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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 1.50 2008/10/10 17:42:15 jkt Exp $ -->
3 <!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
5 <guide link="/doc/en/utf-8.xml">
6 <title>Using UTF-8 with Gentoo</title>
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>
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>
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 />
28 <version>2.28</version>
29 <date>2009-08-11</date>
31 <chapter>
32 <title>Character Encodings</title>
33 <section>
34 <title>What is a Character Encoding?</title>
35 <body>
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>
44 </body>
45 </section>
46 <section>
47 <title>The History of Character Encodings</title>
48 <body>
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>
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>
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>
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>
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>
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>
109 </body>
110 </section>
111 <section>
112 <title>What is Unicode?</title>
113 <body>
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>
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>
132 </body>
133 </section>
134 <section>
135 <title>UTF-8</title>
136 <body>
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>
149 </body>
150 </section>
151 <section>
152 <title>What UTF-8 Can Do for You</title>
153 <body>
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>
165 </body>
166 </section>
167 </chapter>
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>
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>
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>
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>
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>
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>
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>
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>
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>
223 <pre caption="Line in /etc/locale.gen">
224 en_GB.UTF-8 UTF-8
225 </pre>
227 </body>
228 </section>
229 <section>
230 <title>Setting the Locale</title>
231 <body>
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>
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>
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>
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>
264 <note>
265 You can also substitute <c>LC_CTYPE</c> for <c>LANG</c>. For more information on
266 the categories affected by using <c>LC_CTYPE</c>, please read the <uri
267 link="http://www.gnu.org/software/libc/manual/html_node/Locale-Categories.html#Locale-Categories">GNU
268 locale page</uri>.
269 </note>
271 <p>
272 Next, the environment must be updated with the change.
273 </p>
275 <pre caption="Updating the environment">
276 # <i>env-update</i>
277 >>> Regenerating /etc/ld.so.cache...
278 * Caching service dependencies ...
279 # <i>source /etc/profile</i>
280 </pre>
282 <p>
283 Now, run <c>locale</c> with no arguments to see if we have the correct
284 variables in our environment:
285 </p>
287 <pre caption="Checking if our new locale is in the environment">
288 # <i>locale</i>
289 LANG=en_GB.UTF-8
290 LC_CTYPE="en_GB.UTF-8"
291 LC_NUMERIC="en_GB.UTF-8"
292 LC_TIME="en_GB.UTF-8"
293 LC_COLLATE="en_GB.UTF-8"
296 LC_PAPER="en_GB.UTF-8"
297 LC_NAME="en_GB.UTF-8"
298 LC_ADDRESS="en_GB.UTF-8"
302 LC_ALL=
303 </pre>
305 <p>
306 That's everything. You are now using UTF-8 locales, and the next hurdle is the
307 configuration of the applications you use from day to day.
308 </p>
310 </body>
311 </section>
312 </chapter>
314 <chapter>
315 <title>Application Support</title>
316 <section>
317 <body>
319 <p>
320 When Unicode first started gaining momentum in the software world, multibyte
321 character sets were not well suited to languages like C, in which many of the
322 day-to-day programs people use are written. Even today, some programs are not
323 able to handle UTF-8 properly. Fortunately, most are!
324 </p>
326 </body>
327 </section>
328 <section>
329 <title>Filenames, NTFS, and FAT</title>
330 <body>
332 <p>
333 There are several NLS options in the Linux kernel configuration menu, but it is
334 important to not become confused! For the most part, the only thing you need to
335 do is to build UTF-8 NLS support into your kernel, and change the default NLS
336 option to utf8.
337 </p>
339 <pre caption="Kernel configuration steps for UTF-8 NLS">
340 File Systems --&gt;
341 Native Language Support --&gt;
342 (utf8) Default NLS Option
343 &lt;*&gt; NLS UTF8
344 <comment>(Also &lt;*&gt; other character sets that are in use in
345 your FAT filesystems or Joilet CD-ROMs.)</comment>
346 </pre>
348 <p>
349 If you plan on mounting NTFS partitions, you may need to specify an <c>nls=</c>
350 option with mount. If you plan on mounting FAT partitions, you may need to
351 specify a <c>codepage=</c> option with mount. Optionally, you can also set a
352 default codepage for FAT in the kernel configuration. Note that the
353 <c>codepage</c> option with mount will override the kernel settings.
