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#208082: don't use LC_ALL, prefer system-wide LANG, don't set LC_CTYPE when LANG
is already set, advertise utf-8 a bit more...

1 <?xml version='1.0' encoding="UTF-8"?>
2 <!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/utf-8.xml,v 1.48 2008/05/19 21:08:38 swift Exp $ -->
3 <!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
4
5 <guide link="/doc/en/utf-8.xml">
6 <title>Using UTF-8 with Gentoo</title>
7
8 <author title="Author">
9 <mail link="slarti@gentoo.org">Thomas Martin</mail>
10 </author>
11 <author title="Contributor">
12 <mail link="devil@gentoo.org.ua">Alexander Simonov</mail>
13 </author>
14 <author title="Editor">
15 <mail link="fox2mike@gentoo.org">Shyam Mani</mail>
16 </author>
17
18 <abstract>
19 This guide shows you how to set up and use the UTF-8 Unicode character set with
20 your Gentoo Linux system, after explaining the benefits of Unicode and more
21 specifically UTF-8.
22 </abstract>
23
24 <!-- The content of this document is licensed under the CC-BY-SA license -->
25 <!-- See http://creativecommons.org/licenses/by-sa/2.5 -->
26 <license />
27
28 <version>2.26</version>
29 <date>2008-10-10</date>
30
31 <chapter>
32 <title>Character Encodings</title>
33 <section>
34 <title>What is a Character Encoding?</title>
35 <body>
36
37 <p>
38 Computers do not understand text themselves. Instead, every character is
39 represented by a number. Traditionally, each set of numbers used to represent
40 alphabets and characters (known as a coding system, encoding or character set)
41 was limited in size due to limitations in computer hardware.
42 </p>
43
44 </body>
45 </section>
46 <section>
47 <title>The History of Character Encodings</title>
48 <body>
49
50 <p>
51 The most common (or at least the most widely accepted) character set is
52 <b>ASCII</b> (American Standard Code for Information Interchange). It is widely
53 held that ASCII is the most successful software standard ever. Modern ASCII
54 was standardised in 1986 (ANSI X3.4, RFC 20, ISO/IEC 646:1991, ECMA-6) by the
55 American National Standards Institute.
56 </p>
57
58 <p>
59 ASCII is strictly seven-bit, meaning that it uses bit patterns representable
60 with seven binary digits, which provides a range of 0 to 127 in decimal. These
61 include 32 non-visible control characters, most between 0 and 31, with the
62 final control character, DEL or delete at 127. Characters 32 to 126 are
63 visible characters: a space, punctuation marks, Latin letters and numbers.
64 </p>
65
66 <p>
67 The eighth bit in ASCII was originally used as a parity bit for error checking.
68 If this is not desired, it is left as 0. This means that, with ASCII, each
69 character is represented by a single byte.
70 </p>
71
72 <p>
73 Although ASCII was enough for communication in modern English, in other
74 European languages that include accented characters, things were not so easy.
75 The ISO 8859 standards were developed to meet these needs. They were backwards
76 compatible with ASCII, but instead of leaving the eighth bit blank, they used
77 it to allow another 127 characters in each encoding. ISO 8859's limitations
78 soon came to light, and there are currently 15 variants of the ISO 8859
79 standard (8859-1 through to 8859-15). Outside of the ASCII-compatible byte
80 range of these character sets, there is often conflict between the letters
81 represented by each byte. To complicate interoperability between character
82 encodings further, Windows-1252 is used in some versions of Microsoft Windows
83 instead for Western European languages. This is a superset of ISO 8859-1,
84 however it is different in several ways. These sets do all retain ASCII
85 compatibility, however.
86 </p>
87
88 <p>
89 The necessary development of completely different single-byte encodings for
90 non-Latin alphabets, such as EUC (Extended Unix Coding) which is used for
91 Japanese and Korean (and to a lesser extent Chinese) created more confusion,
92 while other operating systems still used different character sets for the same
93 languages, for example, Shift-JIS and ISO-2022-JP. Users wishing to view
94 cyrillic glyphs had to choose between KOI8-R for Russian and Bulgarian or
95 KOI8-U for Ukrainian, as well as all the other cyrillic encodings such as the
96 unsuccessful ISO 8859-5, and the common Windows-1251 set. All of these
97 character sets broke most compatibility with ASCII (although KOI8 encodings
98 place cyrillic characters in Latin order, so in case the eighth bit is
99 stripped, text is still decipherable on an ASCII terminal through case-reversed
100 transliteration.)
