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1 neysx 1.1 <?xml version='1.0' encoding="UTF-8"?>
2 swift 1.18 <!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/utf-8.xml,v 1.17 2005/06/02 18:37:07 swift Exp $ -->
3 neysx 1.1 <!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    
15     <abstract>
16     This guide shows you how to set up and use the UTF-8 Unicode character set with
17     your Gentoo Linux system, after explaining the benefits of Unicode and more
18     specifically UTF-8.
19     </abstract>
20    
21     <license />
22    
23 swift 1.18 <version>2.2</version>
24 swift 1.16 <date>2005-06-02</date>
25 neysx 1.1
26     <chapter>
27     <title>Character Encodings</title>
28     <section>
29     <title>What is a Character Encoding?</title>
30     <body>
31    
32     <p>
33     Computers do not understand text themselves. Instead, every character is
34     represented by a number. Traditionally, each set of numbers used to represent
35     alphabets and characters (known as a coding system, encoding or character set)
36     was limited in size due to limitations in computer hardware.
37     </p>
38    
39     </body>
40     </section>
41     <section>
42     <title>The History of Character Encodings</title>
43     <body>
44    
45     <p>
46     The most common (or at least the most widely accepted) character set is
47     <b>ASCII</b> (American Standard Code for Information Interchange). It is widely
48     held that ASCII is the most successful software standard ever. Modern ASCII
49     was standardised in 1986 (ANSI X3.4, RFC 20, ISO/IEC 646:1991, ECMA-6) by the
50     American National Standards Institute.
51     </p>
52    
53     <p>
54     ASCII is strictly seven-bit, meaning that it uses bit patterns representable
55     with seven binary digits, which provides a range of 0 to 127 in decimal. These
56     include 32 non-visible control characters, most between 0 and 31, with the
57     final control character, DEL or delete at 127. Characters 32 to 126 are
58     visible characters: a space, punctuation marks, Latin letters and numbers.
59     </p>
60    
61     <p>
62     The eighth bit in ASCII was originally used as a parity bit for error checking.
63     If this is not desired, it is left as 0. This means that, with ASCII, each
64     character is represented by a single byte.
65     </p>
66    
67     <p>
68     Although ASCII was enough for communication in modern English, in other
69     European languages that include accented characters, things were not so easy.
70     The ISO 8859 standards were developed to meet these needs. They were backwards
71     compatible with ASCII, but instead of leaving the eighth bit blank, they used
72     it to allow another 127 characters in each encoding. ISO 8859's limitations
73     soon came to light, and there are currently 15 variants of the ISO 8859
74     standard (8859-1 through to 8859-15). Outside of the ASCII-compatible byte
75     range of these character sets, there is often conflict between the letters
76     represented by each byte. To complicate interoperability between character
77     encodings further, Windows-1252 is used in some versions of Microsoft Windows
78     instead for Western European languages. This is a superset of ISO 8859-1,
79     however it is different in several ways. These sets do all retain ASCII
80     compatibility, however.
81     </p>
82    
83     <p>
84     The necessary development of completely different single-byte encodings for
85     non-Latin alphabets, such as EUC (Extended Unix Coding) which is used for
86     Japanese and Korean (and to a lesser extent Chinese) created more confusion,
87     while other operating systems still used different character sets for the same
88     languages, for example, Shift-JIS and ISO-2022-JP. Users wishing to view
89     cyrillic glyphs had to choose between KOI8-R for Russian and Bulgarian or
90     KOI8-U for Ukrainian, as well as all the other cyrillic encodings such as the
91     unsuccessful ISO 8859-5, and the common Windows-1251 set. All of these
92     character sets broke most compatibility with ASCII (although KOI8 encodings
93     place cyrillic characters in Latin order, so in case the eighth bit is
94     stripped, text is still decipherable on an ASCII terminal through case-reversed
95     transliteration.)
96     </p>
97    
98     <p>
99     This has led to confusion, and also to an almost total inability for
100     multilingual communication, especially across different alphabets. Enter
101     Unicode.
102     </p>
103    
104     </body>
105     </section>
106     <section>
107     <title>What is Unicode?</title>
108     <body>
109    
110     <p>
111 bennyc 1.11 Unicode throws away the traditional single-byte limit of character sets. It
112     uses 17 "planes" of 65,536 code points to describe a maximum of 1,114,112
113     characters. As the first plane, aka. "Basic Multilingual Plane" or BMP,
114     contains almost everything you will ever use, many have made the wrong
115     assumption that Unicode was a 16-bit character set.
