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1 neysx 1.1 <?xml version='1.0' encoding="UTF-8"?>
2 neysx 1.25 <!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/utf-8.xml,v 1.24 2005/06/23 21:41:56 smithj 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 fox2mike 1.20 <author title="Editor">
15 neysx 1.21 <mail link="fox2mike@gentoo.org">Shyam Mani</mail>
16 fox2mike 1.20 </author>
17 neysx 1.1
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 fox2mike 1.20 <!-- The content of this document is licensed under the CC-BY-SA license -->
25     <!-- See http://creativecommons.org/licenses/by-sa/2.5 -->
26 neysx 1.1 <license />
27    
28 neysx 1.25 <version>2.5</version>
29 smithj 1.24 <date>2005-06-23</date>
30 neysx 1.1
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 bennyc 1.11 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 neysx 1.1 </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 bennyc 1.11 multilingual environment, with a comparatively low data redundancy. UTF-8 is
158 neysx 1.1 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/locales.build</path> file in combination with the <c>userlocales</c>
184     USE flag. It is beyond the scope of this document to explain the usage of this
185     file though, luckily, the usage of this file is well documented in the comments
186     within it. It is also explained in the <uri
187     link="/doc/en/guide-localization.xml#doc_chap3_sect3"> Gentoo Localisation
188     Guide</uri>.
189     </p>
190    
191     <p>
192     Next, we'll need to decide whether a UTF-8 locale is already available for our
193     language, or whether we need to create one.
194     </p>
195    
196     <pre caption="Checking for an existing UTF-8 locale">
197     <comment>(Replace "en_GB" with your desired locale setting)</comment>
198     # <i>locale -a | grep 'en_GB'</i>
199     en_GB
200 bennyc 1.12 en_GB.UTF-8
201 neysx 1.1 </pre>
202    
203     <p>
204     From the output of this command line, we need to take the result with a suffix
205 bennyc 1.12 similar to <c>.UTF-8</c>. If there is no result with a suffix similar to
206     <c>.UTF-8</c>, we need to create a UTF-8 compatible locale.
207 neysx 1.1 </p>
208    
209     <note>
210     Only execute the following code listing if you do not have a UTF-8 locale
211     available for your language.
212     </note>
213    
214     <pre caption="Creating a UTF-8 locale">
215     <comment>(Replace "en_GB" with your desired locale setting)</comment>
216 bennyc 1.12 # <i>localedef -i en_GB -f UTF-8 en_GB.UTF-8</i>
217 neysx 1.1 </pre>
218    
219 bennyc 1.11 <p>
220     Another way to include a UTF-8 locale is to add it to the
221     <path>/etc/locales.build</path> file and rebuild <c>glibc</c> with the
222     <c>userlocales</c> USE flag set.
223     </p>
224    
225     <pre caption="Line in /etc/locales.build">
226     en_GB.UTF-8/UTF-8
227     </pre>
228    
229 neysx 1.1 </body>
230     </section>
231     <section>
232     <title>Setting the Locale</title>
233     <body>
234    
235     <p>
236 fox2mike 1.19 There is one environment variable that needs to be set in order to use
237 swift 1.17 our new UTF-8 locales: <c>LC_ALL</c> (this variable overrides the <c>LANG</c>
238     setting as well). There are also many different ways to set it; some people
239     prefer to only have a UTF-8 environment for a specific user, in which case
240 swift 1.18 they set them in their <path>~/.profile</path> (if you use <c>/bin/sh</c>),
241     <path>~/.bash_profile</path> or <path>~/.bashrc</path> (if you use
242     <c>/bin/bash</c>).
243     </p>
244    
245     <p>
246 swift 1.17 Others prefer to set the locale globally. One specific circumstance where
247     the author particularly recommends doing this is when
248     <path>/etc/init.d/xdm</path> is in use, because
249 bennyc 1.12 this init script starts the display manager and desktop before any of the
250     aforementioned shell startup files are sourced, and so before any of the
251     variables are in the environment.
252 neysx 1.1 </p>
253    
254 bennyc 1.12 <p>
255     Setting the locale globally should be done using
256 swift 1.15 <path>/etc/env.d/02locale</path>. The file should look something like the
257 bennyc 1.12 following:
258     </p>
259    
260     <pre caption="Demonstration /etc/env.d/02locale">
261     <comment>(As always, change "en_GB.UTF-8" to your locale)</comment>
262     LC_ALL="en_GB.UTF-8"
263     </pre>
264    
265     <p>
266     Next, the environment must be updated with the change.
267     </p>
268 bennyc 1.10
269 bennyc 1.12 <pre caption="Updating the environment">
270     # <i>env-update</i>
271     >>> Regenerating /etc/ld.so.cache...
