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<H1>GNU gettext tools, version 0.10</H1>
<H2>Native Language Support Library and Tools</H2>
<H2>Edition 0.10, 26 November</H2>
<ADDRESS>Ulrich Drepper</ADDRESS>
<ADDRESS>Jim Meyering</ADDRESS>
<ADDRESS>Pinard</ADDRESS>
<P>
<P><HR><P>

<P>
Copyright (C) 1995 Free Software Foundation, Inc.

</P>
<P>
Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
are preserved on all copies.

</P>
<P>
Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the entire
resulting derived work is distributed under the terms of a permission
notice identical to this one.

</P>
<P>
Permission is granted to copy and distribute translations of this manual
into another language, under the above conditions for modified versions,
except that this permission notice may be stated in a translation approved
by the Foundation.

</P>


<H1><A NAME="SEC1" HREF="gettext_toc.html#TOC1">Introduction</A></H1>


<BLOCKQUOTE>
<P>
This manual is still in <EM>DRAFT</EM> state.  Some sections are still
empty, or almost.  We keep merging material from other sources
(essentially email folders) while the proper integration of this
material is delayed.
</BLOCKQUOTE>

<P>
In this manual, we use <EM>he</EM> when speaking of the programmer or
maintainer, <EM>she</EM> when speaking of the translator, and <EM>they</EM>
when speaking of the installers or end users of the translated program.
This is only a convenience for clarifying the documentation.  It is
absolutely not meant to imply that some roles are more appropriate
to males or females.  Besides, as you might guess, GNU <CODE>gettext</CODE>
is meant to be useful for people using computers, whatever their sex,
race, religion or nationality!

</P>
<P>
This chapter explains what are the goals seeked by the mere existence
of GNU <CODE>gettext</CODE>.  Then, it explains a few wide concepts around
Native Language Support, and situates message translation in regard
to other aspects of national and cultural variance, as applicable
to programs.  It also surveys what are those files used to convey
translations.  It explains how the various tools interrelate in the
initial generation for these files, and later, how the maintenance
cycle usually operate.

</P>


<H2><A NAME="SEC2" HREF="gettext_toc.html#TOC2">The Purpose of GNU <CODE>gettext</CODE></A></H2>

<P>
Usually, programs are written and documented in English, and use
English at execution time for interacting with users.  This is true
not only from within GNU, but also in a great deal of commercial
and free software.  Using a common language is quite handy for
communication between developers, maintainers and users from all
countries.  On the other hand, most people are less comfortable with
English than with their own native language, and would rather prefer
using their mother tongue for day to day's work, as far as possible.
Many would simply <EM>love</EM> seeing their computer screen showing
a lot less of English, and far more of their own spoken language.

</P>
<P>
However, to some people, this dream might appear so far fetched that
they may believe it is not even worth spending time thinking about
it, and they have no confidence at all that the dream might ever
become true.  Many did not loose hope yet, and organized themselves.
The GNU Translation Project is a formalization of this hope into a
workable structure, which has a good chance to get all of us nearer
the achievement of a truly multi-lingual set of programs.

</P>
<P>
GNU <CODE>gettext</CODE> is an important step for the GNU Translation
Project, as it is an asset on which we may build many other steps.
This package offers to programmers, translators and even users, a
well integrated set of tools and documentation.  Specifically, the GNU
<CODE>gettext</CODE> utilities are a set of tools that provides a framework
to help other GNU packages produce multi-lingual messages.  These tools
include a set of conventions about how programs should be written to
support message catalogs, a directory and file naming organization
for the message catalogs themselves, a runtime library supporting the
retrieval of translated messages, and a few stand-alone programs to
massage in various ways the sets of translatable strings, or already
translated strings.  A special GNU Emacs mode also helps interested
parties into preparing these sets, or bringing them up to date.

</P>
<P>
GNU <CODE>gettext</CODE> is designed so it minimizes the impact of
internationalization on program sources, keeping this impact as small
and hardly noticeable as possible.  Internationalization has better
chances of succeeding if it is very light weighted, or at least,
appear to be so, when looking at program sources.

</P>
<P>
The GNU Translation Project also uses the GNU <CODE>gettext</CODE>
distribution as a vehicle for documenting its structure and methods,
even if this goes beyond the technicalities of the GNU <CODE>gettext</CODE>
proper.  By doing so, translators will find in a single place, as
far as possible, all they need to know for properly doing their
translating work.  Also, this supplementary documentation might also
help programmers, and even curious users, at understanding how GNU
<CODE>gettext</CODE> is related to the remainder of the GNU Translation
Project, and consequently, have a glimpse at the <EM>big picture</EM>.

</P>


<H2><A NAME="SEC3" HREF="gettext_toc.html#TOC3">I18n, L10n, and Such</A></H2>

<P>
Two long words appear all the time when we discuss support of native
language in programs, and these words have a precise meaning, worth
being explained here, once and for all in this document.  The words are
<EM>internationalization</EM> and <EM>localization</EM>.  Many people,
tired of writing these long words over and over again, took the
habit of writing <STRONG>i18n</STRONG> and <STRONG>l10n</STRONG> instead, quoting the first
and last letter of each word, and replacing the run of intermediate
letters by a number merely telling how many such letters there are.
But in this manual, in the sake of clarity, we will patiently write
the names in full, each time...

</P>
<P>
By <STRONG>internationalization</STRONG>, one refers to the operation by which a
program, or a set of programs turned into a package, is made aware and
able to support multiple languages.  This is a generalization process,
by which the programs are untied from using only English strings or
other English specific habits, and connected to generic ways of doing
the same, instead.  Program developers may use various techniques to
internationalize their programs, some of them have been standardized.
GNU <CODE>gettext</CODE> offers one of these standards.  See section <A HREF="gettext.html#SEC36">The Programmer's View</A>.

</P>
<P>
By <STRONG>localization</STRONG>, one means the operation by which, in a set
of programs already internationalized, one gives the program all
needed information so that it can bend itself to handle its input
and output in a fashion which is correct for some native language and
cultural habits.  This is a particularisation process, by which generic
methods already implemented in an internationalized program are used
in specific ways.  The programming environment puts several functions
to the programmers disposal which allow this runtime configuration.
The formal description of specific set of cultural habits for some
country, together with all associated translations targeted to the
same native language, is called the <STRONG>locale</STRONG> for this language
or country.  Users achieve localization of programs by setting proper
values to special environment variables, prior to executing those
programs, identifying which locale should be used.

</P>
<P>
In fact, locale message support is only one component of the cultural
data that makes up a particular locale.  There are a whole host of
routines and functions provided to aid programmers in developing
internationalized software and which allows them to access the data
stored in a particular locale.  When someone presently refers to a
particular locale, they are obviously referring to the data stored
within that particular locale.  Similarly, if a programmer is referring
to "accessing the locale routines", they are referring to the
complete suite of routines that access all of the locale's information.

</P>
<P>
One uses the expression <STRONG>Native Language Support</STRONG>, or merely NLS,
for speaking of the overall activity or feature encompassing both
internationalization and localization, allowing for multi-lingual
interactions in a program.  In a nutshell, one could say that
internationalization is the operation by which further localizations
are made possible.

</P>
<P>
Also, very roughly said, when it comes to multi-lingual messages,
internationalization is usually taken care of by programmers, and
localization is usually taken care of by translators.

</P>


<H2><A NAME="SEC4" HREF="gettext_toc.html#TOC4">Aspects in Native Language Support</A></H2>

<P>
For a totally multi-lingual distribution, there are many things to
translate beyond output messages.

</P>

<UL>
<LI>

As of today, GNU <CODE>gettext</CODE> offers a complete toolset for
translating messages output by C programs.  Perl scripts and shell
scripts also need to be translated.  Even if there are some hooks
so this can be done, these hooks are not integrated as well as they
should be.

<LI>

Some programs, like <CODE>autoconf</CODE> or <CODE>bison</CODE>, are able
to produce other programs (or scripts).  Even if the generating
programs themselves are internationalized, the generated programs they
produce may need internationalization on their own, and this indirect
internationalization could be automated right from the generating
program.  In fact, quite usually, generating and generated programs
could be internationalized independently, as the effort needed is
fairly orthogonal.

<LI>

A few programs include textual tables which might need translation
themselves, independently of the strings contained in the program
itself.  For example, RFC 1345 gives an English description for each
character which GNU <CODE>recode</CODE> is able to reconstruct at execution.
Since these descriptions are extracted from the RFC by mechanical means,
translating them properly would require a prior translation of the RFC
itself.

<LI>

Almost all programs accept options, which are often worded out so to
be descriptive for the English readers; one might want to consider
offering translated versions for program options as well.

<LI>

Many programs read, interpret, compile, or are somewhat driven by
input files which are texts containing keywords, identifiers, or
replies which are inherently translatable.  For example, one may want
<CODE>gcc</CODE> to allow diacriticized characters in identifiers or use
translated keywords; <SAMP>`rm -i'</SAMP> might accept something else than
<SAMP>`y'</SAMP> or <SAMP>`n'</SAMP> for replies, etc.  Even if the program will
eventually make most of its output in the foreign languages, one has
to decide whether the input syntax, option values, etc., are to be
localized or not.

<LI>

The manual accompanying a package, as well as all documentation files
in the distribution, could surely be translated, too.  Translating a
manual, with the intent of later keeping up with updates, is a major
undertaking in itself, generally.

</UL>

<P>
As we already stressed, translation is only one aspect of locales.
Other internationalization aspects are not currently handled by GNU
<CODE>gettext</CODE>, but perhaps may be handled in future versions.  There
are many attributes that are needed to define a country's cultural
conventions.  These attributes include beside the country's native
language, the formatting of the date and time, the representation of
numbers, the symbols for currency, etc.  These local <STRONG>rules</STRONG> are
termed the country's locale.  The locale represents the knowledge
needed to support the country's native attributes.

</P>
<P>
There are a few major areas which may vary between countries and
hence, define what a locale must describe.  The following list helps
putting multi-lingual messages into the proper context of other tasks
related to locales, and also presents some other areas which GNU
<CODE>gettext</CODE> might eventually tackle, maybe, one of these days.

</P>
<DL COMPACT>

<DT><EM>Characters and Codesets</EM>
<DD>
The codeset most commonly used through out the USA and most English
speaking parts of the world is the ASCII codeset.  However, there are
many characters needed by various locales that are not found within
this codeset.  The 8-bit ISO 8859-1 code set has most of the special
characters needed to handle the major European languages.  However, in
many cases, the ISO 8859-1 font is not adequate.  Hence each locale
will need to specify which codeset they need to use and will need
to have the appropriate character handling routines to cope with
the codeset.

<DT><EM>Currency</EM>
<DD>
The symbols used vary from country to country as does the position
used by the symbol.  Software needs to be able to transparently
display currency figures in the native mode for each locale.

<DT><EM>Dates</EM>
<DD>
The format of date varies between locales.  For example, Christmas day
in 1994 is written as 12/25/94 in the USA and as 25/12/94 in Australia.
Other countries might use ISO 8061 dates, etc.

Time of the day may be noted as <VAR>hh</VAR>:<VAR>mm</VAR>, <VAR>hh</VAR>.<VAR>mm</VAR>,
or otherwise.  Some locales require time to be specified in 24-hour
mode rather than as AM or PM.  Further, the nature and yearly extent
of the Daylight Saving correction vary widely between countries.

<DT><EM>Numbers</EM>
<DD>
Numbers can be represented differently in different locales.
For example, the following numbers are all written correctly for
their respective locales:


<PRE>
12,345.67       English
12.345,67       French
1,2345.67       Asia
</PRE>

Some programs could go further and use different unit systems, like
English units or Metric units, or even take into account variants
about how numbers are spelled in full.

<DT><EM>Messages</EM>
<DD>
The most obvious area is the language support within a locale.  This is
where GNU <CODE>gettext</CODE> provide an ease for developers and users to
easily change the language that the software uses to communicate to
the user.

</DL>

<P>
In the near future we see no chance that beside message handling
more components of locale will be made available for use in other
GNU packages.  The reason for this is that most modern system provide
a more or less reasonable support for at least some of the missing
components.  Another point is that the GNU libc and Linux will get
a new and complete implementation of the whole locale functionality
which could be adopted by system lacking a reasonable locale support.

</P>


<H2><A NAME="SEC5" HREF="gettext_toc.html#TOC5">Files Conveying Translations</A></H2>

<P>
The letters PO in <TT>`.po'</TT> files means Portable Object, to
distinguish it from <TT>`.mo'</TT> files, where MO stands for Machine
Object.  This paradigm, as well as the PO file format, is inspired
by the NLS standard developed by Uniforum, and implemented by Sun
in their Solaris system.

</P>
<P>
PO files are meant to be read and edited by humans, and associate each
original, translatable string of a given package with its translation
in a particular target language.  A single PO file is dedicated to
a single target language.  If a package supports many languages,
there is one such PO file per language supported, and each package
has its own set of PO files.  These PO files are best created by
the <CODE>xgettext</CODE> program, and later updated or refreshed through
the <CODE>tupdate</CODE> program.  Program <CODE>xgettext</CODE> extracts all
marked messages from a set of C files and initializes a PO file with
empty translations.  Program <CODE>tupdate</CODE> takes care of adjusting
PO files between releases of the corresponding sources, commenting
obsolete entries, initializing new ones, and updating all source
line references.  Files ending with <TT>`.pot'</TT> are kind of base
translation files found in distributions, in PO file format, and
<TT>`.pox'</TT> files are often temporary PO files.

</P>
<P>
MO files are meant to be read by programs, and are binary in nature.
A few systems already offer tools for creating and handling MO files
as part of the Native Language Support coming with the system, but the
format of these MO files is often different from system to system,
and non-portable.  They do not necessary use <TT>`.mo'</TT> for file
extensions, but since system libraries are also used for accessing
these files, it works as long as the system is self-consistent about
it.  If GNU <CODE>gettext</CODE> is able to interface with the tools already
provided with systems, it will consequently let these provided tools
take care of generating the MO files.  Or else, if such tools are not
found or do not seem usable, GNU <CODE>gettext</CODE> will use its own ways
and its own format for MO files.  Files ending with <TT>`.gmo'</TT> are
really MO files, when it is known that these files use the GNU format.

</P>


<H2><A NAME="SEC6" HREF="gettext_toc.html#TOC6">Overview of GNU <CODE>gettext</CODE></A></H2>

<P>
The following diagram summarizes the relation between the files
handled by GNU <CODE>gettext</CODE> and the tools acting on these files.
It is followed by a somewhat detailed explanations, which you should
read while keeping an eye on the diagram.  Having a clear understanding
of these interrelations would surely help programmers, translators
and maintainers.

</P>

<PRE>
Original C Sources ---&#62; PO mode ---&#62; Marked C Sources ---.
                                                         |
              .---------&#60;--- GNU gettext Library         |
.--- make &#60;---+                                          |
|             `---------&#60;--------------------+-----------'
|                                            |
|   .-----&#60;--- PACKAGE.pot &#60;--- xgettext &#60;---'   .---&#60;--- PO Compendium
|   |                                            |             ^
|   |                                            `---.         |
|   `---.                                            +---&#62; PO mode ---.
|       +----&#62; tupdate -------&#62; LANG.pox ---&#62;--------'                |
|   .---'                                                             |
|   |                                                                 |
|   `-------------&#60;---------------.                                   |
|                                 +--- LANG.po &#60;--- New LANG.pox &#60;----'
|   .--- LANG.gmo &#60;--- msgfmt &#60;---'
|   |
|   `---&#62; install ---&#62; /.../LANG/PACKAGE.mo ---.
|                                              +---&#62; "Hello world!"
`-------&#62; install ---&#62; /.../bin/PROGRAM -------'
</PRE>

<P>
The indication <SAMP>`PO mode'</SAMP> appears in two places in this picture,
and you may safely read it as merely meaning "hand editing", using
any editor of your choice, really.  However, for those of you being
the lucky users of GNU Emacs, PO mode has been specifically created
for providing a cosy environment for editing or modifying PO files.
While editing a PO file, PO mode allows for the easy browsing of
auxiliary and compendium PO files, as well as following references into
the set of C program sources from which PO files has been derived.
It has a few special features, among which the interactive marking
of program strings as translatable, and the validatation of PO files
with easy repositioning to PO file lines showing errors.

</P>
<P>
As a programmer, the first step into bringing GNU <CODE>gettext</CODE>
into your package is identifying, right in the C sources, which
strings are meant to be translatable, and which are untranslatable.
This tedious job can be done a little more comfortably using PO
mode, but you can use any means being usual to you for modifying your
C sources.  Some other simple, standard changes are also needed to
properly initialize the translation library.  See section <A HREF="gettext.html#SEC13">Preparing Program Sources</A>, for
more information about all this.

</P>
<P>
Once the C sources have been modified, the <CODE>xgettext</CODE> program
is used to find and extract all translatable strings, and create an
initial PO file out of all these.  This <TT>`<VAR>package</VAR>.pot'</TT> file
contains all original program strings, it has sets of pointers to
exactly where in C sources each string is used, and all translations
are set to empty.  The letter <KBD>t</KBD> in <TT>`.pot'</TT> marks that this is
a Template PO file, not yet oriented towards any particular language.
See section <A HREF="gettext.html#SEC19">Invoking the <CODE>xgettext</CODE> Program</A>, for more details about how one calls the
<CODE>xgettext</CODE> program.  If you are <EM>really</EM> lazy, you might
be interested at working a lot more right away, and preparing the
whole distribution setup (see section <A HREF="gettext.html#SEC65">The Maintainer's View</A>).  By doing so, you
spare typing the <CODE>xgettext</CODE> command yourself, as <CODE>make</CODE>
should now generate the proper things automatically for you!

</P>
<P>
The first time through, there is no <TT>`<VAR>lang</VAR>.po'</TT> yet, so the
<CODE>tupdate</CODE> step may be skipped and replaced by a mere copy of
<TT>`<VAR>package</VAR>.pot'</TT> to <TT>`<VAR>lang</VAR>.pox'</TT>, where <VAR>lang</VAR>
represents the target language.

</P>
<P>
Then comes the initial translation of messages.  Translation in
itself is a whole matter, still exclusively meant for humans,
and whose complexity far overwhelms the level of this manual.
Nevertheless, a few hints are given in some other chapter of this
manual (see section <A HREF="gettext.html#SEC54">The Translator's View</A>).  You will also find there indications
about how to contact translating teams, or becoming part of them,
for sharing your translating concerns with others who target the same
native language.

</P>
<P>
While adding the translated messages into the <TT>`<VAR>lang</VAR>.pox'</TT>
PO file, if you do not have GNU Emacs handy, you are on your own
for ensuring that your fully respect the PO file format, and quoting
conventions (see section <A HREF="gettext.html#SEC9">The Format of PO Files</A>).  This is surely not an impossible task,
as this is the way many people handled PO files already for Uniforum or
Solaris.  On the other hand, using PO mode in GNU Emacs, most details
of PO file format are taken care for you, but you have to acquire
some familiarity with PO mode itself.  Besides main PO mode commands
(see section <A HREF="gettext.html#SEC10">Main Commands</A>), you should know how to move between entries
(see section <A HREF="gettext.html#SEC11">Entry Positioning</A>), and how to handle untranslated entries
(see section <A HREF="gettext.html#SEC24">Untranslated Entries</A>).

</P>
<P>
If some common translations have already been saved into a compendium
PO file, translators may use PO mode for initializing untranslated
entries from the compendium, and also save selected translations into
the compendium, updating it (see section <A HREF="gettext.html#SEC21">Using Translation Compendiums</A>).  Compendium files
are meant to be exchanged between members of a given translation team.

</P>
<P>
Programs, or packages of programs, are dynamic in nature: users write
bug reports and suggestion for improvements, maintainers react by
modifying programs in various ways.  The fact that a package has
already been internationalized should not make maintainers shy
of adding new strings, or modifying strings already translated.
They just do their job the best they can.  For the GNU Translation
Project to work smoothly, it is important that maintainers do not
carry translation concerns on their already loaded shoulders, and that
translators be kept as free as possible of programmatic concerns.

</P>
<P>
The only concern maintainers should have is carefully marking new
strings are translatable, when they should be, and do not otherwise
worry about them being translated, as this will come in proper time.
Consequently, when programs and their strings are adjusted in various
ways by maintainers, and for matters usually unrelated to translation,
<CODE>xgettext</CODE> would construct <TT>`<VAR>package</VAR>.pot'</TT> files which are
evolving over time, so the translations carried by <TT>`<VAR>lang</VAR>.po'</TT>
are slowly fading out of date.

</P>
<P>
It is important for translators (and even maintainers) to understand
that package translation is a continuous process in the lifetime of a
package, and not something which is done once and for all at the start.
After an initial burst of translation activity for a given package,
interventions are needed once in a while, because here and there,
translated entries become obsolete, and new untranslated entries
appear, needing translation.

</P>
<P>
The <CODE>tupdate</CODE> program has the purpose of refreshing an already
existing <TT>`<VAR>lang</VAR>.po'</TT> file, by comparing it with a newer
<TT>`<VAR>package</VAR>.pot'</TT> template file, extracted by <CODE>xgettext</CODE>
out of recent C sources.  The refreshing operation adjusts all
references to C source locations for strings, since these strings
move as programs are modified.  Also, <CODE>tupdate</CODE> comments out as
obsolete, in <TT>`<VAR>lang</VAR>.pox'</TT>, those already translated entries
which are no longer used in the program sources (see section <A HREF="gettext.html#SEC25">Obsolete Entries</A>.  It finally discovers new strings and insert them in
the resulting PO file as untranslated entries (see section <A HREF="gettext.html#SEC24">Untranslated Entries</A>.  See section <A HREF="gettext.html#SEC23">Invoking the <CODE>tupdate</CODE> Program</A>, for more information about what
<CODE>tupdate</CODE> really does.

