2003-04-25
Revision History | ||
---|---|---|
Revision 1.1.3 | 2003-10-23 | Pro |
Some info on Qt and KDE 3.2's ability to render bn text is added at the very end. | ||
Revision 1.1.2 | 2003-04-29 | SDG |
Added section on testing the translations. Initial LDP release. | ||
Revision 1.1.1 | 2003-04-20 | Pro |
Initial LDP release, section added on Lekho | ||
Revision 1.1.0 | 2003-02-20 | SDG |
Added Developers' Guide, made some significant changes in the document structure | ||
Revision 1.0.0 | 2003-02-14 | SDG |
Initial Release |
Abstract
The purpose of this document is to guide you setup and develop support for Bengali
(Bangla) in GNU/Linux
.
Table of Contents
One of the foremost things on many GNU/Linuxers' wishlist is better support for their vernacular script on their favourite operating system. But Indic scripts are some of the most difficult in the world to add support for, because of inherent complexities like the existence of conjuncts (yuktakshars) and non-standard spellings. However, the Free/Libre/Open Source community is not one that is easily daunted, and this document tries to outline the process of setting up Bangla support in FLOSS applications. Moreover, it also aims to be the "developers' guide" for new developers in the Bangla in GNU/Linux project.
Copyright (c) 2002-2003 Taneem Ahmed, Santanu Chatterjee, Progga, Sayamindu Dasgupta. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections , with no Front-Cover Texts , and with no Back-Cover Texts. A copy of the license is located at http://www.gnu.org/licences/fdl.html .
All copyrights are held by their respective owners, unless specifically noted otherwise. Use of a term in this document should not be regarded as affecting the validity of any trademark or service mark.
Naming of particular products or brands should not be seen as endorsements.
You are strongly recommended to take a backup of your system before major installation and backups at regular intervals.
The latest version of this HOWTO will always be made available at the www.Bengalinux.org site in a variety of formats.
We are extremely grateful to all the developers/users involved in the Bangla in GNU/Linux project, especially the people at Ankur and at the Free Bangla Fonts project .
The XML-stuff has been done with the help of the template written by Stein Gjoen, Gregory Leblanc and Greg Ferguson.
If you have any comments, criticisms, ideas, additions, corrections, questions then
please do mail them to <users@bengalinux.org>
mailing list. We would be happy to
help you.
We have used a number of special formatting to indicate warning messages, commands, filenames, computer outputs etc. They are listed below.
bash$ ls
NOTE
CAUTION
INFO
WARNING
/usr/src/linux/
application
no such file or directory
#!/bin/bash
logfile begins
This document explains how to setup and develop support for Bangla (or Bengali) in a GNU/Linux systems. Bangla support in GNU/Linux is by no means complete, but, in modern GNU/Linux distributions, you may be able to write in Bangla, send emails in Bangla, chat in Bangla, save with Bangla filenames (UTF-8....), have some of your graphical applications localized in Bangla, etc. Moreover, we have targeted to have the GNOME core translated into Bangla by August 2003, so that it can be included in the 2.4 release of GNOME. (Update- GNOME 2.4 is now out with partial support for Bangla)
However, note that this documents deals with Bangla support in GNU/Linux in GUI based applications only - we have no immediate plans for supporting Bangla on the console.
Also note that the Bangla support that we speak of here is totally Unicode compliant. We do not support any kind of proprietary/non-standard encoding.
This part is mainly for the user - it does not go into the intricacies of development procedures. However, developers planning to work in this field must also read it - so that they can setup the required develoment environment.
The first job that you have to do is to setup the locale for Bangla. 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 “locale” for this
language or country. This sub-section describes how to setup the bn_BD
locale definition file, which is for Bangladeshi Bengali. However, the Indian Bengali definition
file, i.e. bn_IN
, can be used in the same manner.
Remember that this sub-section is not intended to explain how to create a locale definition file, we will just explain how to use the locale defition file for Bangladeshi Bengali.
