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[Emacs-diffs] Changes to mule.texi
|
From: |
Glenn Morris |
|
Subject: |
[Emacs-diffs] Changes to mule.texi |
|
Date: |
Thu, 06 Sep 2007 04:39:00 +0000 |
CVSROOT: /sources/emacs
Module name: emacs
Changes by: Glenn Morris <gm> 07/09/06 04:39:00
Index: mule.texi
===================================================================
RCS file: mule.texi
diff -N mule.texi
--- mule.texi 11 Apr 2007 20:57:52 -0000 1.105
+++ /dev/null 1 Jan 1970 00:00:00 -0000
@@ -1,1535 +0,0 @@
address@hidden This is part of the Emacs manual.
address@hidden Copyright (C) 1997, 1999, 2000, 2001, 2002, 2003, 2004,
address@hidden 2005, 2006, 2007 Free Software Foundation, Inc.
address@hidden See file emacs.texi for copying conditions.
address@hidden International, Major Modes, Frames, Top
address@hidden International Character Set Support
address@hidden MULE
address@hidden international scripts
address@hidden multibyte characters
address@hidden encoding of characters
-
address@hidden Celtic
address@hidden Chinese
address@hidden Cyrillic
address@hidden Czech
address@hidden Devanagari
address@hidden Hindi
address@hidden Marathi
address@hidden Ethiopic
address@hidden German
address@hidden Greek
address@hidden Hebrew
address@hidden IPA
address@hidden Japanese
address@hidden Korean
address@hidden Lao
address@hidden Latin
address@hidden Polish
address@hidden Romanian
address@hidden Slovak
address@hidden Slovenian
address@hidden Thai
address@hidden Tibetan
address@hidden Turkish
address@hidden Vietnamese
address@hidden Dutch
address@hidden Spanish
- Emacs supports a wide variety of international character sets,
-including European and Vietnamese variants of the Latin alphabet, as
-well as Cyrillic, Devanagari (for Hindi and Marathi), Ethiopic, Greek,
-Han (for Chinese and Japanese), Hangul (for Korean), Hebrew, IPA,
-Kannada, Lao, Malayalam, Tamil, Thai, Tibetan, and Vietnamese scripts.
-Emacs also supports various encodings of these characters used by
-other internationalized software, such as word processors and mailers.
-
- Emacs allows editing text with international characters by supporting
-all the related activities:
-
address@hidden @bullet
address@hidden
-You can visit files with address@hidden characters, save address@hidden text,
and
-pass address@hidden text between Emacs and programs it invokes (such as
-compilers, spell-checkers, and mailers). Setting your language
-environment (@pxref{Language Environments}) takes care of setting up the
-coding systems and other options for a specific language or culture.
-Alternatively, you can specify how Emacs should encode or decode text
-for each command; see @ref{Text Coding}.
-
address@hidden
-You can display address@hidden characters encoded by the various
-scripts. This works by using appropriate fonts on graphics displays
-(@pxref{Defining Fontsets}), and by sending special codes to text-only
-displays (@pxref{Terminal Coding}). If some characters are displayed
-incorrectly, refer to @ref{Undisplayable Characters}, which describes
-possible problems and explains how to solve them.
-
address@hidden
-You can insert address@hidden characters or search for them. To do that,
-you can specify an input method (@pxref{Select Input Method}) suitable
-for your language, or use the default input method set up when you set
-your language environment. If
-your keyboard can produce address@hidden characters, you can select an
-appropriate keyboard coding system (@pxref{Terminal Coding}), and Emacs
-will accept those characters. Latin-1 characters can also be input by
-using the @kbd{C-x 8} prefix, see @ref{Unibyte Mode}.
-
-On X Window systems, your locale should be set to an appropriate value
-to make sure Emacs interprets keyboard input correctly; see
address@hidden Environments, locales}.
address@hidden itemize
-
- The rest of this chapter describes these issues in detail.
-
address@hidden
-* International Chars:: Basic concepts of multibyte characters.
-* Enabling Multibyte:: Controlling whether to use multibyte characters.
-* Language Environments:: Setting things up for the language you use.
-* Input Methods:: Entering text characters not on your keyboard.
-* Select Input Method:: Specifying your choice of input methods.
-* Multibyte Conversion:: How single-byte characters convert to multibyte.
-* Coding Systems:: Character set conversion when you read and
- write files, and so on.
-* Recognize Coding:: How Emacs figures out which conversion to use.
-* Specify Coding:: Specifying a file's coding system explicitly.
-* Output Coding:: Choosing coding systems for output.
-* Text Coding:: Choosing conversion to use for file text.
-* Communication Coding:: Coding systems for interprocess communication.
-* File Name Coding:: Coding systems for file @emph{names}.
-* Terminal Coding:: Specifying coding systems for converting
- terminal input and output.
-* Fontsets:: Fontsets are collections of fonts
- that cover the whole spectrum of characters.
-* Defining Fontsets:: Defining a new fontset.
-* Undisplayable Characters:: When characters don't display.
-* Unibyte Mode:: You can pick one European character set
- to use without multibyte characters.
-* Charsets:: How Emacs groups its internal character codes.
address@hidden menu
-
address@hidden International Chars
address@hidden Introduction to International Character Sets
-
- The users of international character sets and scripts have
-established many more-or-less standard coding systems for storing
-files. Emacs internally uses a single multibyte character encoding,
-so that it can intermix characters from all these scripts in a single
-buffer or string. This encoding represents each address@hidden
-character as a sequence of bytes in the range 0200 through 0377.
-Emacs translates between the multibyte character encoding and various
-other coding systems when reading and writing files, when exchanging
-data with subprocesses, and (in some cases) in the @kbd{C-q} command
-(@pxref{Multibyte Conversion}).
-
address@hidden C-h h
address@hidden view-hello-file
address@hidden undisplayable characters
address@hidden @samp{?} in display
- The command @kbd{C-h h} (@code{view-hello-file}) displays the file
address@hidden/HELLO}, which shows how to say ``hello'' in many languages.
-This illustrates various scripts. If some characters can't be
-displayed on your terminal, they appear as @samp{?} or as hollow boxes
-(@pxref{Undisplayable Characters}).
-
- Keyboards, even in the countries where these character sets are used,
-generally don't have keys for all the characters in them. So Emacs
-supports various @dfn{input methods}, typically one for each script or
-language, to make it convenient to type them.
-
address@hidden C-x RET
- The prefix key @kbd{C-x @key{RET}} is used for commands that pertain
-to multibyte characters, coding systems, and input methods.
-
address@hidden Enabling Multibyte
address@hidden Enabling Multibyte Characters
-
- By default, Emacs starts in multibyte mode, because that allows you to
-use all the supported languages and scripts without limitations.
-
address@hidden turn multibyte support on or off
- You can enable or disable multibyte character support, either for
-Emacs as a whole, or for a single buffer. When multibyte characters
-are disabled in a buffer, we call that @dfn{unibyte mode}. Then each
-byte in that buffer represents a character, even codes 0200 through
-0377.
