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1 <?xml version='1.0' encoding="UTF-8"?>
2 <!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/utf-8.xml,v 1.43 2006/07/19 11:56:26 rane 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>2.22</version>
29 <date>2006-08-28</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
235 our new UTF-8 locales: <c>LC_ALL</c> (this variable overrides the <c>LANG</c>
236 setting as well). There are also many different ways to set it; some people
237 prefer to only have a UTF-8 environment for a specific user, in which case
238 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>).
241 </p>
242
243 <p>
244 Others prefer to set the locale globally. One specific circumstance where
245 the author particularly recommends doing this is when
246 <path>/etc/init.d/xdm</path> is in use, because
247 this init script starts the display manager and desktop before any of the
248 aforementioned shell startup files are sourced, and so before any of the
249 variables are in the environment.
250 </p>
251
252 <p>
253 Setting the locale globally should be done using
254 <path>/etc/env.d/02locale</path>. The file should look something like the
255 following:
256 </p>
257
258 <pre caption="Demonstration /etc/env.d/02locale">
259 <comment>(As always, change "en_GB.UTF-8" to your locale)</comment>
260 LC_ALL="en_GB.UTF-8"
261 </pre>
262
263 <p>
264 Next, the environment must be updated with the change.
265 </p>
266
267 <pre caption="Updating the environment">
268 # <i>env-update</i>
269 >>> Regenerating /etc/ld.so.cache...
270 * Caching service dependencies ...
271 # <i>source /etc/profile</i>
272 </pre>
273
274 <p>
275 Now, run <c>locale</c> with no arguments to see if we have the correct
276 variables in our environment:
277 </p>
278
279 <pre caption="Checking if our new locale is in the environment">
280 # <i>locale</i>
281 LANG=
282 LC_CTYPE="en_GB.UTF-8"
283 LC_NUMERIC="en_GB.UTF-8"
284 LC_TIME="en_GB.UTF-8"
285 LC_COLLATE="en_GB.UTF-8"
286 LC_MONETARY="en_GB.UTF-8"
287 LC_MESSAGES="en_GB.UTF-8"
288 LC_PAPER="en_GB.UTF-8"
289 LC_NAME="en_GB.UTF-8"
290 LC_ADDRESS="en_GB.UTF-8"
291 LC_TELEPHONE="en_GB.UTF-8"
292 LC_MEASUREMENT="en_GB.UTF-8"
293 LC_IDENTIFICATION="en_GB.UTF-8"
294 LC_ALL=en_GB.UTF-8
295 </pre>
296
297 <p>
298 That's everything. You are now using UTF-8 locales, and the next hurdle is the
299 configuration of the applications you use from day to day.
300 </p>
301
302 </body>
303 </section>
304 </chapter>
305
306 <chapter>
307 <title>Application Support</title>
308 <section>
309 <body>
310
311 <p>
312 When Unicode first started gaining momentum in the software world, multibyte
313 character sets were not well suited to languages like C, in which many of the
314 day-to-day programs people use are written. Even today, some programs are not
315 able to handle UTF-8 properly. Fortunately, most are!
316 </p>
317
318 </body>
319 </section>
320 <section>
321 <title>Filenames, NTFS, and FAT</title>
322 <body>
323
324 <p>
325 There are several NLS options in the Linux kernel configuration menu, but it is
326 important to not become confused! For the most part, the only thing you need to
327 do is to build UTF-8 NLS support into your kernel, and change the default NLS
328 option to utf8.
329 </p>
330
331 <pre caption="Kernel configuration steps for UTF-8 NLS">
332 File Systems --&gt;
333 Native Language Support --&gt;
334 (utf8) Default NLS Option
335 &lt;*&gt; NLS UTF8
336 <comment>(Also &lt;*&gt; other character sets that are in use in
337 your FAT filesystems or Joilet CD-ROMs.)</comment>
338 </pre>
339
340 <p>
341 If you plan on mounting NTFS partitions, you may need to specify an <c>nls=</c>
342 option with mount. If you plan on mounting FAT partitions, you may need to
343 specify a <c>codepage=</c> option with mount. Optionally, you can also set a
344 default codepage for FAT in the kernel configuration. Note that the
345 <c>codepage</c> option with mount will override the kernel settings.
346 </p>
347
348 <pre caption="FAT settings in kernel configuration">
349 File Systems --&gt;
350 DOS/FAT/NT Filesystems --&gt;
351 (437) Default codepage for fat
352 </pre>
353
354 <p>
355 You should avoid setting <c>Default iocharset for fat</c> to UTF-8, as it is
356 not recommended. Instead, you may want to pass the option utf8=true when
357 mounting your FAT partitions. For further information, see <c>man mount</c> and
358 the kernel documentation at
359 <path>/usr/src/linux/Documentation/filesystems/vfat.txt</path>.