272     * Caching service dependencies ...
273 swift 1.13 # <i>source /etc/profile</i>
274 bennyc 1.10 </pre>
275    
276 bennyc 1.12 <p>
277     Now, run <c>locale</c> with no arguments to see if we have the correct
278     variables in our environment:
279     </p>
280    
281     <pre caption="Checking if our new locale is in the environment">
282     # <i>locale</i>
283 swift 1.16 LANG=
284 bennyc 1.12 LC_CTYPE="en_GB.UTF-8"
285     LC_NUMERIC="en_GB.UTF-8"
286     LC_TIME="en_GB.UTF-8"
287     LC_COLLATE="en_GB.UTF-8"
288     LC_MONETARY="en_GB.UTF-8"
289     LC_MESSAGES="en_GB.UTF-8"
290     LC_PAPER="en_GB.UTF-8"
291     LC_NAME="en_GB.UTF-8"
292     LC_ADDRESS="en_GB.UTF-8"
293     LC_TELEPHONE="en_GB.UTF-8"
294     LC_MEASUREMENT="en_GB.UTF-8"
295     LC_IDENTIFICATION="en_GB.UTF-8"
296     LC_ALL=en_GB.UTF-8
297 neysx 1.1 </pre>
298    
299 bennyc 1.10 <p>
300 bennyc 1.12 That's everything. You are now using UTF-8 locales, and the next hurdle is the
301     configuration of the applications you use from day to day.
302 neysx 1.1 </p>
303    
304     </body>
305     </section>
306     </chapter>
307    
308     <chapter>
309     <title>Application Support</title>
310     <section>
311     <body>
312    
313     <p>
314     When Unicode first started gaining momentum in the software world, multibyte
315     character sets were not well suited to languages like C, in which many of the
316     day-to-day programs people use are written. Even today, some programs are not
317     able to handle UTF-8 properly. Fortunately, most are!
318     </p>
319    
320     </body>
321     </section>
322     <section>
323     <title>Filenames, NTFS, and FAT</title>
324     <body>
325    
326     <p>
327     There are several NLS options in the Linux kernel configuration menu, but it is
328     important to not become confused! For the most part, the only thing you need to
329     do is to build UTF-8 NLS support into your kernel, and change the default NLS
330     option to utf8.
331     </p>
332    
333     <pre caption="Kernel configuration steps for UTF-8 NLS">
334     File Systems --&gt;
335     Native Language Support --&gt;
336     (utf8) Default NLS Option
337     &lt;*&gt; NLS UTF8
338     <comment>(Also &lt;*&gt; other character sets that are in use in
339     your FAT filesystems or Joilet CD-ROMs.)</comment>
340     </pre>
341    
342     <p>
343     If you plan on mounting NTFS partitions, you may need to specify an <c>nls=</c>
344     option with mount. For more information, see <c>man mount</c>.
345     </p>
346    
347     <p>
348     For changing the encoding of filenames, <c>app-text/convmv</c> can be used.
349     </p>
350    
351     <pre caption="Example usage of convmv">
352     # <i>emerge --ask app-text/convmv</i>
353     # <i>convmv -f current-encoding -t utf-8 filename</i>
354     </pre>
355    
356     <p>
357     For changing the <e>contents</e> of files, use the <c>iconv</c> utility,
358     bundled with <c>glibc</c>:
359     </p>
360    
361     <pre caption="Example usage of iconv">
362     <comment>(substitute iso-8859-1 with the charset you are converting from)</comment>
363     <comment>(Check the output is sane)</comment>
364     # <i>iconv -f iso-8859-1 -t utf-8 filename</i>
365     <comment>(Convert a file, you must create another file)</comment>
366     # <i>iconv -f iso-8859-1 -t utf-8 filename > newfile</i>
367     </pre>
368    
369     <p>
370     <c>app-text/recode</c> can also be used for this purpose.