-
- The old features for supporting the European character sets, ISO
-Latin-1 and ISO Latin-2, work in unibyte mode as they did in Emacs 19
-and also work for the other ISO 8859 character sets. However, there
-is no need to turn off multibyte character support to use ISO Latin;
-the Emacs multibyte character set includes all the characters in these
-character sets, and Emacs can translate automatically to and from the
-ISO codes.
-
- To edit a particular file in unibyte representation, visit it using
address@hidden @xref{Visiting}. To convert a buffer in
-multibyte representation into a single-byte representation of the same
-characters, the easiest way is to save the contents in a file, kill the
-buffer, and find the file again with @code{find-file-literally}. You
-can also use @kbd{C-x @key{RET} c}
-(@code{universal-coding-system-argument}) and specify @samp{raw-text} as
-the coding system with which to find or save a file. @xref{Text
-Coding}. Finding a file as @samp{raw-text} doesn't disable format
-conversion, uncompression and auto mode selection as
address@hidden does.
-
address@hidden enable-multibyte-characters
address@hidden default-enable-multibyte-characters
- To turn off multibyte character support by default, start Emacs with
-the @samp{--unibyte} option (@pxref{Initial Options}), or set the
-environment variable @env{EMACS_UNIBYTE}. You can also customize
address@hidden or, equivalently, directly set the
-variable @code{default-enable-multibyte-characters} to @code{nil} in
-your init file to have basically the same effect as @samp{--unibyte}.
-
address@hidden toggle-enable-multibyte-characters
- To convert a unibyte session to a multibyte session, set
address@hidden to @code{t}. Buffers which
-were created in the unibyte session before you turn on multibyte support
-will stay unibyte. You can turn on multibyte support in a specific
-buffer by invoking the command @code{toggle-enable-multibyte-characters}
-in that buffer.
-
address@hidden Lisp files, and multibyte operation
address@hidden multibyte operation, and Lisp files
address@hidden unibyte operation, and Lisp files
address@hidden init file, and address@hidden characters
address@hidden environment variables, and address@hidden characters
- With @samp{--unibyte}, multibyte strings are not created during
-initialization from the values of environment variables,
address@hidden/etc/passwd} entries etc.@: that contain address@hidden 8-bit
-characters.
-
- Emacs normally loads Lisp files as multibyte, regardless of whether
-you used @samp{--unibyte}. This includes the Emacs initialization file,
address@hidden, and the initialization files of Emacs packages such as
-Gnus. However, you can specify unibyte loading for a particular Lisp
-file, by putting @address@hidden: t;-*-}} in a comment on the first
-line (@pxref{File Variables}). Then that file is always loaded as
-unibyte text, even if you did not start Emacs with @samp{--unibyte}.
-The motivation for these conventions is that it is more reliable to
-always load any particular Lisp file in the same way. However, you can
-load a Lisp file as unibyte, on any one occasion, by typing @kbd{C-x
address@hidden c raw-text @key{RET}} immediately before loading it.
-
- The mode line indicates whether multibyte character support is
-enabled in the current buffer. If it is, there are two or more
-characters (most often two dashes) near the beginning of the mode
-line, before the indication of the visited file's end-of-line
-convention (colon, backslash, etc.). When multibyte characters
-are not enabled, nothing precedes the colon except a single dash.
address@hidden Line}, for more details about this.
-
address@hidden Language Environments
address@hidden Language Environments
address@hidden language environments
-
- All supported character sets are supported in Emacs buffers whenever
-multibyte characters are enabled; there is no need to select a
-particular language in order to display its characters in an Emacs
-buffer. However, it is important to select a @dfn{language environment}
-in order to set various defaults. The language environment really
-represents a choice of preferred script (more or less) rather than a
-choice of language.
-
- The language environment controls which coding systems to recognize
-when reading text (@pxref{Recognize Coding}). This applies to files,
-incoming mail, netnews, and any other text you read into Emacs. It may
-also specify the default coding system to use when you create a file.
-Each language environment also specifies a default input method.
-
address@hidden set-language-environment
address@hidden current-language-environment
- To select a language environment, you can customize the variable
address@hidden or use the command @kbd{M-x
-set-language-environment}. It makes no difference which buffer is
-current when you use this command, because the effects apply globally to
-the Emacs session. The supported language environments include:
-
address@hidden Euro sign
address@hidden UTF-8
address@hidden
-ASCII, Belarusian, Brazilian Portuguese, Bulgarian, Chinese-BIG5,
-Chinese-CNS, Chinese-EUC-TW, Chinese-GB, Croatian, Cyrillic-ALT,
-Cyrillic-ISO, Cyrillic-KOI8, Czech, Devanagari, Dutch, English,
-Esperanto, Ethiopic, French, Georgian, German, Greek, Hebrew, IPA,
-Italian, Japanese, Kannada, Korean, Lao, Latin-1, Latin-2, Latin-3,
-Latin-4, Latin-5, Latin-6, Latin-7, Latin-8 (Celtic), Latin-9 (updated
-Latin-1 with the Euro sign), Latvian, Lithuanian, Malayalam, Polish,
-Romanian, Russian, Slovak, Slovenian, Spanish, Swedish, Tajik, Tamil,
-Thai, Tibetan, Turkish, UTF-8 (for a setup which prefers Unicode
-characters and files encoded in UTF-8), Ukrainian, Vietnamese, Welsh,
-and Windows-1255 (for a setup which prefers Cyrillic characters and
-files encoded in Windows-1255).
address@hidden
-\hbadness=10000\par % just avoid underfull hbox warning
address@hidden tex
address@hidden quotation
-
address@hidden fonts for various scripts
address@hidden Intlfonts package, installation
- To display the script(s) used by your language environment on a
-graphical display, you need to have a suitable font. If some of the
-characters appear as empty boxes, you should install the GNU Intlfonts
-package, which includes fonts for most supported address@hidden
-you run Emacs on X, you need to inform the X server about the location
-of the newly installed fonts with the following commands:
-
address@hidden
- xset fp+ /usr/local/share/emacs/fonts
- xset fp rehash
address@hidden example
-}
address@hidden, for more details about setting up your fonts.
-
address@hidden set-locale-environment
address@hidden locale-language-names
address@hidden locale-charset-language-names
address@hidden locales
- Some operating systems let you specify the character-set locale you
-are using by setting the locale environment variables @env{LC_ALL},
address@hidden, or @address@hidden more than one of these is
-set, the first one that is nonempty specifies your locale for this
-purpose.} During startup, Emacs looks up your character-set locale's
-name in the system locale alias table, matches its canonical name
-against entries in the value of the variables
address@hidden and @code{locale-language-names},
-and selects the corresponding language environment if a match is found.
-(The former variable overrides the latter.) It also adjusts the display
-table and terminal coding system, the locale coding system, the
-preferred coding system as needed for the locale, and---last but not
-least---the way Emacs decodes address@hidden characters sent by your keyboard.
-
- If you modify the @env{LC_ALL}, @env{LC_CTYPE}, or @env{LANG}
-environment variables while running Emacs, you may want to invoke the
address@hidden function afterwards to readjust the
-language environment from the new locale.