354 </p>
356 <pre caption="FAT settings in kernel configuration">
357 File Systems --&gt;
358 DOS/FAT/NT Filesystems --&gt;
359 (437) Default codepage for fat
360 </pre>
362 <p>
363 You should avoid setting <c>Default iocharset for fat</c> to UTF-8, as it is
364 not recommended. Instead, you may want to pass the option utf8=true when
365 mounting your FAT partitions. For further information, see <c>man mount</c> and
366 the kernel documentation at
367 <path>/usr/src/linux/Documentation/filesystems/vfat.txt</path>.
368 </p>
370 <p>
371 For changing the encoding of filenames, <c>app-text/convmv</c> can be used.
372 </p>
374 <pre caption="Example usage of convmv">
375 # <i>emerge --ask app-text/convmv</i>
376 <comment>(Command format)</comment>
377 # <i>convmv -f &lt;current-encoding&gt; -t utf-8 &lt;filename&gt;</i>
378 <comment>(Substitute iso-8859-1 with the charset you are converting
379 from)</comment>
380 # <i>convmv -f iso-8859-1 -t utf-8 filename</i>
381 </pre>
383 <p>
384 For changing the <e>contents</e> of files, use the <c>iconv</c> utility,
385 bundled with <c>glibc</c>:
386 </p>
388 <pre caption="Example usage of iconv">
389 <comment>(substitute iso-8859-1 with the charset you are converting from)</comment>
390 <comment>(Check the output is sane)</comment>
391 # <i>iconv -f iso-8859-1 -t utf-8 filename</i>
392 <comment>(Convert a file, you must create another file)</comment>
393 # <i>iconv -f iso-8859-1 -t utf-8 filename > newfile</i>
394 </pre>
396 <p>
397 <c>app-text/recode</c> can also be used for this purpose.
398 </p>
400 </body>
401 </section>
402 <section>
403 <title>The System Console</title>
404 <body>
406 <impo>
407 You need >=sys-apps/baselayout-1.11.9 for Unicode on the console.
408 </impo>
410 <p>
411 To enable UTF-8 on the console, you should edit <path>/etc/rc.conf</path> and
412 set <c>UNICODE="yes"</c>, and also read the comments in that file -- it is
413 important to have a font that has a good range of characters if you plan on
414 making the most of Unicode. For this to work, make sure you have properly
415 created a Unicode locale as explained in <uri link="#doc_chap1">Chapter
416 1</uri>.
417 </p>
419 <p>
420 The <c>KEYMAP</c> variable, set in <path>/etc/conf.d/keymaps</path>, should
421 have a Unicode keymap specified.
422 </p>
424 <pre caption="Example /etc/conf.d/keymaps snippet">
425 <comment>(Change "uk" to your local layout)</comment>
426 KEYMAP="uk"
427 </pre>
429 </body>
430 </section>
431 <section>
432 <title>Ncurses and Slang</title>
433 <body>
435 <note>
436 Ignore any mention of Slang in this section if you do not have it installed or
437 do not use it.
438 </note>
440 <p>
441 It is wise to add <c>unicode</c> to your global USE flags in
442 <path>/etc/make.conf</path>, and then to remerge <c>sys-libs/ncurses</c> and
443 <c>sys-libs/slang</c> if appropriate. Portage will do this automatically when
444 you update your system:
445 </p>
447 <pre caption="Updating your system">
448 # <i>emerge --update --deep --newuse world</i>
449 </pre>
451 <p>
452 We also need to rebuild packages that link to these, now the USE changes have
453 been applied. The tool we use (<c>revdep-rebuild</c>) is part of the
454 <c>gentoolkit</c> package.
455 </p>
457 <pre caption="Rebuilding of programs that link to ncurses or slang">
458 # <i>revdep-rebuild --soname libncurses.so.5</i>
459 # <i>revdep-rebuild --soname libslang.so.1</i>
460 </pre>
462 </body>
463 </section>
464 <section>
465 <title>KDE, GNOME and Xfce</title>
466 <body>
468 <p>
469 All of the major desktop environments have full Unicode support, and will
470 require no further setup than what has already been covered in this guide. This
471 is because the underlying graphical toolkits (Qt or GTK+2) are UTF-8 aware.
472 Subsequently, all applications running on top of these toolkits should be
473 UTF-8-aware out of the box.
474 </p>
476 <p>
477 The exceptions to this rule come in Xlib and GTK+1. GTK+1 requires a
478 iso-10646-1 FontSpec in the ~/.gtkrc, for example
479 <c>-misc-fixed-*-*-*-*-*-*-*-*-*-*-iso10646-1</c>. Also, applications using
480 Xlib or Xaw will need to be given a similar FontSpec, otherwise they will not
481 work.