101 </p>
102
103 <p>
104 This has led to confusion, and also to an almost total inability for
105 multilingual communication, especially across different alphabets. Enter
106 Unicode.
107 </p>
108
109 </body>
110 </section>
111 <section>
112 <title>What is Unicode?</title>
113 <body>
114
115 <p>
116 Unicode throws away the traditional single-byte limit of character sets. It
117 uses 17 "planes" of 65,536 code points to describe a maximum of 1,114,112
118 characters. As the first plane, aka. "Basic Multilingual Plane" or BMP,
119 contains almost everything you will ever use, many have made the wrong
120 assumption that Unicode was a 16-bit character set.
121 </p>
122
123 <p>
124 Unicode has been mapped in many different ways, but the two most common are
125 <b>UTF</b> (Unicode Transformation Format) and <b>UCS</b> (Universal Character
126 Set). A number after UTF indicates the number of bits in one unit, while the
127 number after UCS indicates the number of bytes. UTF-8 has become the most
128 widespread means for the interchange of Unicode text as a result of its
129 eight-bit clean nature, and it is the subject of this document.
130 </p>
131
132 </body>
133 </section>
134 <section>
135 <title>UTF-8</title>
136 <body>
137
138 <p>
139 UTF-8 is a variable-length character encoding, which in this instance means
140 that it uses 1 to 4 bytes per symbol. So, the first UTF-8 byte is used for
141 encoding ASCII, giving the character set full backwards compatibility with
142 ASCII. UTF-8 means that ASCII and Latin characters are interchangeable with
143 little increase in the size of the data, because only the first bit is used.
144 Users of Eastern alphabets such as Japanese, who have been assigned a higher
145 byte range are unhappy, as this results in as much as a 50% redundancy in their
146 data.
147 </p>
148
149 </body>
150 </section>
151 <section>
152 <title>What UTF-8 Can Do for You</title>
153 <body>
154
155 <p>
156 UTF-8 allows you to work in a standards-compliant and internationally accepted
157 multilingual environment, with a comparatively low data redundancy. UTF-8 is
158 the preferred way for transmitting non-ASCII characters over the Internet,
159 through Email, IRC or almost any other medium. Despite this, many people regard
160 UTF-8 in online communication as abusive. It is always best to be aware of the
161 attitude towards UTF-8 in a specific channel, mailing list or Usenet group
162 before using <e>non-ASCII</e> UTF-8.
163 </p>
164
165 </body>
166 </section>
167 </chapter>
168
169 <chapter>
170 <title>Setting up UTF-8 with Gentoo Linux</title>
171 <section>
172 <title>Finding or Creating UTF-8 Locales</title>
173 <body>
174
175 <p>
176 Now that you understand the principles behind Unicode, you're ready to start
177 using UTF-8 with your system.
178 </p>
179
180 <p>
181 The preliminary requirement for UTF-8 is to have a version of glibc installed
182 that has national language support. The recommend means to do this is the
183 <path>/etc/locale.gen</path> file. It is beyond the scope of this document to
184 explain the usage of this file though. It is explained in the <uri
185 link="/doc/en/guide-localization.xml#doc_chap3_sect3">Gentoo Localization
186 Guide</uri>.
187 </p>
188
189 <p>
190 Next, we'll need to decide whether a UTF-8 locale is already available for our
191 language, or whether we need to create one.
192 </p>
193
194 <pre caption="Checking for an existing UTF-8 locale">
195 <comment>(Replace "en_GB" with your desired locale setting)</comment>
196 # <i>locale -a | grep 'en_GB'</i>
197 en_GB
198 en_GB.UTF-8
199 </pre>
200
201 <p>
202 From the output of this command line, we need to take the result with a suffix
203 similar to <c>.UTF-8</c>. If there is no result with a suffix similar to
204 <c>.UTF-8</c>, we need to create a UTF-8 compatible locale.