</P>
<P>
Whatever route or means taken, the goal is obtaining an updated
<TT>`<VAR>lang</VAR>.pox'</TT> file offering translations for all strings.
When this is properly achieved, this file <TT>`<VAR>lang</VAR>.pox'</TT> may
take the place of the previous official <TT>`<VAR>lang</VAR>.po'</TT> file.

</P>
<P>
The time mobility, or fluidity of PO files, is an integral part of
the translation game, and should be well understood, and accepted.
People resisting it will have a hard time participating in the GNU
Translation Project, or will give a hard time to other participants!
In particular, maintainers should relax and include all available PO
files in their distributions, even if these have not recently been
updated, without banging or otherwise trying to exert pressure on the
translator teams to get the job done.  The pressure should rather
come from the community of users speaking a particular language,
and maintainers should consider themselves fairly relieved of any
concern about the adequacy of translation files.  On the other hand,
translators should reasonably try updating the PO files they are
responsible for, while the package is undergoing pretest, prior to
an official distribution.

</P>
<P>
Once the PO file is complete and dependable, the <CODE>msgfmt</CODE> program
is used for turning the PO file into a machine-oriented format, which
may yield efficient retrieval of translations by the programs of the
package, whenever needed at runtime (see section <A HREF="gettext.html#SEC31">The Format of GNU MO Files</A>).  See section <A HREF="gettext.html#SEC30">Invoking the <CODE>msgfmt</CODE> Program</A>, for more information about all modalities of execution
for the <CODE>msgfmt</CODE> program.

</P>
<P>
Finally, the modified and marked C sources are compiled and linked
with the GNU <CODE>gettext</CODE> library, usually through the operation of
<CODE>make</CODE>, given a suitable <TT>`Makefile'</TT> exists for the project,
and the resulting executable is installed somewhere users will find it.
The MO files themselves should also be properly installed.  Given the
appropriate environment variables are set (see section <A HREF="gettext.html#SEC35">Magic for End Users</A>), the
program should localize itself automatically, whenever it executes.

</P>
<P>
The remaining of this manual has the purpose of deepening the various
steps outlined in this section.

</P>


<H1><A NAME="SEC7" HREF="gettext_toc.html#TOC7">PO Files and PO Mode Basics</A></H1>

<P>
The GNU <CODE>gettext</CODE> toolset helps programmers and translators
at producing, updating and using translation files, mainly those
PO files which are textual, editable files.  This chapter insists
on the format of PO files, and contains a PO mode starter.  PO mode
description is spread over this manual instead of being concentrated
in one place, this chapter presents only the basics of PO mode.

</P>


<H2><A NAME="SEC8" HREF="gettext_toc.html#TOC8">Completing GNU <CODE>gettext</CODE> Installation</A></H2>

<P>
Once you have received, unpacked, configured and compiled the GNU
<CODE>gettext</CODE> distribution, the <SAMP>`make install'</SAMP> command puts in
place the programs <CODE>xgettext</CODE>, <CODE>msgfmt</CODE>, <CODE>gettext</CODE>, and
<CODE>tupdate</CODE>, as well as their available message catalogs.  For
completing a comfortable installation, you might also want to make the
PO mode available to your GNU Emacs users.

</P>
<P>
To finish the installation of the PO mode, you might want modify your
file <TT>`.emacs'</TT>, once and for all, so it contains a few lines looking
like:

</P>

<PRE>
(setq auto-mode-alist
      (cons '("\\.pox?\\'" . po-mode) auto-mode-alist))
(autoload 'po-mode "po-mode")
</PRE>

<P>
Later, whenever you edit some <TT>`.po'</TT> or <TT>`.pox'</TT> file, Emacs
loads <TT>`po-mode.elc'</TT> (or <TT>`po-mode.el'</TT>) as needed, and
automatically activate PO mode commands for the associated buffer.
The string <EM>PO</EM> appears in the mode line for any buffer for
which PO mode is active.  Many PO files may be active at once in a
single Emacs session.

</P>


<H2><A NAME="SEC9" HREF="gettext_toc.html#TOC9">The Format of PO Files</A></H2>

<P>
A PO file is made up of many entries, each entry holding the relation
between an original untranslated string and its corresponding
translation.  All entries in a given PO file usually pertain
to a single project, and all translations are expressed in a single
target language.  One PO file <STRONG>entry</STRONG> has the following schematic
structure:

</P>

<PRE>
<VAR>white-space</VAR>
#  <VAR>translator-comments</VAR>
#. <VAR>automatic-comments</VAR>
#: <VAR>reference</VAR>...
msgid <VAR>untranslated-string</VAR>
msgstr <VAR>translated-string</VAR>
</PRE>

<P>
The general structure of a PO file should be well understood by
the translator.  When using PO mode, very little has to be known
about the format details, as PO mode takes care of them for her.

</P>
<P>
Entries begin with some optional white space.  Usually, when generated
through GNU <CODE>gettext</CODE> tools, there is exactly one blank line
between entries.  Then comments follow, on lines all starting with the
character <KBD>#</KBD>.  There are two kinds of comments: those which have
some white space immediately following the <KBD>#</KBD>, which comments are
created and maintained exclusively by the translator, and those which
have some non-white character just after the <KBD>#</KBD>, which comments
are created and maintained automatically by GNU <CODE>gettext</CODE> tools.
All comments, of any kind, are optional.

</P>
<P>
After white space and comments, entries show two strings, giving
first the untranslated string as it appears in the original program
sources, and then, the translation of this string.  The original
string is introduced by the keyword <CODE>msgid</CODE>, and the translation,
by <CODE>msgstr</CODE>.  The two strings, untranslated and translated,
are quoted in various ways in the PO file, using <KBD>"</KBD>
delimiters and <KBD>\</KBD> escapes, but the translator does not really
have to pay attention to the precise quoting format, as PO mode fully
intend to take care of quoting for her.

</P>
<P>
The <CODE>msgid</CODE> strings, as well as automatic comments, are produced
and managed by other GNU <CODE>gettext</CODE> tools, and PO mode does not
provide means for the translator to alter these.  The most she can
do is merely deleting them, and only by deleting the whole entry.
On the other hand, the <CODE>msgstr</CODE> string, as well as translator
comments, are really meant for the translator, and PO mode gives her
the full control she needs.

</P>
<P>
It happens that some lines, usually whitespace or comments, follow the
very last entry of a PO file.  Such lines are not part of any entry,
and PO mode is unable to take action on those lines.  By using the
PO mode function <KBD>M-x po-normalize</KBD>, the translator may get
rid of those spurious lines.  See section <A HREF="gettext.html#SEC12">Normalizing Strings in Entries</A>.

</P>
<P>
The remainder of this section may be safely skipped for those using
PO mode, yet it may be interesting for everybody to have a better
idea of the precise format of a PO file.  On the other hand, those
not having GNU Emacs handy should carefully continue reading on.

</P>
<P>
Each of <VAR>untranslated-string</VAR> and <VAR>translated-string</VAR> respects
the C syntax for a character string, including the surrounding quotes
and imbedded backslashed escape sequences.  When the time comes
to write multi-line strings, one should not use escaped newlines.
Instead, a closing quote should follow the last character on the
line to be continued, and an opening quote should resume the string
at the beginning of the following PO file line.  For example:

</P>

<PRE>
msgid ""
"Here is an example of how one might continue a very long string\n"
"for the common case the string represents multi-line output.\n"
</PRE>

<P>
In this example, the empty string is used on the first line, for
allowing the better alignment of the <KBD>H</KBD> from the word <SAMP>`Here'</SAMP>
over the <KBD>f</KBD> from the word <SAMP>`for'</SAMP>.  In this example, the
<CODE>msgid</CODE> keyword is followed by three strings, which are meant
to be concatenated.  Concatenating the empty string does not change
the resulting overall string, but it is a way for us to comply with
the necessity of <CODE>msgid</CODE> to be followed by a string on the same
line, while keeping the multi-line presentation left-justified, as
we find this to be cleaner disposition.  The empty string could have
been omitted, but only if the string starting with <SAMP>`Here'</SAMP> was
promoted on the first line, right after <CODE>msgid</CODE>.<A NAME="DOCF1" HREF="gettext_foot.html#FOOT1">(1)</A> It was not really necessary
either to switch between the two last quoted strings immediately after
the newline <SAMP>`\n'</SAMP>, the switch could have occurred after <EM>any</EM>
other character, we just did it this way because it is neater.

</P>
<P>
One should carefully distinguish between end of lines marked as
<SAMP>`\n'</SAMP> <EM>inside</EM> quotes, which are part of the represented
string, and end of lines in the PO file itself, outside string quotes,
which have no incidence on the represented string.

</P>
<P>
Outside strings, white lines and comments may be used freely.
Comments start at the beginning of a line with <SAMP>`#'</SAMP> and extend
until the end of the PO file line.  Comments written by translators
should have the initial <SAMP>`#'</SAMP> immediately followed by some white
space.  If the <SAMP>`#'</SAMP> is not immediately followed by white space,
this comment is most likely generated and managed by specialized GNU
tools, and might disappear or be replaced unexpectandly when the PO
file is given to <CODE>tupdate</CODE>.

</P>


<H2><A NAME="SEC10" HREF="gettext_toc.html#TOC10">Main Commands</A></H2>

<P>
When Emacs finds a PO file in a window, PO mode is activated
for that window.  This puts the window read-only and establishes a
po-mode-map, which is a genuine Emacs mode, in that way that it is
not derived from text mode in any way.

</P>
<P>
The main PO commands are those who do not fit in the other categories in
subsequent sections, they allow for quitting PO mode or managing windows
in special ways.

</P>
<DL COMPACT>

<DT><KBD>u</KBD>
<DD>
Undo last modification to the PO file.

<DT><KBD>q</KBD>
<DD>
Quit processing and save the PO file.

<DT><KBD>o</KBD>
<DD>
Temporary leave the PO file window.

<DT><KBD>h</KBD>
<DD>
Show help about PO mode.

<DT><KBD>=</KBD>
<DD>
Give some PO file statistics.

<DT><KBD>v</KBD>
<DD>
Batch validate the format of the whole PO file.

</DL>

<P>
The command <KBD>u</KBD> (<CODE>po-undo</CODE>) interfaces to the GNU Emacs
<EM>undo</EM> facility.  See section `Undoing Changes' in <CITE>The Emacs Editor</CITE>.  Each time <KBD>u</KBD> is typed, modifications the translator
did to the PO file are undone a little more.  For the purpose of
undoing, each PO mode command is atomic.  This is especially true for
the <KBD><KBD>RET</KBD></KBD> command: the whole edition made by using a single
use of this command is undone at once, even if the edition itself
implied several actions.  However, while in the editing window, one
can undo the edition work quite parsimoniously.

</P>
<P>
The command <KBD>q</KBD> (<CODE>po-quit</CODE>) is used when the translator is
done with the PO file.  If the file has been modified, it is saved
on disk first.  However, prior to all this, the command checks if
some untranslated message remains in the PO file and, if yes, the
translator is asked if she really wants to leave working with this
PO file.  This is the preferred way of getting rid of an Emacs PO
file buffer.  Merely killing it through the usual command <KBD>C-x
k</KBD> (<CODE>kill-buffer</CODE>), say, has the unnice effect of leaving a PO
internal work buffer behind.

</P>
<P>
The command <KBD>o</KBD> (<CODE>po-other-window</CODE>) is another, softer
way, to leave PO mode, temporarily.  It just moves the cursor in
some other Emacs window, and pops one if necessary.  For example, if
the translator just got PO mode to show some source context in some
other, she might discover some apparent bug in the program source
that needs correction.  This command allows the translator to change
sex, become a programmer, and have the cursor right into the window
containing the program she (or rather <EM>he</EM>) wants to modify.
By later getting the cursor back in the PO file window, or by
asking Emacs to edit this file once again, PO mode is then recovered.

</P>
<P>
The command <KBD>h</KBD> (<CODE>po-help</CODE>) displays a summary of all
available PO mode commands.  The translator should then type any
character to resume normal PO mode operations.  The command <KBD>?</KBD>
has the same effect as <KBD>h</KBD>.

</P>
<P>
The command <KBD>=</KBD> (<CODE>po-statistics</CODE>) computes the total number
of entries in the PO file, the ordinal of the current entry
(counted from 1), the number of untranslated entries, the number of
obsolete entries, and displays all these numbers.

</P>
<P>
The command <KBD>v</KBD> (<CODE>po-validate</CODE>) launches <CODE>msgfmt</CODE> in
verbose mode over the current PO file.  This command first offers
to save the current PO file on disk.  The <CODE>msgfmt</CODE> tool, from
GNU <CODE>gettext</CODE>, has the purpose of creating an MO file out of a
PO file, and PO mode uses the features of this program for checking
the overall format of a PO file, as well as all individual entries.

</P>
<P>
The program <CODE>msgfmt</CODE> runs asynchronously with Emacs, so
the translator regains control immediately while her PO file
is being studied.  Error output is collected in the GNU Emacs
<SAMP>`*compilation*'</SAMP> buffer, displayed in another window.  The regular
GNU Emacs command <KBD>C-x`</KBD> (<CODE>next-error</CODE>), as well as other
usual compile commands, allow the translator to reposition quickly to
the offending parts of the PO file.  Once the cursor on the line in
error, the translator may decide for any PO mode action which would
help correcting the error.

</P>


<H2><A NAME="SEC11" HREF="gettext_toc.html#TOC11">Entry Positioning</A></H2>

<P>
The cursor in a PO file window is almost always part of
an entry.  The only exceptions are the special case when the cursor
is after the last entry in the file, or when the PO file is
empty.  The entry where the cursor is found to be is said to be the
current entry.  Many PO mode commands operate on the current entry,
so moving the cursor does more than allowing the translator to browse
the PO file, this also selects on which entry commands operate.

</P>
<P>
Some PO mode commands alter the position of the cursor in a specialized
way.  A few of those special purpose positioning are described here,
the others are described in following sections.

</P>
<DL COMPACT>

<DT><KBD>.</KBD>
<DD>
Redisplay the current entry.

<DT><KBD>n</KBD>
<DD>
<DT><KBD>SPC</KBD>
<DD>
Select the entry after the current one.

<DT><KBD>p</KBD>
<DD>
<DT><KBD>DEL</KBD>
<DD>
Select the entry before the current one.

<DT><KBD>&#60;</KBD>
<DD>
Select the first entry in the PO file.

<DT><KBD>&#62;</KBD>
<DD>
Select the last entry in the PO file.

<DT><KBD>m</KBD>
<DD>
Record the location of the current entry for later use.

<DT><KBD>l</KBD>
<DD>
Return to a previously saved entry location.

<DT><KBD>x</KBD>
<DD>
Exchange the current entry location with the previously saved one.

</DL>

<P>
Any GNU Emacs command able to reposition the cursor may be used
to select the current entry in PO mode, including commands which
move by characters, lines, paragraphs, screens or pages, and search
commands.  However, there is a kind of standard way to display the
current entry in PO mode, which usual GNU Emacs commands moving
the cursor do not especially try to enforce.  The command <KBD>.</KBD>
(<CODE>po-current-entry</CODE>) has the sole purpose of redisplaying the
current entry properly, after the current entry has been changed by
means external to PO mode, or the Emacs screen otherwise altered.

</P>
<P>
It is yet to decide if PO mode would help the translator, or otherwise
irritate her, by forcing a more fixed window disposition while she
is doing her work.  We originally had quite precise ideas about
how windows should behave, but on the other hand, anyone used to
GNU Emacs is often happy to keep full control.  Maybe a fixed window
disposition might be offered as a PO mode option that the translator
might activate or deactivate at will, so it could be offered on an
experimental basis.  If nobody feels a real need for using it, or
a compulsion for writing it, we might as well drop this whole idea.
The incentive for doing it should come from translators rather than
programmers, as opinions from an experienced translator are surely
more worth to me than opinions from programmers <EM>thinking</EM> about
how <EM>others</EM> should do translation.

</P>
<P>
The commands <KBD>n</KBD> (<CODE>po-next-entry</CODE>) and <KBD>p</KBD>
(<CODE>po-previous-entry</CODE>) move the cursor the entry following,
or preceding, the current one.  If <KBD>n</KBD> is given while the
cursor is on the last entry of the PO file, or if <KBD>p</KBD>
is given while the cursor is on the first entry, no move is done.
<KBD><KBD>SPC</KBD></KBD> and <KBD><KBD>DEL</KBD></KBD> are alternate keys for <KBD>n</KBD> and
<KBD>p</KBD>, respectively.

</P>
<P>
The commands <KBD>&#60;</KBD> (<CODE>po-first-entry</CODE>) and <KBD>&#62;</KBD>
(<CODE>po-last-entry</CODE>) move the cursor to the first entry, or last
entry, of the PO file.  When the cursor is located past the last
entry in a PO file, most PO mode commands will return an error saying
<SAMP>`After last entry'</SAMP>.  However, the commands <KBD>&#60;</KBD> and <KBD>&#62;</KBD>
have the special property of being able to work even when the cursor
is not into some PO file entry, and you may use them for nicely
correcting this situation.  But even these commands will fail on a
truly empty PO file.  There are development plans for PO mode for it
to interactively fill an empty PO file from sources.  See section <A HREF="gettext.html#SEC16">Marking Translatable Strings</A>.

</P>
<P>
The translator may decide, before working at the translation of
a particular entry, that she needs browsing the remainder of the
PO file, maybe for finding the terminology or phraseology used
in related entries.  She can of course use the standard Emacs idioms
for saving the current cursor location in some register, and use that
register for getting back, or else, to use the location ring.

</P>
<P>
PO mode offers another approach, by which cursor locations may be saved
onto a special stack.  The command <KBD>m</KBD> (<CODE>po-push-location</CODE>)
merely adds the location of current entry to the stack, pushing
the already saved locations under the new one.  The command
<KBD>l</KBD> (<CODE>po-pop-location</CODE>) consumes the top stack element and
reposition the cursor to the entry associated with that top element.
This position is then lost, for the next <KBD>l</KBD> will move the cursor
to the previously saved location, and so on until locations remain
on the stack.

</P>
<P>
If the translator wants the position to be kept on the location stack,
maybe for taking a mere look at the entry associated with the top
element, then go elsewhere with the intent of getting back later, she
ought to use <KBD>m</KBD> immediately after <KBD>l</KBD>.

</P>
<P>
The command <KBD>x</KBD> (<CODE>po-exchange-location</CODE>) simultaneously
reposition the cursor to the entry associated with the top element of
the stack of saved locations, and replace that top element with the
location of the current entry before the move.  Consequently, repeating
the <KBD>x</KBD> command toggles alternatively between two entries.
For achieving this, the translator will position the cursor on the
first entry, use <KBD>m</KBD>, then position to the second entry, and
merely use <KBD>x</KBD> for making the switch.

</P>


<H2><A NAME="SEC12" HREF="gettext_toc.html#TOC12">Normalizing Strings in Entries</A></H2>

<P>
There are many different ways for encoding a particular string into a
PO file entry, because there are so many different ways to split and
quote multi-line strings, and even, to represent special characters
by backslahsed escaped sequences.  Some features of PO mode rely on
the ability for PO mode to scan an already existing PO file for a
particular string encoded into the <CODE>msgid</CODE> field of some entry.
Even if PO mode has internally all the built-in machinery for
implementing this recognition easily, doing it fast is technically
difficult.  For facilitating a solution to this efficiency problem,
we decided for a canonical representation for strings.

</P>
<P>
A conventional representation of strings in a PO file is currently
under discussion, and PO mode experiments a canonical representation.
Having both <CODE>xgettext</CODE> and PO mode converging towards a uniform
way of representing equivalent strings would be useful, as the internal
normalization needed by PO mode could be automatically satisfied
when using <CODE>xgettext</CODE> from GNU <CODE>gettext</CODE>.  An explicit
PO mode normalization should then be only necessary for PO files
imported from elsewhere, or for when the convention itself evolves.

</P>
<P>
So, for achieving normalization of at least the strings of a given
PO file needing a canonical representation, the following PO mode
command is available:

</P>
<DL COMPACT>

<DT><KBD>M-x po-normalize</KBD>
<DD>
Tidy the whole PO file by making entries more uniform.

</DL>

<P>
The special command <KBD>M-x po-normalize</KBD>, which has no associate
keys, revises all entries, ensuring that strings of both original
and translated entries use uniform internal quoting in the PO file.
It also removes any crumb after the last entry.  This command may be
useful for PO files freshly imported from elsewhere, or if we ever
improve on the canonical quoting format we use.  This canonical format
is not only meant for getting cleaner PO files, but also for greatly
speeding up <CODE>msgid</CODE> string lookup for some other PO mode commands.

</P>
<P>
<KBD>M-x po-normalize</KBD> presently makes three passes over the entries.
The first implements heuristics for converting PO files for GNU
<CODE>gettext</CODE> 0.6 and earlier, in which <CODE>msgid</CODE> and <CODE>msgstr</CODE>
fields were using K&#38;R style C string syntax for multi-line strings.
These heuristics may fail for comments not related to obsolete
entries and ending with a backslash; they also depend on subsequent
passes for finalizing the proper commenting of continued lines for
obsolete entries.  This first pass might disappear once all oldish PO
files would have been adjusted.  The second and third pass normalize
all <CODE>msgid</CODE> and <CODE>msgstr</CODE> strings respectively.  They also
clean out those trailing backslashes used by XView's <CODE>msgfmt</CODE>
for continued lines.

