The maintainer of a package has many responsibilities. One of them is ensuring that the package will install easily on many platforms, and that the magic we described earlier (see section The User's View) will work for installers and end users.
Of course, there are many possible ways by which GNU gettext
might be integrated in a distribution, and this chapter does not cover
them in all generality. Instead, it details one possible approach
which is especially adequate for many GNU distributions, because
GNU gettext is purposely for helping the internationalization
of the whole GNU project. So, the maintainer's view presented here
presumes that the package already has a `configure.in' file and
uses Autoconf.
Nevertheless, GNU gettext may surely be useful for non-GNU
packages, but the maintainers of such packages might have to show
imagination and initiative in organizing their distributions so
gettext work for them in all situations. There are surely
many, out there.
Even if gettext methods are now stabilizing, slight adjustments
might be needed between successive gettext versions, so you
should ideally revise this chapter in subsequent releases, looking
for changes.
Some GNU packages are distributed as tar files which unpack
in a single directory, these are said to be flat distributions.
Other GNU packages have a one level hierarchy of subdirectories, using
for example a subdirectory named `doc/' for the Texinfo manual and
man pages, another called `lib/' for holding functions meant to
replace or complement C libraries, and a subdirectory `src/' for
holding the proper sources for the package. These other distributions
are said to be non-flat.
For now, we cannot say much about flat distributions. A flat
directory structure has the disadvantage of increasing the difficulty
of updating to a new version of GNU gettext. Also, if you have
many PO files, this could somewhat pollute your single directory.
In the GNU gettext distribution, the `misc/' directory
contains a shell script named `combine-sh'. That script may
be used for combining all the C files of the `intl/' directory
into a pair of C files (one `.c' and one `.h'). Those two
generated files would fit more easily in a flat directory structure,
and you will then have to add these two files to your project.
Maybe because GNU gettext itself has a non-flat structure,
we have more experience with this approach, and this is what will be
described in the remaining of this chapter. Some maintainers might
use this as an opportunity to unflatten their package structure.
Only later, once gained more experience adapting GNU gettext
to flat distributions, we might add some notes about how to proceed
in flat situations.
There are some works which are required for using GNU gettext
in one of your package. These works have some kind of generality
that escape the point by point descriptions used in the remainder
of this chapter. So, we describe them here.
m4, GNU Autoconf and GNU
gettext are already installed at your site, and if not, proceed
to do this first. If you got to install these things, beware that
GNU m4 must be fully installed before GNU Autoconf is even
configured.
Those three packages are only needed to you, as a maintainer; the
installers of your own package and end users do not really need any
of GNU m4, GNU Autoconf or GNU gettext for successfully
installing and running your package, with messages properly translated.
But this is not completely true if you provide internationalized
shell scripts within your own package: GNU gettext shall
then be installed at the user site if the end users want to see the
translation of shell script messages.
It is worth adding here a few words about how the maintainer should ideally behave with PO files submissions. As a maintainer, your role is to authentify the origin of the submission as being the representative of the appropriate GNU translating team (forward the submission to `[email protected]' in case of doubt), to ensure that the PO file format is not severely broken and does not prevent successful installation, and for the rest, to merely to put these PO files in `po/' for distribution.
As a maintainer, you do not have to take on your shoulders the responsibility of checking if the translations are adequate or complete, and should avoid diving into linguistic matters. Translation teams drive themselves and are fully responsible of their linguistic choices for GNU. Keep in mind that translator teams are not driven by maintainers. You can help by carefully redirecting all communications and reports from users about linguistic matters to the appropriate translation team, or explain users how to reach or join their team. The simplest might be to send them the `NLS' file.
Maintainers should never ever apply PO file bug reports themselves, short-cutting translation teams. If some translator has difficulty to get some of her points through her team, it should not be an issue for her to directly negotiate translations with maintainers. Teams ought to settle their problems themselves, if any. If you, as a maintainer, ever think there is a real problem with a team, please never try to solve a team's problem on your own.
gettextize Program
Some files are consistently and identically needed in every package
internationalized through GNU gettext. As a matter of
convenience, the gettextize program puts all these files right
in your package. This program has the following synopsis:
gettextize [ option... ] [ directory ]
and accepts the following options:
If directory is given, this is the top level directory of a
package to prepare for using GNU gettext. If not given, it
is assumed that the current directory is the top level directory of
such a package.