205 </p>
206
207 <note>
208 Only execute the following code listing if you do not have a UTF-8 locale
209 available for your language.
210 </note>
211
212 <pre caption="Creating a UTF-8 locale">
213 <comment>(Replace "en_GB" with your desired locale setting)</comment>
214 # <i>localedef -i en_GB -f UTF-8 en_GB.UTF-8</i>
215 </pre>
216
217 <p>
218 Another way to include a UTF-8 locale is to add it to the
219 <path>/etc/locale.gen</path> file and generate necessary locales with
220 <c>locale-gen</c> command.
221 </p>
222
223 <pre caption="Line in /etc/locale.gen">
224 en_GB.UTF-8 UTF-8
225 </pre>
226
227 </body>
228 </section>
229 <section>
230 <title>Setting the Locale</title>
231 <body>
232
233 <p>
234 There is one environment variable that needs to be set in order to use our new
235 UTF-8 locales: <c>LC_CTYPE</c> (or optionally <c>LANG</c>, if you want to change
236 the system language as well). There are also many different ways to set it; some
237 people prefer to only have a UTF-8 environment for a specific user, in which
238 case they set them in their <path>~/.profile</path> (if you use <c>/bin/sh</c>),
239 <path>~/.bash_profile</path> or <path>~/.bashrc</path> (if you use
240 <c>/bin/bash</c>). More details and best practices can be found in our <uri
241 link="/doc/en/guide-localization.xml">Locallization Guide</uri>.
242 </p>
243
244 <p>
245 Others prefer to set the locale globally. One specific circumstance where
246 the author particularly recommends doing this is when
247 <path>/etc/init.d/xdm</path> is in use, because
248 this init script starts the display manager and desktop before any of the
249 aforementioned shell startup files are sourced, and so before any of the
250 variables are in the environment.
251 </p>
252
253 <p>
254 Setting the locale globally should be done using
255 <path>/etc/env.d/02locale</path>. The file should look something like the
256 following:
257 </p>
258
259 <pre caption="Demonstration /etc/env.d/02locale">
260 <comment>(As always, change "en_GB.UTF-8" to your locale)</comment>
261 LANG="en_GB.UTF-8"
262 </pre>
263
264 <note>
265 You can also substitute <c>LC_ALL</c> for <c>LANG</c>. This sets your locale
266 for all categories, including numerical and currency values. On a very few
267 systems, it might cause some issues. However, most users should be able to use
268 <c>LC_ALL</c> without problems. For more information on the categories affected
269 by using <c>LC_ALL</c>, please read the <uri
270 link="http://www.gnu.org/software/libc/manual/html_node/Locale-Categories.html#Locale-Categories">GNU
271 locale page</uri>.
272 </note>
273
274 <p>
275 Next, the environment must be updated with the change.
276 </p>
277
278 <pre caption="Updating the environment">
279 # <i>env-update</i>
280 >>> Regenerating /etc/ld.so.cache...
281 * Caching service dependencies ...
282 # <i>source /etc/profile</i>
283 </pre>
284
285 <p>
286 Now, run <c>locale</c> with no arguments to see if we have the correct
287 variables in our environment:
288 </p>
289
290 <pre caption="Checking if our new locale is in the environment">
291 # <i>locale</i>
292 LANG=
293 LC_CTYPE="en_GB.UTF-8"
294 LC_NUMERIC="en_GB.UTF-8"
295 LC_TIME="en_GB.UTF-8"
296 LC_COLLATE="en_GB.UTF-8"
297 LC_MONETARY="en_GB.UTF-8"
298 LC_MESSAGES="en_GB.UTF-8"
299 LC_PAPER="en_GB.UTF-8"
300 LC_NAME="en_GB.UTF-8"
301 LC_ADDRESS="en_GB.UTF-8"
302 LC_TELEPHONE="en_GB.UTF-8"
303 LC_MEASUREMENT="en_GB.UTF-8"
304 LC_IDENTIFICATION="en_GB.UTF-8"
305 LC_ALL=en_GB.UTF-8
306 </pre>
307
308 <p>
309 That's everything. You are now using UTF-8 locales, and the next hurdle is the
310 configuration of the applications you use from day to day.