</P>
<P>
Having such an explicit normalizing command allows for importing PO
files from other sources, but also eases the evolution of the current
convention, evolution driven mostly by aesthetic concerns, as of now.
It is all easy to make suggested adjustments at a later time, as the
normalizing command and eventually, other GNU <CODE>gettext</CODE> tools
should greatly automate conformance.  A description of the canonical
string format is given below, for the particular benefit of those not
having GNU Emacs handy, and who would nevertheless want to handcraft
their PO files in nice ways.

</P>
<P>
Right now, in PO mode, strings are single line or multi-line.  A string
goes multi-line if and only if it has <EM>embedded</EM> newlines, that
is, if it matches <SAMP>`[^\n]\n+[^\n]'</SAMP>.  So, we would have:

</P>

<PRE>
msgstr "\n\nHello, world!\n\n\n"
</PRE>

<P>
but, replacing the space by a newline, this becomes:

</P>

<PRE>
msgstr ""
"\n"
"\n"
"Hello,\n"
"world!\n"
"\n"
"\n"
</PRE>

<P>
We are deliberately using a caricatural example, here, to make the
point clearer.  Usually, multi-lines are not that bad looking.
It is probable that we will implement the following suggestion.
We might lump together all initial newlines into the empty string,
and also all newlines introducing empty lines (that is, for <VAR>n</VAR>
&#62; 1, the <VAR>n</VAR>-1'th last newlines would go together on a separate
string), so making the previous example appear:

</P>

<PRE>
msgstr "\n\n"
"Hello,\n"
"world!\n"
"\n\n"
</PRE>

<P>
There are a few yet undecided little points about string normalization,
to be documented in this manual, once these questions settle.

</P>


<H1><A NAME="SEC13" HREF="gettext_toc.html#TOC13">Preparing Program Sources</A></H1>

<P>
For the programmer, changes to the C source code fall into three
categories.  First, you have to make the localization functions
known to all modules needing message translation.  Second, you should
properly trigger the operation of GNU <CODE>gettext</CODE> when the program
initializes, usually from the <CODE>main</CODE> function.  Last, you should
identify and especially mark all constant strings in your program
needing translation.

</P>
<P>
Presuming that your set of programs, or package, has been adjusted
so all needed GNU <CODE>gettext</CODE> files are available, and your
<TT>`Makefile'</TT> files are adjusted (see section <A HREF="gettext.html#SEC65">The Maintainer's View</A>), each C module
having translated C strings should contain the line:

</P>

<PRE>
#include &#60;libintl.h&#62;
</PRE>

<P>
The remaining changes to your C sources are discussed in the further
sections of this chapter.

</P>


<H2><A NAME="SEC14" HREF="gettext_toc.html#TOC14">Triggering <CODE>gettext</CODE> Operations</A></H2>

<P>
The initialization of locale data should be done with more or less
the same code in every program, as demonstrated below:

</P>

<PRE>
int
main (argc, argv)
     int argc;
     char argv;
{
  ...
  setlocale (LC_ALL, "");
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);
  ...
}
</PRE>

<P>
<VAR>PACKAGE</VAR> and <VAR>LOCALEDIR</VAR> should be provided either by
<TT>`config.h'</TT> or by the Makefile.  For now consult the <CODE>gettext</CODE>
sources for more information.

</P>
<P>
The use of <CODE>LC_ALL</CODE> might not be appropriate for you.
<CODE>LC_ALL</CODE> includes all locale categories and especially
<CODE>LC_CTYPE</CODE>.  This later category is responsible for determining
character classes with the <CODE>isalnum</CODE> etc. functions from
<TT>`ctype.h'</TT> which could especially for programs, which process some
kind of input language, be wrong.  For example this would mean that a
source code using the  (cedille character) is runnable in
France but not in the U.S.

</P>
<P>
So it is sometimes necessary to replace the <CODE>LC_ALL</CODE> line in the
code above by a sequence of <CODE>setlocale</CODE> lines

</P>

<PRE>
{
  ...
  setlocale (LC_TIME, "");
  setlocale (LC_MESSAGES, "");
  ...
}
</PRE>

<P>
or to switch for and back to the character class in question.

</P>


<H2><A NAME="SEC15" HREF="gettext_toc.html#TOC15">How Marks Appears in Sources</A></H2>

<P>
The C sources should mark all strings requiring translation.  Marking
is done in such a way that each translatable string appears to be
the sole argument of some function or preprocessor macro.  There are
only a few such possible functions or macros meant for translation,
and their names are said to be marking keywords.  The marking is
attached to strings themselves, rather than to what we do with them.
This approach has more uses.  A blatant example is an error message
produced by formatting.  The format string needs translation, as
well as some strings inserted through some <SAMP>`%s'</SAMP> specification
in the format, while the result from <CODE>sprintf</CODE> may have so many
different instances that it is unpractical to list them all in some
<SAMP>`error_string_out()'</SAMP> routine, say.

</P>
<P>
This marking operation has two goals.  The first goal of marking
is for triggering the retrieval of the translation, at run time.
The keyword are possibly resolved into a routine able to dynamically
return the proper translation, as far as possible or wanted, for the
argument string.  Most localizable strings are found into executable
positions, that is, affected to variables or given as parameter to
functions.  But this is not universal usage, and some translatable
strings appear in structured initializations.  See section <A HREF="gettext.html#SEC17">Special Cases of Translatable Strings</A>.

</P>
<P>
The second goal of the marking operation is to help <CODE>xgettext</CODE>
at properly extracting all translatable strings when it scans a set
of program sources and produces PO file templates.

</P>
<P>
The canonical keyword for marking translatable strings is
<SAMP>`gettext'</SAMP>, it gave its name to the whole GNU <CODE>gettext</CODE>
package.  For packages making only light use of the <SAMP>`gettext'</SAMP>
keyword, macro or function, it is easily used <EM>as is</EM>.  However,
for packages using the <CODE>gettext</CODE> interface more heavily, it
is usually more convenient giving the main keyword a shorter, less
obtrusive name.  Indeed, the keyword might appear on a lot of strings
all over the package, and programmers usually do not want nor need
that their program sources remind them loud, all the time, that they
are internationalized.  Further, a long keyword has the disadvantage
of using more horizontal space, forcing more indentation work on
sources for those trying to keep them within 79 or 80 columns.

</P>
<P>
Many GNU packages use <SAMP>`_'</SAMP> (a simple underline) as a keyword,
and write <SAMP>`_("Translatable string")'</SAMP> instead of <SAMP>`gettext
("Translatable string")'</SAMP>.  Further, the usual GNU coding rule
wanting that there is a space between the keyword and the opening
parenthesis is relaxed, in practice, for this particular usage.
So, the textual overhead per translatable string is reduced to
only three characters: the underline and the two parentheses.
However, even if GNU <CODE>gettext</CODE> uses this convention internally,
it does not offer it officially.  The real, genuine keyword is truly
<SAMP>`gettext'</SAMP> indeed.  It is fairly easy for those wanting to use
<SAMP>`_'</SAMP> instead of <SAMP>`gettext'</SAMP> to declare:

</P>

<PRE>
#include &#60;libintl.h&#62;
#define _(String) gettext (String)
</PRE>

<P>
instead of merely using <SAMP>`#include &#60;libintl.h&#62;'</SAMP>.

</P>
<P>
Later on, the maintenance is relatively easy.  If, as a programmer,
you add or modify a string, you will have to ask yourself if the
new or altered string requires translation, and include it within
<SAMP>`_()'</SAMP> if you think it should be translated.  <SAMP>`"%s: %d"'</SAMP> is
an example of string <EM>not</EM> requiring translation!

</P>


<H2><A NAME="SEC16" HREF="gettext_toc.html#TOC16">Marking Translatable Strings</A></H2>

<P>
In PO mode, one set of features is meant more for the programmer than
for the translator, and allows him to interactively mark which strings,
in a set of program sources, are translatable, and which are not.
Even if it is a fairly easy job for a programmer to find and mark
such strings by other means, using any editor of his choice, PO mode
makes this work more comfortable.  Further, this gives translators
who feel a little like programmers, or programmers who feel a little
like translators, a tool letting them work at marking translatable
strings in the program sources, while simultaneously producing a set of
translation in some language, for the package being internationalized.

</P>
<P>
The set of program sources, aimed by the PO mode commands describe
here, should have an Emacs tags table constructed for your project,
prior to using these PO file commands.  This is easy to do.  In any
shell window, change the directory to the root of your project, then
execute a command resembling:

</P>

<PRE>
etags src/*.[hc] lib/*.[hc]
</PRE>

<P>
presuming here you want to process all <TT>`.h'</TT> and <TT>`.c'</TT> files
from the <TT>`src/'</TT> and <TT>`lib/'</TT> directories.  This command will
explore all said files and create a <TT>`TAGS'</TT> file in your root
directory, somewhat summarizing the contents using a special file
format Emacs can understand.

</P>
<P>
For official GNU packages which follow the GNU coding standard there is
a make goal <CODE>tags</CODE> or <CODE>TAGS</CODE> which construct the tag files in
all directories and for all files containing source code.

</P>
<P>
Once your <TT>`TAGS'</TT> file is ready, the following commands assist
the programmer at marking translatable strings in his set of sources.
But these commands are necessarily driven from within a PO file
window, and it is likely that you do not even have such a PO file yet.
This is not a problem at all, as you may safely open a new, empty PO
file, mainly for using these commands.  This empty PO file will slowly
fill in while you mark strings as translatable in your program sources.

</P>
<DL COMPACT>

<DT><KBD>,</KBD>
<DD>
Search through program sources for a string which looks like a
candidate for translation.

<DT><KBD>M-,</KBD>
<DD>
Mark the last string found with <SAMP>`_()'</SAMP>.

<DT><KBD>M-.</KBD>
<DD>
Mark the last string found with a keyword taken from a set of possible
keywords.  This command with a prefix allows some management of these
keywords.

</DL>

<P>
The <KBD>,</KBD> (<CODE>po-tags-search</CODE>) command search for the next
occurrence of a string which looks like a possible candidate for
translation, and displays the program source in another Emacs window,
positioned in such a way that the string is near the top of this other
window.  If the string is to big to fit whole in this window, it is
rather positioned so only its end is shown.  In any case, the cursor
is left in the PO file window.  If the shown string would be better
presented differently in different native languages, you may mark it
using <KBD>M-,</KBD> or <KBD>M-.</KBD>.  Otherwise, you might rather ignore it
and skip to the next string by merely repeating the <KBD>,</KBD> command.

</P>
<P>
A string is a good candidate for translation if it contains a sequence
of three or more letters.  A string containing at most two letters in
a row will be considered as a candidate if it has more letters than
non-letters.  The command disregards strings containing no letters,
or isolated letters only.  It also disregards strings within comments,
or strings already marked with some keyword PO mode knows (see below).

</P>
<P>
If you have never told Emacs about some <TT>`TAGS'</TT> file to use, the
command will request that you specify one from the minibuffer, the
first time you use the command.  You may later change your <TT>`TAGS'</TT>
file by using the regular Emacs command <KBD>M-x visit-tags-table</KBD>,
which will ask you to name the precise <TT>`TAGS'</TT> file you want
to use.  See section `Tag Tables' in <CITE>The Emacs Editor</CITE>.

</P>
<P>
Each time you use the <KBD>,</KBD> command, the search resumes where it was
left over by the previous search, and goes through all program sources,
obeying the <TT>`TAGS'</TT> file, until all sources have been processed.
However, by giving a prefix argument to the command (<KBD>C-u
,)</KBD>, you may request that the search be restarted all over again
from the first program source; but in this case, strings that you
recently marked as translatable will be automatically skipped.

</P>
<P>
Using this <KBD>,</KBD> command does not prevent using of other regular
Emacs tags commands.  For example, regular <CODE>tags-search</CODE> or
<CODE>tags-query-replace</CODE> commands may be used without disrupting the
independent <KBD>,</KBD> search sequence.  However, as implemented, the
<EM>initial</EM> <KBD>,</KBD> command (or the <KBD>,</KBD> command is used with a
prefix) might also reinitialize the regular Emacs tags searching to the
first tags file, this reinitialization might be considered spurious.

</P>
<P>
The <KBD>M-,</KBD> (<CODE>po-mark-translatable</CODE>) command will mark the
recently found string with the <SAMP>`_'</SAMP> keyword.  The <KBD>M-.</KBD>
(<CODE>po-select-mark-and-mark</CODE>) command will request that you type
one keyword from the minibuffer and use that keyword for marking
the string.  Both commands will automatically create a new PO file
untranslated entry for the string being marked, and make it the
current entry (making it easy for you to immediately proceed to its
translation, if you feel like doing it right away).  It is possible
that the modifications made to the program source by <KBD>M-,</KBD> or
<KBD>M-.</KBD> render some source line longer than 80 columns, forcing you
to break and re-indent this line differently.  You may use the <KBD>o</KBD>
command from PO mode, or any other window changing command from
GNU Emacs, to break out into the program source window, and do any
needed adjustments.  You will have to use some regular Emacs command
to return the cursor to the PO file window, if you want commanding
<KBD>,</KBD> for the next string, say.

</P>
<P>
The <KBD>M-.</KBD> command has a few built-in speedups, so you do not
have to explicitly type all keywords all the time.  The first such
speedup is that you are presented with a <EM>preferred</EM> keyword,
which you may accept by merely typing <KBD><KBD>RET</KBD></KBD> at the prompt.
The second speedup is that you may type any non-ambiguous prefix of the
keyword you really mean, and the command will complete it automatically
for you.  This also means that PO mode has to <EM>know</EM> all
your possible keywords, and that it will not accept mistyped keywords.

</P>
<P>
If you reply <KBD>?</KBD> to the keyword request, the command gives a
list of all known keywords, from which you may choose.  When the
command is prefixed by an argument (<KBD>C-u M-.</KBD>), it inhibits
updating any program source or PO file buffer, and does some simple
keyword management instead.  In this case, the command asks for a
keyword, written in full, which becomes a new allowed keyword for
later <KBD>M-.</KBD> commands.  Moreover, this new keyword automatically
becomes the <EM>preferred</EM> keyword for later commands.  By typing
an already known keyword in response to <KBD>C-u M-.</KBD>, one merely
changes the <EM>preferred</EM> keyword and does nothing more.

</P>
<P>
All keywords known for <KBD>M-.</KBD> are recognized by the <KBD>,</KBD> command
when scanning for strings, and strings already marked by any of those
known keywords are automatically skipped.  If many PO files are opened
simultaneously, each one has its own independent set of known keywords.
There is no provision in PO mode, currently, for deleting a known
keyword, you have to quit the file (maybe using <KBD>q</KBD>) and reopen
it afresh.  When a PO file is newly brought up in an Emacs window, only
<SAMP>`gettext'</SAMP> and <SAMP>`_'</SAMP> are known as keywords, and <SAMP>`gettext'</SAMP>
is preferred for the <KBD>M-.</KBD> command.  In fact, this is not useful to
prefer <SAMP>`_'</SAMP>, as this one is already built in the <KBD>M-,</KBD> command.

</P>


<H2><A NAME="SEC17" HREF="gettext_toc.html#TOC17">Special Cases of Translatable Strings</A></H2>

<P>
The attentive reader might now point out that it is not always possible
to mark translatable string with <CODE>gettext</CODE> or something like this.
Consider the following case:

</P>

<PRE>
{
  static const char *messages[] = {
    "some very meaningful message",
    "and another one"
  };
  const char *string;
  ...
  string
    = index &#62; 1 ? "a default message" : messages[index];

  fputs (string);
  ...
}
</PRE>

<P>
While it is no problem to mark the string <CODE>"a default message"</CODE> it
is not possible to mark the string initializers for <CODE>messages</CODE>.
What is to do?  We have to fulfill two tasks.  First we have to mark the
strings so that the <CODE>xgettext</CODE> program (see section <A HREF="gettext.html#SEC19">Invoking the <CODE>xgettext</CODE> Program</A>)
can find them, and second we have to translate the string at runtime
before printing them.

</P>
<P>
The first task can be fulfilled by creating a new keyword, which names a
no-op.  For the second we have to mark all access points to a string
from the array.  So one solution can look like this:

</P>

<PRE>
#define gettext_noop(String) (String)

{
  static const char *messages[] = {
    gettext_noop ("some very meaningful message"),
    gettext_noop ("and another one")
  };
  const char *string;
  ...
  string
    = index &#62; 1 ? gettext ("a default message") : gettext (messages[index]);

  fputs (string);
  ...
}
</PRE>

<P>
Please convince yourself that the string which is written by
<CODE>fputs</CODE> is translated in any case.  How to get <CODE>xgettext</CODE> know
the additional keyword <CODE>gettext_noop</CODE> is explained in section <A HREF="gettext.html#SEC19">Invoking the <CODE>xgettext</CODE> Program</A>.

</P>
<P>
The above is of course not the only solution.  You could also come along
with the following one:

</P>

<PRE>
#define gettext_noop(String) (String)

{
  static const char *messages[] = {
    gettext_noop ("some very meaningful message",
    gettext_noop ("and another one")
  };
  const char *string;
  ...
  string
    = index &#62; 1 ? gettext_noop ("a default message") : messages[index];

  fputs (gettext (string));
  ...
}
</PRE>

<P>
But this has some drawbacks.  First the programmer has to take care that
he uses <CODE>gettext_noop</CODE> for the string <CODE>"a default message"</CODE>.
A use of <CODE>gettext</CODE> could have in rare cases unpredictable results.
The second reason is found in the internals of the GNU <CODE>gettext</CODE>
Library which will make this solution less efficient.

</P>
<P>
One advantage is that you need not make control flow analysis to make
sure the output is really translated in any case.  But this analysis is
generally not very difficult.  If it should be in any situation you can
use this second method in this situation.

</P>


<H1><A NAME="SEC18" HREF="gettext_toc.html#TOC18">Making the Initial PO File</A></H1>


<H2><A NAME="SEC19" HREF="gettext_toc.html#TOC19">Invoking the <CODE>xgettext</CODE> Program</A></H2>


<PRE>
xgettext [<VAR>option</VAR>] <VAR>inputfile</VAR> ...
</PRE>

<DL COMPACT>

<DT><SAMP>`-a'</SAMP>
<DD>
<DT><SAMP>`--extract-all'</SAMP>
<DD>
Extract all strings.

<DT><SAMP>`-c [<VAR>tag</VAR>]'</SAMP>
<DD>
<DT><SAMP>`--add-comments[=<VAR>tag</VAR>]'</SAMP>
<DD>
Place comment block with <VAR>tag</VAR> (or those preceding keyword lines)
in output file.

<DT><SAMP>`-C'</SAMP>
<DD>
<DT><SAMP>`--c++'</SAMP>
<DD>
Recognize C++ style comments.

<DT><SAMP>`-d <VAR>name</VAR>'</SAMP>
<DD>
<DT><SAMP>`--default-domain=<VAR>name</VAR>'</SAMP>
<DD>
Use <TT>`<VAR>name</VAR>.po'</TT> for output (instead of <TT>`messages.po'</TT>).

<DT><SAMP>`-D <VAR>directory</VAR>'</SAMP>
<DD>
<DT><SAMP>`--directory=<VAR>directory</VAR>'</SAMP>
<DD>
Change to <VAR>directory</VAR> before beginning to search and scan source
files.  The resulting <TT>`.po'</TT> file will be written relative to the
original directory, though.

<DT><SAMP>`-f <VAR>file</VAR>'</SAMP>
<DD>
<DT><SAMP>`--files-from=<VAR>file</VAR>'</SAMP>
<DD>
Read the names of the input files from <VAR>file</VAR> instead of getting
them from the command line.

<DT><SAMP>`-h'</SAMP>
<DD>
<DT><SAMP>`--help'</SAMP>
<DD>
Display this help and exit.

<DT><SAMP>`-I <VAR>list</VAR>'</SAMP>
<DD>
<DT><SAMP>`--input-path=<VAR>list</VAR>'</SAMP>
<DD>
List of directories searched for input files.

<DT><SAMP>`-j'</SAMP>
<DD>
<DT><SAMP>`--join-existing'</SAMP>
<DD>
Join messages with existing file.

<DT><SAMP>`-k <VAR>word</VAR>'</SAMP>
<DD>
<DT><SAMP>`--keyword[=<VAR>word</VAR>]'</SAMP>
<DD>
Additonal keyword to be looked for (without <VAR>word</VAR> means not to
use default keywords).

The default keywords, which are always looked for if not explicitly
disabled, are <CODE>gettext</CODE>, <CODE>dgettext</CODE>, <CODE>dcgettext</CODE> and
<CODE>gettext_noop</CODE>.

<DT><SAMP>`-m [<VAR>string</VAR>]'</SAMP>
<DD>
<DT><SAMP>`--msgstr-prefix[=<VAR>string</VAR>]'</SAMP>
<DD>
Use <VAR>string</VAR> or "" as prefix for msgstr entries.

<DT><SAMP>`-M [<VAR>string</VAR>]'</SAMP>
<DD>
<DT><SAMP>`--msgstr-suffix[=<VAR>string</VAR>]'</SAMP>
<DD>
Use <VAR>string</VAR> or "" as suffix for msgstr entries.

<DT><SAMP>`--no-location'</SAMP>
<DD>
Do not write <SAMP>`#: <VAR>filename</VAR>:<VAR>line</VAR>'</SAMP> lines.

<DT><SAMP>`-n'</SAMP>
<DD>
<DT><SAMP>`--add-location'</SAMP>
<DD>
Generate <SAMP>`#: <VAR>filename</VAR>:<VAR>line</VAR>'</SAMP> lines (default).

<DT><SAMP>`--omit-header'</SAMP>
<DD>
Don't write header with <SAMP>`msgid ""'</SAMP> entry.