360 </p>
361
362 <p>
363 For changing the encoding of filenames, <c>app-text/convmv</c> can be used.
364 </p>
365
366 <pre caption="Example usage of convmv">
367 # <i>emerge --ask app-text/convmv</i>
368 <comment>(Command format)</comment>
369 # <i>convmv -f &lt;current-encoding&gt; -t utf-8 &lt;filename&gt;</i>
370 <comment>(Substitute iso-8859-1 with the charset you are converting
371 from)</comment>
372 # <i>convmv -f iso-8859-1 -t utf-8 filename</i>
373 </pre>
374
375 <p>
376 For changing the <e>contents</e> of files, use the <c>iconv</c> utility,
377 bundled with <c>glibc</c>:
378 </p>
379
380 <pre caption="Example usage of iconv">
381 <comment>(substitute iso-8859-1 with the charset you are converting from)</comment>
382 <comment>(Check the output is sane)</comment>
383 # <i>iconv -f iso-8859-1 -t utf-8 filename</i>
384 <comment>(Convert a file, you must create another file)</comment>
385 # <i>iconv -f iso-8859-1 -t utf-8 filename > newfile</i>
386 </pre>
387
388 <p>
389 <c>app-text/recode</c> can also be used for this purpose.
390 </p>
391
392 </body>
393 </section>
394 <section>
395 <title>The System Console</title>
396 <body>
397
398 <impo>
399 You need >=sys-apps/baselayout-1.11.9 for Unicode on the console.
400 </impo>
401
402 <p>
403 To enable UTF-8 on the console, you should edit <path>/etc/rc.conf</path> and
404 set <c>UNICODE="yes"</c>, and also read the comments in that file -- it is
405 important to have a font that has a good range of characters if you plan on
406 making the most of Unicode.
407 </p>
408
409 <p>
410 The <c>KEYMAP</c> variable, set in <path>/etc/conf.d/keymaps</path>, should
411 have a Unicode keymap specified.
412 </p>
413
414 <pre caption="Example /etc/conf.d/keymaps snippet">
415 <comment>(Change "uk" to your local layout)</comment>
416 KEYMAP="uk"
417 </pre>
418
419 </body>
420 </section>
421 <section>
422 <title>Ncurses and Slang</title>
423 <body>
424
425 <note>
426 Ignore any mention of Slang in this section if you do not have it installed or
427 do not use it.
428 </note>
429
430 <p>
431 It is wise to add <c>unicode</c> to your global USE flags in
432 <path>/etc/make.conf</path>, and then to remerge <c>sys-libs/ncurses</c> and
433 <c>sys-libs/slang</c> if appropriate. Portage will do this automatically when
434 you update your system:
435 </p>
436
437 <pre caption="Updating your system">
438 # <i>emerge --update --deep --newuse world</i>
439 </pre>
440
441 <p>
442 We also need to rebuild packages that link to these, now the USE changes have
443 been applied. The tool we use (<c>revdep-rebuild</c>) is part of the
444 <c>gentoolkit</c> package.
445 </p>
446
447 <pre caption="Rebuilding of programs that link to ncurses or slang">
448 # <i>revdep-rebuild --soname libncurses.so.5</i>
449 # <i>revdep-rebuild --soname libslang.so.1</i>
450 </pre>
451
452 </body>
453 </section>
454 <section>
455 <title>KDE, GNOME and Xfce</title>
456 <body>
457
458 <p>
459 All of the major desktop environments have full Unicode support, and will
460 require no further setup than what has already been covered in this guide. This
461 is because the underlying graphical toolkits (Qt or GTK+2) are UTF-8 aware.
462 Subsequently, all applications running on top of these toolkits should be
463 UTF-8-aware out of the box.
464 </p>
465
466 <p>
467 The exceptions to this rule come in Xlib and GTK+1. GTK+1 requires a
468 iso-10646-1 FontSpec in the ~/.gtkrc, for example
469 <c>-misc-fixed-*-*-*-*-*-*-*-*-*-*-iso10646-1</c>. Also, applications using
470 Xlib or Xaw will need to be given a similar FontSpec, otherwise they will not
471 work.