482 </p>
484 <note>
485 If you have a version of the gnome1 control center around, use that instead.
486 Pick any iso10646-1 font from there.
487 </note>
489 <pre caption="Example ~/.gtkrc (for GTK+1) that defines a Unicode compatible font">
490 style "user-font"
491 {
492 fontset="-misc-fixed-*-*-*-*-*-*-*-*-*-*-iso10646-1"
493 }
494 widget_class "*" style "user-font"
495 </pre>
497 <p>
498 If an application has support for both a Qt and GTK+2 GUI, the GTK+2 GUI will
499 generally give better results with Unicode.
500 </p>
502 </body>
503 </section>
504 <section>
505 <title>X11 and Fonts</title>
506 <body>
508 <p>
509 TrueType fonts have support for Unicode, and most of the fonts that ship with
510 Xorg have impressive character support, although, obviously, not every single
511 glyph available in Unicode has been created for that font. To build fonts
512 (including the Bitstream Vera set) with support for East Asian letters with X,
513 make sure you have the <c>cjk</c> USE flag set. Many other applications utilise
514 this flag, so it may be worthwhile to add it as a permanent USE flag.
515 </p>
517 <p>
518 Also, several font packages in Portage are Unicode aware.
519 </p>
521 <pre caption="Optional: Install some more Unicode-aware fonts">
522 # <i>emerge terminus-font intlfonts freefonts cronyx-fonts corefonts</i>
523 </pre>
525 </body>
526 </section>
527 <section>
528 <title>Window Managers and Terminal Emulators</title>
529 <body>
531 <p>
532 Window managers not built on GTK or Qt generally have very good Unicode
533 support, as they often use the Xft library for handling fonts. If your window
534 manager does not use Xft for fonts, you can still use the FontSpec mentioned in
535 the previous section as a Unicode font.
536 </p>
538 <p>
539 Terminal emulators that use Xft and support Unicode are harder to come by.
540 Aside from Konsole and gnome-terminal, the best options in Portage are
541 <c>x11-terms/rxvt-unicode</c>, <c>xfce-extra/terminal</c>,
542 <c>gnustep-apps/terminal</c>, <c>x11-terms/mlterm</c>, or plain
543 <c>x11-terms/xterm</c> when built with the <c>unicode</c> USE flag and invoked
544 as <c>uxterm</c>. <c>app-misc/screen</c> supports UTF-8 too, when invoked as
545 <c>screen -U</c> or the following is put into the <path>~/.screenrc</path>:
546 </p>
548 <pre caption="~/.screenrc for UTF-8">
549 defutf8 on
550 </pre>
552 </body>
553 </section>
554 <section>
555 <title>Vim, Emacs, Xemacs and Nano</title>
556 <body>
558 <p>
559 Vim provides full UTF-8 support, and also has builtin detection of UTF-8 files.
560 For further information in Vim, use <c>:help mbyte.txt</c>.
561 </p>
563 <p>
564 Emacs 22.x and higher has full UTF-8 support as well. Xemacs 22.x does not
565 support combining characters yet.
566 </p>
568 <p>
569 Lower versions of Emacs and/or Xemacs might require you to install
570 <c>app-emacs/mule-ucs</c> and/or <c>app-xemacs/mule-ucs</c>
571 and add the following code to your <path>~/.emacs</path> to have support for CJK
572 languages in UTF-8:
573 </p>
575 <pre caption="Emacs CJK UTF-8 support">
576 (require 'un-define)
577 (require 'jisx0213)
578 (set-language-environment "Japanese")
579 (set-default-coding-systems 'utf-8)
580 (set-terminal-coding-system 'utf-8)
581 </pre>
583 <p>
584 Nano has provided full UTF-8 support since version 1.3.6.
585 </p>
587 </body>
588 </section>
589 <section>
590 <title>Shells</title>
591 <body>
593 <p>
594 Currently, <c>bash</c> provides full Unicode support through the GNU readline
595 library. Z Shell (<c>zsh</c>) offers Unicode support with the <c>unicode</c> USE
596 flag.
597 </p>
599 <p>
600 The C shell, <c>tcsh</c> and <c>ksh</c> do not provide UTF-8 support at all.
601 </p>
603 </body>
604 </section>
605 <section>
606 <title>Irssi</title>
607 <body>
609 <p>
610 Irssi has complete UTF-8 support, although it does require a user
611 to set an option.
