/[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 1.11 - (hide annotations) (download) (as text)
Sun Apr 24 12:18:59 2005 UTC (9 years, 8 months ago) by bennyc
Branch: MAIN
Changes since 1.10: +63 -95 lines
File MIME type: application/xml
restoring to rev 1.9. Please ignore rev 1.10!

1 neysx 1.1 <?xml version='1.0' encoding="UTF-8"?>
2 bennyc 1.11 <!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/utf-8.xml,v 1.9 2005/04/05 08:59:28 neysx 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 bennyc 1.11 <version>1.8</version>
24     <date>2005-04-05</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     en_GB.utf8
196     </pre>
197    
198     <p>
199     From the output of this command line, we need to take the result with a suffix
200     similar to <c>.utf8</c>. If there is no result with a suffix similar to
201     <c>.utf8</c>, we need to create a UTF-8 compatible locale.
202     </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     # <i>localedef -i en_GB -f UTF-8 en_GB.utf8</i>
212     </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 bennyc 1.11 Although by now you might be determined to use UTF-8 system wide, the author
232     does not recommend setting UTF-8 for the root user. Instead, it is best to set
233     the locale in your user's <path>~/.profile</path> (or, if you are using a C
234     shell, <path>~/.login</path>).
235 neysx 1.1 </p>
236    
237 bennyc 1.11 <note>
238     If you are not sure which file to use, use <path>~/.profile</path>. Also, if
239     you are unsure which code listing to use, use the Bourne version.
240     </note>
241 bennyc 1.10
242 bennyc 1.11 <pre caption="Setting the locale with environment variables (Bourne version)">
243     export LANG="en_GB.utf8"
244     export LC_ALL="en_GB.utf8"
245 bennyc 1.10 </pre>
246    
247 bennyc 1.11 <pre caption="Setting the locale with environment variables (C shell version)">
248     setenv LANG "en_GB.utf8"
249     setenv LC_ALL "en_GB.utf8"
250 neysx 1.1 </pre>
251    
252 bennyc 1.10 <p>
253 bennyc 1.11 Now, logout and back in to apply the change. We want these environment
254     variables in our entire environment, so it is best to logout and back in, or at
255     the very least to source <path>~/.profile</path> or <path>~/.login</path> in
256     the console from which you have started other processes.
257 neysx 1.1 </p>
258    
259     </body>
260     </section>
261     </chapter>
262    
263     <chapter>
264     <title>Application Support</title>
265     <section>
266     <body>
267    
268     <p>
269     When Unicode first started gaining momentum in the software world, multibyte
270     character sets were not well suited to languages like C, in which many of the
271     day-to-day programs people use are written. Even today, some programs are not
272     able to handle UTF-8 properly. Fortunately, most are!
273     </p>
274    
275     </body>
276     </section>
277     <section>
278     <title>Filenames, NTFS, and FAT</title>
279     <body>
280    
281     <p>
282     There are several NLS options in the Linux kernel configuration menu, but it is
283     important to not become confused! For the most part, the only thing you need to
284     do is to build UTF-8 NLS support into your kernel, and change the default NLS
285     option to utf8.
286     </p>
287    
288     <pre caption="Kernel configuration steps for UTF-8 NLS">
289     File Systems --&gt;
290     Native Language Support --&gt;
291     (utf8) Default NLS Option
292     &lt;*&gt; NLS UTF8
293     <comment>(Also &lt;*&gt; other character sets that are in use in
294     your FAT filesystems or Joilet CD-ROMs.)</comment>
295     </pre>
296    
297     <p>
298     If you plan on mounting NTFS partitions, you may need to specify an <c>nls=</c>
299     option with mount. For more information, see <c>man mount</c>.