472 </p>
473
474 <note>
475 If you have a version of the gnome1 control center around, use that instead.
476 Pick any iso10646-1 font from there.
477 </note>
478
479 <pre caption="Example ~/.gtkrc (for GTK+1) that defines a Unicode compatible font">
480 style "user-font"
481 {
482 fontset="-misc-fixed-*-*-*-*-*-*-*-*-*-*-iso10646-1"
483 }
484 widget_class "*" style "user-font"
485 </pre>
486
487 <p>
488 If an application has support for both a Qt and GTK+2 GUI, the GTK+2 GUI will
489 generally give better results with Unicode.
490 </p>
491
492 </body>
493 </section>
494 <section>
495 <title>X11 and Fonts</title>
496 <body>
497
498 <impo>
499 <c>x11-base/xorg-x11</c> has far better support for Unicode than XFree86
500 and is <e>highly</e> recommended.
501 </impo>
502
503 <p>
504 TrueType fonts have support for Unicode, and most of the fonts that ship with
505 Xorg have impressive character support, although, obviously, not every single
506 glyph available in Unicode has been created for that font. To build fonts
507 (including the Bitstream Vera set) with support for East Asian letters with X,
508 make sure you have the <c>cjk</c> USE flag set. Many other applications utilise
509 this flag, so it may be worthwhile to add it as a permanent USE flag.
510 </p>
511
512 <p>
513 Also, several font packages in Portage are Unicode aware.
514 </p>
515
516 <pre caption="Optional: Install some more Unicode-aware fonts">
517 # <i>emerge terminus-font intlfonts freefonts cronyx-fonts corefonts</i>
518 </pre>
519
520 </body>
521 </section>
522 <section>
523 <title>Window Managers and Terminal Emulators</title>
524 <body>
525
526 <p>
527 Window managers not built on GTK or Qt generally have very good Unicode
528 support, as they often use the Xft library for handling fonts. If your window
529 manager does not use Xft for fonts, you can still use the FontSpec mentioned in
530 the previous section as a Unicode font.
531 </p>
532
533 <p>
534 Terminal emulators that use Xft and support Unicode are harder to come by.
535 Aside from Konsole and gnome-terminal, the best options in Portage are
536 <c>x11-terms/rxvt-unicode</c>, <c>xfce-extra/terminal</c>,
537 <c>gnustep-apps/terminal</c>, <c>x11-terms/mlterm</c>, or plain
538 <c>x11-terms/xterm</c> when built with the <c>unicode</c> USE flag and invoked
539 as <c>uxterm</c>. <c>app-misc/screen</c> supports UTF-8 too, when invoked as
540 <c>screen -U</c> or the following is put into the <path>~/.screenrc</path>:
541 </p>
542
543 <pre caption="~/.screenrc for UTF-8">
544 defutf8 on
545 </pre>
546
547 </body>
548 </section>
549 <section>
550 <title>Vim, Emacs, Xemacs and Nano</title>
551 <body>
552
553 <p>
554 Vim provides full UTF-8 support, and also has builtin detection of UTF-8 files.
555 For further information in Vim, use <c>:help mbyte.txt</c>.
556 </p>
557
558 <p>
559 Emacs 22.x and higher has full UTF-8 support as well. Xemacs 22.x does not
560 support combining characters yet.
561 </p>
562
563 <p>
564 Lower versions of Emacs and/or Xemacs might require you to install
565 <c>app-emacs/mule-ucs</c> and/or <c>app-xemacs/mule-ucs</c>
566 and add the following code to your <path>~/.emacs</path> to have support for CJK
567 languages in UTF-8:
568 </p>
569
570 <pre caption="Emacs CJK UTF-8 support">
571 (require 'un-define)
572 (require 'jisx0213)
573 (set-language-environment "Japanese")
574 (set-default-coding-systems 'utf-8)
575 (set-terminal-coding-system 'utf-8)
576 </pre>
577
578 <p>
579 Nano has provided full UTF-8 support since version 1.3.6.
580 </p>
581
582 </body>
583 </section>
584 <section>
585 <title>Shells</title>
586 <body>
587
588 <p>
589 Currently, <c>bash</c> provides full Unicode support through the GNU readline
590 library. Z Shell users are in a somewhat worse position -- no parts of the
591 shell have Unicode support, although there is a concerted effort to add
592 multibyte character set support underway at the moment.
593 </p>
594
595 <p>
596 The C shell, <c>tcsh</c> and <c>ksh</c> do not provide UTF-8 support at all.
597 </p>
598
599 </body>
600 </section>
601 <section>
602 <title>Irssi</title>
603 <body>
604
605 <p>
606 Irssi has complete UTF-8 support, although it does require a user
607 to set an option.
