1# Core GIT Translations
2
3This directory holds the translations for the core of Git. This document
4describes how you can contribute to the effort of enhancing the language
5coverage and maintaining the translation.
6
7The localization (l10n) coordinator, Jiang Xin <worldhello.net@gmail.com>,
8coordinates our localization effort in the l10 coordinator repository:
9
10    https://github.com/git-l10n/git-po/
11
12The two character language translation codes are defined by ISO\_639-1, as
13stated in the gettext(1) full manual, appendix A.1, Usual Language Codes.
14
15
16## Contributing to an existing translation
17
18As a contributor for a language XX, you should first check TEAMS file in
19this directory to see whether a dedicated repository for your language XX
20exists. Fork the dedicated repository and start to work if it exists.
21
22Sometime, contributors may find that the translations of their Git
23distributions are quite different with the translations of the
24corresponding version from Git official. This is because some Git
25distributions (such as from Ubuntu, etc.) have their own l10n workflow.
26For this case, wrong translations should be reported and fixed through
27their workflows.
28
29
30## Creating a new language translation
31
32If you are the first contributor for the language XX, please fork this
33repository, prepare and/or update the translated message file "po/XX.po"
34(described later), and ask the l10n coordinator to pull your work.
35
36If there are multiple contributors for the same language, please first
37coordinate among yourselves and nominate the team leader for your
38language, so that the l10n coordinator only needs to interact with one
39person per language.
40
41
42## Core translation
43
44The core translation is the smallest set of work that must be completed
45for a new language translation. Because there are more than 5000 messages
46in the template message file "po/git.pot" that need to be translated,
47this is not a piece of cake for the contributor for a new language.
48
49The core template message file which contains a small set of messages
50will be generated in "po-core/core.pot" automatically by running a helper
51program named "git-po-helper" (described later).
52
53```shell
54git-po-helper init --core XX.po
55```
56
57After translating the generated "po-core/XX.po", you can merge it to
58"po/XX.po" using the following commands:
59
60```shell
61msgcat po-core/XX.po po/XX.po -s -o /tmp/XX.po
62mv /tmp/XX.po po/XX.po
63git-po-helper update XX.po
64```
65
66Edit "po/XX.po" by hand to fix "fuzzy" messages, which may have misplaced
67translated messages and duplicate messages.
68
69
70## Translation Process Flow
71
72The overall data-flow looks like this:
73
74    +-------------------+            +------------------+
75    | Git source code   | ---(1)---> | L10n coordinator |
76    | repository        | <---(4)--- | repository       |
77    +-------------------+            +------------------+
78                                          |      ^
79                                         (2)    (3)
80                                          V      |
81                                     +------------------+
82                                     | Language Team XX |
83                                     +------------------+
84
85- Translatable strings are marked in the source file.
86- L10n coordinator pulls from the source (1)
87- L10n coordinator updates the message template "po/git.pot"
88- Language team pulls from L10n coordinator (2)
89- Language team updates the message file "po/XX.po"
90- L10n coordinator pulls from Language team (3)
91- L10n coordinator asks the result to be pulled (4).
92
93
94## Maintaining the "po/git.pot" file
95
96(This is done by the l10n coordinator).
97
98The "po/git.pot" file contains a message catalog extracted from Git's
99sources. The l10n coordinator maintains it by adding new translations with
100msginit(1), or update existing ones with msgmerge(1).  In order to update
101the Git sources to extract the messages from, the l10n coordinator is
102expected to pull from the main git repository at strategic point in
103history (e.g. when a major release and release candidates are tagged),
104and then run "make pot" at the top-level directory.
105
106Language contributors use this file to prepare translations for their
107language, but they are not expected to modify it.
108
109
110## Initializing a "XX.po" file
111
112(This is done by the language teams).
113
114If your language XX does not have translated message file "po/XX.po" yet,
115you add a translation for the first time by running:
116
117```shell
118msginit --locale=XX
119```
120
121in the "po/" directory, where XX is the locale, e.g. "de", "is", "pt\_BR",
122"zh\_CN", etc.
123
124Then edit the automatically generated copyright info in your new "XX.po"
125to be correct, e.g. for Icelandic:
126
127```diff
128@@ -1,6 +1,6 @@
129-# Icelandic translations for PACKAGE package.
130-# Copyright (C) 2010 THE PACKAGE'S COPYRIGHT HOLDER
131-# This file is distributed under the same license as the PACKAGE package.
132+# Icelandic translations for Git.