371     </p>
372    
373     </body>
374     </section>
375     <section>
376     <title>The System Console</title>
377     <body>
378    
379     <impo>
380     You need >=sys-apps/baselayout-1.11.9 for Unicode on the console.
381     </impo>
382    
383     <p>
384     To enable UTF-8 on the console, you should edit <path>/etc/rc.conf</path> and
385     set <c>UNICODE="yes"</c>, and also read the comments in that file -- it is
386     important to have a font that has a good range of characters if you plan on
387     making the most of Unicode.
388     </p>
389    
390     <p>
391     The <c>KEYMAP</c> variable, set in <path>/etc/conf.d/keymaps</path>, should
392     have a Unicode keymap specified. To do this, simply prepend the keymap already
393     specified there with -u.
394     </p>
395    
396     <pre caption="Example /etc/conf.d/keymaps snippet">
397     <comment>(Change "uk" to your local layout)</comment>
398 bennyc 1.11 KEYMAP="-u uk"
399 neysx 1.1 </pre>
400    
401     </body>
402     </section>
403     <section>
404     <title>Ncurses and Slang</title>
405     <body>
406    
407     <note>
408     Ignore any mention of Slang in this section if you do not have it installed or
409     do not use it.
410     </note>
411    
412     <p>
413     It is wise to add <c>unicode</c> to your global USE flags in
414     <path>/etc/make.conf</path>, and then to remerge <c>sys-libs/ncurses</c> and
415 smithj 1.22 <c>sys-libs/slang</c> if appropriate:
416 neysx 1.1 </p>
417    
418     <pre caption="Emerging ncurses and slang">
419     <comment>(We avoid putting these libraries in our world file with --oneshot)</comment>
420 smithj 1.22 # <i>emerge --oneshot sys-libs/ncurses sys-libs/slang</i>
421 neysx 1.1 </pre>
422    
423     <p>
424     We also need to rebuild packages that link to these, now the USE changes have
425 bennyc 1.11 been applied. The tool we use (<c>revdep-rebuild</c>) is part of the
426     <c>gentoolkit</c> package.
427 neysx 1.1 </p>
428    
429     <pre caption="Rebuilding of programs that link to ncurses or slang">
430     # <i>revdep-rebuild --soname libncurses.so.5</i>
431     # <i>revdep-rebuild --soname libslang.so.1</i>
432     </pre>
433    
434     </body>
435     </section>
436     <section>
437     <title>KDE, GNOME and Xfce</title>
438     <body>
439    
440     <p>
441     All of the major desktop environments have full Unicode support, and will
442     require no further setup than what has already been covered in this guide. This
443     is because the underlying graphical toolkits (Qt or GTK+2) are UTF-8 aware.
444     Subsequently, all applications running on top of these toolkits should be
445     UTF-8-aware out of the box.
446     </p>
447    
448     <p>
449     The exceptions to this rule come in Xlib and GTK+1. GTK+1 requires a
450     iso-10646-1 FontSpec in the ~/.gtkrc, for example
451     <c>-misc-fixed-*-*-*-*-*-*-*-*-*-*-iso10646-1</c>. Also, applications using
452     Xlib or Xaw will need to be given a similar FontSpec, otherwise they will not
453     work.
454     </p>
455    
456     <note>
457     If you have a version of the gnome1 control center around, use that instead.
458     Pick any iso10646-1 font from there.
459     </note>
460    
461     <pre caption="Example ~/.gtkrc (for GTK+1) that defines a Unicode compatible font">
462     style "user-font"
463     {
464     fontset="-misc-fixed-*-*-*-*-*-*-*-*-*-*-iso10646-1"
465     }
466     widget_class "*" style "user-font"
467     </pre>
468    
469     <p>
470     If an application has support for both a Qt and GTK+2 GUI, the GTK+2 GUI will
471     generally give better results with Unicode.
472     </p>
473    
474     </body>
475     </section>
476     <section>
477     <title>X11 and Fonts</title>
478     <body>
479    
480 bennyc 1.11 <impo>
481     <c>x11-base/xorg-x11</c> has far better support for Unicode than XFree86
482     and is <e>highly</e> recommended.
483     </impo>
484    
485 neysx 1.1 <p>
486     TrueType fonts have support for Unicode, and most of the fonts that ship with
487     Xorg have impressive character support, although, obviously, not every single
488     glyph available in Unicode has been created for that font. To build fonts
489     (including the Bitstream Vera set) with support for East Asian letters with X,
490     make sure you have the <c>cjk</c> USE flag set. Many other applications utilise
491     this flag, so it may be worthwhile to add it as a permanent USE flag.