608 </p>
609
610 <pre caption="Enabling UTF-8 in Irssi">
611 /set term_charset UTF-8
612 </pre>
613
614 <p>
615 For channels where non-ASCII characters are often exchanged in non-UTF-8
616 charsets, the <c>/recode</c> command may be used to convert the characters.
617 Type <c>/help recode</c> for more information.
618 </p>
619
620 </body>
621 </section>
622 <section>
623 <title>Mutt</title>
624 <body>
625
626 <p>
627 The Mutt mail user agent has very good Unicode support. To use UTF-8 with Mutt,
628 you don't need to put anything in your configuration files. Mutt will work
629 under unicode enviroment without modification if all your configuration files
630 (signature included) are UTF-8 encoded.
631 </p>
632
633 <note>
634 You may still see '?' in mail you read with Mutt. This is a result of people
635 using a mail client which does not indicate the used charset. You can't do much
636 about this than to ask them to configure their client correctly.
637 </note>
638
639 <p>
640 Further information is available from the <uri
641 link="http://wiki.mutt.org/index.cgi?MuttFaq/Charset">Mutt Wiki</uri>.
642 </p>
643
644 </body>
645 </section>
646 <section>
647 <title>Man</title>
648 <body>
649
650 <p>
651 Man pages are an integral part of any Linux machine. To ensure that any
652 unicode in your man pages render correctly, edit <path>/etc/man.conf</path>
653 and replace a line as shown below.
654 </p>
655
656 <pre caption="man.conf changes for Unicode support">
657 <comment>(This is the old line)</comment>
658 NROFF /usr/bin/nroff -Tascii -c -mandoc
659 <comment>(Replace the one above with this)</comment>
660 NROFF /usr/bin/nroff -mandoc -c
661 </pre>
662
663 </body>
664 </section>
665 <section>
666 <title>elinks and links</title>
667 <body>
668
669 <p>
670 These are commonly used text-based browsers, and we shall see how we can enable
671 UTF-8 support on them. On <c>elinks</c> and <c>links</c>, there are two ways to
672 go about this, one using the Setup option from within the browser or editing the
673 config file. To set the option through the browser, open a site with
674 <c>elinks</c> or <c>links</c> and then <c>Alt+S</c> to enter the Setup Menu then
675 select Terminal options, or press <c>T</c>. Scroll down and select the last
676 option <c>UTF-8 I/O</c> by pressing Enter. Then Save and exit the menu. On
677 <c>links</c> you may have to do a repeat <c>Alt+S</c> and then press <c>S</c> to
678 save. The config file option, is shown below.
679 </p>
680
681 <pre caption="Enabling UTF-8 for elinks/links">
682 <comment>(For elinks, edit /etc/elinks/elinks.conf or ~/.elinks/elinks.conf and
683 add the following line)</comment>
684 set terminal.linux.utf_8_io = 1
685
686 <comment>(For links, edit ~/.links/links.cfg and add the following
687 line)</comment>
688 terminal "xterm" 0 1 0 us-ascii utf-8
689 </pre>
690
691 </body>
692 </section>
693 <section>
694 <title>Samba</title>
695 <body>
696
697 <p>
698 Samba is a software suite which implements the SMB (Server Message Block)
699 protocol for UNIX systems such as Macs, Linux and FreeBSD. The protocol
700 is also sometimes referred to as the Common Internet File System (CIFS). Samba
701 also includes the NetBIOS system - used for file sharing over windows networks.
702 </p>
703
704 <pre caption="Enabling UTF-8 for Samba">
705 <comment>(Edit /etc/samba/smb.conf and add the following under the [global] section)</comment>
706 dos charset = 1255
707 unix charset = UTF-8
708 display charset = UTF-8
709 </pre>
710
711 </body>
712 </section>
713 <section>
714 <title>Testing it all out</title>
715 <body>
716
717 <p>
718 There are numerous UTF-8 test websites around. <c>net-www/w3m</c>,
719 <c>net-www/links</c>, <c>net-www/elinks</c>, <c>net-www/lynx</c> and all
720 Mozilla based browsers (including Firefox) support UTF-8. Konqueror and Opera
721 have full UTF-8 support too.
722 </p>
723
724 <p>
725 When using one of the text-only web browsers, make absolutely sure you are
726 using a Unicode-aware terminal.
