command every time you change templates in English,
but also when you receive new or updated translations, because
translators may have worked on an obsolete PO file.
If you rename, add or remove some templates files, remember also to
edit debian/po/POTFILES.in accordingly, otherwise English strings are
missing from PO files and will be displayed to users even if PO files
are fully translated.
The debconf-updatepo program is idempotent, it modifies PO files only
if their content has been updated. Thus the best way to provide up-to-
date PO files in your source package is to call this command from the
"clean" target of the debian/rules file.
Please note that you need to run debconf-updatepo even if you use
dh_installdebconf. The latter calls po2debconf which used to call
debconf-updatepo if outdated files were detected, but this is no more
the case because it was not a good solution for at least two reasons:
1. po2debconf relied on timestamps to detect outdated files, and may be
abused when using "pbuilder" or if an outdated translation has been
stored on disk after templates have been modified
2. dh_installdebconf is called long after ".diff.gz" file has been
generated
MERGE TRANSLATIONS AND ORIGINAL
You have to make sure that when your package is compiled, translations
will get into the built package. You can do that manually, or
automatically using the dh_installdebconf script (make sure to have a
versioned build dependency against "debhelper (>= 4.1.16)").
To do that manually, you'll have to merge the templates and the
translations at compile time (and to have a build depend against
"po-debconf") like this:
$ po2debconf debian/templates > debian/tmp/DEBIAN/templates
BE CAREFUL: the two files called templates are not the same at all.
The first one contains only the English text, with marks to denote some
fields to be translated while the second contains all languages. That
is to say that you CANNOT keep only the merged templates, or you won't
be able to deal with translations as people submit them to you.
NEW MASTER TEMPLATES
The new templates file source format is almost identical to one of
distributed templates files, but translatable fields are prepended with
an underscore. Example:
Template: debconf/frontend
Type: select
_Choices: Dialog, Readline, Gnome, Editor, Noninteractive
Default: Dialog
_Description: Interface to use for configuring packages:
Packages that use debconf for configuration share a common look and
feel. You can select the type of user interface they use.
.
The dialog frontend is a full-screen, character based interface,
while the readline frontend uses a more traditional plain text
interface, and the gnome frontend is a modern X interface. The
editor frontend lets you configure things using your favorite text
editor. The noninteractive frontend never asks you any questions.
SPLITTING CHOICES LIST
Since "po-debconf" 0.6.0, localized fields may contain two leading
underscores. In this case, the field value is supposed to be a comma
separated list of values, which are put in separate msgids. Thus if
the previous example did contain
__Choices: Dialog, Readline, Gnome, Editor, Noninteractive
there would be 5 different msgids. Note that spaces after commas are
not significant.
When a choices list never changes, "_Choices" may be considered fine.
However, splitting such lists may help avoiding frequent mistakes in
translations such as omitting a choice or using non-standard commas.
For such reasons, the use of "__Choices" will ease translator's life
and is strongly recommended.
Unfortunately if you decide to switch from "_Choices" to "__Choices",
all translations become fuzzy. Here is an explanation to make this
change without translation loss (it requires "po-debconf" >= 1.0).
Suppose that we want to switch the previous example to "__Choices".
You copy the templates file into a temporary file.
$ cp debian/templates debian/foo
Edit debian/foo and keep only "Template", "Type" and "_Choices" fields,
which are in this example
Template: debconf/frontend
Type: select
_Choices: Dialog, Readline, Gnome, Kde, Editor, Noninteractive
Run debconf-gettextize with "--merge" and "--choices" flags to build PO
files as if "__Choices" was written, and merge these PO files to
existing ones:
$ debconf-gettextize --merge --choices debian/foo
Eventually you have to remove foo and manually edit debian/templates to
replace "_Choices" by "__Choices" before debconf-updatepo is run.