300     </p>
301    
302     <p>
303     For changing the encoding of filenames, <c>app-text/convmv</c> can be used.
304     </p>
305    
306     <pre caption="Example usage of convmv">
307     # <i>emerge --ask app-text/convmv</i>
308     # <i>convmv -f current-encoding -t utf-8 filename</i>
309     </pre>
310    
311     <p>
312     For changing the <e>contents</e> of files, use the <c>iconv</c> utility,
313     bundled with <c>glibc</c>:
314     </p>
315    
316     <pre caption="Example usage of iconv">
317     <comment>(substitute iso-8859-1 with the charset you are converting from)</comment>
318     <comment>(Check the output is sane)</comment>
319     # <i>iconv -f iso-8859-1 -t utf-8 filename</i>
320     <comment>(Convert a file, you must create another file)</comment>
321     # <i>iconv -f iso-8859-1 -t utf-8 filename > newfile</i>
322     </pre>
323    
324     <p>
325     <c>app-text/recode</c> can also be used for this purpose.
326     </p>
327    
328     </body>
329     </section>
330     <section>
331     <title>The System Console</title>
332     <body>
333    
334     <impo>
335     You need >=sys-apps/baselayout-1.11.9 for Unicode on the console.
336     </impo>
337    
338     <p>
339     To enable UTF-8 on the console, you should edit <path>/etc/rc.conf</path> and
340     set <c>UNICODE="yes"</c>, and also read the comments in that file -- it is
341     important to have a font that has a good range of characters if you plan on
342     making the most of Unicode.
343     </p>
344    
345     <p>
346     The <c>KEYMAP</c> variable, set in <path>/etc/conf.d/keymaps</path>, should
347     have a Unicode keymap specified. To do this, simply prepend the keymap already
348     specified there with -u.
349     </p>
350    
351     <pre caption="Example /etc/conf.d/keymaps snippet">
352     <comment>(Change "uk" to your local layout)</comment>
353 bennyc 1.11 KEYMAP="-u uk"
354 neysx 1.1 </pre>
355    
356     </body>
357     </section>
358     <section>
359     <title>Ncurses and Slang</title>
360     <body>
361    
362     <note>
363     Ignore any mention of Slang in this section if you do not have it installed or
364     do not use it.
365     </note>
366    
367     <p>
368     It is wise to add <c>unicode</c> to your global USE flags in
369     <path>/etc/make.conf</path>, and then to remerge <c>sys-libs/ncurses</c> and
370     also <c>sys-libs/slang</c> if appropriate:
371     </p>
372    
373     <pre caption="Emerging ncurses and slang">
374     <comment>(We avoid putting these libraries in our world file with --oneshot)</comment>
375     # <i>emerge --oneshot --verbose --ask sys-libs/ncurses sys-libs/slang</i>
376     </pre>
377    
378     <p>
379     We also need to rebuild packages that link to these, now the USE changes have
380 bennyc 1.11 been applied. The tool we use (<c>revdep-rebuild</c>) is part of the
381     <c>gentoolkit</c> package.
382 neysx 1.1 </p>
383    
384     <pre caption="Rebuilding of programs that link to ncurses or slang">
385     # <i>revdep-rebuild --soname libncurses.so.5</i>
386     # <i>revdep-rebuild --soname libslang.so.1</i>
387     </pre>
388    
389     </body>
390     </section>
391     <section>
392     <title>KDE, GNOME and Xfce</title>
393     <body>
394    
395     <p>
396     All of the major desktop environments have full Unicode support, and will
397     require no further setup than what has already been covered in this guide. This
398     is because the underlying graphical toolkits (Qt or GTK+2) are UTF-8 aware.
399     Subsequently, all applications running on top of these toolkits should be
400     UTF-8-aware out of the box.
401     </p>
402    
403     <p>
404     The exceptions to this rule come in Xlib and GTK+1. GTK+1 requires a
405     iso-10646-1 FontSpec in the ~/.gtkrc, for example
406     <c>-misc-fixed-*-*-*-*-*-*-*-*-*-*-iso10646-1</c>. Also, applications using
407     Xlib or Xaw will need to be given a similar FontSpec, otherwise they will not
408     work.