This is useful for testing purposes because it eliminates a source
of variance for generated <CODE>.gmo</CODE> files.  We can ship some of
these files in the GNU <CODE>gettext</CODE> package, and the result of
regenerating them through <CODE>msgfmt</CODE> should yield the same values.

<DT><SAMP>`-p <VAR>dir</VAR>'</SAMP>
<DD>
<DT><SAMP>`--output-dir=<VAR>dir</VAR>'</SAMP>
<DD>
Output files will be placed in directory <VAR>dir</VAR>.

<DT><SAMP>`-s'</SAMP>
<DD>
<DT><SAMP>`--sort-output'</SAMP>
<DD>
Generate sorted output and remove duplicates.

<DT><SAMP>`--strict'</SAMP>
<DD>
Write out strict Uniforum conforming PO file.

<DT><SAMP>`-v'</SAMP>
<DD>
<DT><SAMP>`--version'</SAMP>
<DD>
Output version information and exit.

<DT><SAMP>`-x <VAR>file</VAR>'</SAMP>
<DD>
<DT><SAMP>`--exclude-file=<VAR>file</VAR>'</SAMP>
<DD>
Entries from <VAR>file</VAR> are not extracted.

</DL>

<P>
Search path for supplementary PO files is:
<TT>`/usr/local/share/nls/src/'</TT>.

</P>
<P>
If <VAR>inputfile</VAR> is <SAMP>`-'</SAMP>, standard input is read.

</P>
<P>
This implementation of <CODE>xgettext</CODE> is able to process a few awkward
cases, like strings in preprocessor macros, ANSI concatenation of
adjacent strings, and escaped end of lines for continued strings.

</P>


<H2><A NAME="SEC20" HREF="gettext_toc.html#TOC20">C Sources Context</A></H2>

<P>
PO mode is particularily powerful when used with PO files
created through GNU <CODE>gettext</CODE> utilities, as those utilities
insert special comments in the PO files they generate.
Some of these special comments relate the PO file entry to
exactly where the untranslated string appears in the program sources.

</P>
<P>
When the translator gets to an untranslated entry, she is fairly
often faced with an original string which is not as informative as
it normally should, being succinct, cryptic, or otherwise ambiguous.
Before chosing how to translate the string, she needs to understand
better what the string really means and how tight the translation has
to be.  Most of times, when problems arise, the only way left to make
her judgment is looking at the true program sources from where this
string originated, searching for surrounding comments the programmer
might have put in there, and looking around for helping clues of
<EM>any</EM> kind.

</P>
<P>
Surely, when looking at program sources, the translator will receive
more help if she is a fluent programmer.  However, even if she is
not versed in programming and feels a little lost in C code, the
translator should not be shy at taking a look, once in a while.
It is most probable that she will still be able to find some of the
hints she needs.  She will learn quickly to not feel uncomfortable
in program code, paying more attention to programmer's comments,
variable and function names (if he dared chosing them well), and
overall organization, than to programmation itself.

</P>
<P>
The following commands are meant to help the translator at getting
program source context for a PO file entry.

</P>
<DL COMPACT>

<DT><KBD>c</KBD>
<DD>
Resume the display of a program source context, or cycle through them.

<DT><KBD>M-c</KBD>
<DD>
Display of a program source context selected by menu.

<DT><KBD>d</KBD>
<DD>
Add a directory to the search path for source files.

<DT><KBD>M-d</KBD>
<DD>
Delete a directory from the search path for source files.

</DL>

<P>
The commands <KBD>c</KBD> (<CODE>po-cycle-reference</CODE>) and <KBD>M-c</KBD>
(<CODE>po-select-reference</CODE>) both open another window displaying
some source program file, and already positioned in such a way that
it shows an actual use of the current string to translate.  By doing
so, the command gives source program context for the string.  But if
the entry has no source context references, or if all references
are unresolved along the search path for program sources, then the
command diagnoses this as an error.

</P>
<P>
Even if <KBD>c</KBD> (or <KBD>M-c</KBD>) opens a new window, the cursor stays
in the PO file window.  If the translator really wants to
get into the program source window, she ought to do it explicitly,
maybe by using command <KBD>o</KBD>.

</P>
<P>
When <KBD>c</KBD> is typed for the first time, or for a PO file entry which
is different of the last one used for getting source context, then the
command reacts by giving the first context available for this entry,
if any.  If some context has already been recently displayed for the
current PO file entry, and the translator wandered to do other
things, typing <KBD>c</KBD> again will merely resume, in another window,
the context last displayed.  In particular, if the translator moved
the cursor away from the context in the source file, the command will
bring the cursor back to the context.  By using <KBD>c</KBD> many times
in a row, with no interning other commands, PO mode will cycle to
the next available contexts for this particular entry, getting back
to the first context once the last has been shown.

</P>
<P>
The command <KBD>M-c</KBD> behaves differently.  Instead of cycling through
references, it lets the translator choose of particular reference among
many, and displays that reference.  It is best used with completion,
if the translator types <KBD>TAB</KBD> immediately after <KBD>M-c</KBD>, in
response to the question, she will be offered a menu of all possible
references, as a reminder of which are the acceptable answers.
This command is useful only where there are really many contexts
available for a single string to translate.

</P>
<P>
Program source files are usually found relative to where the PO
file stands.  As a special provision, when this fails, the file is
also looked for, but relative to the directory immediately above it.
Those two cases take proper care of most PO files.  However, it might
happen that a PO file has been moved, or is edited in a different
place than its normal location.  When this happens, the translator
should tell PO mode in which directory normally sits the genuine PO
file.  Many such directories may be specified, and all together, they
constitute what is called the <STRONG>search path</STRONG> for program sources.
The command <KBD>d</KBD> (<CODE>po-add-path</CODE>) is used to interactively
enter a new directory at the front of the search path, and the command
<KBD>M-d</KBD> (<CODE>po-delete-path</CODE>) is used to select, with completion,
one of the directories she does not want anymore on the search path.

</P>


<H2><A NAME="SEC21" HREF="gettext_toc.html#TOC21">Using Translation Compendiums</A></H2>

<P>
Compendiums are yet to be implemented.

</P>
<P>
An incoming PO mode feature will let the translator maintain a
compendium of already achieved translations.  A <STRONG>compendium</STRONG>
is a special PO file containing a set of translations recurring in
many different packages.  The translator will be given commands for
adding entries to her compendium, and later initializing untranslated
entries, or updating already translated entries, from translations
kept in the compendium.  For this to work, however, the compendium
would have to be normalized.  See section <A HREF="gettext.html#SEC12">Normalizing Strings in Entries</A>.

</P>


<H1><A NAME="SEC22" HREF="gettext_toc.html#TOC22">Updating Existing PO Files</A></H1>


<H2><A NAME="SEC23" HREF="gettext_toc.html#TOC23">Invoking the <CODE>tupdate</CODE> Program</A></H2>


<PRE>
tupdate --help
tupdate --version
tupdate <VAR>new</VAR> <VAR>old</VAR>
</PRE>

<P>
File <VAR>new</VAR> is the last created PO file (generally by
<CODE>xgettext</CODE>).  It need not contain any translations.  File
<VAR>old</VAR> is the PO file including the old translations which will
be taken over to the newly created file as long as they still match.

</P>
<P>
When English messages change in the programs, this is reflected in
the PO file as extracted by <CODE>xgettext</CODE>.  In large messages, that
can be hard to detect, and will obviously result in an incomplete
translation.  One of the virtues of <CODE>tupdate</CODE> is that it detects
such changes, saving the previous translation into a PO file comment,
so marking the entry as obsolete, and giving the modified string with
an empty translation, that is, marking the entry as untranslated.

</P>


<H2><A NAME="SEC24" HREF="gettext_toc.html#TOC24">Untranslated Entries</A></H2>

<P>
When <CODE>xgettext</CODE> originally creates a PO file, unless told
otherwise, it initializes the <CODE>msgid</CODE> field with the untranslated
string, and leaves the <CODE>msgstr</CODE> string to be empty.  Such entries,
having an empty translation, are said to be <STRONG>untranslated</STRONG> entries.
Later, when the programmer slightly modifies some string right in
the program, this change is later reflected in the PO file
by the appearance of a new untranslated entry for the modified string.

</P>
<P>
The usual commands moving from entry to entry consider untranslated
entries on the same level as active entries.  Untranslated entries
are easily recognizable by the fact they end with <SAMP>`msgstr ""'</SAMP>.

</P>
<P>
The work of the translator might be (quite naively) seen as the process
of seeking after an untranslated entry, editing a translation for
it, and repeating these actions until no untranslated entries remain.
Some commands are more specifically related to untranslated entry
processing.

</P>
<DL COMPACT>

<DT><KBD>e</KBD>
<DD>
Find the next untranslated entry.

<DT><KBD>M-e</KBD>
<DD>
Find the previous untranslated entry.

<DT><KBD>k</KBD>
<DD>
Turn the current entry into an untranslated one.

</DL>

<P>
The commands <KBD>e</KBD> (<CODE>po-next-empty-entry</CODE>) and <KBD>M-e</KBD>
(<CODE>po-previous-empty</CODE>) move forwards or backwards, chasing for an
obsolete entry.  If none is found, the search is extended and wraps
around in the PO file buffer.

</P>
<P>
An entry can be turned back into an untranslated entry by
merely emptying its translation, using the command <KBD>k</KBD>
(<CODE>po-kill-msgstr</CODE>).  See section <A HREF="gettext.html#SEC26">Modifying Translations</A>.

</P>
<P>
Also, when time comes to quit working on a PO file buffer
with the <KBD>q</KBD> command, the translator is asked for confirmation,
if some untranslated string still exists.

</P>


<H2><A NAME="SEC25" HREF="gettext_toc.html#TOC25">Obsolete Entries</A></H2>

<P>
By <STRONG>obsolete</STRONG> PO file entries, we mean those entries which are
commented out, usually by <CODE>tupdate</CODE> when it found that the
translation is not needed anymore by the package being localized.

</P>
<P>
The usual commands moving from entry to entry consider obsolete
entries on the same level as active entries.  Obsolete entries are
easily recognizable by the fact that all their lines start with
<KBD>#</KBD>, even those lines containing <CODE>msgid</CODE> or <CODE>msgstr</CODE>.

</P>
<P>
Commands exist for emptying the translation or reinitializing it
to the original untranslated string.  Commands interfacing with the
kill ring may force some previously saved text into the translation.
The user may interactively edit the translation.  All these commands
may apply to obsolete entries, carefully leaving the entry obsolete
after the fact.

</P>
<P>
Moreover, some commands are more specifically related to obsolete
entry processing.

</P>
<DL COMPACT>

<DT><KBD>M-n</KBD>
<DD>
<DT><KBD>M-<KBD>SPC</KBD></KBD>
<DD>
Find the next obsolete entry.

<DT><KBD>M-p</KBD>
<DD>
<DT><KBD>M-<KBD>DEL</KBD></KBD>
<DD>
Find the previous obsolete entry.

<DT><KBD>z</KBD>
<DD>
Make an active entry obsolete, or zap out an obsolete entry.

</DL>

<P>
The commands <KBD>M-n</KBD> (<CODE>po-next-obsolete-entry</CODE>) and <KBD>M-p</KBD>
(<CODE>po-previous-obsolete-entry</CODE>) move forwards or backwards,
chasing for an obsolete entry.  If none is found, the search is
extended and wraps around in the PO file buffer.  The commands
<KBD>M-<KBD>SPC</KBD></KBD> and <KBD>M-<KBD>DEL</KBD></KBD> are synonymous to <KBD>M-n</KBD>
and <KBD>M-p</KBD>, respectively.

</P>
<P>
PO mode does not provide ways for un-commenting an obsolete entry
and making it active, because this would reintroduce an original
untranslated string which does not correspond to any marked string
in the program sources.  This goes with the philosophy of never
introducing useless <CODE>msgid</CODE> values.

</P>
<P>
However, it is possible to comment out an active entry, so making
it obsolete.  GNU <CODE>gettext</CODE> utilities will later react to the
disappearance of a translation by using the untranslated string.
The command <KBD>z</KBD> (<CODE>po-fade-out-entry</CODE>) pushes the current entry
a little further towards annihilation.  If the entry is active, then
the entry is merely commented out.  If the entry is already obsolete,
then it is completely deleted from the PO file.  It is easy to recycle
the translation so deleted into some other PO file entry, usually
one which is untranslated.  See section <A HREF="gettext.html#SEC26">Modifying Translations</A>.

</P>
<P>
Here is a quite interesting problem to solve for later development of
PO mode, for those nights you are not sleepy.  The idea would be that
PO mode might become bright enough, one of these days, to make good
guesses at retrieving the most probable candidate, among all obsolete
entries, for initializing the translation of a newly appeared string.
I think it might be a quite hard problem to do this algorithmically, as
we have to develop good and efficient measures of string similarity.
Right now, PO mode completely lets the decision to the translator,
when the time comes to find the adequate obsolete translation, it
merely tries to provide handy tools for helping her to do so.

</P>


<H2><A NAME="SEC26" HREF="gettext_toc.html#TOC26">Modifying Translations</A></H2>

<P>
PO mode prevents direct edition of the PO file, by the usual
means Emacs give for altering a buffer's contents.  By doing so,
it pretends helping the translator to avoid little clerical errors
about the overall file format, or the proper quoting of strings,
as those errors would be easily made.  Other kinds of errors are
still possible, but some may be catched and diagnosed by the batch
validation process, which the translator may always trigger by the
<KBD>v</KBD> command.  For all other errors, the translator has to rely on
her own judgment, and also on the linguistic reports submitted to her
by the users of the translated package, having the same mother tongue.

</P>
<P>
When the time comes to create a translation, correct a error diagnosed
mechanically or reported by a user, the translator have to resort to
using the following commands for modifying the translations.

</P>
<DL COMPACT>

<DT><KBD>RET</KBD>
<DD>
Interactively edit the translation.

<DT><KBD>TAB</KBD>
<DD>
Reinitialize the translation with the original, untranslated string.

<DT><KBD>k</KBD>
<DD>
Save the translation on the kill ring, and delete it.

<DT><KBD>w</KBD>
<DD>
Save the translation on the kill ring, without deleting it.

<DT><KBD>y</KBD>
<DD>
Replace the translation, taking the new from the kill ring.

</DL>

<P>
The command <KBD>RET</KBD> (<CODE>po-edit-msgstr</CODE>) opens a new Emacs
window containing a copy of the translation taken from the current
PO file entry, all ready for edition, fully modifiable
and with the complete extent of GNU Emacs modifying commands.
The string is presented to the translator expunged of all quoting
marks, and she will modify the <EM>unquoted</EM> string in this
window to heart's content.  Once done, the regular Emacs command
<KBD>M-C-c</KBD> (<CODE>exit-recursive-edit</CODE>) may be used to return the
edited translation into the PO file, replacing the original
translation.  The keys <KBD>C-c C-c</KBD> are bound so they have the
same effect as <KBD>M-C-c</KBD>.

</P>
<P>
If the translator becomes unsatisfied with her translation to the
extent she prefers keeping the translation which was existent prior to
the <KBD>RET</KBD> command, she may use the regular Emacs command <KBD>C-]</KBD>
(<CODE>abort-recursive-edit</CODE>) to merely get rid of edition, while
preserving the original translation.  Another way would be for her
to exit normally with <KBD>C-c C-c</KBD>, then type <CODE>u</CODE> once for
undoing the whole effect of last edition.

</P>
<P>
While editing her translation, the translator should pay attention at
not inserting unwanted <KBD><KBD>RET</KBD></KBD> (carriage returns) characters at
the end of the translated string if those are not meant to be there,
or removing such characters when they are required.  Since these
characters are not visible in the editing buffer, they are easily to
introduce by mistake.  To help her, <KBD><KBD>RET</KBD></KBD> automatically puts
the character <KBD>&#60;</KBD> at the end of the string being edited, but this
<KBD>&#60;</KBD> is not really part of the string.  On exiting the editing
window with <KBD>C-c C-c</KBD>, PO mode automatically removes such
<KBD>&#60;</KBD> and all whitespace added after it.  If the translator adds
characters after the terminating <KBD>&#60;</KBD>, it looses its delimiting
property and integrally becomes part of the string.  If she removes
the delimiting <KBD>&#60;</KBD>, then the edited string is taken <EM>as
is</EM>, with all trailing newlines, even if invisible.  Also, if the
translated string ought to end itself with a genuine <KBD>&#60;</KBD>, then the
delimiting <KBD>&#60;</KBD> may not be removed; so the string should appear,
in the editing window, as ending with two <KBD>&#60;</KBD> in a row.

</P>
<P>
When a translation (or a comment) is being edited, the translator
may move the cursor back into the PO file buffer and freely
move to other entries, and browsing at will.  The edited entry will
be recovered as soon as the edit ceases, because this is this entry
only which is being modified.  If, with an edition still opened, the
translator wanders in the PO file buffer, she cannot modify
any other entry.  If she tries to, PO mode will react by suggesting
that she aborts the current edit, or else, by inviting her to finish
the current edit prior to any other modification.

</P>
<P>
The command <KBD>TAB</KBD> (<CODE>po-msgid-to-msgstr</CODE>) initializes, or
reinitializes the translation with the original string.  This command
is normally used when the translator wants to redo a fresh translation
of the original string, disregarding any previous work.

</P>
<P>
In fact, whether it is best to start a translation with an empty
string, or rather with a copy of the original string, is a matter of
taste or habit.  Sometimes, the source mother tongue language and the
target language are so different that is simply best to start writing
on an empty page.  At other times, the source and target languages
are so close that it would be a waste to retype a number of words
already being written in the original string.  A translator may also
like having the original string right under her eyes, as she will
progressively overwrite the original text with the translation, even
if this requires some extra editing work to get rid of the original.

</P>
<P>
The command <KBD>k</KBD> (<CODE>po-kill-msgstr</CODE>) merely empties the
translation string, so turning the entry into an untranslated
one.  But while doing so, its previous contents is put apart in
a special place, known as the kill ring.  The command <KBD>w</KBD>
(<CODE>po-kill-ring-save-msgstr</CODE>) has also the effect of taking a
copy of the translation onto the kill ring, but it otherwise leaves
the entry alone, and does <EM>not</EM> remove the translation from the
entry.  Both commands use exactly the Emacs kill ring, which is shared
between buffers, and which is well known already to GNU Emacs lovers.

</P>
<P>
The translator may use <KBD>k</KBD> or <KBD>w</KBD> many times in the course
of her work, as the kill ring may hold several saved translations.
From the kill ring, strings may later be reinserted in various
Emacs buffers.  In particular, the kill ring may be used for moving
translation strings between different entries of a single PO file
buffer, or if the translator is handling many such buffers at once,
even between PO files.

</P>
<P>
To facilitate exchanges with buffers which are not in PO mode, the
translation string put on the kill ring by the <KBD>k</KBD> command is fully
unquoted before being saved: external quotes are removed, multi-lines
strings are concatenated, and backslashed escaped sequences are turned
into their corresponding characters.  In the special case of obsolete
entries, the translation is also uncommented prior to saving.

</P>
<P>
The command <KBD>y</KBD> (<CODE>po-yank-msgstr</CODE>) completely replaces the
translation of the current entry by a string taken from the kill ring.
Following GNU Emacs terminology, we then say that the replacement
string is <STRONG>yanked</STRONG> into the PO file buffer.
See section `Yanking' in <CITE>The Emacs Editor</CITE>.
The first time <KBD>y</KBD> is used, the translation receives the value of
the most recent addition to the kill ring.  If <KBD>y</KBD> is typed once
again, immediately, without intervening keystrokes, the translation
just inserted is taken away and replaced by the second most recent
addition to the kill ring.  By repeating <KBD>y</KBD> many times in a row,
the translator may travel along the kill ring for saved strings,
until she finds the string she really wanted.

</P>
<P>
When a string is yanked into a PO file entry, it is fully and
automatically requoted for complying with the format PO files should
have.  Further, if the entry is obsolete, PO mode then appropriately
push the inserted string inside comments.  Once again, translators
should not burden themselves with quoting considerations besides, of
course, the necessity of the translated string itself respective to
the program using it.

</P>
<P>
Note that <KBD>k</KBD> or <KBD>w</KBD> are not the only commands pushing strings
on the kill ring, as almost any PO mode command replacing translation
strings (or the translator comments) automatically save the old string
on the kill ring.  The main exceptions to this general rule are the
yanking commands themselves.

</P>
<P>
To better illustrate the operation of killing and yanking, let's
use an actual example, taken from a common situation.  When the
programmer slightly modifies some string right in the program, his
change is later reflected in the PO file by the appearance
of a new untranslated entry for the modified string, and the fact
that the entry translating the original or unmodified string becomes
obsolete.  In many cases, the translator might spare herself some work
by retrieving the unmodified translation from the obsolete entry,
then initializing the untranslated entry <CODE>msgstr</CODE> field with
this retrieved translation.  Once this done, the obsolete entry is
not wanted anymore, and may be safely deleted.

</P>
<P>
When the translator finds an untranslated entry and suspects that a
slight variant of the translation exists, she immediately uses <KBD>m</KBD>
to mark the current entry location, then starts chasing obsolete
entries with <KBD>M-SPC</KBD>, hoping to find some translation corresponding
to the unmodified string.  Once found, she uses the <KBD>z</KBD> command
for deleting the obsolete entry, knowing that <KBD>z</KBD> also <EM>kills</EM>
the translation, that is, pushes the translation on the kill ring.
Then, <KBD>l</KBD> returns to the initial untranslated entry, <KBD>y</KBD>
then <EM>yanks</EM> the saved translation right into the <CODE>msgstr</CODE>
field.  The translator is then free to use <KBD><KBD>RET</KBD></KBD> for fine
tuning the translation contents, and maybe to later use <KBD>e</KBD>,
then <KBD>m</KBD> again, for going on with the next untranslated string.