492     </p>
493    
494     <p>
495     Also, several font packages in Portage are Unicode aware.
496     </p>
497    
498     <pre caption="Optional: Install some more Unicode-aware fonts">
499     # <i>emerge terminus-font intlfonts freefonts cronyx-fonts corefonts</i>
500     </pre>
501    
502     </body>
503     </section>
504     <section>
505     <title>Window Managers and Terminal Emulators</title>
506     <body>
507    
508     <p>
509 bennyc 1.11 Window managers not built on GTK or Qt generally have very good Unicode
510     support, as they often use the Xft library for handling fonts. If your window
511     manager does not use Xft for fonts, you can still use the FontSpec mentioned in
512     the previous section as a Unicode font.
513 neysx 1.1 </p>
514    
515     <p>
516     Terminal emulators that use Xft and support Unicode are harder to come by.
517     Aside from Konsole and gnome-terminal, the best options in Portage are
518     <c>x11-terms/rxvt-unicode</c>, <c>xfce-extra/terminal</c>,
519 cam 1.5 <c>gnustep-apps/terminal</c>, <c>x11-terms/mlterm</c>, <c>x11-terms/mrxvt</c> or
520 neysx 1.1 plain <c>x11-terms/xterm</c> when built with the <c>unicode</c> USE flag and
521     invoked as <c>uxterm</c>. <c>app-misc/screen</c> supports UTF-8 too, when
522 bennyc 1.11 invoked as <c>screen -u</c> or the following is put into the
523 neysx 1.1 <path>~/.screenrc</path>:
524     </p>
525    
526     <pre caption="~/.screenrc for UTF-8">
527     defutf8 on
528     </pre>
529    
530     </body>
531     </section>
532     <section>
533     <title>Vim, Emacs, Xemacs and Nano</title>
534     <body>
535    
536     <p>
537     Vim, Emacs and Xemacs provide full UTF-8 support, and also have builtin
538     detection of UTF-8 files. For further information in Vim, use <c>:help
539     mbyte.txt</c>.
540     </p>
541    
542     <p>
543     Nano currently does not provide support for UTF-8, although it has been planned
544     for a long time. With luck, this will change in future. At the time of writing,
545     UTF-8 support is in Nano's CVS, and should be included in the next release.
546     </p>
547    
548     </body>
549     </section>
550     <section>
551     <title>Shells</title>
552     <body>
553    
554     <p>
555     Currently, <c>bash</c> provides full Unicode support through the GNU readline
556     library. Z Shell users are in a somewhat worse position -- no parts of the
557     shell have Unicode support, although there is a concerted effort to add
558     multibyte character set support underway at the moment.
559     </p>
560    
561     <p>
562     The C shell, <c>tcsh</c> and <c>ksh</c> do not provide UTF-8 support at all.
563     </p>
564    
565     </body>
566     </section>
567     <section>
568     <title>Irssi</title>
569     <body>
570    
571     <p>
572 cam 1.5 Since 0.8.10, Irssi has complete UTF-8 support, although it does require a user
573     to set an option.
574 neysx 1.1 </p>
575    
576     <pre caption="Enabling UTF-8 in Irssi">
577     /set term_charset UTF-8
578     </pre>
579    
580     <p>
581     For channels where non-ASCII characters are often exchanged in non-UTF-8
582     charsets, the <c>/recode</c> command may be used to convert the characters.
583     Type <c>/help recode</c> for more information.
584     </p>
585    
586     </body>
587     </section>
588     <section>
589     <title>Mutt</title>
590     <body>
591    
592     <p>
593     The Mutt mail user agent has very good Unicode support. To use UTF-8 with Mutt,
594     put the following in your <path>~/.muttrc</path>:
595     </p>
596    
597     <pre caption="~/.muttrc for UTF-8">
598     set send_charset="utf8" <comment>(outgoing character set)</comment>
599     set charset="utf8" <comment>(display character set)</comment>
600     </pre>
601    
602     <note>
603     You may still see '?' in mail you read with Mutt. This is a result of people
604 bennyc 1.11 using a mail client which does not indicate the used charset. You can't do much
605     about this than to ask them to configure their client correctly.
606 neysx 1.1 </note>
607    
608     <p>
609     Further information is available from the <uri
610 neysx 1.25 link="http://wiki.mutt.org/index.cgi?MuttFaq/Charset">Mutt Wiki</uri>.