311 </p>
312
313 </body>
314 </section>
315 </chapter>
316
317 <chapter>
318 <title>Application Support</title>
319 <section>
320 <body>
321
322 <p>
323 When Unicode first started gaining momentum in the software world, multibyte
324 character sets were not well suited to languages like C, in which many of the
325 day-to-day programs people use are written. Even today, some programs are not
326 able to handle UTF-8 properly. Fortunately, most are!
327 </p>
328
329 </body>
330 </section>
331 <section>
332 <title>Filenames, NTFS, and FAT</title>
333 <body>
334
335 <p>
336 There are several NLS options in the Linux kernel configuration menu, but it is
337 important to not become confused! For the most part, the only thing you need to
338 do is to build UTF-8 NLS support into your kernel, and change the default NLS
339 option to utf8.
340 </p>
341
342 <pre caption="Kernel configuration steps for UTF-8 NLS">
343 File Systems --&gt;
344 Native Language Support --&gt;
345 (utf8) Default NLS Option
346 &lt;*&gt; NLS UTF8
347 <comment>(Also &lt;*&gt; other character sets that are in use in
348 your FAT filesystems or Joilet CD-ROMs.)</comment>
349 </pre>
350
351 <p>
352 If you plan on mounting NTFS partitions, you may need to specify an <c>nls=</c>
353 option with mount. If you plan on mounting FAT partitions, you may need to
354 specify a <c>codepage=</c> option with mount. Optionally, you can also set a
355 default codepage for FAT in the kernel configuration. Note that the
356 <c>codepage</c> option with mount will override the kernel settings.
357 </p>
358
359 <pre caption="FAT settings in kernel configuration">
360 File Systems --&gt;
361 DOS/FAT/NT Filesystems --&gt;
362 (437) Default codepage for fat
363 </pre>
364
365 <p>
366 You should avoid setting <c>Default iocharset for fat</c> to UTF-8, as it is
367 not recommended. Instead, you may want to pass the option utf8=true when
368 mounting your FAT partitions. For further information, see <c>man mount</c> and
369 the kernel documentation at
370 <path>/usr/src/linux/Documentation/filesystems/vfat.txt</path>.
371 </p>
372
373 <p>
374 For changing the encoding of filenames, <c>app-text/convmv</c> can be used.
375 </p>
376
377 <pre caption="Example usage of convmv">
378 # <i>emerge --ask app-text/convmv</i>
379 <comment>(Command format)</comment>
380 # <i>convmv -f &lt;current-encoding&gt; -t utf-8 &lt;filename&gt;</i>
381 <comment>(Substitute iso-8859-1 with the charset you are converting
382 from)</comment>
383 # <i>convmv -f iso-8859-1 -t utf-8 filename</i>
384 </pre>
385
386 <p>
387 For changing the <e>contents</e> of files, use the <c>iconv</c> utility,
388 bundled with <c>glibc</c>:
389 </p>
390
391 <pre caption="Example usage of iconv">
392 <comment>(substitute iso-8859-1 with the charset you are converting from)</comment>
393 <comment>(Check the output is sane)</comment>
394 # <i>iconv -f iso-8859-1 -t utf-8 filename</i>
395 <comment>(Convert a file, you must create another file)</comment>
396 # <i>iconv -f iso-8859-1 -t utf-8 filename > newfile</i>
397 </pre>
398
399 <p>
400 <c>app-text/recode</c> can also be used for this purpose.
401 </p>
402
403 </body>
404 </section>
405 <section>
406 <title>The System Console</title>
407 <body>
408
409 <impo>
410 You need >=sys-apps/baselayout-1.11.9 for Unicode on the console.
411 </impo>
412
413 <p>
414 To enable UTF-8 on the console, you should edit <path>/etc/rc.conf</path> and
415 set <c>UNICODE="yes"</c>, and also read the comments in that file -- it is
416 important to have a font that has a good range of characters if you plan on
417 making the most of Unicode. For this to work, make sure you have properly
418 created a Unicode locale as explained in <uri link="#doc_chap1">Chapter
419 1</uri>.