</P>
<P>
When some sequence of keys has to be typed over and over again, the
translator may find comfortable to become more acquainted with the GNU
Emacs capability of learning these sequences and playing them back under
request.  See section `Keyboard Macros' in <CITE>The Emacs Editor</CITE>.

</P>


<H2><A NAME="SEC27" HREF="gettext_toc.html#TOC27">Modifying Comments</A></H2>

<P>
Any translation work done seriously will raise many linguistic
difficulties, for which decisions have to be made, and the choices
further documented.  These documents may be saved within the
PO file in form of translator comments, which the translator
is free to create, delete, or modify at will.  These comments may
be useful to herself when she returns to this PO file after a while.
Memory forgets!

</P>
<P>
These commands are somewhat similar to those modifying translations,
so the general indications given for these apply here.  See section <A HREF="gettext.html#SEC26">Modifying Translations</A>.

</P>
<DL COMPACT>

<DT><KBD>M-RET</KBD>
<DD>
Interactively edit the translator comments.

<DT><KBD>M-k</KBD>
<DD>
Save the translator comments on the kill ring, and delete it.

<DT><KBD>M-w</KBD>
<DD>
Save the translator comments on the kill ring, without deleting it.

<DT><KBD>M-y</KBD>
<DD>
Replace the translator comments, taking the new from the kill ring.

</DL>

<P>
Those commands parallel PO mode commands for modifying the translation
strings, and behave much the same way as them, except that they handle
this part of PO file comments meant for translator usage, rather
than the translation strings.  So, the descriptions given below are
slightly succinct, because the full details have already been given.
See section <A HREF="gettext.html#SEC26">Modifying Translations</A>.

</P>
<P>
The command <KBD>M-RET</KBD> (<CODE>po-edit-comment</CODE>) opens a new Emacs
window containing a copy of the translator comments the current
PO file entry.  If there is no such comments, PO mode
understands that the translator wants to add a comment to the entry,
and she is presented an empty screen.  Comment marks (<KBD>#</KBD>) and
the space following them are automatically removed before edition,
and reinstated after.  For translator comments pertaining to obsolete
entries, the uncommenting and recommenting operations are done twice.
The command <KBD>#</KBD> also has the same effect as <KBD>M-RET</KBD>, and might
be easier to type.  Once in the editing window, the keys <KBD>C-c
C-c</KBD> allow the translator to tell she is finished with editing
the comment.

</P>
<P>
The command <KBD>M-k</KBD> (<CODE>po-kill-comment</CODE>) get rid of all
translator comments, while saving those comments on the kill ring.
The command <KBD>M-w</KBD> (<CODE>po-kill-ring-save-comment</CODE>) takes
a copy of the translator comments on the kill ring, but leaves
them undisturbed in the current entry.  The command <KBD>M-y</KBD>
(<CODE>po-yank-comment</CODE>) completely replaces the translator comments
by a string taken at the front of the kill ring.  When this command
is immediately repeated, the comments just inserted are withdrawn,
and replaced by other strings taken along the kill ring.

</P>
<P>
On the kill ring, all strings have the same nature.  There is no
distinction between <EM>translation</EM> strings and <EM>translator
comments</EM> strings.  So, for example, let's presume the translator
has just finished editing a translation, and wants to create a new
translator comments for documenting why the previous translation was
not good, just to remember what was the problem.  Foreseeing that she
will do that in her documentation, the translator will want to quote
the previous translation in her translator comments.  For doing so, she
may initialize the translator comments with the previous translation,
still at the head of the kill ring.  Because editing already pushed the
previous translation on the kill ring, she just has to type <KBD>M-w</KBD>
prior to <KBD>#</KBD>, and the previous translation will be right there,
all ready for being introduced by some explanatory text.

</P>
<P>
On the other hand, presume there are some translator comments already
and that the translator wants to add to those comments, instead
of wholly replacing them.  Then, she should edit the comment right
away with <KBD>#</KBD>.  Once inside the editing window, she can use the
regular GNU Emacs commands <KBD>C-y</KBD> (<CODE>yank</CODE>) and <KBD>M-y</KBD>
(<CODE>yank-pop</CODE>) for getting the previous translation where she likes.

</P>


<H2><A NAME="SEC28" HREF="gettext_toc.html#TOC28">Consulting Auxiliary PO Files</A></H2>

<P>
An incoming feature of PO mode should help the knowledgeable translator
to take advantage of translations already achieved in other languages
she just happens to know, by providing these other language translation
as additional context for her own work.  Each PO file existing for
the same package the translator is working on, but targeted to a
different mother tongue language, is called an <STRONG>auxiliary</STRONG> PO file.
Commands will exist for declaring and handling auxiliary PO files,
and also for showing contexts for the entry under work.  For this to
work fully, all auxiliary PO files will have to be normalized.

</P>


<H1><A NAME="SEC29" HREF="gettext_toc.html#TOC29">Producing Binary MO Files</A></H1>


<H2><A NAME="SEC30" HREF="gettext_toc.html#TOC30">Invoking the <CODE>msgfmt</CODE> Program</A></H2>


<PRE>
Usage: msgfmt [<VAR>option</VAR>] <VAR>filename</VAR>.po ...
</PRE>

<DL COMPACT>

<DT><SAMP>`-a <VAR>number</VAR>'</SAMP>
<DD>
<DT><SAMP>`--alignment=<VAR>number</VAR>'</SAMP>
<DD>
Align strings to <VAR>number</VAR> bytes (default: 1).

<DT><SAMP>`-h'</SAMP>
<DD>
<DT><SAMP>`--help'</SAMP>
<DD>
Display this help and exit.

<DT><SAMP>`-I <VAR>list</VAR>'</SAMP>
<DD>
<DT><SAMP>`--input-path=<VAR>list</VAR>'</SAMP>
<DD>
List of directories searched for input files.

<DT><SAMP>`--no-hash'</SAMP>
<DD>
Binary file will not include the hash table.

<DT><SAMP>`-o <VAR>file</VAR>'</SAMP>
<DD>
<DT><SAMP>`--output-file=<VAR>file</VAR>'</SAMP>
<DD>
Specify output file name as <VAR>file</VAR>.

<DT><SAMP>`-v'</SAMP>
<DD>
<DT><SAMP>`--verbose'</SAMP>
<DD>
Detect and diagnose input file anomalies which might represent
translation errors.  The <CODE>msgid</CODE> and <CODE>msgstr</CODE> strings are
studied and compared.  It is considered abnormal that one string
starts or ends with a newline while the other does not.  Also, both
strings should have the same number of <SAMP>`%'</SAMP> format specifiers,
with matching types.  For example, the check will diagnose using
<SAMP>`%.*s'</SAMP> against <SAMP>`%s'</SAMP>, or <SAMP>`%d'</SAMP> against <SAMP>`%s'</SAMP>, or
<SAMP>`%d'</SAMP> against <SAMP>`%x'</SAMP>.  It can even handle positional parameters.

<DT><SAMP>`-V'</SAMP>
<DD>
<DT><SAMP>`--version'</SAMP>
<DD>
Output version information and exit.

</DL>

<P>
If input file is <SAMP>`-'</SAMP>, standard input is read.  If output file
is <SAMP>`-'</SAMP>, output is written to standard output.

</P>
<P>
The search patch for <CODE>msgfmt</CODE> is <TT>`/usr/local/share/nls/src/'</TT>,
by default.  It represents the path to additional directories where
other PO files can be found.  This feature could be used for some
PO files for standard libraries, in case we would like to spare
translating their strings over and over again.  The <SAMP>`-x'</SAMP> option
could then exclude these strings from the generation.

</P>


<H2><A NAME="SEC31" HREF="gettext_toc.html#TOC31">The Format of GNU MO Files</A></H2>

<P>
The format of the generated MO files is best described by a picture,
which appears below.

</P>
<P>
The first two words serve the identification of the file.  The magic
number will always signal GNU MO files.  The number is stored in the
byte order of the generating machine, so the magic number really is
two numbers: <CODE>0x950412de</CODE> and <CODE>0xde120495</CODE>.  The second
word describes the current revision of the file format.  For now the
revision is 0.  This might change in future versions, and ensures
that the readers of MO files can distinguish new formats from old
ones, so that both can be handled correctly.  The version is kept
separate from the magic number, instead of using different magic
numbers for different formats, mainly because <TT>`/etc/magic'</TT> is
not updated often.  It might be better to have magic separated from
internal format version identification.

</P>
<P>
Follow a number of pointers to later tables in the file, allowing
for the extension of the prefix part of MO files without having to
recompile programs reading them.  This might become useful for later
inserting a few flag bits, indication about the charset used, new
tables, or other things.

</P>
<P>
Then, at offset <VAR>O</VAR> and offset <VAR>T</VAR> in the picture, two tables
of string descriptors can be found.  In both tables, each string
descriptor uses two 32 bits integers, one for the string length,
another for the offset of the string in the MO file, counting in bytes
from the start of the file.  The first table contains descriptors
for the original strings, and is sorted so the original strings
are in increasing lexicographical order.  The second table contains
descriptors for the translated strings, and is parallel to the first
table: to find the corresponding translation one has to access the
array slot in the second array with the same index.

</P>
<P>
Having the original strings sorted enables the use of simple binary
search, for when the MO file does not contain an hashing table, or
for when it is not practical to use the hashing table provided in
the MO file.  This also has another advantage, as the empty string
in a PO file GNU <CODE>gettext</CODE> is usually <EM>translated</EM> into
some system information attached to that particular MO file, and the
empty string necessarily becomes the first in both the original and
translated tables, making the system information very easy to find.

</P>
<P>
The size <VAR>S</VAR> of the hash table can be zero.  In this case, the
hash table itself is not contained in the MO file.  Some people might
prefer this because a precomputed hashing table takes disk space, and
does not win <EM>that</EM> much speed.  The hash table contains indices
to the sorted array of strings in the MO file.  Conflict resolution is
done by double hashing.  The precise hashing algorithm used is fairly
dependent of GNU <CODE>gettext</CODE> code, and is not documented here.

</P>
<P>
As for the strings themselves, they follow the hash file, and each
is terminated with a <KBD>NUL</KBD>, and this <KBD>NUL</KBD> is not counted in
the length which appears in the string descriptor.  The <CODE>msgfmt</CODE>
program has an option selecting the alignment for MO file strings.
With this option, each string is separately aligned so it starts at
an offset which is a multiple of the alignment value.  On some RISC
machines, a correct alignment will speed things up.

</P>
<P>
Nothing prevents an MO file from having embedded <KBD>NUL</KBD>s in strings.
However, the program interface currently used already presumes
that strings are <KBD>NUL</KBD> terminated, so embedded <KBD>NUL</KBD>s are
somewhat useless.  But MO file format is general enough so other
interfaces would be later possible, if for example, we ever want to
implement wide characters right in MO files, where <KBD>NUL</KBD> bytes may
accidently appear.

</P>
<P>
This particular issue has been strongly debated in the GNU
<CODE>gettext</CODE> development forum, and it is expectable that MO file
format will evolve or change over time.  It is even possible that many
formats may later be supported concurrently.  But surely, we got to
start somewhere, and the MO file format described here is a good start.
Nothing is cast in concrete, and the format may later evolve fairly
easily, so we should feel comfortable with the current approach.

</P>

<PRE>
        byte
             +------------------------------------------+
          0  | magic number = 0x950412de                |
             |                                          |
          4  | file format revision = 0                 |
             |                                          |
          8  | number of strings                        |  == N
             |                                          |
         12  | offset of table with original strings    |  == O
             |                                          |
         16  | offset of table with translation strings |  == T
             |                                          |
         20  | size of hashing table                    |  == S
             |                                          |
         24  | offset of hashing table                  |  == H
             |                                          |
             .                                          .
             .    (possibly more entries later)         .
             .                                          .
             |                                          |
          O  | length &#38; offset 0th string  ----------------.
      O + 8  | length &#38; offset 1st string  ------------------.
              ...                                    ...   | |
O + ((N-1)*8)| length &#38; offset (N-1)th string           |  | |
             |                                          |  | |
          T  | length &#38; offset 0th translation  ---------------.
      T + 8  | length &#38; offset 1st translation  -----------------.
              ...                                    ...   | | | |
T + ((N-1)*8)| length &#38; offset (N-1)th translation      |  | | | |
             |                                          |  | | | |
          H  | start hash table                         |  | | | |
              ...                                    ...   | | | |
  H + S * 4  | end hash table                           |  | | | |
             |                                          |  | | | |
             | NUL terminated 0th string  &#60;----------------' | | |
             |                                          |    | | |
             | NUL terminated 1st string  &#60;------------------' | |
             |                                          |      | |
              ...                                    ...       | |
             |                                          |      | |
             | NUL terminated 0th translation  &#60;---------------' |
             |                                          |        |
             | NUL terminated 1st translation  &#60;-----------------'
             |                                          |
              ...                                    ...
             |                                          |
             +------------------------------------------+
</PRE>


<H1><A NAME="SEC32" HREF="gettext_toc.html#TOC32">The User's View</A></H1>

<P>
When GNU <CODE>gettext</CODE> will truly have reached is goal, average users
should feel some kind of astonished pleasure, seeing the effect of
that strange kind of magic that just makes their own native language
appear everywhere on their screens.  As for naive users, they would
ideally have no special pleasure about it, merely taking their own
language for <EM>granted</EM>, and becoming rather unhappy otherwise.

</P>
<P>
So, let's try to describe here how we would like the magic to operate,
as we want the users' view to be the simplest, among all ways one
could look at GNU <CODE>gettext</CODE>.  All other software engineers:
programmers, translators, maintainers, should work together in such a
way that the magic becomes possible.  This is a long and progressive
undertaking, and information is available about the progress of the
GNU Translation Project.

</P>
<P>
When a package is distributed, there are two kind of users:
<STRONG>installers</STRONG> who fetch the distribution, unpack it, configure
it, compile it and install it for themselves or others to use; and
<STRONG>end users</STRONG> that call programs of the package, once these have
been installed at their site.  GNU <CODE>gettext</CODE> is offering magic
for both installers and end users.

</P>


<H2><A NAME="SEC33" HREF="gettext_toc.html#TOC33">The Current <TT>`NLS'</TT> Matrix for GNU</A></H2>

<P>
Languages are not equally supported in all GNU packages.  To know
if some GNU package uses GNU <CODE>gettext</CODE>, one may check
the distribution for the <TT>`NLS'</TT> information file, for some
<TT>`<VAR>ll</VAR>.po'</TT> files, often kept together into some <TT>`po/'</TT>
directory, or for an <TT>`intl/'</TT> directory.  Internationalized
packages have usually many <TT>`<VAR>ll</VAR>.po'</TT> files, where <VAR>ll</VAR>
represents the language.  section <A HREF="gettext.html#SEC35">Magic for End Users</A> for a complete description
of the format for <VAR>ll</VAR>.

</P>
<P>
More generally, a matrix is available for showing the current state
of GNU internationalization, listing which packages are prepared
for multi-lingual messages, and which languages is supported by each.
Because this information changes often, this matrix is not kept within
this GNU <CODE>gettext</CODE> manual.  This information is often found in
file <TT>`NLS'</TT> from various GNU distributions, but is also as old
as the distribution itself.  A recent copy of this <TT>`NLS'</TT> file,
containing up-to-date information, should generally be found on most
GNU archive sites.

</P>


<H2><A NAME="SEC34" HREF="gettext_toc.html#TOC34">Magic for Installers</A></H2>

<P>
By default, packages fully using GNU <CODE>gettext</CODE>, internally,
are installed in such a way that they to allow translation of
messages.  At <EM>configuration</EM> time, those packages should
automatically detect whether the underlying host system provides usable
<CODE>catgets</CODE> or <CODE>gettext</CODE> functions.  If neither is present,
the GNU <CODE>gettext</CODE> library should be automatically prepared
and used.  Installers may use special options at configuration
time for changing this behavior.  The command <SAMP>`./configure
--with-gnu-gettext'</SAMP> bypasses system <CODE>catgets</CODE> or <CODE>gettext</CODE> to
use GNU <CODE>gettext</CODE> instead, while <SAMP>`./configure --disable-nls'</SAMP>
produces program totally unable to translate messages.

</P>
<P>
Internationalized packages have usually many <TT>`<VAR>ll</VAR>.po'</TT>
files.  Unless
translations are disabled, all those available are installed together
with the package.  However, the environment variable <CODE>LINGUAS</CODE>
may be set, prior to configuration, to limit the installed set.
<CODE>LINGUAS</CODE> should then contain a space separated list of two-letter
codes, stating which languages are allowed.

</P>


<H2><A NAME="SEC35" HREF="gettext_toc.html#TOC35">Magic for End Users</A></H2>

<P>
We consider here those packages using GNU <CODE>gettext</CODE> internally,
and for which the installers did not disable translation at
<EM>configure</EM> time.  Then, users only have to set the <CODE>LANG</CODE>
environment variable to the appropriate <SAMP>`<VAR>ll</VAR>'</SAMP> prior to
using the programs in the package.  See section <A HREF="gettext.html#SEC33">The Current <TT>`NLS'</TT> Matrix for GNU</A>.  For example,
let's presume a German site.  At the shell prompt, users merely have to
execute <SAMP>`setenv LANG de'</SAMP> (in <CODE>csh</CODE>) or <SAMP>`export
LANG; LANG=de'</SAMP> (in <CODE>sh</CODE>).  They could even do this from their
<TT>`.login'</TT> or <TT>`.profile'</TT> file.

</P>


<H1><A NAME="SEC36" HREF="gettext_toc.html#TOC36">The Programmer's View</A></H1>

<P>
One aim of the current message catalog implementation provided by
GNU <CODE>gettext</CODE> was to use the systems message catalog handling, if the
installer wishes to do so.  So we perhaps should first take a look at
the solutions we know about.  The people in the POSIX committee does not
manage to agree on one of the semi-official standards which we'll
describe below.  In fact they couldn't agree on anything, so nothing
decide only to include an example of an interface.  The major Unix vendors
are split in the usage of the two most important specifications: X/Opens
catgets vs. Uniforums gettext interface.  We'll describe them both and
later explain our solution of this dilemma.

</P>


<H2><A NAME="SEC37" HREF="gettext_toc.html#TOC37">About <CODE>catgets</CODE></A></H2>

<P>
The <CODE>catgets</CODE> implementation is defined in the X/Open Portability
Guide, Volume 3, XSI Supplementary Definitions, Chapter 5.  But the
process of creating this standard seemed to be too slow for some of
the Unix vendors so they created their implementations on preliminary
versions of the standard.  Of course this leads again to problems while
writing platform independent programs: even the usage of <CODE>catgets</CODE>
does not guarantee a unique interface.

</P>
<P>
Another, personal comment on this that only a bunch of committee members
could have made this interface.  They never really tried to program
using this interface.  It is a fast, memory-saving implementation, an
user can happily live with it.  But programmers hate it (at least me and
some others do...)

</P>
<P>
But we must not forget one point: after all the trouble with transfering
the rights on Unix(tm) they at last came to X/Open, the very same who
published this specifications.  This leads me to making the prediction
that this interface will be in future Unix standards (e.g. Spec1170) and
therefore part of all Unix implementation (implementations, which are
<EM>allowed</EM> to wear this name).

</P>


<H3><A NAME="SEC38" HREF="gettext_toc.html#TOC38">The Interface</A></H3>

<P>
The interface to the <CODE>catgets</CODE> implementation consists of three
functions which correspond to those used in file access: <CODE>catopen</CODE>
to open the catalog for using, <CODE>catgets</CODE> for accessing the message
tables, and <CODE>catclose</CODE> for closing after work is done.  Prototypes
for the functions and the needed definitions are in the
<CODE>&#60;nl_types.h&#62;</CODE> header file.

</P>
<P>
<CODE>catopen</CODE> is used like in this:

</P>

<PRE>
nl_catd catd = catopen ("catalog_name", 0);
</PRE>

<P>
The function takes as the argument the name of the catalog.  This usual
refers to the name of the program or the package.  The second parameter
is not further specified in the standard.  I don't even know whether it
is implemented consistently among various systems.  So the common advice
is to use <CODE>0</CODE> as the value.  The return value is a handle to the
message catalog, equivalent to handles to file returned by <CODE>open</CODE>.

</P>
<P>
This handle is of course used in the <CODE>catgets</CODE> function which can
be used like this:

</P>

<PRE>
char *translation = catgets (catd, set_no, msg_id, "original string");
</PRE>

<P>
The first parameter is this catalog descriptor.  The second parameter
specifies the set of messages in this catalog, in which the message
described by <CODE>msg_id</CODE> is obtained.  <CODE>catgets</CODE> therefore uses a
three-stage addressing:

</P>

<PRE>
catalog name => set number => message ID => translation
</PRE>

<P>
The fourth argument is not used to address the translation.  It is given
as a default value in case when one of the addressing stages fail.  One
important thing to remember is that although the return type of catgets
is <CODE>char *</CODE> the resulting string <EM>must not</EM> be changed.  It
should better <CODE>const char *</CODE>, but the standard is published in
1988, one year before ANSI C.

</P>
<P>
The last of these function functions is used and behaves as expected:

</P>

<PRE>
catclose (catd);
</PRE>

<P>
After this no <CODE>catgets</CODE> call using the descriptor is legal anymore.