133+# Copyright (C) 2010 Ævar Arnfjörð Bjarmason <avarab@gmail.com>
134+# This file is distributed under the same license as the Git package.
135 # Ævar Arnfjörð Bjarmason <avarab@gmail.com>, 2010.
136```
137
138And change references to PACKAGE VERSION in the PO Header Entry to
139just "Git":
140
141```shell
142perl -pi -e 's/(?<="Project-Id-Version: )PACKAGE VERSION/Git/' XX.po
143```
144
145Once you are done testing the translation (see below), commit the result
146and ask the l10n coordinator to pull from you.
147
148
149## Updating a "XX.po" file
150
151(This is done by the language teams).
152
153If you are replacing translation strings in an existing "XX.po" file to
154improve the translation, just edit the file.
155
156If there's an existing "XX.po" file for your language, but the repository
157of the l10n coordinator has newer "po/git.pot" file, you would need to first
158pull from the l10n coordinator (see the beginning of this document for its
159URL), and then update the existing translation by running:
160
161```shell
162msgmerge --add-location --backup=off -U XX.po git.pot
163```
164
165in the "po/" directory, where "XX.po" is the file you want to update.
166
167Once you are done testing the translation (see below), commit the result
168and ask the l10n coordinator to pull from you.
169
170
171## Fuzzy translation
172
173Fuzzy translation is a translation marked by comment "fuzzy" to let you
174know that the translation is out of date because the "msgid" has been
175changed. A fuzzy translation will be ignored when compiling using "msgfmt".
176Fuzzy translation can be marked by hands, but for most cases they are
177marked automatically when running "msgmerge" to update your "XX.po" file.
178
179After fixing the corresponding translation, you must remove the "fuzzy"
180tag in the comment.
181
182
183## Testing your changes
184
185(This is done by the language teams, after creating or updating "XX.po" file).
186
187Before you submit your changes go back to the top-level and do:
188
189```shell
190make
191```
192
193On systems with GNU gettext (i.e. not Solaris) this will compile your
194changed PO file with `msgfmt --check`, the --check option flags many
195common errors, e.g. missing printf format strings, or translated
196messages that deviate from the originals in whether they begin/end
197with a newline or not.
198
199
200## Marking strings for translation
201
202(This is done by the core developers).
203
204Before strings can be translated they first have to be marked for
205translation.
206
207Git uses an internationalization interface that wraps the system's
208gettext library, so most of the advice in your gettext documentation
209(on GNU systems `info gettext` in a terminal) applies.
210
211General advice:
212
213- Don't mark everything for translation, only strings which will be
214  read by humans (the porcelain interface) should be translated.
215
216  The output from Git's plumbing utilities will primarily be read by
217  programs and would break scripts under non-C locales if it was
218  translated. Plumbing strings should not be translated, since
219  they're part of Git's API.
220
221- Adjust the strings so that they're easy to translate. Most of the
222  advice in `info '(gettext)Preparing Strings'` applies here.
223
224- If something is unclear or ambiguous you can use a "TRANSLATORS"
225  comment to tell the translators what to make of it. These will be
226  extracted by xgettext(1) and put in the "po/\*.po" files, e.g. from
227  git-am.sh:
228
229  ```shell
230  # TRANSLATORS: Make sure to include [y], [n], [e], [v] and [a]
231  # in your translation. The program will only accept English
232  # input at this point.
233  gettext "Apply? [y]es/[n]o/[e]dit/[v]iew patch/[a]ccept all "
234  ```
235
236  Or in C, from builtin/revert.c:
237
238  ```c
239  /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
240  die(_("%s: Unable to write new index file"), action_name(opts));
241  ```
242
243We provide wrappers for C, Shell and Perl programs. Here's how they're
244used:
245
246
247### C
248
249Include builtin.h at the top, it'll pull in gettext.h, which
250defines the gettext interface. Consult with the list if you need to
251use gettext.h directly.
252
253The C interface is a subset of the normal GNU gettext
254interface. We currently export these functions:
255
256- \_()
257
258  Mark and translate a string. E.g.:
259
260  ```c
261  printf(_("HEAD is now at %s"), hex);
262  ```
263
264- Q\_()
265
266  Mark and translate a plural string. E.g.:
267
268  ```c
269  printf(Q_("%d commit", "%d commits", number_of_commits));
270  ```
271
272  This is just a wrapper for the ngettext() function.
273
274- N\_()
275
276  A no-op pass-through macro for marking strings inside static
277  initializations, e.g.:
278
279  ```c
280  static const char *reset_type_names[] = {
281      N_("mixed"), N_("soft"), N_("hard"), N_("merge"), N_("keep"), NULL
282  };
283  ```
284
285  And then, later:
286
287  ```c
288  die(_("%s reset is not allowed in a bare repository"),
289        _(reset_type_names[reset_type]));
290  ```
291
292  Here `_()` couldn't have statically determined what the translation
293  string will be, but since it was already marked for translation
294  with `N_()` the look-up in the message catalog will succeed.