The bn_BD
file should come with the latest glibc package. in
case you have an older glibc, you can download this file from the
download section of Bengalinux.org.
Make sure you have some Unicode encoded Bengali fonts installed on your system. If you don't have one, check out fonts section.
Now issue the following command as root
:
bash$
localedef -f UTF-8 -i bn_BD bn_BD.UTF-8
This makes your system ready to be used with bn_BD locale definition.
Now make sure your X server is ready for Bengali locale. Check the following file
/usr/X11R6/lib/X11/locale/locale.dir
It should have the following lines:
en_US.UTF-8/XLC_LOCALE bn_BD.UTF-8 en_US.UTF-8/XLC_LOCALE: bn_BD.UTF-8
Now your system is ready to use bn_BD.UTF-8 locale. For example, I use the following command to open up an xterm with my own crappy font:
bash$
LC_ALL=bn_BD.UTF-8
xterm -fn"-misc-Probhat-medium-r-normal--0-0-0-0-p-0-iso10646-1" -u8
Remember, if you want to use Bengali in any application, you will have to start that application under an environment where the locale was set to bn_BD.UTF-8, otherwise it won't work.
If you are a rpm [read: RedHat %#$!@] user, then the easiest way to install the fonts from FBFP is by using the rpm package. The rpm package can be downloaded from http://www.Bengalinux.org/downloads/freebanglafont-0.2-1.noarch.rpm or http://savannah.nongnu.org/files/?group=freebangfont. Just install the rpm package as you would do for any other rpm package with the command
bash$
rpm -ivh freebanglafont-0.2-1.noarch.rpm
If you cannot or do not want to use the rpm package, there is always the good old tgz packages. Remember that you should have root privilege when you execute the commands mentioned here.
Download the files you want to install from http://savannah.nongnu.org/files/?group=freebangfont.
Remember that you will find several different tgz packages in FBFP. Each of them contain different font faces, i.e. they all look different from one another.
Once you have downloaded all the packages you want, extract all the
*.ttf
file(s). Basically run the following command on each
*.tgz
or *.tar.gz
you have downloaded.
bash$
tar -zxvf your_font_package.tar.gz
This will create a new directory that will contain different files that comes
with the font package. We are only interested about the *.ttf
files.
Create a new directory where you want to install these fonts. For the rest of
this document, we will assume we are installing the fonts in
/usr/X11R6/lib/X11/fonts/bengali/
Copy the *.ttf
files we just extracted in to this directory,
and execute the following commands:
bash$
cd /usr/X11R6/lib/X11/fonts/bengali
bash$
ttmkfdir
bash$
mkfontdir
bash$
chkfontpath -q -a /usr/X11R6/lib/X11/fonts/bengali
Now we will add the new directory to fontconfig
configuration. Usually this configuration file is /etc/fonts/fonts.conf
.
Open this file with you choice of text editor and look for the part that looks somewhat like
shown below
<dir>/usr/X11R6/lib/X11/fonts/Type1</dir> <dir>/usr/share/fonts</dir> <dir>~/.fonts</dir>
Add the line
<dir>/usr/X11R6/lib/X11/fonts/bengali</dir>
so that now it looks something like this:
<dir>/usr/X11R6/lib/X11/fonts/Type1</dir> <dir>/usr/share/fonts</dir> <dir>/usr/X11R6/lib/X11/fonts/bengali</dir> <dir>~/.fonts</dir>
After you have saved the file, execute the following command:
bash$
fc-cache
If you have GNOME print library (
libgnomeprint
) installed, then execute the following
commands:
bash$
cd /usr/X11R6/lib/X11/fonts/bengali
bash$
libgnomeprint-2.0-font-install --dynamic
That should be it! If you have any problem, please let us know at
<users@bengalinux.org>
The intention of this HOWTO is not to explain what is xkb symbol file, or how to create a new layout, etc. There are tons of places on the web where one can find a better and more in-depth HOWTO about XFree86 keyboard[layout/xkb/etc].