420 </p>
421
422 <p>
423 The <c>KEYMAP</c> variable, set in <path>/etc/conf.d/keymaps</path>, should
424 have a Unicode keymap specified.
425 </p>
426
427 <pre caption="Example /etc/conf.d/keymaps snippet">
428 <comment>(Change "uk" to your local layout)</comment>
429 KEYMAP="uk"
430 </pre>
431
432 </body>
433 </section>
434 <section>
435 <title>Ncurses and Slang</title>
436 <body>
437
438 <note>
439 Ignore any mention of Slang in this section if you do not have it installed or
440 do not use it.
441 </note>
442
443 <p>
444 It is wise to add <c>unicode</c> to your global USE flags in
445 <path>/etc/make.conf</path>, and then to remerge <c>sys-libs/ncurses</c> and
446 <c>sys-libs/slang</c> if appropriate. Portage will do this automatically when
447 you update your system:
448 </p>
449
450 <pre caption="Updating your system">
451 # <i>emerge --update --deep --newuse world</i>
452 </pre>
453
454 <p>
455 We also need to rebuild packages that link to these, now the USE changes have
456 been applied. The tool we use (<c>revdep-rebuild</c>) is part of the
457 <c>gentoolkit</c> package.
458 </p>
459
460 <pre caption="Rebuilding of programs that link to ncurses or slang">
461 # <i>revdep-rebuild --soname libncurses.so.5</i>
462 # <i>revdep-rebuild --soname libslang.so.1</i>
463 </pre>
464
465 </body>
466 </section>
467 <section>
468 <title>KDE, GNOME and Xfce</title>
469 <body>
470
471 <p>
472 All of the major desktop environments have full Unicode support, and will
473 require no further setup than what has already been covered in this guide. This
474 is because the underlying graphical toolkits (Qt or GTK+2) are UTF-8 aware.
475 Subsequently, all applications running on top of these toolkits should be
476 UTF-8-aware out of the box.
477 </p>
478
479 <p>
480 The exceptions to this rule come in Xlib and GTK+1. GTK+1 requires a
481 iso-10646-1 FontSpec in the ~/.gtkrc, for example
482 <c>-misc-fixed-*-*-*-*-*-*-*-*-*-*-iso10646-1</c>. Also, applications using
483 Xlib or Xaw will need to be given a similar FontSpec, otherwise they will not
484 work.
485 </p>
486
487 <note>
488 If you have a version of the gnome1 control center around, use that instead.
489 Pick any iso10646-1 font from there.
490 </note>
491
492 <pre caption="Example ~/.gtkrc (for GTK+1) that defines a Unicode compatible font">
493 style "user-font"
494 {
495 fontset="-misc-fixed-*-*-*-*-*-*-*-*-*-*-iso10646-1"
496 }
497 widget_class "*" style "user-font"
498 </pre>
499
500 <p>
501 If an application has support for both a Qt and GTK+2 GUI, the GTK+2 GUI will
502 generally give better results with Unicode.
503 </p>
504
505 </body>
506 </section>
507 <section>
508 <title>X11 and Fonts</title>
509 <body>
510
511 <impo>
512 <c>x11-base/xorg-x11</c> has far better support for Unicode than XFree86
513 and is <e>highly</e> recommended.
514 </impo>
515
516 <p>
517 TrueType fonts have support for Unicode, and most of the fonts that ship with
518 Xorg have impressive character support, although, obviously, not every single
519 glyph available in Unicode has been created for that font. To build fonts
520 (including the Bitstream Vera set) with support for East Asian letters with X,
521 make sure you have the <c>cjk</c> USE flag set. Many other applications utilise
522 this flag, so it may be worthwhile to add it as a permanent USE flag.