612 </p>
614 <pre caption="Enabling UTF-8 in Irssi">
615 /set term_charset UTF-8
616 </pre>
618 <p>
619 For channels where non-ASCII characters are often exchanged in non-UTF-8
620 charsets, the <c>/recode</c> command may be used to convert the characters.
621 Type <c>/help recode</c> for more information.
622 </p>
624 </body>
625 </section>
626 <section>
627 <title>Mutt</title>
628 <body>
630 <p>
631 The Mutt mail user agent has very good Unicode support. To use UTF-8 with Mutt,
632 you don't need to put anything in your configuration files. Mutt will work
633 under unicode enviroment without modification if all your configuration files
634 (signature included) are UTF-8 encoded.
635 </p>
637 <note>
638 You may still see '?' in mail you read with Mutt. This is a result of people
639 using a mail client which does not indicate the used charset. You can't do much
640 about this than to ask them to configure their client correctly.
641 </note>
643 <p>
644 Further information is available from the <uri
645 link="http://wiki.mutt.org/index.cgi?MuttFaq/Charset">Mutt Wiki</uri>.
646 </p>
648 </body>
649 </section>
650 <section>
651 <title>Man</title>
652 <body>
654 <p>
655 Man pages are an integral part of any Linux machine. To ensure that any
656 unicode in your man pages render correctly, edit <path>/etc/man.conf</path>
657 and replace a line as shown below.
658 </p>
660 <pre caption="man.conf changes for Unicode support">
661 <comment>(This is the old line)</comment>
662 NROFF /usr/bin/nroff -Tascii -c -mandoc
663 <comment>(Replace the one above with this)</comment>
664 NROFF /usr/bin/nroff -mandoc -c
665 </pre>
667 </body>
668 </section>
669 <section>
670 <title>elinks and links</title>
671 <body>
673 <p>
674 These are commonly used text-based browsers, and we shall see how we can enable
675 UTF-8 support on them. On <c>elinks</c> and <c>links</c>, there are two ways to
676 go about this, one using the Setup option from within the browser or editing the
677 config file. To set the option through the browser, open a site with
678 <c>elinks</c> or <c>links</c> and then <c>Alt+S</c> to enter the Setup Menu then
679 select Terminal options, or press <c>T</c>. Scroll down and select the last
680 option <c>UTF-8 I/O</c> by pressing Enter. Then Save and exit the menu. On
681 <c>links</c> you may have to do a repeat <c>Alt+S</c> and then press <c>S</c> to
682 save. The config file option, is shown below.
683 </p>
685 <pre caption="Enabling UTF-8 for elinks/links">
686 <comment>(For elinks, edit /etc/elinks/elinks.conf or ~/.elinks/elinks.conf and
687 add the following line)</comment>
688 set terminal.linux.utf_8_io = 1
690 <comment>(For links, edit ~/.links/links.cfg and add the following
691 line)</comment>
692 terminal "xterm" 0 1 0 us-ascii utf-8
693 </pre>
695 </body>
696 </section>
697 <section>
698 <title>Samba</title>
699 <body>
701 <p>
702 Samba is a software suite which implements the SMB (Server Message Block)
703 protocol for UNIX systems such as Macs, Linux and FreeBSD. The protocol
704 is also sometimes referred to as the Common Internet File System (CIFS). Samba
705 also includes the NetBIOS system - used for file sharing over windows networks.
706 </p>
708 <pre caption="Enabling UTF-8 for Samba">
709 <comment>(Edit /etc/samba/smb.conf and add the following under the [global] section)</comment>
710 dos charset = 1255
711 unix charset = UTF-8
712 display charset = UTF-8
713 </pre>
715 </body>
716 </section>
717 <section>
718 <title>Testing it all out</title>
719 <body>
721 <p>
722 There are numerous UTF-8 test websites around. <c>net-www/w3m</c>,
723 <c>net-www/links</c>, <c>net-www/elinks</c>, <c>net-www/lynx</c> and all
724 Mozilla based browsers (including Firefox) support UTF-8. Konqueror and Opera
725 have full UTF-8 support too.
726 </p>
728 <p>
729 When using one of the text-only web browsers, make absolutely sure you are
730 using a Unicode-aware terminal.