611 neysx 1.1 </p>
612    
613     </body>
614     </section>
615     <section>
616 swift 1.14 <title>Less</title>
617     <body>
618    
619     <p>
620     We all use a lot of <c>more</c> or <c>less</c> along with the <c>|</c> to be
621     able to correctly see the output of a command, like for example
622     <c>dmesg | less</c>. While <c>more</c> only needs the shell to be UTF-8 aware,
623     <c>less</c> needs an environment variable set, <c>LESSCHARSET</c> to ensure
624     that unicode characters are rendered correctly. This can be set in
625     <path>/etc/profile</path> or <path>~/.bash_profile</path>. Fire up the editor
626     of your choice and the add the following line to one of the files mentioned
627     above.
628     </p>
629    
630     <pre caption="Setting up the Environment variable for less">
631     LESSCHARSET=utf-8
632     </pre>
633    
634     </body>
635     </section>
636     <section>
637     <title>Man</title>
638     <body>
639    
640     <p>
641     Man pages are an integral part of any Linux machine. To ensure that any
642     unicode in your man pages render correctly, edit <path>/etc/man.conf</path>
643     and replace a line as shown below.
644     </p>
645    
646     <pre caption="man.conf changes for Unicode support">
647     <comment>(This is the old line)</comment>
648     NROFF /usr/bin/nroff -Tascii -c -mandoc
649     <comment>(Replace the one above with this)</comment>
650     NROFF /usr/bin/nroff -mandoc -c
651     </pre>
652    
653     </body>
654     </section>
655     <section>
656 fox2mike 1.20 <title>elinks and links</title>
657     <body>
658    
659     <p>
660     These are commonly used text-based browsers, and we shall see how we can enable
661     UTF-8 support on them. On <c>elinks</c> and <c>links</c>, there are two ways to
662     go about this, one using the Setup option from within the browser or editing the
663     config file. To set the option through the browser, open a site with
664     <c>elinks</c> or <c>links</c> and then <c>Alt+S</c> to enter the Setup Menu then
665     select Terminal options, or press <c>T</c>. Scroll down and select the last
666     option <c>UTF-8 I/O</c> by pressing Enter. Then Save and exit the menu. On
667     <c>links</c> you may have to do a repeat <c>Alt+S</c> and then press <c>S</c> to
668     save. The config file option, is shown below.
669     </p>
670    
671     <pre caption="Enabling UTF-8 for elinks/links">
672     <comment>(For elinks, edit /etc/elinks/elinks.conf or ~/.elinks/elinks.conf and
673     add the following line)</comment>
674     set terminal.linux.utf_8_io = 1
675    
676     <comment>(For links, edit ~/.links/links.cfg and add the following
677     line)</comment>
678     terminal "xterm" 0 1 0 us-ascii utf-8
679     </pre>
680    
681     </body>
682     </section>
683     <section>
684 neysx 1.1 <title>Testing it all out</title>
685     <body>
686    
687     <p>
688     There are numerous UTF-8 test websites around. <c>net-www/w3m</c>,
689     <c>net-www/links</c>, <c>net-www/elinks</c>, <c>net-www/lynx</c> and all
690 cam 1.3 Mozilla based browsers (including Firefox) support UTF-8. Konqueror and Opera
691     have full UTF-8 support too.
692 neysx 1.1 </p>
693    
694     <p>
695     When using one of the text-only web browsers, make absolutely sure you are
696     using a Unicode-aware terminal.
697     </p>
698    
699     <p>
700     If you see certain characters displayed as boxes with letters or numbers
701     inside, this means that your font does not have a character for the symbol or
702     glyph that the UTF-8 wants. Instead, it displays a box with the hex code of the
703     UTF-8 symbol.
704     </p>
705    
706     <ul>
707     <li>
708     <uri link="http://www.w3.org/2001/06/utf-8-test/UTF-8-demo.html">A W3C
709     UTF-8 Test Page</uri>
710     </li>
711     <li>
712     <uri link="http://titus.uni-frankfurt.de/indexe.htm?/unicode/unitest.htm">
713     A UTF-8 test page provided by the University of Frankfurt</uri>
714     </li>
715     </ul>
716    
717     </body>
718     </section>
719     <section>
720     <title>Input Methods</title>
721     <body>
722    
723     <p>
724     <e>Dead keys</e> may be used to input characters in X that are not included on
725     your keyboard. These work by pressing your right Alt key (or in some countries,
726     AltGr) and an optional key from the non-alphabetical section of the keyboard to
727     the left of the return key at once, releasing them, and then pressing a letter.