116 neysx 1.1 </p>
117    
118     <p>
119     Unicode has been mapped in many different ways, but the two most common are
120     <b>UTF</b> (Unicode Transformation Format) and <b>UCS</b> (Universal Character
121     Set). A number after UTF indicates the number of bits in one unit, while the
122     number after UCS indicates the number of bytes. UTF-8 has become the most
123     widespread means for the interchange of Unicode text as a result of its
124     eight-bit clean nature, and it is the subject of this document.
125     </p>
126    
127     </body>
128     </section>
129     <section>
130     <title>UTF-8</title>
131     <body>
132    
133     <p>
134     UTF-8 is a variable-length character encoding, which in this instance means
135     that it uses 1 to 4 bytes per symbol. So, the first UTF-8 byte is used for
136     encoding ASCII, giving the character set full backwards compatibility with
137     ASCII. UTF-8 means that ASCII and Latin characters are interchangeable with
138     little increase in the size of the data, because only the first bit is used.
139     Users of Eastern alphabets such as Japanese, who have been assigned a higher
140     byte range are unhappy, as this results in as much as a 50% redundancy in their
141     data.
142     </p>
143    
144     </body>
145     </section>
146     <section>
147     <title>What UTF-8 Can Do for You</title>
148     <body>
149    
150     <p>
151     UTF-8 allows you to work in a standards-compliant and internationally accepted
152 bennyc 1.11 multilingual environment, with a comparatively low data redundancy. UTF-8 is
153 neysx 1.1 the preferred way for transmitting non-ASCII characters over the Internet,
154     through Email, IRC or almost any other medium. Despite this, many people regard
155     UTF-8 in online communication as abusive. It is always best to be aware of the
156     attitude towards UTF-8 in a specific channel, mailing list or Usenet group
157     before using <e>non-ASCII</e> UTF-8.
158     </p>
159    
160     </body>
161     </section>
162     </chapter>
163    
164     <chapter>
165     <title>Setting up UTF-8 with Gentoo Linux</title>
166     <section>
167     <title>Finding or Creating UTF-8 Locales</title>
168     <body>
169    
170     <p>
171     Now that you understand the principles behind Unicode, you're ready to start
172     using UTF-8 with your system.
173     </p>
174    
175     <p>
176     The preliminary requirement for UTF-8 is to have a version of glibc installed
177     that has national language support. The recommend means to do this is the
178     <path>/etc/locales.build</path> file in combination with the <c>userlocales</c>
179     USE flag. It is beyond the scope of this document to explain the usage of this
180     file though, luckily, the usage of this file is well documented in the comments
181     within it. It is also explained in the <uri
182     link="/doc/en/guide-localization.xml#doc_chap3_sect3"> Gentoo Localisation
183     Guide</uri>.
184     </p>
185    
186     <p>
187     Next, we'll need to decide whether a UTF-8 locale is already available for our
188     language, or whether we need to create one.
189     </p>
190    
191     <pre caption="Checking for an existing UTF-8 locale">
192     <comment>(Replace "en_GB" with your desired locale setting)</comment>
193     # <i>locale -a | grep 'en_GB'</i>
194     en_GB
195 bennyc 1.12 en_GB.UTF-8
196 neysx 1.1 </pre>
197    
198     <p>
199     From the output of this command line, we need to take the result with a suffix
200 bennyc 1.12 similar to <c>.UTF-8</c>. If there is no result with a suffix similar to
201     <c>.UTF-8</c>, we need to create a UTF-8 compatible locale.
202 neysx 1.1 </p>
203    
204     <note>
205     Only execute the following code listing if you do not have a UTF-8 locale
206     available for your language.
207     </note>
208    
209     <pre caption="Creating a UTF-8 locale">
210     <comment>(Replace "en_GB" with your desired locale setting)</comment>
211 bennyc 1.12 # <i>localedef -i en_GB -f UTF-8 en_GB.UTF-8</i>
212 neysx 1.1 </pre>
213    
214 bennyc 1.11 <p>
215     Another way to include a UTF-8 locale is to add it to the
216     <path>/etc/locales.build</path> file and rebuild <c>glibc</c> with the
217     <c>userlocales</c> USE flag set.