731 </p>
733 <p>
734 If you see certain characters displayed as boxes with letters or numbers
735 inside, this means that your font does not have a character for the symbol or
736 glyph that the UTF-8 wants. Instead, it displays a box with the hex code of the
737 UTF-8 symbol.
738 </p>
740 <ul>
741 <li>
742 <uri link="http://www.w3.org/2001/06/utf-8-test/UTF-8-demo.html">A W3C
743 UTF-8 Test Page</uri>
744 </li>
745 <li>
746 <uri link="http://titus.uni-frankfurt.de/indexe.htm?/unicode/unitest.htm">
747 A UTF-8 test page provided by the University of Frankfurt</uri>
748 </li>
749 </ul>
751 </body>
752 </section>
753 <section>
754 <title>Input Methods</title>
755 <body>
757 <p>
758 <e>Dead keys</e> may be used to input characters in X that are not included on
759 your keyboard. These work by pressing your right Alt key (or in some countries,
760 AltGr) and an optional key from the non-alphabetical section of the keyboard to
761 the left of the return key at once, releasing them, and then pressing a letter.
762 The dead key should modify it. Input can be further modified by using the Shift
763 key at the same time as pressing the AltGr and modifier.
764 </p>
766 <p>
767 To enable dead keys in X, you need a layout that supports it. Most European
768 layouts already have dead keys with the default variant. However, this is not
769 true of North American layouts. Although there is a degree of inconsistency
770 between layouts, the easiest solution seems to be to use a layout in the form
771 "en_US" rather than "us", for example. The layout is set in
772 <path>/etc/X11/xorg.conf</path> like so:
773 </p>
775 <pre caption="/etc/X11/xorg.conf snippet">
776 Section "InputDevice"
777 Identifier "Keyboard0"
778 Driver "kbd"
779 Option "XkbLayout" "en_US" <comment># Rather than just "us"</comment>
780 <comment>(Other Xkb options here)</comment>
781 EndSection
782 </pre>
784 <note>
785 The preceding change only needs to be applied if you are using a North American
786 layout, or another layout where dead keys do not seem to be working. European
787 users should have working dead keys as is.
788 </note>
790 <p>
791 This change will come into effect when your X server is restarted. To apply the
792 change now, use the <c>setxkbmap</c> tool, for example, <c>setxkbmap en_US</c>.
793 </p>
795 <p>
796 It is probably easiest to describe dead keys with examples. Although the
797 results are locale dependent, the concepts should remain the same regardless of
798 locale. The examples contain UTF-8, so to view them you need to either tell
799 your browser to view the page as UTF-8, or have a UTF-8 locale already
800 configured.
801 </p>
803 <p>
804 When I press AltGr and [ at once, release them, and then press a, 'ä' is
805 produced. When I press AltGr and [ at once, and then press e, 'ë' is produced.
806 When I press AltGr and ; at once, 'á' is produced, and when I press AltGr and ;
807 at once, release them, and then press e, 'é' is produced.
808 </p>
810 <p>
811 By pressing AltGr, Shift and [ at once, releasing them, and then pressing a, a
812 Scandinavian 'å' is produced. Similarly, when I press AltGr, Shift and [ at
813 once, release <e>only</e> the [, and then press it again, '˚' is produced.
814 Although it looks like one, this (U+02DA) is not the same as a degree symbol
815 (U+00B0). This works for other accents produced by dead keys — AltGr and [,
816 releasing only the [, then pressing it again makes '¨'.
817 </p>
819 <p>
820 AltGr can be used with alphabetical keys alone. For example, AltGr and m, a
821 Greek lower-case letter mu is produced: 'µ'. AltGr and s produce a
822 scharfes s or esszet: 'ß'. As many European users would expect (because
823 it is marked on their keyboard), AltGr and 4 (or E depending on the keyboard
824 layout) produces a Euro sign, '€'.
825 </p>
827 </body>
828 </section>
829 <section>
830 <title>Resources</title>
831 <body>
833 <ul>
834 <li>
835 <uri link="http://en.wikipedia.org/wiki/Unicode">The Wikipedia entry for
836 Unicode</uri>
837 </li>
838 <li>
839 <uri link="http://en.wikipedia.org/wiki/UTF-8">The Wikipedia entry for
840 UTF-8</uri>
841 </li>
842 <li><uri link="http://www.unicode.org">Unicode.org</uri></li>
843 <li><uri link="http://www.utf-8.com">UTF-8.com</uri></li>
844 <li><uri link="http://www.ietf.org/rfc/rfc3629.txt">RFC 3629</uri></li>
845 <li><uri link="http://www.ietf.org/rfc/rfc2277.txt">RFC 2277</uri></li>
846 <li>
847 <uri
848 link="http://www.tbray.org/ongoing/When/200x/2003/04/26/UTF">Characters vs.
849 Bytes</uri>
850 </li>
851 </ul>
853 </body>
854 </section>
855 </chapter>
856 </guide>

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