/[gentoo]/xml/htdocs/doc/en/utf-8.xml
Gentoo

Contents of /xml/htdocs/doc/en/utf-8.xml

Parent Directory Parent Directory | Revision Log Revision Log


Revision 1.60 - (hide annotations) (download) (as text)
Wed Jul 24 20:40:40 2013 UTC (17 months ago) by swift
Branch: MAIN
CVS Tags: HEAD
Changes since 1.59: +4 -4 lines
File MIME type: application/xml
UTF-8 guide is now at https://wiki.gentoo.org/wiki/UTF-8

1 neysx 1.1 <?xml version='1.0' encoding="UTF-8"?>
2     <!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
3 swift 1.60 <!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/utf-8.xml,v 1.59 2013/07/22 13:59:36 swift Exp $ -->
4 neysx 1.1
5 swift 1.60 <guide disclaimer="obsolete" redirect="https://wiki.gentoo.org/wiki/UTF-8">
6 neysx 1.1 <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 nightmorph 1.54 <author title="Editor">
18     <mail link="nightmorph"/>
19     </author>
20 neysx 1.1
21     <abstract>
22     This guide shows you how to set up and use the UTF-8 Unicode character set with
23     your Gentoo Linux system, after explaining the benefits of Unicode and more
24     specifically UTF-8.
25     </abstract>
26    
27 fox2mike 1.20 <!-- The content of this document is licensed under the CC-BY-SA license -->
28     <!-- See http://creativecommons.org/licenses/by-sa/2.5 -->
29 neysx 1.1 <license />
30    
31 swift 1.60 <version>9</version>
32     <date>2013-07-24</date>
33 neysx 1.1
34     <chapter>
35     <title>Character Encodings</title>
36     <section>
37     <title>What is a Character Encoding?</title>
38     <body>
39    
40     <p>
41     Computers do not understand text themselves. Instead, every character is
42     represented by a number. Traditionally, each set of numbers used to represent
43     alphabets and characters (known as a coding system, encoding or character set)
44     was limited in size due to limitations in computer hardware.
45     </p>
46    
47     </body>
48     </section>
49     <section>
50     <title>The History of Character Encodings</title>
51     <body>
52    
53     <p>
54     The most common (or at least the most widely accepted) character set is
55     <b>ASCII</b> (American Standard Code for Information Interchange). It is widely
56     held that ASCII is the most successful software standard ever. Modern ASCII
57     was standardised in 1986 (ANSI X3.4, RFC 20, ISO/IEC 646:1991, ECMA-6) by the
58     American National Standards Institute.
59     </p>
60    
61     <p>
62     ASCII is strictly seven-bit, meaning that it uses bit patterns representable
63     with seven binary digits, which provides a range of 0 to 127 in decimal. These
64     include 32 non-visible control characters, most between 0 and 31, with the
65     final control character, DEL or delete at 127. Characters 32 to 126 are
66     visible characters: a space, punctuation marks, Latin letters and numbers.
67     </p>
68    
69     <p>
70     The eighth bit in ASCII was originally used as a parity bit for error checking.
71     If this is not desired, it is left as 0. This means that, with ASCII, each
72     character is represented by a single byte.
73     </p>
74    
75     <p>
76     Although ASCII was enough for communication in modern English, in other
77     European languages that include accented characters, things were not so easy.
78     The ISO 8859 standards were developed to meet these needs. They were backwards
79     compatible with ASCII, but instead of leaving the eighth bit blank, they used
80     it to allow another 127 characters in each encoding. ISO 8859's limitations
81     soon came to light, and there are currently 15 variants of the ISO 8859
82     standard (8859-1 through to 8859-15). Outside of the ASCII-compatible byte
83     range of these character sets, there is often conflict between the letters
84     represented by each byte. To complicate interoperability between character
85     encodings further, Windows-1252 is used in some versions of Microsoft Windows
86     instead for Western European languages. This is a superset of ISO 8859-1,
87     however it is different in several ways. These sets do all retain ASCII
88     compatibility, however.
89     </p>
90    
91     <p>
92     The necessary development of completely different single-byte encodings for
93     non-Latin alphabets, such as EUC (Extended Unix Coding) which is used for
94     Japanese and Korean (and to a lesser extent Chinese) created more confusion,
95     while other operating systems still used different character sets for the same
96     languages, for example, Shift-JIS and ISO-2022-JP. Users wishing to view
97     cyrillic glyphs had to choose between KOI8-R for Russian and Bulgarian or
98     KOI8-U for Ukrainian, as well as all the other cyrillic encodings such as the
99     unsuccessful ISO 8859-5, and the common Windows-1251 set. All of these
100     character sets broke most compatibility with ASCII (although KOI8 encodings
101     place cyrillic characters in Latin order, so in case the eighth bit is
102     stripped, text is still decipherable on an ASCII terminal through case-reversed
103     transliteration.)