The program gettextize provides the following files. However,
no existing file will be replaced unless the option --force
(-f) is specified.
gettextize, if
you have one handy. You may also fetch a more recent copy of file
`NLS' from most GNU archive sites.
gettext distribution.
(beware the double `.in' in the file name). If the `po/'
directory already exists, it will be preserved along with the files
it contains, and only `Makefile.in.in' will be overwritten.
gettext
distribution. Also, if option --force (-f) is given,
the `intl/' directory is emptied first.
If your site support symbolic links, gettextize will not
actually copy the files into your package, but establish symbolic
links instead. This avoids duplicating the disk space needed in
all packages. Merely using the `-h' option while creating the
tar archive of your distribution will resolve each link by an
actual copy in the distribution archive. So, to insist, you really
should use `-h' option with tar within your dist
goal of your main `Makefile.in'.
It is interesting to understand that most new files for supporting
GNU gettext facilities in one package go in `intl/'
and `po/' subdirectories. One distinction between these two
directories is that `intl/' is meant to be completely identical
in all packages using GNU gettext, while all newly created
files, which have to be different, go into `po/'. There is a
common `Makefile.in.in' in `po/', because the `po/'
directory needs its own `Makefile', and it has been designed so
it can be identical in all packages.
Besides files which are automatically added through gettextize,
there are many files needing revision for properly interacting with
GNU gettext. If you are closely following GNU standards for
Makefile engineering and auto-configuration, the adaptations should
be easier to achieve. Here is a point by point description of the
changes needed in each.
So, here comes a list of files, each one followed by a description of
all alterations it needs. Many examples are taken out from the GNU
gettext 0.10 distribution itself. You may indeed
refer to the source code of the GNU gettext package, as it
is intended to be a good example and master implementation for using
its own functionality.
The `po/' directory should receive a file named `POTFILES.in'. This file tells which files, among all program sources, have marked strings needing translation. Here is an example of such a file:
# List of source files containing translatable strings. # Copyright (C) 1995 Free Software Foundation, Inc. # Common library files lib/error.c lib/getopt.c lib/xmalloc.c # Package source files src/gettextp.c src/msgfmt.c src/xgettext.c
Dashed comments and white lines are ignored. All other lines list those source files containing strings marked for translation (see section How Marks Appears in Sources), in a notation relative to the top level of your whole distribution, rather than the location of the `POTFILES.in' file itself.
PACKAGE=gettext VERSION=0.10 AC_DEFINE_UNQUOTED(PACKAGE, "$PACKAGE") AC_DEFINE_UNQUOTED(VERSION, "$VERSION") AC_SUBST(PACKAGE) AC_SUBST(VERSION)Of course, you replace `gettext' with the name of your package, and `0.10' by its version numbers, exactly as they should appear in the packaged
tar file name of your distribution
(`gettext-0.10.tar.gz', here).
ALL_LINGUAS to the white separated,
quoted list of available languages, in a single line, like this:
ALL_LINGUAS="de fr"This example means that German and French PO files are available, so that these languages are currently supported by your package. If you want to further restrict, at installation time, the set of installed languages, this should not be done by modifying
ALL_LINGUAS in
`configure.in', but rather by using the LINGUAS environment
variable (see section Magic for Installers).
m4 macro for triggering internationalization
support. Just add this line to `configure.in':
ud_GNU_GETTEXTThis call is purposely simple, even if it generates a lot of configure time checking and actions.
ud_GNU_GETTEXT in `configure.in', use:
AC_LINK_FILES($nls_cv_header_libgt, $nls_cv_header_intl)This will create one header file `libintl.h'. The reason for this has to do with the fact that some systems, using the Uniforum message handling functions, already have a file of this name. The
AC_LINK_FILES call has not been integrated into the
ud_GNU_GETTEXT macro because there can be only one such call
in a `configure' file. If you already use it, you will have to
merge the needed AC_LINK_FILES within yours, by adding
the first argument at the end of the list of your first argument,
and adding the second argument at the end of the list of your second
argument.
AC_OUTPUT directive, at the end of your `configure.in'
file, needs to be modified in two ways:
AC_OUTPUT([existing configuration files intl/Makefile po/Makefile.in], [sed -e "/POTFILES =/r po/POTFILES" po/Makefile.in > po/Makefile existing additional actions])The modification to the first argument to
AC_OUTPUT asks
for substitution in the `intl/' and `po/' directories.