523 </p>
524
525 <p>
526 Also, several font packages in Portage are Unicode aware.
527 </p>
528
529 <pre caption="Optional: Install some more Unicode-aware fonts">
530 # <i>emerge terminus-font intlfonts freefonts cronyx-fonts corefonts</i>
531 </pre>
532
533 </body>
534 </section>
535 <section>
536 <title>Window Managers and Terminal Emulators</title>
537 <body>
538
539 <p>
540 Window managers not built on GTK or Qt generally have very good Unicode
541 support, as they often use the Xft library for handling fonts. If your window
542 manager does not use Xft for fonts, you can still use the FontSpec mentioned in
543 the previous section as a Unicode font.
544 </p>
545
546 <p>
547 Terminal emulators that use Xft and support Unicode are harder to come by.
548 Aside from Konsole and gnome-terminal, the best options in Portage are
549 <c>x11-terms/rxvt-unicode</c>, <c>xfce-extra/terminal</c>,
550 <c>gnustep-apps/terminal</c>, <c>x11-terms/mlterm</c>, or plain
551 <c>x11-terms/xterm</c> when built with the <c>unicode</c> USE flag and invoked
552 as <c>uxterm</c>. <c>app-misc/screen</c> supports UTF-8 too, when invoked as
553 <c>screen -U</c> or the following is put into the <path>~/.screenrc</path>:
554 </p>
555
556 <pre caption="~/.screenrc for UTF-8">
557 defutf8 on
558 </pre>
559
560 </body>
561 </section>
562 <section>
563 <title>Vim, Emacs, Xemacs and Nano</title>
564 <body>
565
566 <p>
567 Vim provides full UTF-8 support, and also has builtin detection of UTF-8 files.
568 For further information in Vim, use <c>:help mbyte.txt</c>.
569 </p>
570
571 <p>
572 Emacs 22.x and higher has full UTF-8 support as well. Xemacs 22.x does not
573 support combining characters yet.
574 </p>
575
576 <p>
577 Lower versions of Emacs and/or Xemacs might require you to install
578 <c>app-emacs/mule-ucs</c> and/or <c>app-xemacs/mule-ucs</c>
579 and add the following code to your <path>~/.emacs</path> to have support for CJK
580 languages in UTF-8:
581 </p>
582
583 <pre caption="Emacs CJK UTF-8 support">
584 (require 'un-define)
585 (require 'jisx0213)
586 (set-language-environment "Japanese")
587 (set-default-coding-systems 'utf-8)
588 (set-terminal-coding-system 'utf-8)
589 </pre>
590
591 <p>
592 Nano has provided full UTF-8 support since version 1.3.6.
593 </p>
594
595 </body>
596 </section>
597 <section>
598 <title>Shells</title>
599 <body>
600
601 <p>
602 Currently, <c>bash</c> provides full Unicode support through the GNU readline
603 library. Z Shell (<c>zsh</c>) offers Unicode support with the <c>unicode</c> USE
604 flag.
605 </p>
606
607 <p>
608 The C shell, <c>tcsh</c> and <c>ksh</c> do not provide UTF-8 support at all.
609 </p>
610
611 </body>
612 </section>
613 <section>
614 <title>Irssi</title>
615 <body>
616
617 <p>
618 Irssi has complete UTF-8 support, although it does require a user
619 to set an option.
620 </p>
621
622 <pre caption="Enabling UTF-8 in Irssi">
623 /set term_charset UTF-8
624 </pre>
625
626 <p>
627 For channels where non-ASCII characters are often exchanged in non-UTF-8
628 charsets, the <c>/recode</c> command may be used to convert the characters.
629 Type <c>/help recode</c> for more information.
630 </p>
631
632 </body>
633 </section>
634 <section>
635 <title>Mutt</title>
636 <body>
637
638 <p>
639 The Mutt mail user agent has very good Unicode support. To use UTF-8 with Mutt,
640 you don't need to put anything in your configuration files. Mutt will work
641 under unicode enviroment without modification if all your configuration files
642 (signature included) are UTF-8 encoded.
643 </p>
644
645 <note>
646 You may still see '?' in mail you read with Mutt. This is a result of people
647 using a mail client which does not indicate the used charset. You can't do much
648 about this than to ask them to configure their client correctly.
649 </note>
650
651 <p>
652 Further information is available from the <uri
653 link="http://wiki.mutt.org/index.cgi?MuttFaq/Charset">Mutt Wiki</uri>.