104     </p>
105    
106     <p>
107     This has led to confusion, and also to an almost total inability for
108     multilingual communication, especially across different alphabets. Enter
109     Unicode.
110     </p>
111    
112     </body>
113     </section>
114     <section>
115     <title>What is Unicode?</title>
116     <body>
117    
118     <p>
119 bennyc 1.11 Unicode throws away the traditional single-byte limit of character sets. It
120     uses 17 "planes" of 65,536 code points to describe a maximum of 1,114,112
121     characters. As the first plane, aka. "Basic Multilingual Plane" or BMP,
122     contains almost everything you will ever use, many have made the wrong
123     assumption that Unicode was a 16-bit character set.
124 neysx 1.1 </p>
125    
126     <p>
127     Unicode has been mapped in many different ways, but the two most common are
128     <b>UTF</b> (Unicode Transformation Format) and <b>UCS</b> (Universal Character
129     Set). A number after UTF indicates the number of bits in one unit, while the
130     number after UCS indicates the number of bytes. UTF-8 has become the most
131     widespread means for the interchange of Unicode text as a result of its
132     eight-bit clean nature, and it is the subject of this document.
133     </p>
134    
135     </body>
136     </section>
137     <section>
138     <title>UTF-8</title>
139     <body>
140    
141     <p>
142     UTF-8 is a variable-length character encoding, which in this instance means
143     that it uses 1 to 4 bytes per symbol. So, the first UTF-8 byte is used for
144     encoding ASCII, giving the character set full backwards compatibility with
145     ASCII. UTF-8 means that ASCII and Latin characters are interchangeable with
146     little increase in the size of the data, because only the first bit is used.
147     Users of Eastern alphabets such as Japanese, who have been assigned a higher
148     byte range are unhappy, as this results in as much as a 50% redundancy in their
149     data.
150     </p>
151    
152     </body>
153     </section>
154     <section>
155     <title>What UTF-8 Can Do for You</title>
156     <body>
157    
158     <p>
159     UTF-8 allows you to work in a standards-compliant and internationally accepted
160 bennyc 1.11 multilingual environment, with a comparatively low data redundancy. UTF-8 is
161 neysx 1.1 the preferred way for transmitting non-ASCII characters over the Internet,
162     through Email, IRC or almost any other medium. Despite this, many people regard
163     UTF-8 in online communication as abusive. It is always best to be aware of the
164     attitude towards UTF-8 in a specific channel, mailing list or Usenet group
165     before using <e>non-ASCII</e> UTF-8.
166     </p>
167    
168     </body>
169     </section>
170     </chapter>
171    
172     <chapter>
173     <title>Setting up UTF-8 with Gentoo Linux</title>
174     <section>
175     <title>Finding or Creating UTF-8 Locales</title>
176     <body>
177    
178     <p>
179     Now that you understand the principles behind Unicode, you're ready to start
180     using UTF-8 with your system.
181     </p>
182    
183     <p>
184     The preliminary requirement for UTF-8 is to have a version of glibc installed
185     that has national language support. The recommend means to do this is the
186 rane 1.43 <path>/etc/locale.gen</path> file. It is beyond the scope of this document to
187     explain the usage of this file though. It is explained in the <uri
188 swift 1.59 link="https://wiki.gentoo.org/wiki/Localization/HOWTO">Gentoo Localization
189 neysx 1.1 Guide</uri>.
190     </p>
191    
192     <p>
193     Next, we'll need to decide whether a UTF-8 locale is already available for our
194     language, or whether we need to create one.
195     </p>
196    
197     <pre caption="Checking for an existing UTF-8 locale">
198     <comment>(Replace "en_GB" with your desired locale setting)</comment>
199     # <i>locale -a | grep 'en_GB'</i>
200     en_GB
201 bennyc 1.12 en_GB.UTF-8
202 neysx 1.1 </pre>
203    
204     <p>
205     From the output of this command line, we need to take the result with a suffix
206 bennyc 1.12 similar to <c>.UTF-8</c>. If there is no result with a suffix similar to
207     <c>.UTF-8</c>, we need to create a UTF-8 compatible locale.