</P>


<H3><A NAME="SEC39" HREF="gettext_toc.html#TOC39">Problems with the <CODE>catgets</CODE> Interface?!</A></H3>

<P>
Now that this descriptions seemed to be really easy where are the
problem we speak of.  In fact the interface could be used in a
reasonable way, but constructing the message catalogs is a pain.  The
reason for this lies in the third argument of <CODE>catgets</CODE>: the unique
message ID.  This has to be a numeric value for all messages in a single
set.  Perhaps you could imagine the problems keeping such list while
changing the source code.  Add a new message here, remove one there.  Of
course there have been developed a lot of tools helping to organize this
chaos but one as the other fails in one aspect or the other.  We don't
want to say that the other approach has no problems but they are far
more easily to manage.

</P>


<H2><A NAME="SEC40" HREF="gettext_toc.html#TOC40">About <CODE>gettext</CODE></A></H2>

<P>
The definition of the <CODE>gettext</CODE> interface comes from a Uniforum
proposal and it is followed by at least one major Unix vendor
(Sun) in its last developments.  It is not specified in any official
standard, though.

</P>
<P>
The main points about this solution is that it does not follow the
method of normal file handling (open-use-close) and that it does not
burden the programmer so many task, especially the unique key handling.
Of course here is also a unique key needed, but this key is the
message itself (how long or short it is).  See section <A HREF="gettext.html#SEC45">Comparing the Two Interfaces</A> for a
more detailed comparison of the two methods.

</P>
<P>
The following section contains a rather detailed description of the
interface.  We make it that detailed because this is the interface
we chose for the GNU <CODE>gettext</CODE> Library.  Programmers interested
in using this library will be interested in this description.

</P>


<H3><A NAME="SEC41" HREF="gettext_toc.html#TOC41">The Interface</A></H3>

<P>
The minimal functionality an interface must have is a) to select a
domain the strings are coming from (a single domain for all programs is
not reasonable because its construction and maintenance is difficult,
perhaps impossible) and b) to access a string in a selected domain.

</P>
<P>
This is principally the description of the <CODE>gettext</CODE> interface.  It
has an global domain which unqualified usages reference.  Of course this
domain is selectable by the user.

</P>

<PRE>
char *textdomain (const char *domain_name);
</PRE>

<P>
This provides the possibility to change or query the current status of
the current global domain of the <CODE>LC_MESSAGE</CODE> category.  The
argument is a null-terminated string, whose characters must be legal in
the use in filenames.  If the <VAR>domain_name</VAR> argument is <CODE>NULL</CODE>,
the function return the current value.  If no value has been set
before, the name of the default domain is returned: <EM>messages</EM>.
Please note that although the return value of <CODE>textdomain</CODE> is of
type <CODE>char *</CODE> no changing is allowed.  It is also important to know
that no checks of the availability are made.  If the name is not
available you will see this by the fact that no translations are provided.

</P>
<P>
To use a domain set by <CODE>textdomain</CODE> the function

</P>

<PRE>
char *gettext (const char *msgid);
</PRE>

<P>
is to be used.  This is the simplest reasonable form one can imagine.
The translation of the string <VAR>msgid</VAR> is returned if it is available
in the current domain.  If not available the argument itself is
returned.  If the argument is <CODE>NULL</CODE> the result is undefined.

</P>
<P>
One things which should come into mind is that no explicit dependency to
the used domain is given.  The current value of the domain for the
<CODE>LC_MESSAGES</CODE> locale is used.  If this changes between two
executions of the same <CODE>gettext</CODE> call in the program, both calls
reference a different message catalog.

</P>
<P>
For the easiest case, which is normally used in internationalized GNU
packages, once at the beginning of execution a call to <CODE>textdomain</CODE>
is issued, setting the domain to a unique name, normally the package
name.  In the following code all strings which have to be translated are
filtered through the gettext function.  That's all, the package speaks
your language.

</P>


<H3><A NAME="SEC42" HREF="gettext_toc.html#TOC42">Solving Ambiguities</A></H3>

<P>
While this single name domain work good for most applications there
might be the need to get translations from more than one domain.  Of
course one could switch between different domains with calls to
<CODE>textdomain</CODE>, but this is really not convenient nor is it fast.  A
possible situation could be one case discussing while this writing:  all
error messages of functions in the set of common used functions should
go into a separate domain <CODE>error</CODE>.  By this mean we would only need
to translate them once.

</P>
<P>
For this reasons there are two more functions to retrieve strings:

</P>

<PRE>
char *dgettext (const char *domain_name, const char *msgid);
char *dcgettext (const char *domain_name, const char *msgid,
                 int category);
</PRE>

<P>
Both take an additional argument at the first place, which corresponds
to the argument of <CODE>textdomain</CODE>.  The third argument of
<CODE>dcgettext</CODE> allows to use another locale but <CODE>LC_MESSAGES</CODE>.
But I really don't know where this can be useful.  If the
<VAR>domain_name</VAR> is <CODE>NULL</CODE> or <VAR>category</VAR> has an value beside
the known ones, the result is undefined.  It should also be noted that
this function is not part of the second known implementation of this
function family, the one found in Solaris.

</P>
<P>
A second ambiguity can arise by the fact, that perhaps more than one
domain has the same name.  This can be solved by specifying where the
needed message catalog files can be found.

</P>

<PRE>
char *bindtextdomain (const char *domain_name,
                      const char *dir_name);
</PRE>

<P>
Calling this function binds the given domain to a file in the specified
directory (how this file is determined follows below).  Esp a file in
the systems default place is not favored against the specified file
anymore (as it would be by solely using <CODE>textdomain</CODE>).  A <CODE>NULL</CODE>
pointer for the <VAR>dir_name</VAR> parameter returns the binding associated
with <VAR>domain_name</VAR>.  If <VAR>domain_name</VAR> itself is <CODE>NULL</CODE>
nothing happens and a <CODE>NULL</CODE> pointer is returned.  Here again as
for all the other functions is true that none of the return value must
be changed!

</P>


<H3><A NAME="SEC43" HREF="gettext_toc.html#TOC43">Locating Message Catalog Files</A></H3>

<P>
Because many different languages for many different packages have to be
stored we need some way to add these information to file message catalog
files.  The way usually used in Unix environments is have this encoding
in the file name.  This is also done here.  The directory name given in
<CODE>bindtextdomain</CODE>s second argument (or the default directory),
followed by the value and name of the locale and the domain name are
concatenated:

</P>

<PRE>
<VAR>dir_name</VAR>/<VAR>locale</VAR>/LC_<VAR>category</VAR>/<VAR>domain_name</VAR>.mo
</PRE>

<P>
The default value for <VAR>dir_name</VAR> is system specific.  For the GNU
library it's:

<PRE>
/usr/local/share/locale
</PRE>

<P>
<VAR>locale</VAR> is the value of the locale whose name is this
<CODE>LC_<VAR>category</VAR></CODE>.  For <CODE>gettext</CODE> and <CODE>dgettext</CODE> this
locale is always <CODE>LC_MESSAGES</CODE>.  <CODE>dcgettext</CODE> specifies the
locale by the third argument.<A NAME="DOCF2" HREF="gettext_foot.html#FOOT2">(2)</A> <A NAME="DOCF3" HREF="gettext_foot.html#FOOT3">(3)</A>

</P>


<H3><A NAME="SEC44" HREF="gettext_toc.html#TOC44">Optimization of the *gettext functions</A></H3>

<P>
At this point of the discussion we should talk about an advantage of the
GNU <CODE>gettext</CODE> implementation.  Some readers might have pointed out
that an internationalized program might have a poor performance if some
string has to be translated in an inner loop.  While this is unavoidable
when the string varies from one run of the loop to the other it is
simply a waste of time when the string is always the same.  Take the
following example:

</P>

<PRE>
{
  while (...)
    {
      puts (gettext ("Hello world"));
    }
}
</PRE>

<P>
When the locale selection does not change between two runs the resulting
string is always the same.  One way to use this is:

</P>

<PRE>
{
  str = gettext ("Hello world");
  while (...)
    {
      puts (str);
    }
}
</PRE>

<P>
But this solution is not usable in all situation (e.g. when the locale
selection changes) nor is it good readable.

</P>
<P>
The GNU C compiler, version 2.7 and above, provide another solution for
this.  To describe this we show here some lines of the
<TT>`intl/libgettext.h'</TT> file.  For an explanation of the expression
command block see section `Statements and Declarations in Expressions' in <CITE>The GNU CC Manual</CITE>.

</P>

<PRE>
#  if defined __GNUC__ &#38;&#38; __GNUC__ == 2 &#38;&#38; __GNUC_MINOR__ &#62;= 7
#   define	dcgettext(domainname, msgid, category)           \
  (__extension__                                                 \
   ({                                                            \
     char *result;                                               \
     if (__builtin_constant_p (msgid))                           \
       {                                                         \
         extern int _nl_msg_cat_cntr;                            \
         static char *__translation__;                           \
         static int __catalog_counter__;                         \
         if (! __translation__                                   \
             || __catalog_counter__ != _nl_msg_cat_cntr)         \
           {                                                     \
             __translation__ =                                   \
               dcgettext__ ((domainname), (msgid), (category));  \
             __catalog_counter__ = _nl_msg_cat_cntr;             \
           }                                                     \
         result = __translation__;                               \
       }                                                         \
     else                                                        \
       result = dcgettext__ ((domainname), (msgid), (category)); \
     result;                                                     \
    }))
#  endif
</PRE>

<P>
The interesting thing here is the <CODE>__builtin_constant_p</CODE> predicate.
This is evaluated at compile time and so optimization can take place
immediately.  Here two cases are distinguished: the argument to
<CODE>gettext</CODE> is not a constant value in which case simply the function
<CODE>dcgettext__</CODE> is called, the real implementation of the
<CODE>dcgettext</CODE> function.

</P>
<P>
If the string argument <EM>is</EM> constant we can reuse the once gained
translation when the locale selection has not changed.  This is exactly
what is done here.  The <CODE>_nl_msg_cat_cntr</CODE> variable is defined in
the <TT>`loadmsgcat.c'</TT> which is available in <TT>`libintl.a'</TT> and is
changed whenever a new message catalog is loaded.

</P>


<H2><A NAME="SEC45" HREF="gettext_toc.html#TOC45">Comparing the Two Interfaces</A></H2>

<P>
The following discussion is perhaps a little bit colored.  As said
above we implemented GNU <CODE>gettext</CODE> following the Uniforum
proposal and this surely has its reasons.  But it should show how we
came to this decision.

</P>
<P>
First we take a look at the developing process.  When we write an
application using NLS provided by <CODE>gettext</CODE> we proceed as always.
Only when we come to a string which might be seen by the users and thus
has to be translated we use <CODE>gettext("...")</CODE> instead of
<CODE>"..."</CODE>.  At the beginning of each source file (or in a central
header file) we define

</P>

<PRE>
#define gettext(String) (String)
</PRE>

<P>
Even this definition can be avoided when the system supports the
<CODE>gettext</CODE> function in its C library.  When we compile this code the
result is the same as if no NLS code is used.  When  you take a look at
the GNU <CODE>gettext</CODE> code you will see that we use <CODE>_("...")</CODE>
instead of <CODE>gettext("...")</CODE>.  This reduces the number of
additional characters per translatable string to <EM>3</EM> (in words:
three).

</P>
<P>
When now a production version of the program is needed we simply replace
the definition

</P>

<PRE>
#define _(String) (String)
</PRE>

<P>
by

</P>

<PRE>
#include &#60;libintl.h&#62;
#define _(String) gettext (String)
</PRE>

<P>
and include the header <TT>`libintl.h'</TT>.  Additionally we run the
program <TT>`xgettext'</TT> on all source code file which contain
translatable strings and we are gone.  We have a running program which
does not depend on translations to be available, but which can use any
that becomes available.

</P>
<P>
The same procedure can be done for the <CODE>gettext_noop</CODE> invocations
(see section <A HREF="gettext.html#SEC17">Special Cases of Translatable Strings</A>).  First you can define <CODE>gettext_noop</CODE> to a
no-op macro and later use the definition from <TT>`libintl.h'</TT>.  Because
this name is not used in Suns implementation of <TT>`libintl.h'</TT>,
you should consider the following code for your project:

</P>

<PRE>
#ifdef gettext_noop
# define N_(Str) gettext_noop (Str)
#else
# define N_(Str) (Str)
#endif
</PRE>

<P>
<CODE>N_</CODE> is a short form similar to <CODE>_</CODE>.  The <TT>`Makefile'</TT> in
the <TT>`po/'</TT> directory of GNU gettext knows by default both of the
mentioned short forms so you are invited to follow this proposal for
your own ease.

</P>
<P>
Now to <CODE>catgets</CODE>.  The main problem is the work for the
programmer.  Every time he comes to a translatable string he has to
define a number (or a symbolic constant) which has also be defined in
the message catalog file.  He also has to take care for duplicate
entries, duplicate message IDs etc.  If he wants to have the same
quality in the message catalog as the GNU <CODE>gettext</CODE> program
provides he also has to put the descriptive comments for the strings and
the location in all source code files in the message catalog.  This is
nearly a Mission: Impossible.

</P>
<P>
But there are also some points people might call advantages speaking for
<CODE>catgets</CODE>.  If you have a single word in a string and this string
is used in different contexts it is likely that in one or the other
language the word has different translations.  Example:

</P>

<PRE>
printf ("%s: %d", gettext ("number"), number_of_errors)

printf ("you should see %d %s", number_count,
        number_count == 1 ? gettext ("number") : gettext ("numbers"))
</PRE>

<P>
Here we have to translate two times the string <CODE>"number"</CODE>.  Even
if you do not speak a language beside English it might be possible to
recognize that the two words have a different meaning.  In German the
first appearance has to be translated to <CODE>"Anzahl"</CODE> and the second
to <CODE>"Zahl"</CODE>.

</P>
<P>
Now you can say that this example is really esoteric.  And you are
right!  This is exactly how we felt about this problem and decide that
it does not weight that much.  The solution for the above problem could
be very easy:

</P>

<PRE>
printf (gettext ("number: %d"), number_of_errors)

printf (number_count == 1 ? gettext ("you should see %d number")
                          : gettext ("you should see %d numbers"),
        number_count)
</PRE>

<P>
We believe that we can solve all conflicts with this method.  If it is
difficult one can also consider changing one of the conflicting string a
little bit.  But it is not impossible to overcome.

</P>
<P>
Translator note: It is perhaps appropriate here to tell those English
speaking programmers that the plural form of a noun cannot be formed by
appending a single `s'.  Most other languages use different methods.  So
you should at least use the method given in the above example.

</P>
<P>
But I have been told that some languages have even more complex rules.
A good approach might be to consider methods like the one used for
<CODE>LC_TIME</CODE> in the POSIX.2 standard.

</P>


<H2><A NAME="SEC46" HREF="gettext_toc.html#TOC46">Using libintl.a in own programs</A></H2>

<P>
Starting with version 0.9.4 the library <CODE>libintl.h</CODE> should be more
or less self-contained.  I.e. you can use it in your own programs.  The
<TT>`Makefile'</TT> will put the header and the library in directories
selected using the <CODE>$(prefix)</CODE>.

</P>
<P>
One exception of the above is found on HP-UX systems.  Here the C library
does not contain the <CODE>alloca</CODE> function (and the HP compiler does
not generate it inlined).  But it is not intended to rewrite the whole
library just because of this dumb system.  Instead include the
<CODE>alloca</CODE> function in all package you use the <CODE>libintl.a</CODE> in.

</P>


<H2><A NAME="SEC47" HREF="gettext_toc.html#TOC47">Being a <CODE>gettext</CODE> grok</A></H2>

<P>
To fully exploit the functionality of the GNU <CODE>gettext</CODE> library it
is surely helpful to read the source code.  But for those who don't want
to spend that much time in reading the (sometimes complicated) code here
is a list comments:

</P>

<UL>
<LI>Changing the language at runtime

For interactive programs it might be useful to offer a selection of the
used language at runtime.  To understand how to do this one need to know
how the used language is determined while executing the <CODE>gettext</CODE>
function.  The method which is presented here only works correctly
with the GNU implementation of the <CODE>gettext</CODE> functions.  It is not
possible with underlying <CODE>catgets</CODE> functions or <CODE>gettext</CODE>
functions from the systems C library.  The exception is of course the
GNU C Library which uses the GNU gettext Library for message handling.

In the function <CODE>dcgettext</CODE> at every call the current setting of
the highest priority environment variable is determined and used.
Highest priority means here the following list with decreasing
priority:


<OL>
<LI><CODE>LANGUAGE</CODE>

<LI><CODE>LC_ALL</CODE>

<LI><CODE>LC_xxx</CODE>, according to selected locale

<LI><CODE>LANG</CODE>

</OL>

Afterwards the path is constructed using the found value and the
translation file is loaded if available.

What is now when the value for, say, <CODE>LANGUAGE</CODE> changes.  According
to the process explained above the new value of this variable is found
as soon as the <CODE>dcgettext</CODE> function is called.  But this also means
the (perhaps) different message catalog file is loaded.  In other
words: the used language is changed.

But there is one little hook.  The code for gcc-2.7.0 and up provides
some optimization.  This optimization normally prevents the calling of
the <CODE>dcgettext</CODE> function as long as now new catalog is loaded.  But
if <CODE>dcgettext</CODE> is not called we program also cannot find the
<CODE>LANGUAGE</CODE> variable be changed (see section <A HREF="gettext.html#SEC44">Optimization of the *gettext functions</A>).  But the
solution is very easy.  Include the following code in the language
switching function.


<PRE>
  /* Change language.  */
  setenv ("LANGUAGE", "fr", 1);

  /* Make change known.  */
  {
    extern int  _nl_msg_cat_cntr;
    ++_nl_msg_cat_cntr;
  }
</PRE>

The variable <CODE>_nl_msg_cat_cntr</CODE> is defined in <TT>`loadmsgcat.c'</TT>.

</UL>


<H2><A NAME="SEC48" HREF="gettext_toc.html#TOC48">Temporary Notes for the Programmers Chapter</A></H2>


<H3><A NAME="SEC49" HREF="gettext_toc.html#TOC49">Temporary - Two Possible Implementations</A></H3>

<P>
There are two competing methods for language independent messages:
the X/Open <CODE>catgets</CODE> method, and the Uniforum <CODE>gettext</CODE>
method.  The <CODE>catgets</CODE> method indexes messages by integers; the
<CODE>gettext</CODE> method indexes them by their English translations.
The <CODE>catgets</CODE> method has been around longer and is supported
by more vendors.  The <CODE>gettext</CODE> method is supported by Sun,
and it has been heard that the COSE multi-vendor initiative is
supporting it.  Neither method is a POSIX standard; the POSIX.1
committee had a lot of disagreement in this area.

</P>
<P>
Neither one is in the POSIX standard.  There was much disagreement
in the POSIX.1 committee about using the <CODE>gettext</CODE> routines
vs. <CODE>catgets</CODE> (XPG).  In the end the committee couldn't
agree on anything, so no messaging system was included as part
of the standard.  I believe the informative annex of the standard
includes the XPG3 messaging interfaces, "...as an example of
a messaging system that has been implemented..."

</P>
<P>
They were very careful not to say anywhere that you should use one
set of interfaces over the other.  For more on this topic please
see the Programming for Internationalization FAQ.

</P>


<H3><A NAME="SEC50" HREF="gettext_toc.html#TOC50">Temporary - About <CODE>catgets</CODE></A></H3>

<P>
There have been a few discussions of late on the use of
<CODE>catgets</CODE> as a base.  I think it important to present both
sides of the argument and hence am opting to play devil's advocate
for a little bit.

</P>
<P>
I'll not deny the fact that <CODE>catgets</CODE> could have been designed
a lot better.  It currently has quite a number of limitations and
these have already been pointed out.

</P>
<P>
However there is a great deal to be said for consistency and
standardization.  A common recurring problem when writing Unix
software is the myriad portability problems across Unix platforms.
It seems as if every Unix vendor had a look at the operating system
and found parts they could improve upon.  Undoubtedly, these
modifications are probably innovative and solve real problems.
However, software developers have a hard time keeping up with all
these changes across so many platforms.

</P>
<P>
And this has prompted the Unix vendors to begin to standardize their
systems.  Hence the impetus for Spec1170.  Every major Unix vendor
has committed to supporting this standard and every Unix software
developer waits with glee the day they can write software to this
standard and simply recompile (without having to use autoconf)
across different platforms.

</P>
<P>
As I understand it, Spec1170 is roughly based upon version 4 of the
X/Open Portability Guidelines (XPG4).  Because <CODE>catgets</CODE> and
friends are defined in XPG4, I'm led to believe that <CODE>catgets</CODE>
is a part of Spec1170 and hence will become a standardized component
of all Unix systems.

</P>


<H3><A NAME="SEC51" HREF="gettext_toc.html#TOC51">Temporary - Why a single implementation</A></H3>

<P>
Now it seems kind of wasteful to me to have two different systems
installed for accessing message catalogs.  If we do want to remedy
<CODE>catgets</CODE> deficiencies why don't we try to expand <CODE>catgets</CODE>
(in a compatible manner) rather than implement an entirely new system.
Otherwise, we'll end up with two message catalog access systems
installed with an operating system - one set of routines for GNU
software, and another set of routines (catgets) for all other software.
Bloated?

</P>
<P>
Supposing another catalog access system is implemented.  Which do
we recommend?  At least for Linux, we need to attract as many
software developers as possible.  Hence we need to make it as easy
for them to port their software as possible.  Which means supporting
<CODE>catgets</CODE>.  We will be implementing the <CODE>glocale</CODE> code
within our <CODE>libc</CODE>, but does this mean we also have to incorporate
another message catalog access scheme within our <CODE>libc</CODE> as well?
And what about people who are going to be using the <CODE>glocale</CODE>
+ non-<CODE>catgets</CODE> routines.  When they port their software to
other platforms, they're now going to have to include the front-end
(<CODE>glocale</CODE>) code plus the back-end code (the non-<CODE>catgets</CODE>
access routines) with their software instead of just including the
<CODE>glocale</CODE> code with their software.