409     </p>
410    
411     <note>
412     If you have a version of the gnome1 control center around, use that instead.
413     Pick any iso10646-1 font from there.
414     </note>
415    
416     <pre caption="Example ~/.gtkrc (for GTK+1) that defines a Unicode compatible font">
417     style "user-font"
418     {
419     fontset="-misc-fixed-*-*-*-*-*-*-*-*-*-*-iso10646-1"
420     }
421     widget_class "*" style "user-font"
422     </pre>
423    
424     <p>
425     If an application has support for both a Qt and GTK+2 GUI, the GTK+2 GUI will
426     generally give better results with Unicode.
427     </p>
428    
429     </body>
430     </section>
431     <section>
432     <title>X11 and Fonts</title>
433     <body>
434    
435 bennyc 1.11 <impo>
436     <c>x11-base/xorg-x11</c> has far better support for Unicode than XFree86
437     and is <e>highly</e> recommended.
438     </impo>
439    
440 neysx 1.1 <p>
441     TrueType fonts have support for Unicode, and most of the fonts that ship with
442     Xorg have impressive character support, although, obviously, not every single
443     glyph available in Unicode has been created for that font. To build fonts
444     (including the Bitstream Vera set) with support for East Asian letters with X,
445     make sure you have the <c>cjk</c> USE flag set. Many other applications utilise
446     this flag, so it may be worthwhile to add it as a permanent USE flag.
447     </p>
448    
449     <p>
450     Also, several font packages in Portage are Unicode aware.
451     </p>
452    
453     <pre caption="Optional: Install some more Unicode-aware fonts">
454     # <i>emerge terminus-font intlfonts freefonts cronyx-fonts corefonts</i>
455     </pre>
456    
457     </body>
458     </section>
459     <section>
460     <title>Window Managers and Terminal Emulators</title>
461     <body>
462    
463     <p>
464 bennyc 1.11 Window managers not built on GTK or Qt generally have very good Unicode
465     support, as they often use the Xft library for handling fonts. If your window
466     manager does not use Xft for fonts, you can still use the FontSpec mentioned in
467     the previous section as a Unicode font.
468 neysx 1.1 </p>
469    
470     <p>
471     Terminal emulators that use Xft and support Unicode are harder to come by.
472     Aside from Konsole and gnome-terminal, the best options in Portage are
473     <c>x11-terms/rxvt-unicode</c>, <c>xfce-extra/terminal</c>,
474 cam 1.5 <c>gnustep-apps/terminal</c>, <c>x11-terms/mlterm</c>, <c>x11-terms/mrxvt</c> or
475 neysx 1.1 plain <c>x11-terms/xterm</c> when built with the <c>unicode</c> USE flag and
476     invoked as <c>uxterm</c>. <c>app-misc/screen</c> supports UTF-8 too, when
477 bennyc 1.11 invoked as <c>screen -u</c> or the following is put into the
478 neysx 1.1 <path>~/.screenrc</path>:
479     </p>
480    
481     <pre caption="~/.screenrc for UTF-8">
482     defutf8 on
483     </pre>
484    
485     </body>
486     </section>
487     <section>
488     <title>Vim, Emacs, Xemacs and Nano</title>
489     <body>
490    
491     <p>
492     Vim, Emacs and Xemacs provide full UTF-8 support, and also have builtin
493     detection of UTF-8 files. For further information in Vim, use <c>:help
494     mbyte.txt</c>.
495     </p>
496    
497     <p>
498     Nano currently does not provide support for UTF-8, although it has been planned
499     for a long time. With luck, this will change in future. At the time of writing,
500     UTF-8 support is in Nano's CVS, and should be included in the next release.
501     </p>
502    
503     </body>
504     </section>
505     <section>
506     <title>Shells</title>
507     <body>
508    
509     <p>
510     Currently, <c>bash</c> provides full Unicode support through the GNU readline
511     library. Z Shell users are in a somewhat worse position -- no parts of the
512     shell have Unicode support, although there is a concerted effort to add
513     multibyte character set support underway at the moment.