208 neysx 1.1 </p>
209    
210     <note>
211     Only execute the following code listing if you do not have a UTF-8 locale
212     available for your language.
213     </note>
214    
215     <pre caption="Creating a UTF-8 locale">
216     <comment>(Replace "en_GB" with your desired locale setting)</comment>
217 bennyc 1.12 # <i>localedef -i en_GB -f UTF-8 en_GB.UTF-8</i>
218 neysx 1.1 </pre>
219    
220 bennyc 1.11 <p>
221     Another way to include a UTF-8 locale is to add it to the
222 rane 1.43 <path>/etc/locale.gen</path> file and generate necessary locales with
223     <c>locale-gen</c> command.
224 bennyc 1.11 </p>
225    
226 rane 1.43 <pre caption="Line in /etc/locale.gen">
227     en_GB.UTF-8 UTF-8
228 bennyc 1.11 </pre>
229    
230 neysx 1.1 </body>
231     </section>
232     <section>
233     <title>Setting the Locale</title>
234     <body>
235    
236     <p>
237 nightmorph 1.45 There is one environment variable that needs to be set in order to use our new
238 jkt 1.49 UTF-8 locales: <c>LC_CTYPE</c> (or optionally <c>LANG</c>, if you want to change
239     the system language as well). There are also many different ways to set it; some
240     people prefer to only have a UTF-8 environment for a specific user, in which
241     case they set them in their <path>~/.profile</path> (if you use <c>/bin/sh</c>),
242     <path>~/.bash_profile</path> or <path>~/.bashrc</path> (if you use
243     <c>/bin/bash</c>). More details and best practices can be found in our <uri
244 swift 1.59 link="https://wiki.gentoo.org/wiki/Localization/HOWTO">Localization Guide</uri>.
245 swift 1.18 </p>
246    
247     <p>
248 swift 1.48 Others prefer to set the locale globally. One specific circumstance where
249     the author particularly recommends doing this is when
250 swift 1.17 <path>/etc/init.d/xdm</path> is in use, because
251 bennyc 1.12 this init script starts the display manager and desktop before any of the
252     aforementioned shell startup files are sourced, and so before any of the
253     variables are in the environment.
254 neysx 1.1 </p>
255    
256 bennyc 1.12 <p>
257     Setting the locale globally should be done using
258 swift 1.15 <path>/etc/env.d/02locale</path>. The file should look something like the
259 bennyc 1.12 following:
260     </p>
261    
262     <pre caption="Demonstration /etc/env.d/02locale">
263     <comment>(As always, change "en_GB.UTF-8" to your locale)</comment>
264 nightmorph 1.45 LANG="en_GB.UTF-8"
265 bennyc 1.12 </pre>
266    
267 nightmorph 1.45 <note>
268 jkt 1.50 You can also substitute <c>LC_CTYPE</c> for <c>LANG</c>. For more information on
269     the categories affected by using <c>LC_CTYPE</c>, please read the <uri
270 nightmorph 1.45 link="http://www.gnu.org/software/libc/manual/html_node/Locale-Categories.html#Locale-Categories">GNU
271     locale page</uri>.
272     </note>
273    
274 bennyc 1.12 <p>
275     Next, the environment must be updated with the change.
276     </p>
277 bennyc 1.10
278 bennyc 1.12 <pre caption="Updating the environment">
279     # <i>env-update</i>
280     >>> Regenerating /etc/ld.so.cache...
281     * Caching service dependencies ...
282 swift 1.13 # <i>source /etc/profile</i>
283 bennyc 1.10 </pre>
284    
285 bennyc 1.12 <p>
286     Now, run <c>locale</c> with no arguments to see if we have the correct
287     variables in our environment:
288     </p>
289    
290     <pre caption="Checking if our new locale is in the environment">
291     # <i>locale</i>
292 jkt 1.50 LANG=en_GB.UTF-8
293 bennyc 1.12 LC_CTYPE="en_GB.UTF-8"
294     LC_NUMERIC="en_GB.UTF-8"
295     LC_TIME="en_GB.UTF-8"
296     LC_COLLATE="en_GB.UTF-8"
297     LC_MONETARY="en_GB.UTF-8"
298     LC_MESSAGES="en_GB.UTF-8"
299     LC_PAPER="en_GB.UTF-8"
300     LC_NAME="en_GB.UTF-8"
301     LC_ADDRESS="en_GB.UTF-8"
302     LC_TELEPHONE="en_GB.UTF-8"
303     LC_MEASUREMENT="en_GB.UTF-8"
304     LC_IDENTIFICATION="en_GB.UTF-8"
305 jkt 1.50 LC_ALL=
306 neysx 1.1 </pre>
307    
308 bennyc 1.10 <p>
309 bennyc 1.12 That's everything. You are now using UTF-8 locales, and the next hurdle is the
310     configuration of the applications you use from day to day.