There is nothing special about setting up a Bengali Keyboard, just follow the steps described below. Remember everything you need in the following steps can be downloaded from the download section of Bengalinux.org, except the machine and the OS :-).
Make sure you have some Unicode encoded Bengali fonts installed on your system. If you don't have one, check out fonts section.
Download the xkb symbol file ben
and copy it to the directory
where the other xkb symbol files are. Usually this would be
/usr/X11R6/lib/X11/xkb/symbols
BTW, usually only root can copy files into this directory.
You are now one command away from starting the keyboard. On my system I just type the following command:
bash$
setxkbmap -symbols "us(pc101)+ben+group(ctrl_shift_toggle)"
On your system you are most likely to use a different value for
-symbols
option. Let me explain what they mean, then you can decide what should
be the value for your system. My default keyboard layout for X is us(pc101)
.
If you don't know what is the default you use, check the XF86Config
file
As the Bengali keyboard layout is defined in the second group we can simply add everything from
ben
to our keyboard layout. Now you have setup your keyboard with
us(pc101)
as group one and ben
as your second group. What
does that mean? Well in simple words: with X you can have different layouts in different groups
and you can switch between these different layouts. And that is exactly why we added
“group(ctrl_shift_toggle)”. This means we can switch between the two groups by
pressing ctrl+shift buttons together.
Matter of fact there are other options for the toggle switch. If your XFree86 is new enough, you
will find a file named group
in the same directory you copied
ben
. If your system does not have this file do not worry. You can use an
option like “grp:shift_toggle” which will toggle by pressing both shift buttons. In
which case your command becomes:
bash$
setxkbmap -symbols "us(pc101)+ben" -option "grp:shift_toggle"
Lekho is a text editor for creating Bangla Unicode files without using any type of Unicode font.
This section must not be taken as "The Complete Reference of Lekho". At best it can be regarded as a short introduction to the editor. The main purpose of this section is to make you aware of the presence of this wonderful editor. In any case, the primary source of information on Lekho is it's website or the documentation provided with the package distribution.
You may find Lekho helpful if you are
Too lazy/busy to install the necessary Locale, Opentype fonts and Keyboard.
Currently using a Gnome version prior to 2.0 .
Don't have gtk+ in your system at all.
Want to export as Latex for use with Bangtex macro package.
Some of the major features of Lekho are as follows
Keyboard Layout- Phonetic (i.e. k=ka, kh=kha etc)
Minimum Requirements- Qt 2.3
Font Usage- Adarshalipi
Save As- UTF-8, UTF-16, ISO-8859-1
Export As- HTML, Bangtex
Development Status- Beta
Support- Through Mailing list
Download the latest tarball from Lekho's website at http://lekho.sourceforge.net (Rumours are that an RPM is on the pipeline. By the time you read this HOWTO, it may be already out. So please check it if you prefer RPMs). Now untar the tarball:
bash$
tar xfz Lekho.tar.gz
'CD' to the Lekho source directory and then go through the traditional way of compilation+installation:
bash$
./configure
bash$
make
bash$
make install
At the very end of 'make install', the Adarshalipi fonts are copied to a seperate directory and the name of this directory is also printed. Now add that directory to your fontpath. There are several ways to do this depending on the XFree86 version you are using. Please consult Lekho's documentation for details.
Although Lekho is still in development stage, it has enough features to meet the requirements of most people IMHO.
This part of the HOWTO is mainly for developers - though the user who is interested in the internals can also go through it ;-). However, the developer should not start from here - he/she should at first read the preceding section to setup the system for Bengali support.
The development center is the
www.Bengalinux.org website. The model followed is
the generic FLOSS type "bazaar" model (slightly localized version ;-), and you get all the
goodies (CVS, shell access, scp, email lists, etc). If you are interested in
developing, send a mail to <core@bengalinux.org>
announcing your intentions.