218     </p>
219    
220     <pre caption="Line in /etc/locales.build">
221     en_GB.UTF-8/UTF-8
222     </pre>
223    
224 neysx 1.1 </body>
225     </section>
226     <section>
227     <title>Setting the Locale</title>
228     <body>
229    
230     <p>
231 swift 1.16 There is one environment variables that needs to be set in order to use
232 swift 1.17 our new UTF-8 locales: <c>LC_ALL</c> (this variable overrides the <c>LANG</c>
233     setting as well). There are also many different ways to set it; some people
234     prefer to only have a UTF-8 environment for a specific user, in which case
235 swift 1.18 they set them in their <path>~/.profile</path> (if you use <c>/bin/sh</c>),
236     <path>~/.bash_profile</path> or <path>~/.bashrc</path> (if you use
237     <c>/bin/bash</c>).
238     </p>
239    
240     <p>
241 swift 1.17 Others prefer to set the locale globally. One specific circumstance where
242     the author particularly recommends doing this is when
243     <path>/etc/init.d/xdm</path> is in use, because
244 bennyc 1.12 this init script starts the display manager and desktop before any of the
245     aforementioned shell startup files are sourced, and so before any of the
246     variables are in the environment.
247 neysx 1.1 </p>
248    
249 bennyc 1.12 <p>
250     Setting the locale globally should be done using
251 swift 1.15 <path>/etc/env.d/02locale</path>. The file should look something like the
252 bennyc 1.12 following:
253     </p>
254    
255     <pre caption="Demonstration /etc/env.d/02locale">
256     <comment>(As always, change "en_GB.UTF-8" to your locale)</comment>
257     LC_ALL="en_GB.UTF-8"
258     </pre>
259    
260     <p>
261     Next, the environment must be updated with the change.
262     </p>
263 bennyc 1.10
264 bennyc 1.12 <pre caption="Updating the environment">
265     # <i>env-update</i>
266     >>> Regenerating /etc/ld.so.cache...
267     * Caching service dependencies ...
268 swift 1.13 # <i>source /etc/profile</i>
269 bennyc 1.10 </pre>
270    
271 bennyc 1.12 <p>
272     Now, run <c>locale</c> with no arguments to see if we have the correct
273     variables in our environment:
274     </p>
275    
276     <pre caption="Checking if our new locale is in the environment">
277     # <i>locale</i>
278 swift 1.16 LANG=
279 bennyc 1.12 LC_CTYPE="en_GB.UTF-8"
280     LC_NUMERIC="en_GB.UTF-8"
281     LC_TIME="en_GB.UTF-8"
282     LC_COLLATE="en_GB.UTF-8"
283     LC_MONETARY="en_GB.UTF-8"
284     LC_MESSAGES="en_GB.UTF-8"
285     LC_PAPER="en_GB.UTF-8"
286     LC_NAME="en_GB.UTF-8"
287     LC_ADDRESS="en_GB.UTF-8"
288     LC_TELEPHONE="en_GB.UTF-8"
289     LC_MEASUREMENT="en_GB.UTF-8"
290     LC_IDENTIFICATION="en_GB.UTF-8"
291     LC_ALL=en_GB.UTF-8
292 neysx 1.1 </pre>
293    
294 bennyc 1.10 <p>
295 bennyc 1.12 That's everything. You are now using UTF-8 locales, and the next hurdle is the
296     configuration of the applications you use from day to day.
297 neysx 1.1 </p>
298    
299     </body>
300     </section>
301     </chapter>
302    
303     <chapter>
304     <title>Application Support</title>
305     <section>
306     <body>
307    
308     <p>
309     When Unicode first started gaining momentum in the software world, multibyte
310     character sets were not well suited to languages like C, in which many of the
311     day-to-day programs people use are written. Even today, some programs are not
312     able to handle UTF-8 properly. Fortunately, most are!
313     </p>
314    
315     </body>
316     </section>
317     <section>
318     <title>Filenames, NTFS, and FAT</title>
319     <body>
320    
321     <p>
322     There are several NLS options in the Linux kernel configuration menu, but it is
323     important to not become confused! For the most part, the only thing you need to
324     do is to build UTF-8 NLS support into your kernel, and change the default NLS
325     option to utf8.