-
address@hidden locale-preferred-coding-systems
- The @code{set-locale-environment} function normally uses the preferred
-coding system established by the language environment to decode system
-messages. But if your locale matches an entry in the variable
address@hidden, Emacs uses the corresponding
-coding system instead. For example, if the locale @samp{ja_JP.PCK}
-matches @code{japanese-shift-jis} in
address@hidden, Emacs uses that encoding even
-though it might normally use @code{japanese-iso-8bit}.
-
- You can override the language environment chosen at startup with
-explicit use of the command @code{set-language-environment}, or with
-customization of @code{current-language-environment} in your init
-file.
-
address@hidden C-h L
address@hidden describe-language-environment
- To display information about the effects of a certain language
-environment @var{lang-env}, use the command @kbd{C-h L @var{lang-env}
address@hidden (@code{describe-language-environment}). This tells you
-which languages this language environment is useful for, and lists the
-character sets, coding systems, and input methods that go with it. It
-also shows some sample text to illustrate scripts used in this
-language environment. If you give an empty input for @var{lang-env},
-this command describes the chosen language environment.
-
address@hidden set-language-environment-hook
- You can customize any language environment with the normal hook
address@hidden The command
address@hidden runs that hook after setting up the new
-language environment. The hook functions can test for a specific
-language environment by checking the variable
address@hidden This hook is where you should
-put non-default settings for specific language environment, such as
-coding systems for keyboard input and terminal output, the default
-input method, etc.
-
address@hidden exit-language-environment-hook
- Before it starts to set up the new language environment,
address@hidden first runs the hook
address@hidden This hook is useful for undoing
-customizations that were made with @code{set-language-environment-hook}.
-For instance, if you set up a special key binding in a specific language
-environment using @code{set-language-environment-hook}, you should set
-up @code{exit-language-environment-hook} to restore the normal binding
-for that key.
-
address@hidden Input Methods
address@hidden Input Methods
-
address@hidden input methods
- An @dfn{input method} is a kind of character conversion designed
-specifically for interactive input. In Emacs, typically each language
-has its own input method; sometimes several languages which use the same
-characters can share one input method. A few languages support several
-input methods.
-
- The simplest kind of input method works by mapping @acronym{ASCII} letters
-into another alphabet; this allows you to use one other alphabet
-instead of @acronym{ASCII}. The Greek and Russian input methods
-work this way.
-
- A more powerful technique is composition: converting sequences of
-characters into one letter. Many European input methods use composition
-to produce a single address@hidden letter from a sequence that consists of a
-letter followed by accent characters (or vice versa). For example, some
-methods convert the sequence @kbd{a'} into a single accented letter.
-These input methods have no special commands of their own; all they do
-is compose sequences of printing characters.
-
- The input methods for syllabic scripts typically use mapping followed
-by composition. The input methods for Thai and Korean work this way.
-First, letters are mapped into symbols for particular sounds or tone
-marks; then, sequences of these which make up a whole syllable are
-mapped into one syllable sign.
-
- Chinese and Japanese require more complex methods. In Chinese input
-methods, first you enter the phonetic spelling of a Chinese word (in
-input method @code{chinese-py}, among others), or a sequence of
-portions of the character (input methods @code{chinese-4corner} and
address@hidden, and others). One input sequence typically
-corresponds to many possible Chinese characters. You select the one
-you mean using keys such as @kbd{C-f}, @kbd{C-b}, @kbd{C-n},
address@hidden, and digits, which have special meanings in this situation.
-
- The possible characters are conceptually arranged in several rows,
-with each row holding up to 10 alternatives. Normally, Emacs displays
-just one row at a time, in the echo area; @code{(@var{i}/@var{j})}
-appears at the beginning, to indicate that this is the @var{i}th row
-out of a total of @var{j} rows. Type @kbd{C-n} or @kbd{C-p} to
-display the next row or the previous row.
-
- Type @kbd{C-f} and @kbd{C-b} to move forward and backward among
-the alternatives in the current row. As you do this, Emacs highlights
-the current alternative with a special color; type @address@hidden
-to select the current alternative and use it as input. The
-alternatives in the row are also numbered; the number appears before
-the alternative. Typing a digit @var{n} selects the @var{n}th
-alternative of the current row and uses it as input.
-
- @key{TAB} in these Chinese input methods displays a buffer showing
-all the possible characters at once; then clicking @kbd{Mouse-2} on
-one of them selects that alternative. The keys @kbd{C-f}, @kbd{C-b},
address@hidden, @kbd{C-p}, and digits continue to work as usual, but they
-do the highlighting in the buffer showing the possible characters,
-rather than in the echo area.
-
- In Japanese input methods, first you input a whole word using
-phonetic spelling; then, after the word is in the buffer, Emacs
-converts it into one or more characters using a large dictionary. One
-phonetic spelling corresponds to a number of different Japanese words;
-to select one of them, use @kbd{C-n} and @kbd{C-p} to cycle through
-the alternatives.
-
- Sometimes it is useful to cut off input method processing so that the
-characters you have just entered will not combine with subsequent
-characters. For example, in input method @code{latin-1-postfix}, the
-sequence @kbd{e '} combines to form an @samp{e} with an accent. What if
-you want to enter them as separate characters?
-
- One way is to type the accent twice; this is a special feature for
-entering the separate letter and accent. For example, @kbd{e ' '} gives
-you the two characters @samp{e'}. Another way is to type another letter
-after the @kbd{e}---something that won't combine with that---and
-immediately delete it. For example, you could type @kbd{e e @key{DEL}
-'} to get separate @samp{e} and @samp{'}.
-
- Another method, more general but not quite as easy to type, is to use
address@hidden C-\} between two characters to stop them from combining. This
-is the command @kbd{C-\} (@code{toggle-input-method}) used twice.
address@hidden
address@hidden Input Method}.
address@hidden ifnottex
-
address@hidden incremental search, input method interference
- @kbd{C-\ C-\} is especially useful inside an incremental search,
-because it stops waiting for more characters to combine, and starts
-searching for what you have already entered.
-
- To find out how to input the character after point using the current
-input method, type @kbd{C-u C-x =}. @xref{Position Info}.
-
address@hidden input-method-verbose-flag
address@hidden input-method-highlight-flag
- The variables @code{input-method-highlight-flag} and
address@hidden control how input methods explain
-what is happening. If @code{input-method-highlight-flag} is
address@hidden, the partial sequence is highlighted in the buffer (for
-most input methods---some disable this feature). If
address@hidden is address@hidden, the list of
-possible characters to type next is displayed in the echo area (but
-not when you are in the minibuffer).
-
address@hidden Select Input Method
address@hidden Selecting an Input Method
-
address@hidden @kbd
address@hidden C-\
-Enable or disable use of the selected input method.
-
address@hidden C-x @key{RET} C-\ @var{method} @key{RET}
-Select a new input method for the current buffer.