PUTTING IN COMMENTS FOR TRANSLATORS
"Dpkg" maintainers decided that by convention lines beginning with a
number sign ("#") are comments in debian/control files, and
"po-debconf" follows this rule. Since "po-debconf" 0.8.0, such
comments are written into PO files, and can then contain valuable
information for translators. Incidentally all previous "po-debconf"
versions ignore lines which do not contain a colon, thus if your
comments does not contain any colons, there is no need to add a
versioned build dependency against "po-debconf". Here is an example:
Template: debconf/button-yes
Type: text
# Translators, this text will appear on a button, so KEEP IT SHORT
_Description: Yes
Special comments have been introduced in "po-debconf" 1.0 to deal with
strings which are composed of several items (as with Choices field) or
paragraphs (like Description). With these directives, developers have
a better control over what is exposed to translators. They are in the
form "#flag:directive"; directives are detailed below.
translate:spec, translate!:spec
Mark only some items as translatable; spec is a comma separated list
of numbers, it specifies which strings will be printed into PO
files. Ranges can also be defined via a minus sign (for instance
"2-6"), and a star ("*") means all strings. For instance, with
Template: partman-basicfilesystems/fat_mountpoint
Type: select
#flag:translate:3,4
__Choices: /dos, /windows, Enter manually, Do not mount it
_Description: Mount point for this partition:
"Enter manually" and "Do not mount it" will appear in PO files but
not "/dos" and "/windows". When an exclamation mark follows the
translate keyword, spec specifies which strings will be discarded
from PO files, all other strings are printed. Previous example is
similar to
Template: partman-basicfilesystems/fat_mountpoint
Type: select
#flag:translate!:1,2
__Choices: /dos, /windows, Enter manually, Do not mount it
_Description: Mount point for this partition:
The same keyword can also be applied to the Description field to
make sure that some strings are not translated.
Template: partman-crypto/options_missing
Type: error
#flag:translate!:3
_Description: Required encryption options missing
The encryption options for ${DEVICE} are incomplete. Please
return to the partition menu and select all required options.
.
${ITEMS}
But this is hazardous because context may be dropped from PO files,
please add comments in this case so that translators are not
confused.
comment:spec, comment!:spec
The comment just below this directive applies to the strings
specified by spec, which is defined above. By default, a comment
written before a translatable field is printed along with all
strings belonging to this field. (Note: with "po-debconf" < 1.0,
the comment was printed only with the first string)
Template: arcboot-installer/prom-variables
Type: note
# Translators, the 4th string of this description has been dropped
# from PO files. It contains shell commands and should not be
# translated.
#flag:comment:3
# "Stop for Maintenance" should be left in English
#flag:translate!:4
_Description: Setting PROM variables for Arcboot
If this is the first Linux installation on this machine, or if the
hard drives have been repartitioned, some variables need to be set
in the PROM before the system is able to boot normally.
.
At the end of this installation stage, the system will reboot.
After this, enter the command monitor from the "Stop for
Maintenance" option, and enter the following commands:
.
setenv OSLoader arcboot
setenv OSLoadFilename Linux
.
You will only need to do this once. Afterwards, enter the "boot"
command or reboot the system to proceed to the next stage of the
installation.
The example above has a comment without "#flag:comment" directive,
where an implicit "#flag:comment:*" is added. This comment appears
with all strings, but the one about Stop for Maintenance is printed
only before the relevant string.
partial
This keyword tells po2debconf to keep translated strings even if all
strings have not been translated. Please use with caution, this
keyword has been introduced for very specific purposes.
GIVING NOTICES TO TRANSLATORS BEFORE UPLOADING
Usually translators notice on the status web pages (see below) that
translations are outdated, and send patches which will be included in
future uploads. But developers are encouraged to ask maintainers of
outdated translations for an update before an upload, for instance one
week in advance. A dedicated tool, podebconf-report-po, has been
written for this purpose. Do not hesitate to abuse it!
DEBUGGING
You will find that debconf-loadtemplate will not accept a templates
file with i18n markups. However, it will accept a merged file, so if
you have been debugging your debconf setup like this
rm /tmp/{config,templates}.dat{,-old}
debconf-loadtemplate debian/templates
DEBIAN_PRIORITY=low debconf -freadline debian/config configure 28.0
you will now need something like this instead:
po2debconf debian/templates > debian/tmp/DEBIAN/templates
rm /tmp/{config,templates}.dat{,-old}
debconf-loadtemplate debian/tmp/DEBIAN/templates
DEBIAN_PRIORITY=low debconf -freadline debian/config configure 28.0
CAVEATS
* "Debconf" 1.2.0 recognizes fields in the form Name-lang.encoding,
e.g. "Description-de.ISO-8859-1" or "Choices-ru.KOI8-R". By default
po2debconf writes templates files in that new format. Older
"debconf" will ignore these fields, and English text is displayed.