326     </p>
327    
328     <pre caption="Kernel configuration steps for UTF-8 NLS">
329     File Systems --&gt;
330     Native Language Support --&gt;
331     (utf8) Default NLS Option
332     &lt;*&gt; NLS UTF8
333     <comment>(Also &lt;*&gt; other character sets that are in use in
334     your FAT filesystems or Joilet CD-ROMs.)</comment>
335     </pre>
336    
337     <p>
338     If you plan on mounting NTFS partitions, you may need to specify an <c>nls=</c>
339     option with mount. For more information, see <c>man mount</c>.
340     </p>
341    
342     <p>
343     For changing the encoding of filenames, <c>app-text/convmv</c> can be used.
344     </p>
345    
346     <pre caption="Example usage of convmv">
347     # <i>emerge --ask app-text/convmv</i>
348     # <i>convmv -f current-encoding -t utf-8 filename</i>
349     </pre>
350    
351     <p>
352     For changing the <e>contents</e> of files, use the <c>iconv</c> utility,
353     bundled with <c>glibc</c>:
354     </p>
355    
356     <pre caption="Example usage of iconv">
357     <comment>(substitute iso-8859-1 with the charset you are converting from)</comment>
358     <comment>(Check the output is sane)</comment>
359     # <i>iconv -f iso-8859-1 -t utf-8 filename</i>
360     <comment>(Convert a file, you must create another file)</comment>
361     # <i>iconv -f iso-8859-1 -t utf-8 filename > newfile</i>
362     </pre>
363    
364     <p>
365     <c>app-text/recode</c> can also be used for this purpose.
366     </p>
367    
368     </body>
369     </section>
370     <section>
371     <title>The System Console</title>
372     <body>
373    
374     <impo>
375     You need >=sys-apps/baselayout-1.11.9 for Unicode on the console.
376     </impo>
377    
378     <p>
379     To enable UTF-8 on the console, you should edit <path>/etc/rc.conf</path> and
380     set <c>UNICODE="yes"</c>, and also read the comments in that file -- it is
381     important to have a font that has a good range of characters if you plan on
382     making the most of Unicode.
383     </p>
384    
385     <p>
386     The <c>KEYMAP</c> variable, set in <path>/etc/conf.d/keymaps</path>, should
387     have a Unicode keymap specified. To do this, simply prepend the keymap already
388     specified there with -u.
389     </p>
390    
391     <pre caption="Example /etc/conf.d/keymaps snippet">
392     <comment>(Change "uk" to your local layout)</comment>
393 bennyc 1.11 KEYMAP="-u uk"
394 neysx 1.1 </pre>
395    
396     </body>
397     </section>
398     <section>
399     <title>Ncurses and Slang</title>
400     <body>
401    
402     <note>
403     Ignore any mention of Slang in this section if you do not have it installed or
404     do not use it.
405     </note>
406    
407     <p>
408     It is wise to add <c>unicode</c> to your global USE flags in
409     <path>/etc/make.conf</path>, and then to remerge <c>sys-libs/ncurses</c> and
410     also <c>sys-libs/slang</c> if appropriate:
411     </p>
412    
413     <pre caption="Emerging ncurses and slang">
414     <comment>(We avoid putting these libraries in our world file with --oneshot)</comment>
415     # <i>emerge --oneshot --verbose --ask sys-libs/ncurses sys-libs/slang</i>
416     </pre>
417    
418     <p>
419     We also need to rebuild packages that link to these, now the USE changes have
420 bennyc 1.11 been applied. The tool we use (<c>revdep-rebuild</c>) is part of the
421     <c>gentoolkit</c> package.
422 neysx 1.1 </p>
423    
424     <pre caption="Rebuilding of programs that link to ncurses or slang">
425     # <i>revdep-rebuild --soname libncurses.so.5</i>
426     # <i>revdep-rebuild --soname libslang.so.1</i>
427     </pre>
428    
429     </body>
430     </section>
431     <section>
432     <title>KDE, GNOME and Xfce</title>
433     <body>
434    
435     <p>
436     All of the major desktop environments have full Unicode support, and will
437     require no further setup than what has already been covered in this guide. This
438     is because the underlying graphical toolkits (Qt or GTK+2) are UTF-8 aware.
439     Subsequently, all applications running on top of these toolkits should be
440     UTF-8-aware out of the box.
441     </p>
442    
443     <p>
444     The exceptions to this rule come in Xlib and GTK+1. GTK+1 requires a
445     iso-10646-1 FontSpec in the ~/.gtkrc, for example
446     <c>-misc-fixed-*-*-*-*-*-*-*-*-*-*-iso10646-1</c>. Also, applications using
447     Xlib or Xaw will need to be given a similar FontSpec, otherwise they will not
448     work.