514     </p>
515    
516     <p>
517     The C shell, <c>tcsh</c> and <c>ksh</c> do not provide UTF-8 support at all.
518     </p>
519    
520     </body>
521     </section>
522     <section>
523     <title>Irssi</title>
524     <body>
525    
526     <p>
527 cam 1.5 Since 0.8.10, Irssi has complete UTF-8 support, although it does require a user
528     to set an option.
529 neysx 1.1 </p>
530    
531     <pre caption="Enabling UTF-8 in Irssi">
532     /set term_charset UTF-8
533     </pre>
534    
535     <p>
536     For channels where non-ASCII characters are often exchanged in non-UTF-8
537     charsets, the <c>/recode</c> command may be used to convert the characters.
538     Type <c>/help recode</c> for more information.
539     </p>
540    
541     </body>
542     </section>
543     <section>
544     <title>Mutt</title>
545     <body>
546    
547     <p>
548     The Mutt mail user agent has very good Unicode support. To use UTF-8 with Mutt,
549     put the following in your <path>~/.muttrc</path>:
550     </p>
551    
552     <pre caption="~/.muttrc for UTF-8">
553     set send_charset="utf8" <comment>(outgoing character set)</comment>
554     set charset="utf8" <comment>(display character set)</comment>
555     </pre>
556    
557     <note>
558     You may still see '?' in mail you read with Mutt. This is a result of people
559 bennyc 1.11 using a mail client which does not indicate the used charset. You can't do much
560     about this than to ask them to configure their client correctly.
561 neysx 1.1 </note>
562    
563     <p>
564     Further information is available from the <uri
565     link="http://wiki.mutt.org/index.cgi?MuttFaq/Charset"> Mutt WikiWiki</uri>.
566     </p>
567    
568     </body>
569     </section>
570     <section>
571     <title>Testing it all out</title>
572     <body>
573    
574     <p>
575     There are numerous UTF-8 test websites around. <c>net-www/w3m</c>,
576     <c>net-www/links</c>, <c>net-www/elinks</c>, <c>net-www/lynx</c> and all
577 cam 1.3 Mozilla based browsers (including Firefox) support UTF-8. Konqueror and Opera
578     have full UTF-8 support too.
579 neysx 1.1 </p>
580    
581     <p>
582     When using one of the text-only web browsers, make absolutely sure you are
583     using a Unicode-aware terminal.
584     </p>
585    
586     <p>
587     If you see certain characters displayed as boxes with letters or numbers
588     inside, this means that your font does not have a character for the symbol or
589     glyph that the UTF-8 wants. Instead, it displays a box with the hex code of the
590     UTF-8 symbol.
591     </p>
592    
593     <ul>
594     <li>
595     <uri link="http://www.w3.org/2001/06/utf-8-test/UTF-8-demo.html">A W3C
596     UTF-8 Test Page</uri>
597     </li>
598     <li>
599     <uri link="http://titus.uni-frankfurt.de/indexe.htm?/unicode/unitest.htm">
600     A UTF-8 test page provided by the University of Frankfurt</uri>
601     </li>
602     </ul>
603    
604     </body>
605     </section>
606     <section>
607     <title>Input Methods</title>
608     <body>
609    
610     <p>
611     <e>Dead keys</e> may be used to input characters in X that are not included on
612     your keyboard. These work by pressing your right Alt key (or in some countries,
613     AltGr) and an optional key from the non-alphabetical section of the keyboard to
614     the left of the return key at once, releasing them, and then pressing a letter.
615     The dead key should modify it. Input can be further modified by using the Shift
616     key at the same time as pressing the AltGr and modifier.