-
address@hidden C-h I @var{method} @key{RET}
address@hidden C-h C-\ @var{method} @key{RET}
address@hidden describe-input-method
address@hidden C-h I
address@hidden C-h C-\
-Describe the input method @var{method} (@code{describe-input-method}).
-By default, it describes the current input method (if any). This
-description should give you the full details of how to use any
-particular input method.
-
address@hidden M-x list-input-methods
-Display a list of all the supported input methods.
address@hidden table
-
address@hidden set-input-method
address@hidden current-input-method
address@hidden C-x RET C-\
- To choose an input method for the current buffer, use @kbd{C-x
address@hidden C-\} (@code{set-input-method}). This command reads the
-input method name from the minibuffer; the name normally starts with the
-language environment that it is meant to be used with. The variable
address@hidden records which input method is selected.
-
address@hidden toggle-input-method
address@hidden C-\
- Input methods use various sequences of @acronym{ASCII} characters to
-stand for address@hidden characters. Sometimes it is useful to
-turn off the input method temporarily. To do this, type @kbd{C-\}
-(@code{toggle-input-method}). To reenable the input method, type
address@hidden again.
-
- If you type @kbd{C-\} and you have not yet selected an input method,
-it prompts for you to specify one. This has the same effect as using
address@hidden @key{RET} C-\} to specify an input method.
-
- When invoked with a numeric argument, as in @kbd{C-u C-\},
address@hidden always prompts you for an input method,
-suggesting the most recently selected one as the default.
-
address@hidden default-input-method
- Selecting a language environment specifies a default input method for
-use in various buffers. When you have a default input method, you can
-select it in the current buffer by typing @kbd{C-\}. The variable
address@hidden specifies the default input method
-(@code{nil} means there is none).
-
- In some language environments, which support several different input
-methods, you might want to use an input method different from the
-default chosen by @code{set-language-environment}. You can instruct
-Emacs to select a different default input method for a certain
-language environment, if you wish, by using
address@hidden (@pxref{Language Environments,
-set-language-environment-hook}). For example:
-
address@hidden
-(defun my-chinese-setup ()
- "Set up my private Chinese environment."
- (if (equal current-language-environment "Chinese-GB")
- (setq default-input-method "chinese-tonepy")))
-(add-hook 'set-language-environment-hook 'my-chinese-setup)
address@hidden lisp
-
address@hidden
-This sets the default input method to be @code{chinese-tonepy}
-whenever you choose a Chinese-GB language environment.
-
address@hidden quail-set-keyboard-layout
- Some input methods for alphabetic scripts work by (in effect)
-remapping the keyboard to emulate various keyboard layouts commonly used
-for those scripts. How to do this remapping properly depends on your
-actual keyboard layout. To specify which layout your keyboard has, use
-the command @kbd{M-x quail-set-keyboard-layout}.
-
address@hidden quail-show-key
- You can use the command @kbd{M-x quail-show-key} to show what key (or
-key sequence) to type in order to input the character following point,
-using the selected keyboard layout. The command @kbd{C-u C-x =} also
-shows that information in addition to the other information about the
-character.
-
address@hidden list-input-methods
- To see a list of all the supported input methods, type @kbd{M-x
-list-input-methods}. The list gives information about each input
-method, including the string that stands for it in the mode line.
-
address@hidden Multibyte Conversion
address@hidden Unibyte and Multibyte address@hidden characters
-
- When multibyte characters are enabled, character codes 0240 (octal)
-through 0377 (octal) are not really legitimate in the buffer. The valid
address@hidden printing characters have codes that start from 0400.
-
- If you type a self-inserting character in the range 0240 through
-0377, or if you use @kbd{C-q} to insert one, Emacs assumes you
-intended to use one of the ISO address@hidden character sets, and
-converts it to the Emacs code representing that address@hidden
-character. You select @emph{which} ISO Latin character set to use
-through your choice of language environment
address@hidden
-(see above).
address@hidden iftex
address@hidden
-(@pxref{Language Environments}).
address@hidden ifnottex
-If you do not specify a choice, the default is Latin-1.
-
- If you insert a character in the range 0200 through 0237, which
-forms the @code{eight-bit-control} character set, it is inserted
-literally. You should normally avoid doing this since buffers
-containing such characters have to be written out in either the
address@hidden or @code{raw-text} coding system, which is usually
-not what you want.
-
address@hidden Coding Systems
address@hidden Coding Systems
address@hidden coding systems
-
- Users of various languages have established many more-or-less standard
-coding systems for representing them. Emacs does not use these coding
-systems internally; instead, it converts from various coding systems to
-its own system when reading data, and converts the internal coding
-system to other coding systems when writing data. Conversion is
-possible in reading or writing files, in sending or receiving from the
-terminal, and in exchanging data with subprocesses.
-
- Emacs assigns a name to each coding system. Most coding systems are
-used for one language, and the name of the coding system starts with the
-language name. Some coding systems are used for several languages;
-their names usually start with @samp{iso}. There are also special
-coding systems @code{no-conversion}, @code{raw-text} and
address@hidden which do not convert printing characters at all.
-
address@hidden international files from DOS/Windows systems
- A special class of coding systems, collectively known as
address@hidden, is designed to support text encoded by MS-Windows and
-MS-DOS software. The names of these coding systems are
address@hidden@var{nnnn}}, where @var{nnnn} is a 3- or 4-digit number of the
-codepage. You can use these encodings just like any other coding
-system; for example, to visit a file encoded in codepage 850, type
address@hidden @key{RET} c cp850 @key{RET} C-x C-f @var{filename}
address@hidden@footnote{
-In the MS-DOS port of Emacs, you need to create a @address@hidden
-coding system with @kbd{M-x codepage-setup}, before you can use it.
address@hidden
address@hidden and MULE,,,emacs-extra,Specialized Emacs Features}.
address@hidden iftex
address@hidden
address@hidden and MULE}.
address@hidden ifnottex
-}.
-
- In addition to converting various representations of address@hidden
-characters, a coding system can perform end-of-line conversion. Emacs
-handles three different conventions for how to separate lines in a file:
-newline, carriage-return linefeed, and just carriage-return.
-
address@hidden @kbd
address@hidden C-h C @var{coding} @key{RET}
-Describe coding system @var{coding}.
-
address@hidden C-h C @key{RET}
-Describe the coding systems currently in use.
-
address@hidden M-x list-coding-systems
-Display a list of all the supported coding systems.
address@hidden table
-
address@hidden C-h C
address@hidden describe-coding-system
- The command @kbd{C-h C} (@code{describe-coding-system}) displays
-information about particular coding systems, including the end-of-line
-conversion specified by those coding systems. You can specify a coding
-system name as the argument; alternatively, with an empty argument, it
-describes the coding systems currently selected for various purposes,
-both in the current buffer and as the defaults, and the priority list
-for recognizing coding systems (@pxref{Recognize Coding}).
-
address@hidden list-coding-systems
- To display a list of all the supported coding systems, type @kbd{M-x
-list-coding-systems}. The list gives information about each coding
-system, including the letter that stands for it in the mode line
-(@pxref{Mode Line}).