449     </p>
450    
451     <note>
452     If you have a version of the gnome1 control center around, use that instead.
453     Pick any iso10646-1 font from there.
454     </note>
455    
456     <pre caption="Example ~/.gtkrc (for GTK+1) that defines a Unicode compatible font">
457     style "user-font"
458     {
459     fontset="-misc-fixed-*-*-*-*-*-*-*-*-*-*-iso10646-1"
460     }
461     widget_class "*" style "user-font"
462     </pre>
463    
464     <p>
465     If an application has support for both a Qt and GTK+2 GUI, the GTK+2 GUI will
466     generally give better results with Unicode.
467     </p>
468    
469     </body>
470     </section>
471     <section>
472     <title>X11 and Fonts</title>
473     <body>
474    
475 bennyc 1.11 <impo>
476     <c>x11-base/xorg-x11</c> has far better support for Unicode than XFree86
477     and is <e>highly</e> recommended.
478     </impo>
479    
480 neysx 1.1 <p>
481     TrueType fonts have support for Unicode, and most of the fonts that ship with
482     Xorg have impressive character support, although, obviously, not every single
483     glyph available in Unicode has been created for that font. To build fonts
484     (including the Bitstream Vera set) with support for East Asian letters with X,
485     make sure you have the <c>cjk</c> USE flag set. Many other applications utilise
486     this flag, so it may be worthwhile to add it as a permanent USE flag.
487     </p>
488    
489     <p>
490     Also, several font packages in Portage are Unicode aware.
491     </p>
492    
493     <pre caption="Optional: Install some more Unicode-aware fonts">
494     # <i>emerge terminus-font intlfonts freefonts cronyx-fonts corefonts</i>
495     </pre>
496    
497     </body>
498     </section>
499     <section>
500     <title>Window Managers and Terminal Emulators</title>
501     <body>
502    
503     <p>
504 bennyc 1.11 Window managers not built on GTK or Qt generally have very good Unicode
505     support, as they often use the Xft library for handling fonts. If your window
506     manager does not use Xft for fonts, you can still use the FontSpec mentioned in
507     the previous section as a Unicode font.
508 neysx 1.1 </p>
509    
510     <p>
511     Terminal emulators that use Xft and support Unicode are harder to come by.
512     Aside from Konsole and gnome-terminal, the best options in Portage are
513     <c>x11-terms/rxvt-unicode</c>, <c>xfce-extra/terminal</c>,
514 cam 1.5 <c>gnustep-apps/terminal</c>, <c>x11-terms/mlterm</c>, <c>x11-terms/mrxvt</c> or
515 neysx 1.1 plain <c>x11-terms/xterm</c> when built with the <c>unicode</c> USE flag and
516     invoked as <c>uxterm</c>. <c>app-misc/screen</c> supports UTF-8 too, when
517 bennyc 1.11 invoked as <c>screen -u</c> or the following is put into the
518 neysx 1.1 <path>~/.screenrc</path>:
519     </p>
520    
521     <pre caption="~/.screenrc for UTF-8">
522     defutf8 on
523     </pre>
524    
525     </body>
526     </section>
527     <section>
528     <title>Vim, Emacs, Xemacs and Nano</title>
529     <body>
530    
531     <p>
532     Vim, Emacs and Xemacs provide full UTF-8 support, and also have builtin
533     detection of UTF-8 files. For further information in Vim, use <c>:help
534     mbyte.txt</c>.
535     </p>
536    
537     <p>
538     Nano currently does not provide support for UTF-8, although it has been planned
539     for a long time. With luck, this will change in future. At the time of writing,
540     UTF-8 support is in Nano's CVS, and should be included in the next release.
541     </p>
542    
543     </body>
544     </section>
545     <section>
546     <title>Shells</title>
547     <body>
548    
549     <p>
550     Currently, <c>bash</c> provides full Unicode support through the GNU readline
551     library. Z Shell users are in a somewhat worse position -- no parts of the
552     shell have Unicode support, although there is a concerted effort to add
553     multibyte character set support underway at the moment.
554     </p>
555    
556     <p>
557     The C shell, <c>tcsh</c> and <c>ksh</c> do not provide UTF-8 support at all.
558     </p>
559    
560     </body>
561     </section>
562     <section>
563     <title>Irssi</title>
564     <body>
565    
566     <p>
567 cam 1.5 Since 0.8.10, Irssi has complete UTF-8 support, although it does require a user
568     to set an option.