Note the `.in' suffix used for `po/' only. This is because
the distributed file is really `po/Makefile.in.in'.
The modification to the second argument ensures that `po/Makefile'
gets generated out of the `po/Makefile.in' just created, including
in it the `po/POTFILES' produced by ud_GNU_GETTEXT.
Two steps are needed because `po/POTFILES' can get lengthy in
some packages, too lengthy in fact for being able to merely use an
Autoconf substituted variable, as many seds cannot handle very
long lines.
If you do not have an `aclocal.m4' file in your distribution,
the simplest is taking a copy of `aclocal.m4' from
GNU gettext. But to be precise, you only need macros
ud_LC_MESSAGES, ud_WITH_NLS and ud_GNU_GETTEXT,
so you may use an editor and remove macros you do not need.
If you already have an `aclocal.m4' file, then you will have
to merge the said macros into your `aclocal.m4'. Note that if
you are upgrading from a previous release of GNU gettext, you
should most probably replace the said macros, as they usually
change a little from one release of GNU gettext to the next.
Their contents may vary as we get more experience with strange systems
out there.
These macros check for the internationalization support functions
and related informations. Hopefully, once stabilized, these macros
might be integrated in the standard Autoconf set, because this
piece of m4 code will be the same for all projects using GNU
gettext.
If you do not have an `acconfig.h' file in your distribution,
the simplest is use take a copy of `acconfig.h' from
GNU gettext. But to be precise, you only need the
lines and comments for ENABLE_NLS, HAVE_CATGETS,
HAVE_GETTEXT and HAVE_LC_MESSAGES, so you may use
an editor and remove everything else. If you already have an
`acconfig.h' file, then you should merge the said definitions
into your `acconfig.h'.
Here are a few modifications you need to make to your main, top-level `Makefile.in' file.
PACKAGE = @PACKAGE@ VERSION = @VERSION@
DISTFILES definition, so the file gets
distributed.
@INTLSUB@ and @POSUB@, which
are replaced respectively by `intl' and `po', or empty
when the configuration processes decides these directories should
not be processed.
Here is an example of a canonical order of processing. In this
example, we also define SUBDIRS in Makefile.in for it
to be further used in the `dist:' goal.
SUBDIRS = doc lib @INTLSUB@ src @POSUB@that you will have to adapt to your own package.
distdir = $(PACKAGE)-$(VERSION) dist: Makefile rm -fr $(distdir) mkdir $(distdir) chmod 777 $(distdir) for file in $(DISTFILES); do \ ln $$file $(distdir) 2>/dev/null || cp -p $$file $(distdir); \ done for subdir in $(SUBDIRS); do \ mkdir $(distdir)/$$subdir || exit 1; \ chmod 777 $(distdir)/$$subdir; \ (cd $$subdir && $(MAKE) $@) || exit 1; \ done tar chozf $(distdir).tar.gz $(distdir) rm -fr $(distdir)
Some of the modifications made in the main `Makefile.in' will also be needed in the `Makefile.in' from your package sources, which we assume here to be in the `src/' subdirectory. Here are all the modifications needed in `src/Makefile.in':
PACKAGE = @PACKAGE@ VERSION = @VERSION@
top_srcdir
gets defined. This will serve for cpp include files. Just add
the line:
top_srcdir = @top_srcdir@
subdir as `src', later
allowing for almost uniform `dist:' goals in all your
`Makefile.in'. At list, the `dist:' goal below assume that
you used:
subdir = src
@INTLLIBS@ as
a library. An easy way to achieve this is to manage that it gets into
LIBS, like this:
LIBS = @INTLLIBS@ @LIBS@In most GNU packages one will find a directory `lib/' in which a library containing some helper functions will be build. (You need at least the few functions which the GNU
gettext Library itself
needs.) However some of the functions in the `lib/' also give
messages to the user which of course should be translated, too. Taking
care of this it is not enough to place the support library (say
`libsupport.a') just between the @INTLLIBS@ and
@LIBS@ in the above example. Instead one has to write this:
LIBS = ../lib/libsupport.a @INTLLIBS@ ../lib/libsupport.a @LIBS@
distdir = ../$(PACKAGE)-$(VERSION)/$(subdir) dist: Makefile $(DISTFILES) for file in $(DISTFILES); do \ ln $$file $(distdir) 2>/dev/null || cp -p $$file $(distdir); \ done
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