</P>
<P>
Message catalog support is however only the tip of the iceberg.
What about the data for the other locale categories.  They also have
a number of deficiencies.  Are we going to abandon them as well and
develop another duplicate set of routines (should <CODE>glocale</CODE>
expand beyond message catalog support)?

</P>
<P>
Like many parts of Unix that can be improved upon, we're stuck with balancing
compatibility with the past with useful improvements and innovations for
the future.

</P>


<H3><A NAME="SEC52" HREF="gettext_toc.html#TOC52">Temporary - Double layer solution</A></H3>

<P>
GNU locale implements a <CODE>gettext</CODE>-style interface on top of a
<CODE>catgets</CODE>-style interface.

</P>
<P>
This is not needless complexity.  It is absolutely vital, because
it enables <CODE>gettext</CODE> to run on top of <CODE>catgets</CODE>, which
enables Linux International to recommend users use it <EM>today</EM>.

</P>
<P>
Rewriting <CODE>gettext</CODE> so that it could use <EM>either</EM>
<CODE>catgets</CODE> <EM>or</EM> some simpler mechanism would not break
anything, but would not reduce complexity either.  It might be
worth doing, but it isn't urgent.

</P>
<P>
In general, simplicity is not enough of a reason to rewrite a
program that works.  Simplicity is just one desirable thing.
It is not overridingly important.

</P>


<H3><A NAME="SEC53" HREF="gettext_toc.html#TOC53">Temporary - Notes</A></H3>

<P>
X/Open agreed very late on the standard form so that many
implementations differ from the final form.  Both of my system (old
Linux catgets and Ultrix-4) have a strange variation.

</P>
<P>
OK.  After incorporating the last changes I have to spend some time on
making the GNU/Linux libc gettext functions.  So in future Solaris is
not the only system having gettext.

</P>


<H1><A NAME="SEC54" HREF="gettext_toc.html#TOC54">The Translator's View</A></H1>


<H2><A NAME="SEC55" HREF="gettext_toc.html#TOC55">Introduction 0</A></H2>

<P>
GNU is going international!  The GNU Translation Project is a way
to get maintainers, translators and users all together, so GNU will
gradually become able to speak many native languages.

</P>
<P>
The GNU <CODE>gettext</CODE> tool set contains <EM>everything</EM> maintainers
need for internationalizing their packages for messages.  It also
contains quite useful tools for helping translators at localizing
messages to their native language, once a package has already been
internationalized.

</P>
<P>
To achieve the GNU Translation Project, we need many interested
people who like their own language and write it well, and who are also
able to synergize with other translators speaking the same language.
If you'd like to volunteer to <EM>work</EM> at translating messages,
please send mail to your translating team.

</P>
<P>
Each team has its own mailing list, courtesy of Linux
International.  You may reach your translating team at the address
<TT>`<VAR>ll</VAR>@li.org'</TT>, replacing <VAR>ll</VAR> by the two-letter ISO 639
code for your language.  Language codes are <EM>not</EM> the same as
country codes given in ISO 3166.  The following translating teams
exist:

</P>

<BLOCKQUOTE>
<P>
Chinese <CODE>zh</CODE>, Czech <CODE>cs</CODE>, Danish <CODE>da</CODE>, Dutch <CODE>nl</CODE>,
Esperanto <CODE>eo</CODE>, Finnish <CODE>fi</CODE>, French <CODE>fr</CODE>, Irish
<CODE>ga</CODE>, German <CODE>de</CODE>, Greek <CODE>el</CODE>, Italian <CODE>it</CODE>,
Japanese <CODE>ja</CODE>, Indonesian <CODE>in</CODE>, Norwegian <CODE>no</CODE>, Polish
<CODE>pl</CODE>, Portuguese <CODE>pt</CODE>, Russian <CODE>ru</CODE>, Spanish <CODE>es</CODE>,
Swedish <CODE>sv</CODE> and Turkish <CODE>tr</CODE>.
</BLOCKQUOTE>

<P>
For example, you may reach the Chinese translating team by writing to
<TT>`zh@li.org'</TT>.  When you become a member of the translating team
for your own language, you may subscribe to its list.  For example,
Swedish people can send a message to <TT>`sv-request@li.org'</TT>,
having this message body:

</P>

<PRE>
subscribe
</PRE>

<P>
Keep in mind that team members should be interested in <EM>working</EM>
at translations, or at solving translational difficulties, rather than
merely lurking around.  If your team does not exist yet and you want to
start one, please write to <TT>`gnu-translation@prep.ai.mit.edu'</TT>;
you will then reach the GNU coordinator for all translator teams.

</P>
<P>
A handful of GNU packages have already been adapted and provided
with message translations for several languages.  Translation
teams have begun to organize, using these packages as a starting
point.  But there are many more packages and many languages for
which we have no volunteer translators.  If you would like to
volunteer to work at translating messages, please send mail to
<TT>`gnu-translation@prep.ai.mit.edu'</TT> indicating what language(s)
you can work on.

</P>


<H2><A NAME="SEC56" HREF="gettext_toc.html#TOC56">Introduction 1</A></H2>

<P>
This is now official, GNU is going international!  Here is the
announcement submitted for the January 1995 GNU Bulletin:

</P>

<BLOCKQUOTE>
<P>
A handful of GNU packages have already been adapted and provided
with message translations for several languages.  Translation
teams have begun to organize, using these packages as a starting
point.  But there are many more packages and many languages
for which we have no volunteer translators.  If you'd like to
volunteer to work at translating messages, please send mail to
<SAMP>`gnu-translation@prep.ai.mit.edu'</SAMP> indicating what language(s)
you can work on.
</BLOCKQUOTE>

<P>
This document should answer many questions for those who are curious
about the process or would like to contribute.  Please at least skim
over it, hoping to cut down a little of the high volume of email
generated by this collective effort towards GNU internationalization.

</P>
<P>
GNU programming is done in English, and currently, English is used
as the main communicating language between national communities
collaborating to the GNU project.  This very document is written
in English.  This will not change in the foreseeable future.

</P>
<P>
However, there is a strong appetite from national communities for
having more software able to write using national language and habits,
and there is an on-going effort to modify GNU software in such a way
that it becomes able to do so.  The experiments driven so far raised
an enthusiastic response from pretesters, so we believe that GNU
internationalization is dedicated to succeed.

</P>
<P>
For suggestion clarifications, additions or corrections to this
document, please email to <TT>`gnu-translation@prep.ai.mit.edu'</TT>.

</P>


<H2><A NAME="SEC57" HREF="gettext_toc.html#TOC57">Discussions</A></H2>

<P>
Facing this internationalization effort, a few users expressed their
concerns.  Some of these doubts are presented and discussed, here.

</P>

<UL>
<LI>Smaller groups

Some languages are not spoken by a very large number of people,
so people speaking them sometimes consider that there may not be
all that much demand such versions of GNU packages.  Moreover, many
people being <EM>into computers</EM>, in some countries, generally seem
to prefer English versions of their software.

On the other end, people might enjoy their own language a lot, and
be very motivated at providing to themselves the pleasure of having
their beloved GNU software speaking their mother tongue.  They do
themselves a personal favor, and do not pay that much attention to
the number of people beneficiating of their work.

<LI>Misinterpretation

Other users are shy to push forward their own language, seeing in this
some kind of misplaced propaganda.  Someone thought there must be some
users of the language over the networks pestering other people with it.

But any spoken language is worth localization, because there are
people behind the language for whom the language is important and
dear to their hearts.

<LI>Odd translations

The biggest problem is to find the right translations so that
everybody can understand the messages.  Translations are usually a
little odd.  Some people get used to English, to the extent they may
find translations into their own language "rather pushy, obnoxious
and sometimes even hilarious."  As a French speaking man, I have
the experience of those instruction manuals for goods, so poorly
translated in French in Korea or Taiwan...

The fact is that we sometimes have to create a kind of national
computer culture, and this is not easy without the collaboration of
many people liking their mother tongue.  This is why translations are
better achieved by people knowing and loving their own language, and
ready to work together at improving the results they obtain.

<LI>Dependencies over the GPL

Some people wonder if using GNU <CODE>gettext</CODE> necessarily brings their package
under the protective wing of the GNU General Public License, when they
do not want to make their program free, or want other kinds of freedom.
The simplest answer is yes.

The mere marking of localizable strings in a package, or conditional
inclusion of a few lines for initialization, is not really including
GPL'ed code.  However, the localization routines themselves are under
the GPL and would bring the remainder of the package under the GPL
if they were distributed with it.  So, I presume that, for those
for which this is a problem, it could be circumvented by letting to
the end installers the burden of assembling a package prepared for
localization, but not providing the localization routines themselves.

</UL>


<H2><A NAME="SEC58" HREF="gettext_toc.html#TOC58">Organization</A></H2>

<P>
On a larger scale, the true solution would be to organize some kind of
fairly precise set up in which volunteers could participate.  I gave
some thought to this idea lately, and realize there will be some
touchy points.  I thought of writing to Richard Stallman to launch
such a project, but feel it might be good to shake out the ideas
between ourselves first.  Most probably that Linux International has
some experience in the field already, or would like to orchestrate
the volunteer work, maybe.  Food for thought, in any case!

</P>
<P>
I guess we have to setup something early, somehow, that will help
many possible contributors of the same language to interlock and avoid
work duplication, and further be put in contact for solving together
problems particular to their tongue (in most languages, there are many
difficulties peculiar to translating technical English).  My Swedish
contributor acknowledged these difficulties, and I'm well aware of
them for French.

</P>
<P>
This is surely not a technical issue, but we should manage so the
effort of locale contributors be maximally useful, despite the national
team layer interface between contributors and maintainers.

</P>
<P>
GNU needs some setup for coordinating language coordinators.
Localizing evolving GNU programs will surely become a permanent
and continuous activity in GNU, once started.  The setup should be
minimally completed and tested before GNU <CODE>gettext</CODE> becomes an official
reality.  The email address <TT>`gnu-translation@prep.ai.mit.edu'</TT>
has been setup for receiving offers from volunteers and general
email on these topics.  This address reaches the GNU Translation
Project coordinator.

</P>


<H3><A NAME="SEC59" HREF="gettext_toc.html#TOC59">Central Coordination</A></H3>

<P>
I also think GNU will need sooner than it thinks, that someone setup
a way to organize and coordinate these groups.  Some kind of group
of groups.  My opinion is that it would be good that GNU delegate
this task to a small group of collaborating volunteers, shortly.
Perhaps in <TT>`gnu.announce'</TT> a list of this national committee's
can be published.

</P>
<P>
My role as coordinator would simply be to refer to Ulrich any German
speaking volunteer interested to localization of GNU programs, and
maybe helping national groups to initially organize, while maintaining
national registries for until national groups are ready to take over.
In fact, the coordinator should ease volunteers to get in contact with
one another for creating national teams, which should then select
one coordinator per language, or country (regionalized language).
If well done, the coordination should be useful without being an
overwhelming task, the time to put delegations in place.

</P>


<H3><A NAME="SEC60" HREF="gettext_toc.html#TOC60">National Teams</A></H3>

<P>
I suggest we look for volunteer coordinators/editors for individual
languages.  These people will scan contributions of translation files
for various programs, for their own languages, and will ensure high
and uniform standards of diction.

</P>
<P>
From my current experience with other people in these days, those who
provide localizations are very enthusiastic about the process, and are
more interested in the localization process than in the program they
localize, and want to do many programs, not just one.  This seems
to confirm that having a coordinator/editor for each language is a
good idea.

</P>
<P>
We need to choose someone who is good at writing clear and concise
prose in the language in question.  That is hard--we can't check
it ourselves.  So we need to ask a few people to judge each others'
writing and select the one who is best.

</P>
<P>
I announce my prerelease to a few dozen people, and you would not
believe all the discussions it generated already.  I shudder to think
what will happen when this will be launched, for true, officially,
world wide.  Who am I to arbitrate between two Czekolsovak users
contradicting each other, for example?

</P>
<P>
I assume that your German is not much better than my French so that
I would not be able to judge about these formulations.  What I would
suggest is that for each language there is a group for people who
maintain the PO files and judge about changes.  I suspect there will
be cultural differences between how such groups of people will behave.
Some will have relaxed ways, reach consensus easily, and have anyone
of the group relate to the maintainers, while others will fight to
death, organize heavy administrations up to national standards, and
use strict channels.

</P>
<P>
The German team is putting out a good example.  Right now, they are
maybe half a dozen people revising translations of each other and
discussing the linguistic issues.  I do not even have all the names.
Ulrich Drepper is taking care of coordinating the German team.
He subscribed to all my pretest lists, so I do not even have to warn
him specifically of incoming releases.

</P>
<P>
I'm sure, that is a good idea to get teams for each language working
on translations. That will make the translations better and more
consistent.

</P>


<H4><A NAME="SEC61" HREF="gettext_toc.html#TOC61">Sub-Cultures</A></H4>

<P>
Taking French for example, there are a few sub-cultures around
computers which developed diverging vocabularies.  Picking volunteers
here and there without addressing this problem in an organized way,
soon in the project, might produce a distasteful mix of GNU programs,
and possibly trigger endless quarrels among those who really care.

</P>
<P>
Keeping some kind of unity in the way French localization of GNU
programs is achieved is a difficult (and delicate) job.  Knowing the
latin character of French people (:-), if we take this the wrong
way, we could end up nowhere, or spoil a lot of energies.  Maybe we
should begin to address this problem seriously <EM>before</EM> GNU
<CODE>gettext</CODE> become officially published.  And I suspect that this
means soon!

</P>


<H4><A NAME="SEC62" HREF="gettext_toc.html#TOC62">Organizational Ideas</A></H4>

<P>
I expect the next big changes after the official release.  Please note
that I use the German translation of the short GPL message.  We need
to set a few good examples before the localization goes out for true
in GNU.  Here are a few points to discuss:

</P>

<UL>
<LI>

Each group should have one FTP server (at least one master).

<LI>

The files on the server should reflect the latest version (of
course!) and it should also contain a RCS directory with the
corresponding archives (I don't have this now).

<LI>

There should also be a ChangeLog file (this is more useful than the
RCS archive but can be generated automatically from the later by
Emacs).

<LI>

A <STRONG>core group</STRONG> should judge about questionable changes (for now
this group consists solely by me but I ask some others occasionally;
this also seems to work).

</UL>


<H3><A NAME="SEC63" HREF="gettext_toc.html#TOC63">Mailing Lists</A></H3>

<P>
If we get any inquiries about GNU <CODE>gettext</CODE>, send them on to:

</P>

<PRE>
<TT>`gnu-translation@prep.ai.mit.edu'</TT>
</PRE>

<P>
The <TT>`*-pretest'</TT> lists are quite useful to me, maybe the idea could
be generalized to all GNU packages.  But each maintainer his/her way!

</P>
<P>
, we have a mechanism in place here at
<TT>`gnu.ai.mit.edu'</TT> to track teams, support mailing lists for
them and log members.  We have a slight preference that you use it.
If this is OK with you, I can get you clued in.

</P>
<P>
Things are changing!  A few years ago, when Daniel Fekete and I
asked for a mailing list for GNU localization, nested at the FSF, we
were politely invited to organize it anywhere else, and so did we.
For communicating with my pretesters, I later made a handful of
mailing lists located at iro.umontreal.ca and administrated by
<CODE>majordomo</CODE>.  These lists have been <EM>very</EM> dependable
so far...

</P>
<P>
I suspect that the German team will organize itself a mailing list
located in Germany, and so forth for other countries.  But before they
organize for true, it could surely be useful to offer mailing lists
located at the FSF to each national team.  So yes, please explain me
how I should proceed to create and handle them.

</P>
<P>
We should create temporary mailing lists, one per country, to help
people organize.  Temporary, because once regrouped and structured, it
would be fair the volunteers from country bring back <EM>their</EM> list
in there and manage it as they want.  My feeling is that, in the long
run, each team should run its own list, from within their country.
There also should be some central list to which all teams could
subscribe as they see fit, as long as each team is represented in it.

</P>


<H2><A NAME="SEC64" HREF="gettext_toc.html#TOC64">Information Flow</A></H2>

<P>
There will surely be some discussion about this messages after the
packages are finally released.  If people now send you some proposals
for better messages, how do you proceed?  Jim, please note that
right now, as I put forward nearly a dozen of localizable programs, I
receive both the translations and the coordination concerns about them.

</P>
<P>
If I put one of my things to pretest, Ulrich receives the announcement
and passes it on to the German team, who make last minute revisions.
Then he submits the translation files to me <EM>as the maintainer</EM>.
For GNU packages I do not maintain, I would not even hear about it.
This scheme could be made to work GNU-wide, I think.  For security
reasons, maybe Ulrich (national coordinators, in fact) should update
central registry kept by GNU (Jim, me, or Len's recruits) once in
a while.

</P>
<P>
In December/January, I was aggressively ready to internationalize
all of GNU, giving myself the duty of one small GNU package per week
or so, taking many weeks or months for bigger packages.  But it does
not work this way.  I first did all the things I'm responsible for.
I've nothing against some missionary work on other maintainers, but
I'm also loosing a lot of energy over it--same debates over again.

</P>
<P>
And when the first localized packages are released we'll get a lot of
responses about ugly translations :-).  Surely, and we need to have
beforehand a fairly good idea about how to handle the information
flow between the national teams and the package maintainers.

</P>
<P>
Please start saving somewhere a quick history of each PO file.  I know
for sure that the file format will change, allowing for comments.
It would be nice that each file has a kind of log, and references for
those who want to submit comments or gripes, or otherwise contribute.
I sent a proposal for a fast and flexible format, but it is not
receiving acceptance yet by the GNU deciders.  I'll tell you when I
have more information about this.

</P>


<H1><A NAME="SEC65" HREF="gettext_toc.html#TOC65">The Maintainer's View</A></H1>

<P>
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 <A HREF="gettext.html#SEC32">The User's View</A>) will work
for installers and end users.

</P>
<P>
Of course, there are many possible ways by which GNU <CODE>gettext</CODE>
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 <CODE>gettext</CODE> 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 <TT>`configure.in'</TT> file and
uses Autoconf.

</P>
<P>
Nevertheless, GNU <CODE>gettext</CODE> 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
<CODE>gettext</CODE> work for them in all situations.  There are surely
many, out there.

</P>
<P>
Even if <CODE>gettext</CODE> methods are now stabilizing, slight adjustments
might be needed between successive <CODE>gettext</CODE> versions, so you
should ideally revise this chapter in subsequent releases, looking
for changes.

</P>


<H2><A NAME="SEC66" HREF="gettext_toc.html#TOC66">Flat or Non-Flat Directory Structures</A></H2>

<P>
Some GNU packages are distributed as <CODE>tar</CODE> files which unpack
in a single directory, these are said to be <STRONG>flat</STRONG> distributions.
Other GNU packages have a one level hierarchy of subdirectories, using
for example a subdirectory named <TT>`doc/'</TT> for the Texinfo manual and
man pages, another called <TT>`lib/'</TT> for holding functions meant to
replace or complement C libraries, and a subdirectory <TT>`src/'</TT> for
holding the proper sources for the package.  These other distributions
are said to be <STRONG>non-flat</STRONG>.

</P>
<P>
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 <CODE>gettext</CODE>.  Also, if you have
many PO files, this could somewhat pollute your single directory.
In the GNU <CODE>gettext</CODE> distribution, the <TT>`misc/'</TT> directory
contains a shell script named <TT>`combine-sh'</TT>.  That script may
be used for combining all the C files of the <TT>`intl/'</TT> directory
into a pair of C files (one <TT>`.c'</TT> and one <TT>`.h'</TT>).  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.

</P>
<P>
Maybe because GNU <CODE>gettext</CODE> 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 <CODE>gettext</CODE>
to flat distributions, we might add some notes about how to proceed
in flat situations.

</P>


<H2><A NAME="SEC67" HREF="gettext_toc.html#TOC67">Prerequisite Works</A></H2>

<P>
There are some works which are required for using GNU <CODE>gettext</CODE>
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.

</P>

<UL>
<LI>

Before attempting to use you should install some other packages first.
Ensure that recent versions of GNU <CODE>m4</CODE>, GNU Autoconf and GNU
<CODE>gettext</CODE> are already installed at your site, and if not, proceed
to do this first.  If you got to install these things, beware that
GNU <CODE>m4</CODE> must be fully installed before GNU Autoconf is even
<EM>configured</EM>.

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 <CODE>m4</CODE>, GNU Autoconf or GNU <CODE>gettext</CODE> 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 <CODE>gettext</CODE> shall
then be installed at the user site if the end users want to see the
translation of shell script messages.

<LI>

Your package should use Autoconf and have a <TT>`configure.in'</TT> file.
If it does not, you have to learn how.  The Autoconf documentation
is quite well written, it is a good idea that you print it and get
familiar with it.

<LI>

Your C sources should have already been modified according to
instructions given earlier in this manual.  See section <A HREF="gettext.html#SEC13">Preparing Program Sources</A>.

<LI>

Your <TT>`po/'</TT> directory should receive all PO files submitted to you
by the translator teams, each having <TT>`<VAR>ll</VAR>.po'</TT> as a name.
This is not usually easy to get translation
work done before your package gets internationalized and available!
Since the cycle has to start somewhere, the easiest for the maintainer
is to start with absolutely no PO files, and wait until various
translator teams get interested in your package, and submit PO files.

</UL>

<P>
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 <TT>`gnu-translation@prep.ai.mit.edu'</TT> 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 <TT>`po/'</TT> for distribution.