569 neysx 1.1 </p>
570    
571     <pre caption="Enabling UTF-8 in Irssi">
572     /set term_charset UTF-8
573     </pre>
574    
575     <p>
576     For channels where non-ASCII characters are often exchanged in non-UTF-8
577     charsets, the <c>/recode</c> command may be used to convert the characters.
578     Type <c>/help recode</c> for more information.
579     </p>
580    
581     </body>
582     </section>
583     <section>
584     <title>Mutt</title>
585     <body>
586    
587     <p>
588     The Mutt mail user agent has very good Unicode support. To use UTF-8 with Mutt,
589     put the following in your <path>~/.muttrc</path>:
590     </p>
591    
592     <pre caption="~/.muttrc for UTF-8">
593     set send_charset="utf8" <comment>(outgoing character set)</comment>
594     set charset="utf8" <comment>(display character set)</comment>
595     </pre>
596    
597     <note>
598     You may still see '?' in mail you read with Mutt. This is a result of people
599 bennyc 1.11 using a mail client which does not indicate the used charset. You can't do much
600     about this than to ask them to configure their client correctly.
601 neysx 1.1 </note>
602    
603     <p>
604     Further information is available from the <uri
605     link="http://wiki.mutt.org/index.cgi?MuttFaq/Charset"> Mutt WikiWiki</uri>.
606     </p>
607    
608     </body>
609     </section>
610     <section>
611 swift 1.14 <title>Less</title>
612     <body>
613    
614     <p>
615     We all use a lot of <c>more</c> or <c>less</c> along with the <c>|</c> to be
616     able to correctly see the output of a command, like for example
617     <c>dmesg | less</c>. While <c>more</c> only needs the shell to be UTF-8 aware,
618     <c>less</c> needs an environment variable set, <c>LESSCHARSET</c> to ensure
619     that unicode characters are rendered correctly. This can be set in
620     <path>/etc/profile</path> or <path>~/.bash_profile</path>. Fire up the editor
621     of your choice and the add the following line to one of the files mentioned
622     above.
623     </p>
624    
625     <pre caption="Setting up the Environment variable for less">
626     LESSCHARSET=utf-8
627     </pre>
628    
629     </body>
630     </section>
631     <section>
632     <title>Man</title>
633     <body>
634    
635     <p>
636     Man pages are an integral part of any Linux machine. To ensure that any
637     unicode in your man pages render correctly, edit <path>/etc/man.conf</path>
638     and replace a line as shown below.
639     </p>
640    
641     <pre caption="man.conf changes for Unicode support">
642     <comment>(This is the old line)</comment>
643     NROFF /usr/bin/nroff -Tascii -c -mandoc
644     <comment>(Replace the one above with this)</comment>
645     NROFF /usr/bin/nroff -mandoc -c
646     </pre>
647    
648     </body>
649     </section>
650     <section>
651 neysx 1.1 <title>Testing it all out</title>
652     <body>
653    
654     <p>
655     There are numerous UTF-8 test websites around. <c>net-www/w3m</c>,
656     <c>net-www/links</c>, <c>net-www/elinks</c>, <c>net-www/lynx</c> and all
657 cam 1.3 Mozilla based browsers (including Firefox) support UTF-8. Konqueror and Opera
658     have full UTF-8 support too.
659 neysx 1.1 </p>
660    
661     <p>
662     When using one of the text-only web browsers, make absolutely sure you are
663     using a Unicode-aware terminal.
664     </p>
665    
666     <p>
667     If you see certain characters displayed as boxes with letters or numbers
668     inside, this means that your font does not have a character for the symbol or
669     glyph that the UTF-8 wants. Instead, it displays a box with the hex code of the
670     UTF-8 symbol.
671     </p>
672    
673     <ul>
674     <li>
675     <uri link="http://www.w3.org/2001/06/utf-8-test/UTF-8-demo.html">A W3C
676     UTF-8 Test Page</uri>
677     </li>
678     <li>
679     <uri link="http://titus.uni-frankfurt.de/indexe.htm?/unicode/unitest.htm">
680     A UTF-8 test page provided by the University of Frankfurt</uri>
681     </li>
682     </ul>
683    
684     </body>
685     </section>
686     <section>
687     <title>Input Methods</title>
688     <body>
689    
690     <p>
691     <e>Dead keys</e> may be used to input characters in X that are not included on
692     your keyboard. These work by pressing your right Alt key (or in some countries,
693     AltGr) and an optional key from the non-alphabetical section of the keyboard to
694     the left of the return key at once, releasing them, and then pressing a letter.