-
address@hidden end-of-line conversion
address@hidden line endings
address@hidden MS-DOS end-of-line conversion
address@hidden Macintosh end-of-line conversion
- Each of the coding systems that appear in this list---except for
address@hidden, which means no conversion of any kind---specifies
-how and whether to convert printing characters, but leaves the choice of
-end-of-line conversion to be decided based on the contents of each file.
-For example, if the file appears to use the sequence carriage-return
-linefeed to separate lines, DOS end-of-line conversion will be used.
-
- Each of the listed coding systems has three variants which specify
-exactly what to do for end-of-line conversion:
-
address@hidden @code
address@hidden @dots{}-unix
-Don't do any end-of-line conversion; assume the file uses
-newline to separate lines. (This is the convention normally used
-on Unix and GNU systems.)
-
address@hidden @dots{}-dos
-Assume the file uses carriage-return linefeed to separate lines, and do
-the appropriate conversion. (This is the convention normally used on
-Microsoft address@hidden is also specified for MIME @samp{text/*}
-bodies and in other network transport contexts. It is different
-from the SGML reference syntax record-start/record-end format which
-Emacs doesn't support directly.})
-
address@hidden @dots{}-mac
-Assume the file uses carriage-return to separate lines, and do the
-appropriate conversion. (This is the convention normally used on the
-Macintosh system.)
address@hidden table
-
- These variant coding systems are omitted from the
address@hidden display for brevity, since they are entirely
-predictable. For example, the coding system @code{iso-latin-1} has
-variants @code{iso-latin-1-unix}, @code{iso-latin-1-dos} and
address@hidden
-
address@hidden @code{undecided}, coding system
- The coding systems @code{unix}, @code{dos}, and @code{mac} are
-aliases for @code{undecided-unix}, @code{undecided-dos}, and
address@hidden, respectively. These coding systems specify only
-the end-of-line conversion, and leave the character code conversion to
-be deduced from the text itself.
-
- The coding system @code{raw-text} is good for a file which is mainly
address@hidden text, but may contain byte values above 127 which are
-not meant to encode address@hidden characters. With
address@hidden, Emacs copies those byte values unchanged, and sets
address@hidden to @code{nil} in the current buffer
-so that they will be interpreted properly. @code{raw-text} handles
-end-of-line conversion in the usual way, based on the data
-encountered, and has the usual three variants to specify the kind of
-end-of-line conversion to use.
-
- In contrast, the coding system @code{no-conversion} specifies no
-character code conversion at all---none for address@hidden byte values and
-none for end of line. This is useful for reading or writing binary
-files, tar files, and other files that must be examined verbatim. It,
-too, sets @code{enable-multibyte-characters} to @code{nil}.
-
- The easiest way to edit a file with no conversion of any kind is with
-the @kbd{M-x find-file-literally} command. This uses
address@hidden, and also suppresses other Emacs features that
-might convert the file contents before you see them. @xref{Visiting}.
-
- The coding system @code{emacs-mule} means that the file contains
address@hidden characters stored with the internal Emacs encoding. It
-handles end-of-line conversion based on the data encountered, and has
-the usual three variants to specify the kind of end-of-line conversion.
-
address@hidden unify-8859-on-decoding-mode
address@hidden Translation}
- The @dfn{character translation} feature can modify the effect of
-various coding systems, by changing the internal Emacs codes that
-decoding produces. For instance, the command
address@hidden enables a mode that ``unifies'' the
-Latin alphabets when decoding text. This works by converting all
address@hidden address@hidden characters to either Latin-1 or
-Unicode characters. This way it is easier to use various
address@hidden alphabets together. (In a future Emacs version we hope
-to move towards full Unicode support and complete unification of
-character sets.)
-
address@hidden enable-character-translation
- If you set the variable @code{enable-character-translation} to
address@hidden, that disables all character translation (including
address@hidden).
-
address@hidden Recognize Coding
address@hidden Recognizing Coding Systems
-
- Emacs tries to recognize which coding system to use for a given text
-as an integral part of reading that text. (This applies to files
-being read, output from subprocesses, text from X selections, etc.)
-Emacs can select the right coding system automatically most of the
-time---once you have specified your preferences.
-
- Some coding systems can be recognized or distinguished by which byte
-sequences appear in the data. However, there are coding systems that
-cannot be distinguished, not even potentially. For example, there is no
-way to distinguish between Latin-1 and Latin-2; they use the same byte
-values with different meanings.
-
- Emacs handles this situation by means of a priority list of coding
-systems. Whenever Emacs reads a file, if you do not specify the coding
-system to use, Emacs checks the data against each coding system,
-starting with the first in priority and working down the list, until it
-finds a coding system that fits the data. Then it converts the file
-contents assuming that they are represented in this coding system.
-
- The priority list of coding systems depends on the selected language
-environment (@pxref{Language Environments}). For example, if you use
-French, you probably want Emacs to prefer Latin-1 to Latin-2; if you use
-Czech, you probably want Latin-2 to be preferred. This is one of the
-reasons to specify a language environment.
-
address@hidden prefer-coding-system
- However, you can alter the coding system priority list in detail
-with the command @kbd{M-x prefer-coding-system}. This command reads
-the name of a coding system from the minibuffer, and adds it to the
-front of the priority list, so that it is preferred to all others. If
-you use this command several times, each use adds one element to the
-front of the priority list.
-
- If you use a coding system that specifies the end-of-line conversion
-type, such as @code{iso-8859-1-dos}, what this means is that Emacs
-should attempt to recognize @code{iso-8859-1} with priority, and should
-use DOS end-of-line conversion when it does recognize @code{iso-8859-1}.
-
address@hidden file-coding-system-alist
- Sometimes a file name indicates which coding system to use for the
-file. The variable @code{file-coding-system-alist} specifies this
-correspondence. There is a special function
address@hidden for adding elements to this list. For
-example, to read and write all @samp{.txt} files using the coding system
address@hidden, you can execute this Lisp expression:
-
address@hidden
-(modify-coding-system-alist 'file "\\.txt\\'" 'chinese-iso-8bit)
address@hidden smallexample
-
address@hidden
-The first argument should be @code{file}, the second argument should be
-a regular expression that determines which files this applies to, and
-the third argument says which coding system to use for these files.
-
address@hidden inhibit-eol-conversion
address@hidden DOS-style end-of-line display
- Emacs recognizes which kind of end-of-line conversion to use based on
-the contents of the file: if it sees only carriage-returns, or only
-carriage-return linefeed sequences, then it chooses the end-of-line
-conversion accordingly. You can inhibit the automatic use of
-end-of-line conversion by setting the variable @code{inhibit-eol-conversion}
-to address@hidden If you do that, DOS-style files will be displayed
-with the @samp{^M} characters visible in the buffer; some people
-prefer this to the more subtle @samp{(DOS)} end-of-line type
-indication near the left edge of the mode line (@pxref{Mode Line,
-eol-mnemonic}).