A developer must be subscribed to the mailing list of the project he or she is work on - please see the Projects section of Bengalinux.org.
Usual netiquettes are applicable to all the lists - be polite/gentle, do not send HTML mails, do not shout, etc.
Must know how to read and write proper Bangla (at least Grammar should be OK).
Must have some sort of editor which can be used to edit Unicode encoded Bangla. (Proprietary editors are not advisable - no support will be provided.)
(This one is optional) - must have basic idea about l10n (if possible, RTFM by going through the GNU gettext info page)
Must be willing to follow the general FLOSS philosophy and procedures while developing for the project - and in general behave like a saint ;-).
Translation is pretty straight forward - you need to edit the
*.po
(Portable Object) files. To get the PO files -
check out which files are untranslated from
http://developer.gnome.org/projects/gtp/status/gnome-2.2/bn/index.html. Download any one
of the untranslated files and open it in an editor that supports Bangla (sorry - vi/emacs won't
work here). I personally use Yudit
- and other possible options are
Lekho and the good old Gedit2.
Before you start working on something, make sure that you announce the file
you are working on at <gnome-translations@bengalinux.org>
. This may save a lot of
trouble and frustation ;-).
At the beginning of the file you will see some fields for filling in the translators' name, email, translation time, package name, etc. Fill them up, and proceed to the next part.
You will find some lines like
#: atk/atkobject.c:1183 msgid "invalid" msgstr ""
The first line specifies the filename and the position in which the string in the second line occurs. The second line contains the actual string that is to be translated and the third line is the placeholder for the translated string in Bangla. Thus, in a translated file this set would look like
#: atk/atkobject.c:1183 msgid "invalid" msgstr "bhul"
Here, I have written the word bhul in English due the limitations of present day technology. However, when you do the actual translation, you will need to write the translated strings in Bangla - and not English.
You will have to translate all the sets in a po file before it is considered to
be complete. When it is complete, mail it to the translation list
<gnome-translation@bengalinux.org>
, so that the other developers can also go
through it.
Before submitting the translation as final - please check the file with the command:
bash$
msgfmt -c filename_bn.po -o /dev/null
where filename_bn.po
is the file you are working on.
While translating, remember not to kill the language ;-). Do not overdo the translation - do not use Sadhu Basha . Also, when the computer is addressing the user, it is samman-shuchak (karun, balun, etc) while the computer is addressed by karo, balo, etc. If a Bangla equivalent sounds too out of the ordinary - keep the English word (in Bangla script) - it can be always changed/improved later. DO NOT overdo anything.
Also, keep proper nouns and trademarks/brandnames as they are. (Bourne Again Shell (BASH) should not be called Aabaar Bourne Shell).
Use the more common word (jaanlaa and not gabaakhya). Also always remember that the words need not be very much applicable to the actual action - an Englishman from the nineteenth century could not even have guessed what “Save” can do in a computer ;-).
If you have comments regarding a certain translated string, please write that (commented out with a “#”), so that we can go through it later. If you have more than one equivalent string in your mind, write all of them, and comment all of them except the one you think is the best.
However, while commenting, remember that you cannot have any comments between the msgid and msgstr lines.
That means
#: atk/atkobject.c:1183 msgid "invalid" # yadayadayada msgstr "bhul"
is invalid. Instead you should write-
#: atk/atkobject.c:1183 msgid "invalid" msgstr "bhul" # yadayadayada
Also ...last but in no way the least, spellcheck, spellcheck, spellcheck. During translation session - always sit with your dictionary, or even better, the Bangla Baanaan Abhidhan from the Bangladesh Bangla Academy. The bspeller from Bengalinux may be useful here.
Another recommended book is the Samartha-ShabdaKosh (Bangla Thesaraus) by Ashok Mukherjee from Sahitya Samsad.