See po2debconf(1) to know how to change encoding and output format.
* A given English string may be given only one unique translation in a
given language. It is impossible to give two different translations,
depending on the context. To solve this issue, you have to add
special markups to the different occurrences of a given string to
make them different. (These markers will only be visible to
translators, and they will be removed from the string before being
displayed to user)
Such markers must be added to the end of the strings to translate,
they must start with "[ " (a left bracket followed by a space) and
end with "]" (right bracket), and may contain any character but
brackets or new lines. For example "[ blahblah]" is a valid marker
while "[ bla[bla]bla]" isn't. For Perl regexp addicts, the markers
are recognized (and removed) using this rule:
$msg =~ s/\[\s[^\[\]]*\]$//s;
* Spacing is not handled exactly the same way by "po-debconf" and
"debconf-utils"; with the latter, paragraphs are reformatted when
updating and merging translations, so "debconf-utils" is very smart
and spaces are not considered as being part of strings when
determining fuzzy entries. (i.e., the ones needing translator's
attention because the original changed)
On the other hand "po-debconf" relies on "gettext" to detect fuzzy
entries, and it does not treat spaces as special characters. Thus
superfluous spaces must be removed at end of lines in master
templates files, or they will appear in PO and POT files.
For the same reason, debconf-gettextize can mark text fuzzy because
of mismatch with space characters, and translators have to manually
unfuzzy such strings. This only happens once when converting
templates to "po-debconf" format, unless you randomly change spaces
in master templates files, which will be painful for translators.
* Normally the Default: field must not be translated when template type
is Select or Multiselect. Under rare circumstances (e.g. when
selecting the default language for an application) localized values
may be meaningful.
The localized value must not be translated, but chosen from the
English values listed in the Choices field. The best way to achieve
this goal is to insert a comment in your templates file which will be
copied into PO files.
Template: geneweb/lang
Type: select
__Choices: Danish (da), Dutch (nl), English (en), Esperanto (eo)
# You must NOT translate this string, but you can change its value.
# The comment between brackets is used to distinguish this msgid
# from the one in the Choices list; you do not have to worry about
# them, and have to simply choose a msgstr among the English values
# listed in the Choices field above, e.g. msgstr "Dutch (nl)"
_Default: English (en)[ default language]
_Description: Geneweb default language
The default value also appears in the Choices field, and both have
different translations: the former is an untranslated value chosen
among Choices values, whereas the latter is a normal translation. As
"gettext" cannot have two different translations for the same msgid,
both msgids must be different by using bracketed comments as
described in a previous subsection.
Prior to "po-debconf" 0.8.0, such comments were not available and
maintainers had to replace the _Default: field by _DefaultChoice: in
order to highlight such fields in PO files:
#. DefaultChoice
msgid ""
"English[ default: do not translate bracketed material, put your "
"own language here but UNTRANSLATED. If it is not in the list, "
"put English (without bracketed material)]"
msgstr ""
"Swedish"
Plain comments in templates files are less error prone and are
encouraged.
STATUS WEB PAGES
Statistics for "po-debconf" translations are available at
<http://www.debian.org/intl/l10n/po-debconf/> (or from mirrors); they
are automatically updated when new packages are uploaded. Only
packages shipping debian/po/templates.pot and debian/po/POTFILES.in
files are considered, so you should make sure your source package
provides them.
Translators can grab PO and POT files from there, but they must always
get in touch with the previous translator (her mail address can be
found in the PO file) and/or their fellow translators on
debian-l10n-<language>@lists.debian.org (if such a list does exist) to
make sure that no one is currently working on the same translation, and
read current bugreports against the package they are going to translate
to see if a translation has already been reported.
After translating these files, they should submit their work to the
maintainer as bug report of severity wishlist with the patch tag.
SEE ALSO
debconf-gettextize(1), debconf-updatepo(1), dh_installdebconf(1),
podebconf-report-po(1), po2debconf(1), debconf-devel(7).
AUTHORS
Martin Quinson <Martin.Quinson@ens-lyon.fr>
Denis Barbier <barbier@linuxfr.org>
2016-10-01 PO-DEBCONF(7)
Free and Open Source Software