311 neysx 1.1 </p>
312    
313     </body>
314     </section>
315     </chapter>
316    
317     <chapter>
318     <title>Application Support</title>
319     <section>
320     <body>
321    
322     <p>
323     When Unicode first started gaining momentum in the software world, multibyte
324     character sets were not well suited to languages like C, in which many of the
325     day-to-day programs people use are written. Even today, some programs are not
326     able to handle UTF-8 properly. Fortunately, most are!
327     </p>
328    
329     </body>
330     </section>
331     <section>
332     <title>Filenames, NTFS, and FAT</title>
333     <body>
334    
335     <p>
336     There are several NLS options in the Linux kernel configuration menu, but it is
337     important to not become confused! For the most part, the only thing you need to
338     do is to build UTF-8 NLS support into your kernel, and change the default NLS
339     option to utf8.
340     </p>
341    
342     <pre caption="Kernel configuration steps for UTF-8 NLS">
343     File Systems --&gt;
344     Native Language Support --&gt;
345     (utf8) Default NLS Option
346     &lt;*&gt; NLS UTF8
347     <comment>(Also &lt;*&gt; other character sets that are in use in
348     your FAT filesystems or Joilet CD-ROMs.)</comment>
349     </pre>
350    
351     <p>
352     If you plan on mounting NTFS partitions, you may need to specify an <c>nls=</c>
353 nightmorph 1.40 option with mount. If you plan on mounting FAT partitions, you may need to
354 fox2mike 1.28 specify a <c>codepage=</c> option with mount. Optionally, you can also set a
355     default codepage for FAT in the kernel configuration. Note that the
356     <c>codepage</c> option with mount will override the kernel settings.
357     </p>
358    
359     <pre caption="FAT settings in kernel configuration">
360     File Systems --&gt;
361     DOS/FAT/NT Filesystems --&gt;
362     (437) Default codepage for fat
363     </pre>
364    
365     <p>
366     You should avoid setting <c>Default iocharset for fat</c> to UTF-8, as it is
367     not recommended. Instead, you may want to pass the option utf8=true when
368     mounting your FAT partitions. For further information, see <c>man mount</c> and
369     the kernel documentation at
370     <path>/usr/src/linux/Documentation/filesystems/vfat.txt</path>.
371 neysx 1.1 </p>
372    
373     <p>
374     For changing the encoding of filenames, <c>app-text/convmv</c> can be used.
375     </p>
376    
377     <pre caption="Example usage of convmv">
378     # <i>emerge --ask app-text/convmv</i>
379 fox2mike 1.29 <comment>(Command format)</comment>
380     # <i>convmv -f &lt;current-encoding&gt; -t utf-8 &lt;filename&gt;</i>
381     <comment>(Substitute iso-8859-1 with the charset you are converting
382     from)</comment>
383     # <i>convmv -f iso-8859-1 -t utf-8 filename</i>
384 neysx 1.1 </pre>
385    
386     <p>
387     For changing the <e>contents</e> of files, use the <c>iconv</c> utility,
388     bundled with <c>glibc</c>:
389     </p>
390    
391     <pre caption="Example usage of iconv">
392     <comment>(substitute iso-8859-1 with the charset you are converting from)</comment>
393     <comment>(Check the output is sane)</comment>
394 swift 1.48 # <i>iconv -f iso-8859-1 -t utf-8 filename</i>
395 neysx 1.1 <comment>(Convert a file, you must create another file)</comment>
396     # <i>iconv -f iso-8859-1 -t utf-8 filename > newfile</i>
397     </pre>
398    
399     <p>
400     <c>app-text/recode</c> can also be used for this purpose.
401     </p>
402    
403     </body>
404     </section>
405     <section>
406     <title>The System Console</title>
407     <body>
408    
409     <impo>
410     You need >=sys-apps/baselayout-1.11.9 for Unicode on the console.
411     </impo>
412    
413     <p>
414     To enable UTF-8 on the console, you should edit <path>/etc/rc.conf</path> and
415     set <c>UNICODE="yes"</c>, and also read the comments in that file -- it is
416     important to have a font that has a good range of characters if you plan on
417 nightmorph 1.46 making the most of Unicode. For this to work, make sure you have properly
418     created a Unicode locale as explained in <uri link="#doc_chap1">Chapter
419     1</uri>.