617     </p>
618    
619     <p>
620     To enable dead keys in X, you need a layout that supports it. Most European
621     layouts already have dead keys with the default variant. However, this is not
622     true of North American layouts. Although there is a degree of inconsistency
623     between layouts, the easiest solution seems to be to use a layout in the form
624     "en_US" rather than "us", for example. The layout is set in
625     <path>/etc/X11/xorg.conf</path> like so:
626     </p>
627    
628     <pre caption="/etc/X11/xorg.conf snippet">
629     Section "InputDevice"
630     Identifier "Keyboard0"
631     Driver "kbd"
632     Option "XkbLayout" "en_US" <comment># Rather than just "us"</comment>
633     <comment>(Other Xkb options here)</comment>
634     EndSection
635     </pre>
636    
637     <note>
638     The preceding change only needs to be applied if you are using a North American
639     layout, or another layout where dead keys do not seem to be working. European
640     users should have working dead keys as is.
641     </note>
642    
643     <p>
644 bennyc 1.11 This change will come into effect when your X server is restarted. To apply the
645 neysx 1.1 change now, use the <c>setxkbmap</c> tool, for example, <c>setxkbmap en_US</c>.
646     </p>
647    
648     <p>
649     It is probably easiest to describe dead keys with examples. Although the
650 bennyc 1.11 results are locale dependent, the concepts should remain the same regardless of
651 neysx 1.1 locale. The examples contain UTF-8, so to view them you need to either tell
652     your browser to view the page as UTF-8, or have a UTF-8 locale already
653     configured.
654     </p>
655    
656     <p>
657     When I press AltGr and [ at once, release them, and then press a, 'ä' is
658 bennyc 1.11 produced. When I press AltGr and [ at once, and then press e, 'ë' is produced.
659     When I press AltGr and ; at once, 'á' is produced, and when I press AltGr and ;
660     at once, release them, and then press e, 'é' is produced.
661 neysx 1.1 </p>
662    
663     <p>
664     By pressing AltGr, Shift and [ at once, releasing them, and then pressing a, a
665     Scandinavian 'å' is produced. Similarly, when I press AltGr, Shift and [ at
666     once, release <e>only</e> the [, and then press it again, '˚' is produced.
667     Although it looks like one, this (U+02DA) is not the same as a degree symbol
668     (U+00B0). This works for other accents produced by dead keys — AltGr and [,
669     releasing only the [, then pressing it again makes '¨'.
670     </p>
671    
672     <p>
673     AltGr can be used with alphabetical keys alone. For example, AltGr and m, a
674 bennyc 1.11 Greek lower-case letter mu is produced: 'µ'.
675 neysx 1.1 </p>
676    
677     </body>
678     </section>
679     <section>
680     <title>Resources</title>
681     <body>
682    
683     <ul>
684     <li>
685     <uri link="http://www.wikipedia.com/wiki/Unicode">The Wikipedia entry for
686     Unicode</uri>
687     </li>
688     <li>
689     <uri link="http://www.wikipedia.com/wiki/UTF-8">The Wikipedia entry for
690     UTF-8</uri>
691     </li>
692     <li><uri link="http://www.unicode.org">Unicode.org</uri></li>
693     <li><uri link="http://www.utf-8.com">UTF-8.com</uri></li>
694     <li><uri link="http://www.ietf.org/rfc/rfc3629.txt">RFC 3629</uri></li>
695     <li><uri link="http://www.ietf.org/rfc/rfc2277.txt">RFC 2277</uri></li>
696 bennyc 1.11 <li>
697     <uri
698     link="http://www.tbray.org/ongoing/When/200x/2003/04/26/UTF">Characters vs.
699     Bytes</uri>
700     </li>
701 neysx 1.1 </ul>
702    
703     </body>
704     </section>
705     </chapter>
706     </guide>

  ViewVC Help
Powered by ViewVC 1.1.20