-
address@hidden inhibit-iso-escape-detection
address@hidden escape sequences in files
- By default, the automatic detection of coding system is sensitive to
-escape sequences. If Emacs sees a sequence of characters that begin
-with an escape character, and the sequence is valid as an ISO-2022
-code, that tells Emacs to use one of the ISO-2022 encodings to decode
-the file.
-
- However, there may be cases that you want to read escape sequences
-in a file as is. In such a case, you can set the variable
address@hidden to address@hidden Then the code
-detection ignores any escape sequences, and never uses an ISO-2022
-encoding. The result is that all escape sequences become visible in
-the buffer.
-
- The default value of @code{inhibit-iso-escape-detection} is
address@hidden We recommend that you not change it permanently, only for
-one specific operation. That's because many Emacs Lisp source files
-in the Emacs distribution contain address@hidden characters encoded in the
-coding system @code{iso-2022-7bit}, and they won't be
-decoded correctly when you visit those files if you suppress the
-escape sequence detection.
-
address@hidden auto-coding-alist
address@hidden auto-coding-regexp-alist
address@hidden auto-coding-functions
- The variables @code{auto-coding-alist},
address@hidden and @code{auto-coding-functions} are
-the strongest way to specify the coding system for certain patterns of
-file names, or for files containing certain patterns; these variables
-even override @samp{-*-coding:-*-} tags in the file itself. Emacs
-uses @code{auto-coding-alist} for tar and archive files, to prevent it
-from being confused by a @samp{-*-coding:-*-} tag in a member of the
-archive and thinking it applies to the archive file as a whole.
-Likewise, Emacs uses @code{auto-coding-regexp-alist} to ensure that
-RMAIL files, whose names in general don't match any particular
-pattern, are decoded correctly. One of the builtin
address@hidden detects the encoding for XML files.
-
address@hidden rmail-decode-mime-charset
- When you get new mail in Rmail, each message is translated
-automatically from the coding system it is written in, as if it were a
-separate file. This uses the priority list of coding systems that you
-have specified. If a MIME message specifies a character set, Rmail
-obeys that specification, unless @code{rmail-decode-mime-charset} is
address@hidden
-
address@hidden rmail-file-coding-system
- For reading and saving Rmail files themselves, Emacs uses the coding
-system specified by the variable @code{rmail-file-coding-system}. The
-default value is @code{nil}, which means that Rmail files are not
-translated (they are read and written in the Emacs internal character
-code).
-
address@hidden Specify Coding
address@hidden Specifying a File's Coding System
-
- If Emacs recognizes the encoding of a file incorrectly, you can
-reread the file using the correct coding system by typing @kbd{C-x
address@hidden r @var{coding-system} @key{RET}}. To see what coding system
-Emacs actually used to decode the file, look at the coding system
-mnemonic letter near the left edge of the mode line (@pxref{Mode
-Line}), or type @kbd{C-h C @key{RET}}.
-
address@hidden coding
- You can specify the coding system for a particular file in the file
-itself, using the @address@hidden@dots{}-*-}} construct at the beginning,
-or a local variables list at the end (@pxref{File Variables}). You do
-this by defining a value for the ``variable'' named @code{coding}.
-Emacs does not really have a variable @code{coding}; instead of
-setting a variable, this uses the specified coding system for the
-file. For example, @samp{-*-mode: C; coding: latin-1;-*-} specifies
-use of the Latin-1 coding system, as well as C mode. When you specify
-the coding explicitly in the file, that overrides
address@hidden
-
- If you add the character @samp{!} at the end of the coding system
-name in @code{coding}, it disables any character translation
-(@pxref{Character Translation}) while decoding the file. This is
-useful when you need to make sure that the character codes in the
-Emacs buffer will not vary due to changes in user settings; for
-instance, for the sake of strings in Emacs Lisp source files.
-
address@hidden Output Coding
address@hidden Choosing Coding Systems for Output
-
address@hidden buffer-file-coding-system
- Once Emacs has chosen a coding system for a buffer, it stores that
-coding system in @code{buffer-file-coding-system}. That makes it the
-default for operations that write from this buffer into a file, such
-as @code{save-buffer} and @code{write-region}. You can specify a
-different coding system for further file output from the buffer using
address@hidden (@pxref{Text Coding}).
-
- You can insert any character Emacs supports into any Emacs buffer,
-but most coding systems can only handle a subset of these characters.
-Therefore, you can insert characters that cannot be encoded with the
-coding system that will be used to save the buffer. For example, you
-could start with an @acronym{ASCII} file and insert a few Latin-1
-characters into it, or you could edit a text file in Polish encoded in
address@hidden and add some Russian words to it. When you save
-that buffer, Emacs cannot use the current value of
address@hidden, because the characters you added
-cannot be encoded by that coding system.
-
- When that happens, Emacs tries the most-preferred coding system (set
-by @kbd{M-x prefer-coding-system} or @kbd{M-x
-set-language-environment}), and if that coding system can safely
-encode all of the characters in the buffer, Emacs uses it, and stores
-its value in @code{buffer-file-coding-system}. Otherwise, Emacs
-displays a list of coding systems suitable for encoding the buffer's
-contents, and asks you to choose one of those coding systems.
-
- If you insert the unsuitable characters in a mail message, Emacs
-behaves a bit differently. It additionally checks whether the
-most-preferred coding system is recommended for use in MIME messages;
-if not, Emacs tells you that the most-preferred coding system is not
-recommended and prompts you for another coding system. This is so you
-won't inadvertently send a message encoded in a way that your
-recipient's mail software will have difficulty decoding. (You can
-still use an unsuitable coding system if you type its name in response
-to the question.)
-
address@hidden sendmail-coding-system
- When you send a message with Mail mode (@pxref{Sending Mail}), Emacs has
-four different ways to determine the coding system to use for encoding
-the message text. It tries the buffer's own value of
address@hidden, if that is address@hidden Otherwise,
-it uses the value of @code{sendmail-coding-system}, if that is
address@hidden The third way is to use the default coding system for
-new files, which is controlled by your choice of language environment,
-if that is address@hidden If all of these three values are @code{nil},
-Emacs encodes outgoing mail using the Latin-1 coding system.
-
address@hidden Text Coding
address@hidden Specifying a Coding System for File Text
-
- In cases where Emacs does not automatically choose the right coding
-system for a file's contents, you can use these commands to specify
-one:
-
address@hidden @kbd
address@hidden C-x @key{RET} f @var{coding} @key{RET}
-Use coding system @var{coding} for saving or revisiting the visited
-file in the current buffer.
-
address@hidden C-x @key{RET} c @var{coding} @key{RET}
-Specify coding system @var{coding} for the immediately following
-command.
-
address@hidden C-x @key{RET} r @var{coding} @key{RET}
-Revisit the current file using the coding system @var{coding}.