420 neysx 1.1 </p>
421    
422     <p>
423     The <c>KEYMAP</c> variable, set in <path>/etc/conf.d/keymaps</path>, should
424 swift 1.48 have a Unicode keymap specified.
425 neysx 1.1 </p>
426    
427     <pre caption="Example /etc/conf.d/keymaps snippet">
428     <comment>(Change "uk" to your local layout)</comment>
429 fox2mike 1.26 KEYMAP="uk"
430 neysx 1.1 </pre>
431    
432     </body>
433     </section>
434     <section>
435     <title>Ncurses and Slang</title>
436     <body>
437    
438     <note>
439     Ignore any mention of Slang in this section if you do not have it installed or
440     do not use it.
441     </note>
442    
443     <p>
444     It is wise to add <c>unicode</c> to your global USE flags in
445 swift 1.57 <path>/etc/portage/make.conf</path>, and then to remerge <c>sys-libs/ncurses</c> and
446 swift 1.30 <c>sys-libs/slang</c> if appropriate. Portage will do this automatically when
447     you update your system:
448 neysx 1.1 </p>
449    
450 swift 1.30 <pre caption="Updating your system">
451     # <i>emerge --update --deep --newuse world</i>
452 neysx 1.1 </pre>
453    
454     <p>
455     We also need to rebuild packages that link to these, now the USE changes have
456 bennyc 1.11 been applied. The tool we use (<c>revdep-rebuild</c>) is part of the
457     <c>gentoolkit</c> package.
458 neysx 1.1 </p>
459    
460     <pre caption="Rebuilding of programs that link to ncurses or slang">
461     # <i>revdep-rebuild --soname libncurses.so.5</i>
462     # <i>revdep-rebuild --soname libslang.so.1</i>
463     </pre>
464    
465     </body>
466     </section>
467     <section>
468     <title>KDE, GNOME and Xfce</title>
469     <body>
470    
471     <p>
472     All of the major desktop environments have full Unicode support, and will
473     require no further setup than what has already been covered in this guide. This
474     is because the underlying graphical toolkits (Qt or GTK+2) are UTF-8 aware.
475     Subsequently, all applications running on top of these toolkits should be
476     UTF-8-aware out of the box.
477     </p>
478    
479     <p>
480     The exceptions to this rule come in Xlib and GTK+1. GTK+1 requires a
481     iso-10646-1 FontSpec in the ~/.gtkrc, for example
482     <c>-misc-fixed-*-*-*-*-*-*-*-*-*-*-iso10646-1</c>. Also, applications using
483     Xlib or Xaw will need to be given a similar FontSpec, otherwise they will not
484     work.
485     </p>
486    
487     <note>
488     If you have a version of the gnome1 control center around, use that instead.
489     Pick any iso10646-1 font from there.
490     </note>
491    
492     <pre caption="Example ~/.gtkrc (for GTK+1) that defines a Unicode compatible font">
493     style "user-font"
494     {
495     fontset="-misc-fixed-*-*-*-*-*-*-*-*-*-*-iso10646-1"
496     }
497     widget_class "*" style "user-font"
498     </pre>
499    
500     <p>
501     If an application has support for both a Qt and GTK+2 GUI, the GTK+2 GUI will
502     generally give better results with Unicode.
503     </p>
504    
505     </body>
506     </section>
507     <section>
508     <title>X11 and Fonts</title>
509     <body>
510    
511     <p>
512     TrueType fonts have support for Unicode, and most of the fonts that ship with
513     Xorg have impressive character support, although, obviously, not every single
514     glyph available in Unicode has been created for that font. To build fonts
515     (including the Bitstream Vera set) with support for East Asian letters with X,
516     make sure you have the <c>cjk</c> USE flag set. Many other applications utilise
517     this flag, so it may be worthwhile to add it as a permanent USE flag.