695     The dead key should modify it. Input can be further modified by using the Shift
696     key at the same time as pressing the AltGr and modifier.
697     </p>
698    
699     <p>
700     To enable dead keys in X, you need a layout that supports it. Most European
701     layouts already have dead keys with the default variant. However, this is not
702     true of North American layouts. Although there is a degree of inconsistency
703     between layouts, the easiest solution seems to be to use a layout in the form
704     "en_US" rather than "us", for example. The layout is set in
705     <path>/etc/X11/xorg.conf</path> like so:
706     </p>
707    
708     <pre caption="/etc/X11/xorg.conf snippet">
709     Section "InputDevice"
710     Identifier "Keyboard0"
711     Driver "kbd"
712     Option "XkbLayout" "en_US" <comment># Rather than just "us"</comment>
713     <comment>(Other Xkb options here)</comment>
714     EndSection
715     </pre>
716    
717     <note>
718     The preceding change only needs to be applied if you are using a North American
719     layout, or another layout where dead keys do not seem to be working. European
720     users should have working dead keys as is.
721     </note>
722    
723     <p>
724 bennyc 1.11 This change will come into effect when your X server is restarted. To apply the
725 neysx 1.1 change now, use the <c>setxkbmap</c> tool, for example, <c>setxkbmap en_US</c>.
726     </p>
727    
728     <p>
729     It is probably easiest to describe dead keys with examples. Although the
730 bennyc 1.11 results are locale dependent, the concepts should remain the same regardless of
731 neysx 1.1 locale. The examples contain UTF-8, so to view them you need to either tell
732     your browser to view the page as UTF-8, or have a UTF-8 locale already
733     configured.
734     </p>
735    
736     <p>
737     When I press AltGr and [ at once, release them, and then press a, 'ä' is
738 bennyc 1.11 produced. When I press AltGr and [ at once, and then press e, 'ë' is produced.
739     When I press AltGr and ; at once, 'á' is produced, and when I press AltGr and ;
740     at once, release them, and then press e, 'é' is produced.
741 neysx 1.1 </p>
742    
743     <p>
744     By pressing AltGr, Shift and [ at once, releasing them, and then pressing a, a
745     Scandinavian 'å' is produced. Similarly, when I press AltGr, Shift and [ at
746     once, release <e>only</e> the [, and then press it again, '˚' is produced.
747     Although it looks like one, this (U+02DA) is not the same as a degree symbol
748     (U+00B0). This works for other accents produced by dead keys — AltGr and [,
749     releasing only the [, then pressing it again makes '¨'.
750     </p>
751    
752     <p>
753     AltGr can be used with alphabetical keys alone. For example, AltGr and m, a
754 bennyc 1.12 Greek lower-case letter mu is produced: 'µ'. AltGr and s produce a
755     scharfes s or esszet: 'ß'. As many European users would expect (because
756     it is marked on their keyboard), AltGr and 4 produces a Euro sign, '€'.
757 neysx 1.1 </p>
758    
759     </body>
760     </section>
761     <section>
762     <title>Resources</title>
763     <body>
764    
765     <ul>
766     <li>
767     <uri link="http://www.wikipedia.com/wiki/Unicode">The Wikipedia entry for
768     Unicode</uri>
769     </li>
770     <li>
771     <uri link="http://www.wikipedia.com/wiki/UTF-8">The Wikipedia entry for
772     UTF-8</uri>
773     </li>
774     <li><uri link="http://www.unicode.org">Unicode.org</uri></li>
775     <li><uri link="http://www.utf-8.com">UTF-8.com</uri></li>
776     <li><uri link="http://www.ietf.org/rfc/rfc3629.txt">RFC 3629</uri></li>
777     <li><uri link="http://www.ietf.org/rfc/rfc2277.txt">RFC 2277</uri></li>
778 bennyc 1.11 <li>
779     <uri
780     link="http://www.tbray.org/ongoing/When/200x/2003/04/26/UTF">Characters vs.
781     Bytes</uri>
782     </li>
783 neysx 1.1 </ul>
784    
785     </body>
786     </section>
787     </chapter>
788     </guide>

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