295
296
297### Shell
298
299The Git gettext shell interface is just a wrapper for
300gettext.sh. Import it right after git-sh-setup like this:
301
302```shell
303. git-sh-setup
304. git-sh-i18n
305```
306
307And then use the `gettext` or `eval_gettext` functions:
308
309```shell
310# For constant interface messages:
311gettext "A message for the user"; echo
312
313# To interpolate variables:
314details="oh noes"
315eval_gettext "An error occurred: \$details"; echo
316```
317
318In addition we have wrappers for messages that end with a trailing
319newline. I.e. you could write the above as:
320
321```shell
322# For constant interface messages:
323gettextln "A message for the user"
324
325# To interpolate variables:
326details="oh noes"
327eval_gettextln "An error occurred: \$details"
328```
329
330More documentation about the interface is available in the GNU info
331page: `info '(gettext)sh'`. Looking at git-am.sh (the first shell
332command to be translated) for examples is also useful:
333
334```shell
335git log --reverse -p --grep=i18n git-am.sh
336```
337
338
339### Perl
340
341The Git::I18N module provides a limited subset of the
342Locale::Messages functionality, e.g.:
343
344```perl
345use Git::I18N;
346print __("Welcome to Git!\n");
347printf __("The following error occurred: %s\n"), $error;
348```
349
350Run `perldoc perl/Git/I18N.pm` for more info.
351
352
353## Testing marked strings
354
355Git's tests are run under `LANG=C LC_ALL=C`. So the tests do not need be
356changed to account for translations as they're added.
357
358
359## PO helper
360
361To make the maintenance of "XX.po" easier, the l10n coordinator and l10n
362team leaders can use a helper program named "git-po-helper". It is a
363wrapper to gettext suite, specifically written for the purpose of Git
364l10n workflow.
365
366To build and install the helper program from source, see
367[git-po-helper/README][].
368
369Usage for git-po-helper:
370
371- To start a new language translation:
372
373  ```shell
374  git-po-helper init XX.po
375  ```
376
377- To update your "XX.po" file:
378
379  ```shell
380  git-po-helper update XX.po
381  ```
382
383- To check commit log and syntax of "XX.po":
384
385  ```shell
386  git-po-helper check-po XX.po
387  git-po-helper check-commits
388  ```
389
390Run "git-po-helper" without arguments to show usage.
391
392
393## Conventions
394
395There are some conventions that l10n contributors must follow:
396
397- The subject of each l10n commit should be prefixed with "l10n: ".
398
399- Do not use non-ASCII characters in the subject of a commit.
400
401- The length of commit subject (first line of the commit log) should
402  be less than 50 characters, and the length of other lines of the
403  commit log should be no more than 72 characters.
404
405- Add "Signed-off-by" trailer to your commit log, like other commits
406  in Git. You can automatically add the trailer by committing with
407  the following command:
408
409  ```shell
410  git commit -s
411  ```
412
413- Check syntax with "msgfmt" or the following command before creating
414  your commit:
415
416  ```shell
417  git-po-helper check-po <XX.po>
418  ```
419
420- Squash trivial commits to make history clear.
421
422- DO NOT edit files outside "po/" directory.
423
424- Other subsystems ("git-gui", "gitk", and Git itself) have their
425  own workflow. See [Documentation/SubmittingPatches][] for
426  instructions on how to contribute patches to these subsystems.
427
428
429To contribute for a new l10n language, contributor should follow
430additional conventions:
431
432- Initialize proper filename of the "XX.po" file conforming to
433  iso-639 and iso-3166.
434
435- Must complete a minimal translation based on the "po-core/core.pot"
436  template. Using the following command to initialize the minimal
437  "po-core/XX.po" file:
438
439  ```shell
440  git-po-helper init --core <your-language>
441  ```
442
443- Add a new entry in the "po/TEAMS" file with proper format, and check
444  the syntax of "po/TEAMS" by running the following command:
445
446  ```shell
447  git-po-helper team --check
448  ```
449
450
451[git-po-helper/README]: https://github.com/git-l10n/git-po-helper#readme
452[Documentation/SubmittingPatches]: Documentation/SubmittingPatches
453