518     </p>
519    
520     <p>
521     Also, several font packages in Portage are Unicode aware.
522     </p>
523    
524     <pre caption="Optional: Install some more Unicode-aware fonts">
525 nightmorph 1.54 # <i>emerge terminus-font intlfonts freefonts corefonts</i>
526 neysx 1.1 </pre>
527    
528     </body>
529     </section>
530     <section>
531     <title>Window Managers and Terminal Emulators</title>
532     <body>
533    
534     <p>
535 bennyc 1.11 Window managers not built on GTK or Qt generally have very good Unicode
536     support, as they often use the Xft library for handling fonts. If your window
537     manager does not use Xft for fonts, you can still use the FontSpec mentioned in
538     the previous section as a Unicode font.
539 neysx 1.1 </p>
540    
541     <p>
542     Terminal emulators that use Xft and support Unicode are harder to come by.
543     Aside from Konsole and gnome-terminal, the best options in Portage are
544 nightmorph 1.58 <c>x11-terms/rxvt-unicode</c>, <c>x11-terms/xfce4-terminal</c>,
545 neysx 1.34 <c>gnustep-apps/terminal</c>, <c>x11-terms/mlterm</c>, or plain
546     <c>x11-terms/xterm</c> when built with the <c>unicode</c> USE flag and invoked
547     as <c>uxterm</c>. <c>app-misc/screen</c> supports UTF-8 too, when invoked as
548 rane 1.35 <c>screen -U</c> or the following is put into the <path>~/.screenrc</path>:
549 neysx 1.1 </p>
550    
551     <pre caption="~/.screenrc for UTF-8">
552     defutf8 on
553     </pre>
554    
555     </body>
556     </section>
557     <section>
558     <title>Vim, Emacs, Xemacs and Nano</title>
559     <body>
560    
561     <p>
562 swift 1.48 Vim provides full UTF-8 support, and also has builtin detection of UTF-8 files.
563 swift 1.27 For further information in Vim, use <c>:help mbyte.txt</c>.
564 neysx 1.1 </p>
565    
566     <p>
567 nightmorph 1.55 Emacs version 23 and Xemacs version 21.5 have full UTF-8 support. Emacs 24 will
568     also support editing bidirectional text.
569 swift 1.27 </p>
570    
571     <p>
572 nightmorph 1.38 Nano has provided full UTF-8 support since version 1.3.6.
573 neysx 1.1 </p>
574    
575     </body>
576     </section>
577     <section>
578     <title>Shells</title>
579     <body>
580    
581     <p>
582     Currently, <c>bash</c> provides full Unicode support through the GNU readline
583 nightmorph 1.47 library. Z Shell (<c>zsh</c>) offers Unicode support with the <c>unicode</c> USE
584     flag.
585 neysx 1.1 </p>
586    
587     <p>
588     The C shell, <c>tcsh</c> and <c>ksh</c> do not provide UTF-8 support at all.
589     </p>
590    
591     </body>
592     </section>
593     <section>
594     <title>Irssi</title>
595     <body>
596    
597     <p>
598 swift 1.33 Irssi has complete UTF-8 support, although it does require a user
599 cam 1.5 to set an option.
600 neysx 1.1 </p>
601    
602     <pre caption="Enabling UTF-8 in Irssi">
603 nightmorph 1.39 /set term_charset UTF-8
604 neysx 1.1 </pre>
605    
606     <p>
607     For channels where non-ASCII characters are often exchanged in non-UTF-8
608     charsets, the <c>/recode</c> command may be used to convert the characters.
609     Type <c>/help recode</c> for more information.
610     </p>
611    
612     </body>
613     </section>
614     <section>
615     <title>Mutt</title>
616     <body>
617    
618     <p>
619     The Mutt mail user agent has very good Unicode support. To use UTF-8 with Mutt,
620 rane 1.36 you don't need to put anything in your configuration files. Mutt will work
621     under unicode enviroment without modification if all your configuration files
622     (signature included) are UTF-8 encoded.
623 neysx 1.1 </p>
624    
625     <note>
626     You may still see '?' in mail you read with Mutt. This is a result of people
627 bennyc 1.11 using a mail client which does not indicate the used charset. You can't do much
628     about this than to ask them to configure their client correctly.
629 neysx 1.1 </note>
630    
631     <p>
632     Further information is available from the <uri
633 neysx 1.25 link="http://wiki.mutt.org/index.cgi?MuttFaq/Charset">Mutt Wiki</uri>.
634 neysx 1.1 </p>
635    
636     </body>
637     </section>
638     <section>
639 swift 1.14 <title>Man</title>
640     <body>
641    
642     <p>
643 swift 1.48 Man pages are an integral part of any Linux machine. To ensure that any
644     unicode in your man pages render correctly, edit <path>/etc/man.conf</path>
645 swift 1.14 and replace a line as shown below.