</P>
<P>
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 <EM>not</EM>
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 <TT>`NLS'</TT> file.

</P>
<P>
Maintainers should <EM>never ever</EM> 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 <EM>solve</EM> a team's problem on your own.

</P>


<H2><A NAME="SEC68" HREF="gettext_toc.html#TOC68">Invoking the <CODE>gettextize</CODE> Program</A></H2>

<P>
Some files are consistently and identically needed in every package
internationalized through GNU <CODE>gettext</CODE>.  As a matter of
convenience, the <CODE>gettextize</CODE> program puts all these files right
in your package.  This program has the following synopsis:

</P>

<PRE>
gettextize [ <VAR>option</VAR>... ] [ <VAR>directory</VAR> ]
</PRE>

<P>
and accepts the following options:

</P>
<DL COMPACT>

<DT><SAMP>`-f'</SAMP>
<DD>
<DT><SAMP>`--force'</SAMP>
<DD>
Force replacement of files which already exist.

<DT><SAMP>`-h'</SAMP>
<DD>
<DT><SAMP>`--help'</SAMP>
<DD>
Display this help and exit.

<DT><SAMP>`--version'</SAMP>
<DD>
Output version information and exit.

</DL>

<P>
If <VAR>directory</VAR> is given, this is the top level directory of a
package to prepare for using GNU <CODE>gettext</CODE>.  If not given, it
is assumed that the current directory is the top level directory of
such a package.

</P>
<P>
The program <CODE>gettextize</CODE> provides the following files.  However,
no existing file will be replaced unless the option <CODE>--force</CODE>
(<CODE>-f</CODE>) is specified.

</P>

<OL>
<LI>

The <TT>`NLS'</TT> file is copied in the main directory of your package,
the one being at the top level.  This file gives the main indications
about how to install and use the Native Language Support features
of your program.  You might elect to use a more recent copy of this
<TT>`NLS'</TT> file than the one provided through <CODE>gettextize</CODE>, if
you have one handy.  You may also fetch a more recent copy of file
<TT>`NLS'</TT> from most GNU archive sites.

<LI>

A <TT>`po/'</TT> directory is created for eventually holding
all translation files, but initially only containing the file
<TT>`po/Makefile.in.in'</TT> from the GNU <CODE>gettext</CODE> distribution.
(beware the double <SAMP>`.in'</SAMP> in the file name). If the <TT>`po/'</TT>
directory already exists, it will be preserved along with the files
it contains, and only <TT>`Makefile.in.in'</TT> will be overwritten.

<LI>

A <TT>`intl/'</TT> directory is created and filled with most of the files
originally in the <TT>`intl/'</TT> directory of the GNU <CODE>gettext</CODE>
distribution.  Also, if option <CODE>--force</CODE> (<CODE>-f</CODE>) is given,
the <TT>`intl/'</TT> directory is emptied first.

</OL>

<P>
If your site support symbolic links, <CODE>gettextize</CODE> 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 <SAMP>`-h'</SAMP> option while creating the
<CODE>tar</CODE> archive of your distribution will resolve each link by an
actual copy in the distribution archive.  So, to insist, you really
should use <SAMP>`-h'</SAMP> option with <CODE>tar</CODE> within your <CODE>dist</CODE>
goal of your main <TT>`Makefile.in'</TT>.

</P>
<P>
It is interesting to understand that most new files for supporting
GNU <CODE>gettext</CODE> facilities in one package go in <TT>`intl/'</TT>
and <TT>`po/'</TT> subdirectories.  One distinction between these two
directories is that <TT>`intl/'</TT> is meant to be completely identical
in all packages using GNU <CODE>gettext</CODE>, while all newly created
files, which have to be different, go into <TT>`po/'</TT>.  There is a
common <TT>`Makefile.in.in'</TT> in <TT>`po/'</TT>, because the <TT>`po/'</TT>
directory needs its own <TT>`Makefile'</TT>, and it has been designed so
it can be identical in all packages.

</P>


<H2><A NAME="SEC69" HREF="gettext_toc.html#TOC69">Files You Must Create or Alter</A></H2>

<P>
Besides files which are automatically added through <CODE>gettextize</CODE>,
there are many files needing revision for properly interacting with
GNU <CODE>gettext</CODE>.  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.

</P>
<P>
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
<CODE>gettext</CODE> 0.10 distribution itself.  You may indeed
refer to the source code of the GNU <CODE>gettext</CODE> package, as it
is intended to be a good example and master implementation for using
its own functionality.

</P>


<H3><A NAME="SEC70" HREF="gettext_toc.html#TOC70"><TT>`POTFILES'</TT> in <TT>`po/'</TT></A></H3>

<P>
The <TT>`po/'</TT> directory should receive a file named
<TT>`POTFILES.in'</TT>.  This file tells which files, among all program
sources, have marked strings needing translation.  Here is an example
of such a file:

</P>

<PRE>
# 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
</PRE>

<P>
Dashed comments and white lines are ignored.  All other lines
list those source files containing strings marked for translation
(see section <A HREF="gettext.html#SEC15">How Marks Appears in Sources</A>), in a notation relative to the top level
of your whole distribution, rather than the location of the
<TT>`POTFILES.in'</TT> file itself.

</P>


<H3><A NAME="SEC71" HREF="gettext_toc.html#TOC71"><TT>`configure.in'</TT> at top level</A></H3>


<OL>
<LI>Declare the package and version.

This is done by a set of lines like these:


<PRE>
PACKAGE=gettext
VERSION=0.10
AC_DEFINE_UNQUOTED(PACKAGE, "$PACKAGE")
AC_DEFINE_UNQUOTED(VERSION, "$VERSION")
AC_SUBST(PACKAGE)
AC_SUBST(VERSION)
</PRE>

Of course, you replace <SAMP>`gettext'</SAMP> with the name of your package,
and <SAMP>`0.10'</SAMP> by its version numbers, exactly as they
should appear in the packaged <CODE>tar</CODE> file name of your distribution
(<TT>`gettext-0.10.tar.gz'</TT>, here).

<LI>Declare the available translations.

This is done by defining <CODE>ALL_LINGUAS</CODE> to the white separated,
quoted list of available languages, in a single line, like this:


<PRE>
ALL_LINGUAS="de fr"
</PRE>

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 <CODE>ALL_LINGUAS</CODE> in
<TT>`configure.in'</TT>, but rather by using the <CODE>LINGUAS</CODE> environment
variable (see section <A HREF="gettext.html#SEC34">Magic for Installers</A>).

<LI>Check for internationalization support.

Here is the main <CODE>m4</CODE> macro for triggering internationalization
support.  Just add this line to <TT>`configure.in'</TT>:


<PRE>
ud_GNU_GETTEXT
</PRE>

This call is purposely simple, even if it generates a lot of configure
time checking and actions.

<LI>Obtain some <TT>`libintl.h'</TT> header file.

Once you called <CODE>ud_GNU_GETTEXT</CODE> in <TT>`configure.in'</TT>, use:


<PRE>
AC_LINK_FILES($nls_cv_header_libgt, $nls_cv_header_intl)
</PRE>

This will create one header file <TT>`libintl.h'</TT>.  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 <CODE>AC_LINK_FILES</CODE> call has not been integrated into the
<CODE>ud_GNU_GETTEXT</CODE> macro because there can be only one such call
in a <TT>`configure'</TT> file.  If you already use it, you will have to
<EM>merge</EM> the needed <CODE>AC_LINK_FILES</CODE> 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.

<LI>Have output files created.

The <CODE>AC_OUTPUT</CODE> directive, at the end of your <TT>`configure.in'</TT>
file, needs to be modified in two ways:


<PRE>
AC_OUTPUT([<VAR>existing configuration files</VAR> intl/Makefile po/Makefile.in],
[sed -e "/POTFILES =/r po/POTFILES" po/Makefile.in &#62; po/Makefile
<VAR>existing additional actions</VAR>])
</PRE>

The modification to the first argument to <CODE>AC_OUTPUT</CODE> asks
for substitution in the <TT>`intl/'</TT> and <TT>`po/'</TT> directories.
Note the <SAMP>`.in'</SAMP> suffix used for <TT>`po/'</TT> only.  This is because
the distributed file is really <TT>`po/Makefile.in.in'</TT>.

The modification to the second argument ensures that <TT>`po/Makefile'</TT>
gets generated out of the <TT>`po/Makefile.in'</TT> just created, including
in it the <TT>`po/POTFILES'</TT> produced by <CODE>ud_GNU_GETTEXT</CODE>.
Two steps are needed because <TT>`po/POTFILES'</TT> can get lengthy in
some packages, too lengthy in fact for being able to merely use an
Autoconf substituted variable, as many <CODE>sed</CODE>s cannot handle very
long lines.

</OL>


<H3><A NAME="SEC72" HREF="gettext_toc.html#TOC72"><TT>`aclocal.m4'</TT> at top level</A></H3>

<P>
If you do not have an <TT>`aclocal.m4'</TT> file in your distribution,
the simplest is taking a copy of <TT>`aclocal.m4'</TT> from
GNU <CODE>gettext</CODE>.  But to be precise, you only need macros
<CODE>ud_LC_MESSAGES</CODE>, <CODE>ud_WITH_NLS</CODE> and <CODE>ud_GNU_GETTEXT</CODE>,
so you may use an editor and remove macros you do not need.

</P>
<P>
If you already have an <TT>`aclocal.m4'</TT> file, then you will have
to merge the said macros into your <TT>`aclocal.m4'</TT>.  Note that if
you are upgrading from a previous release of GNU <CODE>gettext</CODE>, you
should most probably <EM>replace</EM> the said macros, as they usually
change a little from one release of GNU <CODE>gettext</CODE> to the next.
Their contents may vary as we get more experience with strange systems
out there.

</P>
<P>
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 <CODE>m4</CODE> code will be the same for all projects using GNU
<CODE>gettext</CODE>.

</P>


<H3><A NAME="SEC73" HREF="gettext_toc.html#TOC73"><TT>`acconfig.h'</TT> at top level</A></H3>

<P>
If you do not have an <TT>`acconfig.h'</TT> file in your distribution,
the simplest is use take a copy of <TT>`acconfig.h'</TT> from
GNU <CODE>gettext</CODE>.  But to be precise, you only need the
lines and comments for <CODE>ENABLE_NLS</CODE>, <CODE>HAVE_CATGETS</CODE>,
<CODE>HAVE_GETTEXT</CODE> and <CODE>HAVE_LC_MESSAGES</CODE>, so you may use
an editor and remove everything else.  If you already have an
<TT>`acconfig.h'</TT> file, then you should merge the said definitions
into your <TT>`acconfig.h'</TT>.

</P>


<H3><A NAME="SEC74" HREF="gettext_toc.html#TOC74"><TT>`Makefile.in'</TT> at top level</A></H3>

<P>
Here are a few modifications you need to make to your main, top-level
<TT>`Makefile.in'</TT> file.

</P>

<OL>
<LI>

Add the following lines near the beginning of your <TT>`Makefile.in'</TT>,
so the <SAMP>`dist:'</SAMP> goal will work properly (as explained further down):


<PRE>
PACKAGE = @PACKAGE@
VERSION = @VERSION@
</PRE>

<LI>

Add file <TT>`NLS'</TT> to the <CODE>DISTFILES</CODE> definition, so the file gets
distributed.

<LI>

Wherever you process subdirectories in your <TT>`Makefile.in'</TT>, be
sure you also process <CODE>@INTLSUB@</CODE> and <CODE>@POSUB@</CODE>, which
are replaced respectively by <SAMP>`intl'</SAMP> and <SAMP>`po'</SAMP>, 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 <CODE>SUBDIRS</CODE> in <CODE>Makefile.in</CODE> for it
to be further used in the <SAMP>`dist:'</SAMP> goal.


<PRE>
SUBDIRS = doc lib @INTLSUB@ src @POSUB@
</PRE>

that you will have to adapt to your own package.

<LI>

A delicate point is the <SAMP>`dist:'</SAMP> goal, as both
<TT>`intl/Makefile'</TT> and <TT>`po/Makefile'</TT> will later assume that the
proper directory has been set up from the main <TT>`Makefile'</TT>.  Here is
an example at what the <SAMP>`dist:'</SAMP> goal might look like:


<PRE>
distdir = $(PACKAGE)-$(VERSION)
dist: Makefile
	rm -fr $(distdir)
	mkdir $(distdir)
	chmod 777 $(distdir)
	for file in $(DISTFILES); do \
	  ln $$file $(distdir) 2&#62;/dev/null || cp -p $$file $(distdir); \
	done
	for subdir in $(SUBDIRS); do \
	  mkdir $(distdir)/$$subdir || exit 1; \
	  chmod 777 $(distdir)/$$subdir; \
	  (cd $$subdir &#38;&#38; $(MAKE) $@) || exit 1; \
	done
	tar chozf $(distdir).tar.gz $(distdir)
	rm -fr $(distdir)
</PRE>

</OL>


<H3><A NAME="SEC75" HREF="gettext_toc.html#TOC75"><TT>`Makefile.in'</TT> in <TT>`src/'</TT></A></H3>

<P>
Some of the modifications made in the main <TT>`Makefile.in'</TT> will
also be needed in the <TT>`Makefile.in'</TT> from your package sources,
which we assume here to be in the <TT>`src/'</TT> subdirectory.  Here are
all the modifications needed in <TT>`src/Makefile.in'</TT>:

</P>

<OL>
<LI>

In view of the <SAMP>`dist:'</SAMP> goal, you should have these lines near the
beginning of <TT>`src/Makefile.in'</TT>:


<PRE>
PACKAGE = @PACKAGE@
VERSION = @VERSION@
</PRE>

<LI>

If not done already, you should guarantee that <CODE>top_srcdir</CODE>
gets defined.  This will serve for <CODE>cpp</CODE> include files.  Just add
the line:


<PRE>
top_srcdir = @top_srcdir@
</PRE>

<LI>

You might also want to define <CODE>subdir</CODE> as <SAMP>`src'</SAMP>, later
allowing for almost uniform <SAMP>`dist:'</SAMP> goals in all your
<TT>`Makefile.in'</TT>.  At list, the <SAMP>`dist:'</SAMP> goal below assume that
you used:


<PRE>
subdir = src
</PRE>

<LI>

You should ensure that the final linking will use <CODE>@INTLLIBS@</CODE> as
a library.  An easy way to achieve this is to manage that it gets into
<CODE>LIBS</CODE>, like this:


<PRE>
LIBS = @INTLLIBS@ @LIBS@
</PRE>

In most GNU packages one will find a directory <TT>`lib/'</TT> in which a
library containing some helper functions will be build.  (You need at
least the few functions which the GNU <CODE>gettext</CODE> Library itself
needs.)  However some of the functions in the <TT>`lib/'</TT> 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
<TT>`libsupport.a'</TT>) just between the <CODE>@INTLLIBS@</CODE> and
<CODE>@LIBS@</CODE> in the above example.  Instead one has to write this:


<PRE>
LIBS = ../lib/libsupport.a @INTLLIBS@ ../lib/libsupport.a @LIBS@
</PRE>

<LI>

You should also ensure that directory <TT>`intl/'</TT> will be searched for
C preprocessor include files in all circumstances.  So, you have to
manage so both <SAMP>`-I../intl'</SAMP> and <SAMP>`-I$(top_srcdir)/intl'</SAMP> will
be given to the C compiler.

<LI>

Your <SAMP>`dist:'</SAMP> goal has to conform with others.  Here is a
reasonable definition for it:


<PRE>
distdir = ../$(PACKAGE)-$(VERSION)/$(subdir)
dist: Makefile $(DISTFILES)
	for file in $(DISTFILES); do \
	  ln $$file $(distdir) 2&#62;/dev/null || cp -p $$file $(distdir); \
	done
</PRE>

</OL>


<H1><A NAME="SEC76" HREF="gettext_toc.html#TOC76">Concluding Remarks</A></H1>

<P>
We would like to conclude this GNU <CODE>gettext</CODE> manual by presenting
an history of the GNU Translation Project so far.  We finally give
a few pointers for those who want to do further research or readings
about Native Language Support matters.

</P>


<H2><A NAME="SEC77" HREF="gettext_toc.html#TOC77">History of GNU <CODE>gettext</CODE></A></H2>

<P>
Internationalization concerns and algorithms have been informally
and casually discussed for years in GNU, sometimes around GNU
<CODE>libc</CODE>, maybe around the incoming <CODE>Hurd</CODE>, or otherwise
(nobody clearly remembers).  And even then, when the work started for
real, this was somewhat independently of these previous discussions.

</P>
<P>
This all began in July 1994, when Patrick D'Cruze had the idea and
initiative of internationalizing version 3.9.2 of GNU <CODE>fileutils</CODE>.
He then asked Jim Meyering, the maintainer, how to get those changes
folded into an official release.  That first draft was full of
<CODE>#ifdef</CODE>s and somewhat disconcerting, and Jim wanted to find
nicer ways.  Patrick and Jim shared some tries and experimentations
in this area.  Then, feeling that this might eventually have a deeper
impact on GNU, Jim wanted to know what standards were, and contacted
Richard Stallman, who very quickly and verbally described an overall
design for what was meant to become <CODE>glocale</CODE>, at that time.

</P>
<P>
Jim implemented <CODE>glocale</CODE> and got a lot of exhausting feedback
from Patrick and Richard, of course, but also from Mitchum DSouza
(who wrote a <CODE>catgets</CODE>-like package), Roland McGrath, maybe David
MacKenzie,  Pinard, and Paul Eggert, all pushing and
pulling in various directions, not always compatible, to the extent
that after a couple of test releases, <CODE>glocale</CODE> was torn apart.

</P>
<P>
While Jim took some distance and time and became dad for a second
time, Roland wanted to get GNU <CODE>libc</CODE> internationalized, and
got Ulrich Drepper involved in that project.  Instead of starting
from <CODE>glocale</CODE>, Ulrich rewrote something from scratch, but
more conformant to the set of guidelines who emerged out of the
<CODE>glocale</CODE> effort.  Then, Ulrich got people from the previous
forum to involve themselves into this new project, and the switch
from <CODE>glocale</CODE> to what was first named <CODE>msgutils</CODE>, renamed
<CODE>nlsutils</CODE>, and later <CODE>gettext</CODE>, became officially accepted
by Richard in May 1995 or so.

</P>
<P>
Let's summarize by saying that Ulrich Drepper wrote GNU <CODE>gettext</CODE>
in April 1995.  The first official release of the package, including
PO mode, occurred in July 1995, and was numbered 0.7.  Other people
contributed to the effort by providing a discussion forum around
Ulrich, writing little pieces of code, or testing.  These are quoted
in the <CODE>THANKS</CODE> file which comes with the GNU <CODE>gettext</CODE>
distribution.

</P>
<P>
While this was being done,  adapted half a dozen of
GNU packages to <CODE>glocale</CODE> first, then later to <CODE>gettext</CODE>,
putting them in pretest, so providing along the way an effective
user environment for fine tuning the evolving tools.  He also took
the responsibility of organizing and coordinating the GNU Translation
Project.  After nearly a year of informal exchanges between people from
many countries, translator teams started to exist in May 1995, through
the creation and support by Patrick D'Cruze of twenty unmoderated
mailing lists for that many native languages, and two moderated
lists: one for reaching all teams at once, the other for reaching
all maintainers of internationalized packages in GNU.

</P>
<P>
 also wrote PO mode in June 1995 with the collaboration
of Greg McGary, as a kind of contribution to Ulrich's package.
He also gave a hand with the GNU <CODE>gettext</CODE> Texinfo manual.

</P>


<H2><A NAME="SEC78" HREF="gettext_toc.html#TOC78">Related Readings</A></H2>

<P>
Eugene H. Dorr (<TT>`dorre@well.com'</TT>) maintains an interesting
bibliography on internationalization matters, called
<CITE>Internationalization Reference List</CITE>, which is available as:

<PRE>
ftp://ftp.ora.com/pub/examples/nutshell/ujip/doc/i18n-books.txt
</PRE>

<P>
Michael Gschwind (<TT>`mike@vlsivie.tuwien.ac.at'</TT>) maintains a
Frequently Asked Questions (FAQ) list, entitled <CITE>Programming for
Internationalisation</CITE>.  This FAQ discusses writing programs which
can handle different language conventions, character sets, etc.;
and is applicable to all character set encodings, with particular
emphasis on ISO 8859-1.  It is regularly published in Usenet
groups <TT>`comp.unix.questions'</TT>, <TT>`comp.std.internat'</TT>,
<TT>`comp.software.international'</TT>, <TT>`comp.lang.c'</TT>,
<TT>`comp.windows.x'</TT>, <TT>`comp.std.c'</TT>, <TT>`comp.answers'</TT>
and <TT>`news.answers'</TT>.  The home location of this document is:

<PRE>
ftp://ftp.vlsivie.tuwien.ac.at/pub/8bit/ISO-programming
</PRE>

<P>
Patrick D'Cruze (<TT>`pdcruze@li.org'</TT>) wrote a tutorial about NLS
matters, and Jochen Hein (<TT>`Hein@student.tu-clausthal.de'</TT>) took
over the responsibility of maintaining it.  It may be found as:

<PRE>
ftp://sunsite.unc.edu/pub/Linux/utils/nls/catalogs/Incoming/...
     ...locale-tutorial-0.8.txt.gz
</PRE>

<P>
This site is mirrored in:

<PRE>
ftp://ftp.ibp.fr/pub/linux/sunsite/
</PRE>

<P>
A French version of the same tutorial should be findable at:

<PRE>
ftp://ftp.ibp.fr/pub/linux/french/docs/
</PRE>

<P>
together with French translations of many Linux-related documents.

</P>
<P><HR><P>
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