Section: Po4a Tools (7)
po4a-runtime - po4a and runtime gettext translation without Autotools
also includes support for adding translation
of runtime script output messages using gettext but without requiring
the package to adopt Autotools and the typical ./configure
Using example Makefile snippets, packages can harness intltool
with minimal effort.
Documentation translation should NOT
use the same po/
as the runtime translation. Whilst runtime translation can use
directories other than po/
, it is usually easiest to go with
Just a word on packages that use scripts in multiple programming
languages. A common mix is Perl and shell. Note bene: gettext WILL
get confused and omit strings from one or other language unless file
extensions are used for whichever is the least problematic language.
When using multiple languages, experiment with various settings in
po/Makevars until you get all the strings you need in the POT file.
In particular, specifying two languages in po/Makevars can be
problematic. Instead of:
# Don't do this:
XGETTEXT_OPTIONS = -L Perl -L Shell --from-code=iso-8859-1
Consider renaming (or providing symlink(s) for) all files for one of
the languages involved and omitting the explicit -L options. The file
extension only needs to exist during the time that po/POTFILES.in
is being processed.
The --keywords option can also be useful - see the xgettext(1)
So, create your top level po/
directory and then use the example
files in /usr/share/doc/po4a/examples/
to populate it.
Must exist, even if empty. Consists of a list of translations -
each line not starting with a '#' must match an existing PO file.
E.g. if LINGUAS contains a single line, 'fr', an fr.po file
must exist alongside the LINGUAS file.
$ cat po/LINGUAS
By convention, the LINGUAS file is sorted alphabetically but that
is a manual process.
The list of files containing the messages that need to be translated
at runtime - i.e. your scripts. If you've used the top level po/
directory, the paths should be relative to the top level directory,
not the po/ directory itself.
$ ls -l
$ cat po/POTFILES.in
Note that it is explicitly supported that the scripts themselves can
contain strings for both runtime and documentation translation, e.g.
using gettext functions for runtime and embedded POD content for
documentation. So it is not a problem to have the same file listed
in po/POTFILES.in and doc/po4a-build.conf
If your scripts are in Perl, copy this example file as
po/Makevars and edit it to suit.
If your scripts are in shell, copy this example file as
po/Makevars and edit it to suit.
Copy this example file as po/Makefile - it shouldn't need editing
but you may want to keep it updated against
/usr/share/doc/po4a/examples/po4a-build.make as it may need to
be updated within po4a releases as the underlying intltool support
changes. (The file itself was generated from another project
using Autotools and intltool.)
These snippets need to be added to your top level Makefile or whatever
other method you use to prepare your sources for distribution.
$(MAKE) -C po/ clean
$(MAKE) -C po/ install DESTDIR=$(DESTDIR)
$(MAKE) -C po/ pot
(In an Autotools project, this would happen automatically by simply
adding po to the "SUBDIRS" value in Makefile.am.)
Runtime translation isn't quite as easy as po4a-build
in that adding
a new translation does require editing po/LINGUAS
, but apart from
that, updating translations is merely a case of replacing the relevant
file with the new version.
Depending on how you prepare your source tarball, you may also need
to list new PO files in the MANIFEST file or add to the script(s) that
prepare the tarball. (That also applies to po4a-build.)
Any *.mo or *.gmo files in po/ can be deleted / cleaned up.
Whilst the example files are part of the po4a project, you are free
to use, modify and distribute them in your own projects without needing
to refer back to po4a or list the po4a team in your own copyright
notices, in the same manner as other build tools like Automake itself.
If you want to mention po4a, that is fine too.
Neil Williams <email@example.com>