646     </p>
647    
648     <pre caption="man.conf changes for Unicode support">
649     <comment>(This is the old line)</comment>
650     NROFF /usr/bin/nroff -Tascii -c -mandoc
651     <comment>(Replace the one above with this)</comment>
652     NROFF /usr/bin/nroff -mandoc -c
653     </pre>
654    
655     </body>
656     </section>
657     <section>
658 fox2mike 1.20 <title>elinks and links</title>
659     <body>
660    
661     <p>
662     These are commonly used text-based browsers, and we shall see how we can enable
663     UTF-8 support on them. On <c>elinks</c> and <c>links</c>, there are two ways to
664     go about this, one using the Setup option from within the browser or editing the
665     config file. To set the option through the browser, open a site with
666     <c>elinks</c> or <c>links</c> and then <c>Alt+S</c> to enter the Setup Menu then
667     select Terminal options, or press <c>T</c>. Scroll down and select the last
668     option <c>UTF-8 I/O</c> by pressing Enter. Then Save and exit the menu. On
669     <c>links</c> you may have to do a repeat <c>Alt+S</c> and then press <c>S</c> to
670     save. The config file option, is shown below.
671     </p>
672    
673     <pre caption="Enabling UTF-8 for elinks/links">
674     <comment>(For elinks, edit /etc/elinks/elinks.conf or ~/.elinks/elinks.conf and
675     add the following line)</comment>
676     set terminal.linux.utf_8_io = 1
677    
678     <comment>(For links, edit ~/.links/links.cfg and add the following
679     line)</comment>
680     terminal "xterm" 0 1 0 us-ascii utf-8
681     </pre>
682    
683     </body>
684     </section>
685     <section>
686 fox2mike 1.41 <title>Samba</title>
687     <body>
688    
689     <p>
690     Samba is a software suite which implements the SMB (Server Message Block)
691     protocol for UNIX systems such as Macs, Linux and FreeBSD. The protocol
692     is also sometimes referred to as the Common Internet File System (CIFS). Samba
693 rane 1.42 also includes the NetBIOS system - used for file sharing over windows networks.
694 fox2mike 1.41 </p>
695    
696     <pre caption="Enabling UTF-8 for Samba">
697     <comment>(Edit /etc/samba/smb.conf and add the following under the [global] section)</comment>
698     dos charset = 1255
699     unix charset = UTF-8
700     display charset = UTF-8
701     </pre>
702    
703     </body>
704     </section>
705     <section>
706 neysx 1.1 <title>Testing it all out</title>
707     <body>
708    
709     <p>
710     There are numerous UTF-8 test websites around. <c>net-www/w3m</c>,
711     <c>net-www/links</c>, <c>net-www/elinks</c>, <c>net-www/lynx</c> and all
712 cam 1.3 Mozilla based browsers (including Firefox) support UTF-8. Konqueror and Opera
713     have full UTF-8 support too.
714 neysx 1.1 </p>
715    
716     <p>
717     When using one of the text-only web browsers, make absolutely sure you are
718     using a Unicode-aware terminal.
719     </p>
720    
721     <p>
722     If you see certain characters displayed as boxes with letters or numbers
723     inside, this means that your font does not have a character for the symbol or
724     glyph that the UTF-8 wants. Instead, it displays a box with the hex code of the
725     UTF-8 symbol.
726     </p>
727    
728     <ul>
729     <li>
730     <uri link="http://www.w3.org/2001/06/utf-8-test/UTF-8-demo.html">A W3C
731     UTF-8 Test Page</uri>
732     </li>
733     <li>
734     <uri link="http://titus.uni-frankfurt.de/indexe.htm?/unicode/unitest.htm">
735     A UTF-8 test page provided by the University of Frankfurt</uri>
736     </li>
737     </ul>
738    
739     </body>
740     </section>
741     <section>
742     <title>Input Methods</title>
743     <body>
744    
745     <p>
746     <e>Dead keys</e> may be used to input characters in X that are not included on
747     your keyboard. These work by pressing your right Alt key (or in some countries,
748     AltGr) and an optional key from the non-alphabetical section of the keyboard to
749     the left of the return key at once, releasing them, and then pressing a letter.
750     The dead key should modify it. Input can be further modified by using the Shift
751     key at the same time as pressing the AltGr and modifier.