727 </p>
728
729 <p>
730 If you see certain characters displayed as boxes with letters or numbers
731 inside, this means that your font does not have a character for the symbol or
732 glyph that the UTF-8 wants. Instead, it displays a box with the hex code of the
733 UTF-8 symbol.
734 </p>
735
736 <ul>
737 <li>
738 <uri link="http://www.w3.org/2001/06/utf-8-test/UTF-8-demo.html">A W3C
739 UTF-8 Test Page</uri>
740 </li>
741 <li>
742 <uri link="http://titus.uni-frankfurt.de/indexe.htm?/unicode/unitest.htm">
743 A UTF-8 test page provided by the University of Frankfurt</uri>
744 </li>
745 </ul>
746
747 </body>
748 </section>
749 <section>
750 <title>Input Methods</title>
751 <body>
752
753 <p>
754 <e>Dead keys</e> may be used to input characters in X that are not included on
755 your keyboard. These work by pressing your right Alt key (or in some countries,
756 AltGr) and an optional key from the non-alphabetical section of the keyboard to
757 the left of the return key at once, releasing them, and then pressing a letter.
758 The dead key should modify it. Input can be further modified by using the Shift
759 key at the same time as pressing the AltGr and modifier.
760 </p>
761
762 <p>
763 To enable dead keys in X, you need a layout that supports it. Most European
764 layouts already have dead keys with the default variant. However, this is not
765 true of North American layouts. Although there is a degree of inconsistency
766 between layouts, the easiest solution seems to be to use a layout in the form
767 "en_US" rather than "us", for example. The layout is set in
768 <path>/etc/X11/xorg.conf</path> like so:
769 </p>
770
771 <pre caption="/etc/X11/xorg.conf snippet">
772 Section "InputDevice"
773 Identifier "Keyboard0"
774 Driver "kbd"
775 Option "XkbLayout" "en_US" <comment># Rather than just "us"</comment>
776 <comment>(Other Xkb options here)</comment>
777 EndSection
778 </pre>
779
780 <note>
781 The preceding change only needs to be applied if you are using a North American
782 layout, or another layout where dead keys do not seem to be working. European
783 users should have working dead keys as is.
784 </note>
785
786 <p>
787 This change will come into effect when your X server is restarted. To apply the
788 change now, use the <c>setxkbmap</c> tool, for example, <c>setxkbmap en_US</c>.
789 </p>
790
791 <p>
792 It is probably easiest to describe dead keys with examples. Although the
793 results are locale dependent, the concepts should remain the same regardless of
794 locale. The examples contain UTF-8, so to view them you need to either tell
795 your browser to view the page as UTF-8, or have a UTF-8 locale already
796 configured.
797 </p>
798
799 <p>
800 When I press AltGr and [ at once, release them, and then press a, 'ä' is
801 produced. When I press AltGr and [ at once, and then press e, 'ë' is produced.
802 When I press AltGr and ; at once, 'á' is produced, and when I press AltGr and ;
803 at once, release them, and then press e, 'é' is produced.
804 </p>
805
806 <p>
807 By pressing AltGr, Shift and [ at once, releasing them, and then pressing a, a
808 Scandinavian 'å' is produced. Similarly, when I press AltGr, Shift and [ at
809 once, release <e>only</e> the [, and then press it again, '˚' is produced.
810 Although it looks like one, this (U+02DA) is not the same as a degree symbol
811 (U+00B0). This works for other accents produced by dead keys — AltGr and [,
812 releasing only the [, then pressing it again makes '¨'.
813 </p>
814
815 <p>
816 AltGr can be used with alphabetical keys alone. For example, AltGr and m, a
817 Greek lower-case letter mu is produced: 'µ'. AltGr and s produce a
818 scharfes s or esszet: 'ß'. As many European users would expect (because
819 it is marked on their keyboard), AltGr and 4 (or E depending on the keyboard
820 layout) produces a Euro sign, '€'.
821 </p>
822
823 </body>
824 </section>
825 <section>
826 <title>Resources</title>
827 <body>
828
829 <ul>
830 <li>
831 <uri link="http://en.wikipedia.org/wiki/Unicode">The Wikipedia entry for
832 Unicode</uri>
833 </li>
834 <li>
835 <uri link="http://en.wikipedia.org/wiki/UTF-8">The Wikipedia entry for
836 UTF-8</uri>
837 </li>
838 <li><uri link="http://www.unicode.org">Unicode.org</uri></li>
839 <li><uri link="http://www.utf-8.com">UTF-8.com</uri></li>
840 <li><uri link="http://www.ietf.org/rfc/rfc3629.txt">RFC 3629</uri></li>
841 <li><uri link="http://www.ietf.org/rfc/rfc2277.txt">RFC 2277</uri></li>
842 <li>
843 <uri
844 link="http://www.tbray.org/ongoing/When/200x/2003/04/26/UTF">Characters vs.
845 Bytes</uri>
846 </li>
847 </ul>
848
849 </body>
850 </section>
851 </chapter>
852 </guide>

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