-
address@hidden M-x recode-region @key{RET} @var{right} @key{RET} @var{wrong}
@key{RET}
-Convert a region that was decoded using coding system @var{wrong},
-decoding it using coding system @var{right} instead.
address@hidden table
-
address@hidden C-x RET f
address@hidden set-buffer-file-coding-system
- The command @kbd{C-x @key{RET} f}
-(@code{set-buffer-file-coding-system}) sets the file coding system for
-the current buffer---in other words, it says which coding system to
-use when saving or reverting the visited file. You specify which
-coding system using the minibuffer. If you specify a coding system
-that cannot handle all of the characters in the buffer, Emacs warns
-you about the troublesome characters when you actually save the
-buffer.
-
address@hidden specify end-of-line conversion
- You can also use this command to specify the end-of-line conversion
-(@pxref{Coding Systems, end-of-line conversion}) for encoding the
-current buffer. For example, @kbd{C-x @key{RET} f dos @key{RET}} will
-cause Emacs to save the current buffer's text with DOS-style CRLF line
-endings.
-
address@hidden C-x RET c
address@hidden universal-coding-system-argument
- Another way to specify the coding system for a file is when you visit
-the file. First use the command @kbd{C-x @key{RET} c}
-(@code{universal-coding-system-argument}); this command uses the
-minibuffer to read a coding system name. After you exit the minibuffer,
-the specified coding system is used for @emph{the immediately following
-command}.
-
- So if the immediately following command is @kbd{C-x C-f}, for example,
-it reads the file using that coding system (and records the coding
-system for when you later save the file). Or if the immediately following
-command is @kbd{C-x C-w}, it writes the file using that coding system.
-When you specify the coding system for saving in this way, instead
-of with @kbd{C-x @key{RET} f}, there is no warning if the buffer
-contains characters that the coding system cannot handle.
-
- Other file commands affected by a specified coding system include
address@hidden i} and @kbd{C-x C-v}, as well as the other-window variants
-of @kbd{C-x C-f}. @kbd{C-x @key{RET} c} also affects commands that
-start subprocesses, including @kbd{M-x shell} (@pxref{Shell}). If the
-immediately following command does not use the coding system, then
address@hidden @key{RET} c} ultimately has no effect.
-
- An easy way to visit a file with no conversion is with the @kbd{M-x
-find-file-literally} command. @xref{Visiting}.
-
address@hidden default-buffer-file-coding-system
- The variable @code{default-buffer-file-coding-system} specifies the
-choice of coding system to use when you create a new file. It applies
-when you find a new file, and when you create a buffer and then save it
-in a file. Selecting a language environment typically sets this
-variable to a good choice of default coding system for that language
-environment.
-
address@hidden C-x RET r
address@hidden revert-buffer-with-coding-system
- If you visit a file with a wrong coding system, you can correct this
-with @kbd{C-x @key{RET} r} (@code{revert-buffer-with-coding-system}).
-This visits the current file again, using a coding system you specify.
-
address@hidden recode-region
- If a piece of text has already been inserted into a buffer using the
-wrong coding system, you can redo the decoding of it using @kbd{M-x
-recode-region}. This prompts you for the proper coding system, then
-for the wrong coding system that was actually used, and does the
-conversion. It first encodes the region using the wrong coding system,
-then decodes it again using the proper coding system.
-
address@hidden Communication Coding
address@hidden Coding Systems for Interprocess Communication
-
- This section explains how to specify coding systems for use
-in communication with other processes.
-
address@hidden @kbd
address@hidden C-x @key{RET} x @var{coding} @key{RET}
-Use coding system @var{coding} for transferring selections to and from
-other window-based applications.
-
address@hidden C-x @key{RET} X @var{coding} @key{RET}
-Use coding system @var{coding} for transferring @emph{one}
-selection---the next one---to or from another window-based application.
-
address@hidden C-x @key{RET} p @var{input-coding} @key{RET} @var{output-coding}
@key{RET}
-Use coding systems @var{input-coding} and @var{output-coding} for
-subprocess input and output in the current buffer.
-
address@hidden C-x @key{RET} c @var{coding} @key{RET}
-Specify coding system @var{coding} for the immediately following
-command.
address@hidden table
-
address@hidden C-x RET x
address@hidden C-x RET X
address@hidden set-selection-coding-system
address@hidden set-next-selection-coding-system
- The command @kbd{C-x @key{RET} x} (@code{set-selection-coding-system})
-specifies the coding system for sending selected text to other windowing
-applications, and for receiving the text of selections made in other
-applications. This command applies to all subsequent selections, until
-you override it by using the command again. The command @kbd{C-x
address@hidden X} (@code{set-next-selection-coding-system}) specifies the
-coding system for the next selection made in Emacs or read by Emacs.
-
address@hidden C-x RET p
address@hidden set-buffer-process-coding-system
- The command @kbd{C-x @key{RET} p} (@code{set-buffer-process-coding-system})
-specifies the coding system for input and output to a subprocess. This
-command applies to the current buffer; normally, each subprocess has its
-own buffer, and thus you can use this command to specify translation to
-and from a particular subprocess by giving the command in the
-corresponding buffer.
-
- You can also use @kbd{C-x @key{RET} c} just before the command that
-runs or starts a subprocess, to specify the coding system to use for
-communication with that subprocess.
-
- The default for translation of process input and output depends on the
-current language environment.
-
address@hidden locale-coding-system
address@hidden decoding address@hidden keyboard input on X
- The variable @code{locale-coding-system} specifies a coding system
-to use when encoding and decoding system strings such as system error
-messages and @code{format-time-string} formats and time stamps. That
-coding system is also used for decoding address@hidden keyboard input on X
-Window systems. You should choose a coding system that is compatible
-with the underlying system's text representation, which is normally
-specified by one of the environment variables @env{LC_ALL},
address@hidden, and @env{LANG}. (The first one, in the order
-specified above, whose value is nonempty is the one that determines
-the text representation.)
-
address@hidden File Name Coding
address@hidden Coding Systems for File Names
-
address@hidden @kbd
address@hidden C-x @key{RET} F @var{coding} @key{RET}
-Use coding system @var{coding} for encoding and decoding file
address@hidden
address@hidden table
-
address@hidden file-name-coding-system
address@hidden file names with address@hidden characters
- The variable @code{file-name-coding-system} specifies a coding
-system to use for encoding file names. It has no effect on reading
-and writing the @emph{contents} of files.
-
address@hidden set-file-name-coding-system
address@hidden C-x @key{RET} F
- If you set the variable to a coding system name (as a Lisp symbol or
-a string), Emacs encodes file names using that coding system for all
-file operations. This makes it possible to use address@hidden
-characters in file names---or, at least, those address@hidden
-characters which the specified coding system can encode. Use @kbd{C-x
address@hidden F} (@code{set-file-name-coding-system}) to specify this
-interactively.
-
- If @code{file-name-coding-system} is @code{nil}, Emacs uses a
-default coding system determined by the selected language environment.
-In the default language environment, any address@hidden
-characters in file names are not encoded specially; they appear in the
-file system using the internal Emacs representation.