752     </p>
753    
754     <p>
755     To enable dead keys in X, you need a layout that supports it. Most European
756     layouts already have dead keys with the default variant. However, this is not
757     true of North American layouts. Although there is a degree of inconsistency
758     between layouts, the easiest solution seems to be to use a layout in the form
759     "en_US" rather than "us", for example. The layout is set in
760     <path>/etc/X11/xorg.conf</path> like so:
761     </p>
762    
763     <pre caption="/etc/X11/xorg.conf snippet">
764     Section "InputDevice"
765     Identifier "Keyboard0"
766     Driver "kbd"
767     Option "XkbLayout" "en_US" <comment># Rather than just "us"</comment>
768     <comment>(Other Xkb options here)</comment>
769     EndSection
770     </pre>
771    
772     <note>
773     The preceding change only needs to be applied if you are using a North American
774     layout, or another layout where dead keys do not seem to be working. European
775     users should have working dead keys as is.
776     </note>
777    
778     <p>
779 bennyc 1.11 This change will come into effect when your X server is restarted. To apply the
780 neysx 1.1 change now, use the <c>setxkbmap</c> tool, for example, <c>setxkbmap en_US</c>.
781     </p>
782    
783     <p>
784     It is probably easiest to describe dead keys with examples. Although the
785 bennyc 1.11 results are locale dependent, the concepts should remain the same regardless of
786 neysx 1.1 locale. The examples contain UTF-8, so to view them you need to either tell
787     your browser to view the page as UTF-8, or have a UTF-8 locale already
788     configured.
789     </p>
790    
791     <p>
792     When I press AltGr and [ at once, release them, and then press a, 'ä' is
793 bennyc 1.11 produced. When I press AltGr and [ at once, and then press e, 'ë' is produced.
794     When I press AltGr and ; at once, 'á' is produced, and when I press AltGr and ;
795     at once, release them, and then press e, 'é' is produced.
796 neysx 1.1 </p>
797    
798     <p>
799     By pressing AltGr, Shift and [ at once, releasing them, and then pressing a, a
800     Scandinavian 'å' is produced. Similarly, when I press AltGr, Shift and [ at
801     once, release <e>only</e> the [, and then press it again, '˚' is produced.
802     Although it looks like one, this (U+02DA) is not the same as a degree symbol
803     (U+00B0). This works for other accents produced by dead keys — AltGr and [,
804     releasing only the [, then pressing it again makes '¨'.
805     </p>
806    
807     <p>
808     AltGr can be used with alphabetical keys alone. For example, AltGr and m, a
809 bennyc 1.12 Greek lower-case letter mu is produced: 'µ'. AltGr and s produce a
810     scharfes s or esszet: 'ß'. As many European users would expect (because
811 swift 1.31 it is marked on their keyboard), AltGr and 4 (or E depending on the keyboard
812     layout) produces a Euro sign, '€'.
813 neysx 1.1 </p>
814    
815     </body>
816     </section>
817     <section>
818     <title>Resources</title>
819     <body>
820    
821     <ul>
822     <li>
823 swift 1.37 <uri link="http://en.wikipedia.org/wiki/Unicode">The Wikipedia entry for
824 neysx 1.1 Unicode</uri>
825     </li>
826     <li>
827 swift 1.37 <uri link="http://en.wikipedia.org/wiki/UTF-8">The Wikipedia entry for
828 neysx 1.1 UTF-8</uri>
829     </li>
830     <li><uri link="http://www.unicode.org">Unicode.org</uri></li>
831     <li><uri link="http://www.utf-8.com">UTF-8.com</uri></li>
832     <li><uri link="http://www.ietf.org/rfc/rfc3629.txt">RFC 3629</uri></li>
833     <li><uri link="http://www.ietf.org/rfc/rfc2277.txt">RFC 2277</uri></li>
834 bennyc 1.11 <li>
835     <uri
836     link="http://www.tbray.org/ongoing/When/200x/2003/04/26/UTF">Characters vs.
837     Bytes</uri>
838     </li>
839 neysx 1.1 </ul>
840    
841     </body>
842     </section>
843     </chapter>
844 swift 1.56
845     <chapter>
846     <title>Reported Issues or Problems</title>
847     <section>
848     <title>System Configuration Files (in /etc)</title>
849     <body>
850    
851     <p>
852     Most system configuration files, such as <path>/etc/fstab</path>, do not support
853     UTF-8. It is recommended to stick with the ASCII character set for these files.
854     </p>
855    
856     </body>
857     </section>
858     </chapter>
859 neysx 1.1 </guide>

  ViewVC Help
Powered by ViewVC 1.1.20