One of the most tricky things for a translator is understanding the context. For example, by simply looking at a pofile, a translator will have no clue whether Open stands for Kholo or Khola. To do context sensitive translation, a translator has to check out his/her translations in action, that is, in the application interfaces. This section describes a hack to see the translations without having to recompile the program.
This process works for most systems with GDM as the login manager. However, I cannot guarantee that this will work on your system.
To begin with, setup the locale for Bangla and install some Bangla fonts.
Once that is done, get all the translated pofiles in a single folder in your machine (to avoid mess), and one by one convert them into MO files with the command:
bash$
msgfmt -o file.mo file.version.gnomeversion_bn.po
While doing this, remember to strip all the version and language information
from the mo file's name, ie, gnome-games.gnome-2-4.bn.po
should be
converted to gnome-games.mo
.
If you are unsure about a package, do a rpm -ql packagename, and you will get the naming
scheme for the package. For example, a part of the output of rpm -ql
gdm
reads
/usr/share/locale/ru/LC_MESSAGES/gdm-2.4.mo /usr/share/locale/sk/LC_MESSAGES/gdm-2.4.mo /usr/share/locale/sl/LC_MESSAGES/gdm-2.4.mo /usr/share/locale/sv/LC_MESSAGES/gdm-2.4.mo /usr/share/locale/ta/LC_MESSAGES/gdm-2.4.mo
From this, it becomes apparent that one has to issue the command
msgfmt -o
gdm-2.4.mo gdm2.gnome-2-2.bn.po
for the GDM package.
Once you are finished with that, copy the MO files to
/usr/share/locale/bn_IN.UTF-8
or
/usr/share/locale/bn_BD.UTF-8
, depending on how you set up your locale.
Now, open up /etc/X11/gdm/locale.alias
and add the following
lines to it.
Bengali bn_IN.UTF-8,bn_IN
After this, restart X, select Bengali in the Languages menu and relogin into GNOME. You will be presented with a Bangla system.
For testing a single application, you don't have to go through all this stuff. Just setup the locale, install the font and put the MO file in the proper place. Now, fire up xterm, and issue the command export LANG=bn_IN.UTF-8 or export LANG=bn_BD.UTF-8. After this, from xterm itself, start the program you want to check, and it will start up with a Bangla interface.
This section contains some miscellaneous information.
www.Bengalinux.org or www.AnkurBangla.Org: The mother site of all major projects related to Bangla in GNU/Linux.
http://www.nongnu.org/freebangfont: The font wing of Ankur.
www.unicode.org: The official site of the Unicode Consortium.
If you want to help us in bringing Bangla support in GNU/Linux and in other
Free/Libre/Open Source Software (FLOSS) applications, then please let us know at
<users@bengalinux.org>
. We are looking for mentors, developers, beta testers,
translators, font designers to volunteer for our project. Even if you are not a conventional
technically skilled person, you may help us by letting us know your comments on the work we are
doing (especially the translation jobs.)
Also, if you are a font developer, you may consider (re)licensing your work under the GNU GPL so that we can reuse the fonts in our projects (of course, with due credit to you).
Rendering of the Bangla script is a complex job, especially when one has to be
within the Unicode limits. Hence, the technology behind Bangla rendering is considered to be
quite “bleeding edge”, and only the latest software support it. For example, Bangla
text rendering support is there only in the latest Qt
toolkit (Qt 3.2) which is used for KDE and
Pango, which is the text
rendering/layout engine of GTK 2
. Pango 1.1.1 and above
has a seperate module for Bangla. In addition to that, in the Free Software world,
Yudit can render Bangla
text correctly. However, the situation is improving slowly, and in the near future, we will
probably see Bangla rendering in Mozilla,
OpenOffice, etc. In fact, the beta version of OpenOffice (at the time
of writing) has partial support for Bangla - however, it still has some serious problems with
the split vowel signs. Starting from version 3.2.0, KDE applications (will) officially support
Bangla rendering too.