728     The dead key should modify it. Input can be further modified by using the Shift
729     key at the same time as pressing the AltGr and modifier.
730     </p>
731    
732     <p>
733     To enable dead keys in X, you need a layout that supports it. Most European
734     layouts already have dead keys with the default variant. However, this is not
735     true of North American layouts. Although there is a degree of inconsistency
736     between layouts, the easiest solution seems to be to use a layout in the form
737     "en_US" rather than "us", for example. The layout is set in
738     <path>/etc/X11/xorg.conf</path> like so:
739     </p>
740    
741     <pre caption="/etc/X11/xorg.conf snippet">
742     Section "InputDevice"
743     Identifier "Keyboard0"
744     Driver "kbd"
745     Option "XkbLayout" "en_US" <comment># Rather than just "us"</comment>
746     <comment>(Other Xkb options here)</comment>
747     EndSection
748     </pre>
749    
750     <note>
751     The preceding change only needs to be applied if you are using a North American
752     layout, or another layout where dead keys do not seem to be working. European
753     users should have working dead keys as is.
754     </note>
755    
756     <p>
757 bennyc 1.11 This change will come into effect when your X server is restarted. To apply the
758 neysx 1.1 change now, use the <c>setxkbmap</c> tool, for example, <c>setxkbmap en_US</c>.
759     </p>
760    
761     <p>
762     It is probably easiest to describe dead keys with examples. Although the
763 bennyc 1.11 results are locale dependent, the concepts should remain the same regardless of
764 neysx 1.1 locale. The examples contain UTF-8, so to view them you need to either tell
765     your browser to view the page as UTF-8, or have a UTF-8 locale already
766     configured.
767     </p>
768    
769     <p>
770     When I press AltGr and [ at once, release them, and then press a, 'ä' is
771 bennyc 1.11 produced. When I press AltGr and [ at once, and then press e, 'ë' is produced.
772     When I press AltGr and ; at once, 'á' is produced, and when I press AltGr and ;
773     at once, release them, and then press e, 'é' is produced.
774 neysx 1.1 </p>
775    
776     <p>
777     By pressing AltGr, Shift and [ at once, releasing them, and then pressing a, a
778     Scandinavian 'å' is produced. Similarly, when I press AltGr, Shift and [ at
779     once, release <e>only</e> the [, and then press it again, '˚' is produced.
780     Although it looks like one, this (U+02DA) is not the same as a degree symbol
781     (U+00B0). This works for other accents produced by dead keys — AltGr and [,
782     releasing only the [, then pressing it again makes '¨'.
783     </p>
784    
785     <p>
786     AltGr can be used with alphabetical keys alone. For example, AltGr and m, a
787 bennyc 1.12 Greek lower-case letter mu is produced: 'µ'. AltGr and s produce a
788     scharfes s or esszet: 'ß'. As many European users would expect (because
789     it is marked on their keyboard), AltGr and 4 produces a Euro sign, '€'.
790 neysx 1.1 </p>
791    
792     </body>
793     </section>
794     <section>
795     <title>Resources</title>
796     <body>
797    
798     <ul>
799     <li>
800     <uri link="http://www.wikipedia.com/wiki/Unicode">The Wikipedia entry for
801     Unicode</uri>
802     </li>
803     <li>
804     <uri link="http://www.wikipedia.com/wiki/UTF-8">The Wikipedia entry for
805     UTF-8</uri>
806     </li>
807     <li><uri link="http://www.unicode.org">Unicode.org</uri></li>
808     <li><uri link="http://www.utf-8.com">UTF-8.com</uri></li>
809     <li><uri link="http://www.ietf.org/rfc/rfc3629.txt">RFC 3629</uri></li>
810     <li><uri link="http://www.ietf.org/rfc/rfc2277.txt">RFC 2277</uri></li>
811 bennyc 1.11 <li>
812     <uri
813     link="http://www.tbray.org/ongoing/When/200x/2003/04/26/UTF">Characters vs.
814     Bytes</uri>
815     </li>
816 neysx 1.1 </ul>
817    
818     </body>
819     </section>
820     </chapter>
821     </guide>

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