654 </p>
655
656 </body>
657 </section>
658 <section>
659 <title>Man</title>
660 <body>
661
662 <p>
663 Man pages are an integral part of any Linux machine. To ensure that any
664 unicode in your man pages render correctly, edit <path>/etc/man.conf</path>
665 and replace a line as shown below.
666 </p>
667
668 <pre caption="man.conf changes for Unicode support">
669 <comment>(This is the old line)</comment>
670 NROFF /usr/bin/nroff -Tascii -c -mandoc
671 <comment>(Replace the one above with this)</comment>
672 NROFF /usr/bin/nroff -mandoc -c
673 </pre>
674
675 </body>
676 </section>
677 <section>
678 <title>elinks and links</title>
679 <body>
680
681 <p>
682 These are commonly used text-based browsers, and we shall see how we can enable
683 UTF-8 support on them. On <c>elinks</c> and <c>links</c>, there are two ways to
684 go about this, one using the Setup option from within the browser or editing the
685 config file. To set the option through the browser, open a site with
686 <c>elinks</c> or <c>links</c> and then <c>Alt+S</c> to enter the Setup Menu then
687 select Terminal options, or press <c>T</c>. Scroll down and select the last
688 option <c>UTF-8 I/O</c> by pressing Enter. Then Save and exit the menu. On
689 <c>links</c> you may have to do a repeat <c>Alt+S</c> and then press <c>S</c> to
690 save. The config file option, is shown below.
691 </p>
692
693 <pre caption="Enabling UTF-8 for elinks/links">
694 <comment>(For elinks, edit /etc/elinks/elinks.conf or ~/.elinks/elinks.conf and
695 add the following line)</comment>
696 set terminal.linux.utf_8_io = 1
697
698 <comment>(For links, edit ~/.links/links.cfg and add the following
699 line)</comment>
700 terminal "xterm" 0 1 0 us-ascii utf-8
701 </pre>
702
703 </body>
704 </section>
705 <section>
706 <title>Samba</title>
707 <body>
708
709 <p>
710 Samba is a software suite which implements the SMB (Server Message Block)
711 protocol for UNIX systems such as Macs, Linux and FreeBSD. The protocol
712 is also sometimes referred to as the Common Internet File System (CIFS). Samba
713 also includes the NetBIOS system - used for file sharing over windows networks.
714 </p>
715
716 <pre caption="Enabling UTF-8 for Samba">
717 <comment>(Edit /etc/samba/smb.conf and add the following under the [global] section)</comment>
718 dos charset = 1255
719 unix charset = UTF-8
720 display charset = UTF-8
721 </pre>
722
723 </body>
724 </section>
725 <section>
726 <title>Testing it all out</title>
727 <body>
728
729 <p>
730 There are numerous UTF-8 test websites around. <c>net-www/w3m</c>,
731 <c>net-www/links</c>, <c>net-www/elinks</c>, <c>net-www/lynx</c> and all
732 Mozilla based browsers (including Firefox) support UTF-8. Konqueror and Opera
733 have full UTF-8 support too.
734 </p>
735
736 <p>
737 When using one of the text-only web browsers, make absolutely sure you are
738 using a Unicode-aware terminal.
739 </p>
740
741 <p>
742 If you see certain characters displayed as boxes with letters or numbers
743 inside, this means that your font does not have a character for the symbol or
744 glyph that the UTF-8 wants. Instead, it displays a box with the hex code of the
745 UTF-8 symbol.
746 </p>
747
748 <ul>
749 <li>
750 <uri link="http://www.w3.org/2001/06/utf-8-test/UTF-8-demo.html">A W3C
751 UTF-8 Test Page</uri>
752 </li>
753 <li>
754 <uri link="http://titus.uni-frankfurt.de/indexe.htm?/unicode/unitest.htm">
755 A UTF-8 test page provided by the University of Frankfurt</uri>
756 </li>
757 </ul>
758
759 </body>
760 </section>
761 <section>
762 <title>Input Methods</title>
763 <body>
764
765 <p>
766 <e>Dead keys</e> may be used to input characters in X that are not included on
767 your keyboard. These work by pressing your right Alt key (or in some countries,
768 AltGr) and an optional key from the non-alphabetical section of the keyboard to
769 the left of the return key at once, releasing them, and then pressing a letter.
770 The dead key should modify it. Input can be further modified by using the Shift
771 key at the same time as pressing the AltGr and modifier.
772 </p>
773
774 <p>
775 To enable dead keys in X, you need a layout that supports it. Most European
776 layouts already have dead keys with the default variant. However, this is not
777 true of North American layouts. Although there is a degree of inconsistency
778 between layouts, the easiest solution seems to be to use a layout in the form
779 "en_US" rather than "us", for example. The layout is set in
780 <path>/etc/X11/xorg.conf</path> like so:
781 </p>
782
783 <pre caption="/etc/X11/xorg.conf snippet">
784 Section "InputDevice"
785 Identifier "Keyboard0"
786 Driver "kbd"
787 Option "XkbLayout" "en_US" <comment># Rather than just "us"</comment>
788 <comment>(Other Xkb options here)</comment>
789 EndSection
790 </pre>
791
792 <note>
793 The preceding change only needs to be applied if you are using a North American
794 layout, or another layout where dead keys do not seem to be working. European
795 users should have working dead keys as is.
796 </note>
797
798 <p>
799 This change will come into effect when your X server is restarted. To apply the
800 change now, use the <c>setxkbmap</c> tool, for example, <c>setxkbmap en_US</c>.
801 </p>
802
803 <p>
804 It is probably easiest to describe dead keys with examples. Although the
805 results are locale dependent, the concepts should remain the same regardless of
806 locale. The examples contain UTF-8, so to view them you need to either tell
807 your browser to view the page as UTF-8, or have a UTF-8 locale already
808 configured.
809 </p>
810
811 <p>
812 When I press AltGr and [ at once, release them, and then press a, 'ä' is
813 produced. When I press AltGr and [ at once, and then press e, 'ë' is produced.
814 When I press AltGr and ; at once, 'á' is produced, and when I press AltGr and ;
815 at once, release them, and then press e, 'é' is produced.
816 </p>
817
818 <p>
819 By pressing AltGr, Shift and [ at once, releasing them, and then pressing a, a
820 Scandinavian 'å' is produced. Similarly, when I press AltGr, Shift and [ at
821 once, release <e>only</e> the [, and then press it again, '˚' is produced.
822 Although it looks like one, this (U+02DA) is not the same as a degree symbol
823 (U+00B0). This works for other accents produced by dead keys — AltGr and [,
824 releasing only the [, then pressing it again makes '¨'.
825 </p>
826
827 <p>
828 AltGr can be used with alphabetical keys alone. For example, AltGr and m, a
829 Greek lower-case letter mu is produced: 'µ'. AltGr and s produce a
830 scharfes s or esszet: 'ß'. As many European users would expect (because
831 it is marked on their keyboard), AltGr and 4 (or E depending on the keyboard
832 layout) produces a Euro sign, '€'.
833 </p>
834
835 </body>
836 </section>
837 <section>
838 <title>Resources</title>
839 <body>
840
841 <ul>
842 <li>
843 <uri link="http://en.wikipedia.org/wiki/Unicode">The Wikipedia entry for
844 Unicode</uri>
845 </li>
846 <li>
847 <uri link="http://en.wikipedia.org/wiki/UTF-8">The Wikipedia entry for
848 UTF-8</uri>
849 </li>
850 <li><uri link="http://www.unicode.org">Unicode.org</uri></li>
851 <li><uri link="http://www.utf-8.com">UTF-8.com</uri></li>
852 <li><uri link="http://www.ietf.org/rfc/rfc3629.txt">RFC 3629</uri></li>
853 <li><uri link="http://www.ietf.org/rfc/rfc2277.txt">RFC 2277</uri></li>
854 <li>
855 <uri
856 link="http://www.tbray.org/ongoing/When/200x/2003/04/26/UTF">Characters vs.
857 Bytes</uri>
858 </li>
859 </ul>
860
861 </body>
862 </section>
863 </chapter>
864 </guide>

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