-
- @strong{Warning:} if you change @code{file-name-coding-system} (or the
-language environment) in the middle of an Emacs session, problems can
-result if you have already visited files whose names were encoded using
-the earlier coding system and cannot be encoded (or are encoded
-differently) under the new coding system. If you try to save one of
-these buffers under the visited file name, saving may use the wrong file
-name, or it may get an error. If such a problem happens, use @kbd{C-x
-C-w} to specify a new file name for that buffer.
-
address@hidden recode-file-name
- If a mistake occurs when encoding a file name, use the command
address@hidden recode-file-name} to change the file name's coding
-system. This prompts for an existing file name, its old coding
-system, and the coding system to which you wish to convert.
-
address@hidden Terminal Coding
address@hidden Coding Systems for Terminal I/O
-
address@hidden @kbd
address@hidden C-x @key{RET} k @var{coding} @key{RET}
-Use coding system @var{coding} for keyboard input.
-
address@hidden C-x @key{RET} t @var{coding} @key{RET}
-Use coding system @var{coding} for terminal output.
address@hidden table
-
address@hidden C-x RET t
address@hidden set-terminal-coding-system
- The command @kbd{C-x @key{RET} t} (@code{set-terminal-coding-system})
-specifies the coding system for terminal output. If you specify a
-character code for terminal output, all characters output to the
-terminal are translated into that coding system.
-
- This feature is useful for certain character-only terminals built to
-support specific languages or character sets---for example, European
-terminals that support one of the ISO Latin character sets. You need to
-specify the terminal coding system when using multibyte text, so that
-Emacs knows which characters the terminal can actually handle.
-
- By default, output to the terminal is not translated at all, unless
-Emacs can deduce the proper coding system from your terminal type or
-your locale specification (@pxref{Language Environments}).
-
address@hidden C-x RET k
address@hidden set-keyboard-coding-system
address@hidden keyboard-coding-system
- The command @kbd{C-x @key{RET} k} (@code{set-keyboard-coding-system})
-or the variable @code{keyboard-coding-system} specifies the coding
-system for keyboard input. Character-code translation of keyboard
-input is useful for terminals with keys that send address@hidden
-graphic characters---for example, some terminals designed for ISO
-Latin-1 or subsets of it.
-
- By default, keyboard input is translated based on your system locale
-setting. If your terminal does not really support the encoding
-implied by your locale (for example, if you find it inserts a
address@hidden character if you type @kbd{M-i}), you will need to set
address@hidden to @code{nil} to turn off encoding.
-You can do this by putting
-
address@hidden
-(set-keyboard-coding-system nil)
address@hidden lisp
-
address@hidden
-in your @file{~/.emacs} file.
-
- There is a similarity between using a coding system translation for
-keyboard input, and using an input method: both define sequences of
-keyboard input that translate into single characters. However, input
-methods are designed to be convenient for interactive use by humans, and
-the sequences that are translated are typically sequences of @acronym{ASCII}
-printing characters. Coding systems typically translate sequences of
-non-graphic characters.
-
address@hidden Fontsets
address@hidden Fontsets
address@hidden fontsets
-
- A font typically defines shapes for a single alphabet or script.
-Therefore, displaying the entire range of scripts that Emacs supports
-requires a collection of many fonts. In Emacs, such a collection is
-called a @dfn{fontset}. A fontset is defined by a list of fonts, each
-assigned to handle a range of character codes.
-
- Each fontset has a name, like a font. However, while fonts are
-stored in the system and the available font names are defined by the
-system, fontsets are defined within Emacs itself. Once you have
-defined a fontset, you can use it within Emacs by specifying its name,
-anywhere that you could use a single font. Of course, Emacs fontsets
-can use only the fonts that the system supports; if certain characters
-appear on the screen as hollow boxes, this means that the fontset in
-use for them has no font for those address@hidden Emacs
-installation instructions have information on additional font
-support.}
-
- Emacs creates two fontsets automatically: the @dfn{standard fontset}
-and the @dfn{startup fontset}. The standard fontset is most likely to
-have fonts for a wide variety of address@hidden characters;
-however, this is not the default for Emacs to use. (By default, Emacs
-tries to find a font that has bold and italic variants.) You can
-specify use of the standard fontset with the @samp{-fn} option. For
-example,
-
address@hidden
-emacs -fn fontset-standard
address@hidden example
-
address@hidden
-You can also specify a fontset with the @samp{Font} resource (@pxref{X
-Resources}).
-
- A fontset does not necessarily specify a font for every character
-code. If a fontset specifies no font for a certain character, or if it
-specifies a font that does not exist on your system, then it cannot
-display that character properly. It will display that character as an
-empty box instead.
-
address@hidden Defining Fontsets
address@hidden Defining fontsets
-
address@hidden standard-fontset-spec
address@hidden standard fontset
- Emacs creates a standard fontset automatically according to the value
-of @code{standard-fontset-spec}. This fontset's name is
-
address@hidden
--*-fixed-medium-r-normal-*-16-*-*-*-*-*-fontset-standard
address@hidden example
-
address@hidden
-or just @samp{fontset-standard} for short.
-
- Bold, italic, and bold-italic variants of the standard fontset are
-created automatically. Their names have @samp{bold} instead of
address@hidden, or @samp{i} instead of @samp{r}, or both.
-
address@hidden startup fontset
- If you specify a default @acronym{ASCII} font with the @samp{Font} resource
or
-the @samp{-fn} argument, Emacs generates a fontset from it
-automatically. This is the @dfn{startup fontset} and its name is
address@hidden It does this by replacing the @var{foundry},
address@hidden, @var{add_style}, and @var{average_width} fields of the
-font name with @samp{*}, replacing @var{charset_registry} field with
address@hidden, and replacing @var{charset_encoding} field with
address@hidden, then using the resulting string to specify a fontset.
-
- For instance, if you start Emacs this way,
-
address@hidden
-emacs -fn "*courier-medium-r-normal--14-140-*-iso8859-1"
address@hidden example
-
address@hidden
-Emacs generates the following fontset and uses it for the initial X
-window frame:
-
address@hidden
--*-*-medium-r-normal-*-14-140-*-*-*-*-fontset-startup
address@hidden example
-
- With the X resource @samp{Emacs.Font}, you can specify a fontset name
-just like an actual font name. But be careful not to specify a fontset
-name in a wildcard resource like @samp{Emacs*Font}---that wildcard
-specification matches various other resources, such as for menus, and
-menus cannot handle fontsets.
-
- You can specify additional fontsets using X resources named
address@hidden@var{n}}, where @var{n} is an integer starting from 0.
-The resource value should have this form:
-
address@hidden
address@hidden, @address@hidden:@address@hidden@dots{}}
address@hidden smallexample
-
address@hidden
address@hidden should have the form of a standard X font name, except
-for the last two fields. They should have the form
address@hidden@var{alias}}.
-
- The fontset has two names, one long and one short. The long name is
address@hidden The short name is @address@hidden You
-can refer to the fontset by either name.
-
- The construct @address@hidden:@var{font}} specifies which font to
-use (in this fontset) for one particular character set. Here,
address@hidden is the name of a character set, and @var{font} is the
-font to use for that character set. You can use this construct any
-number of times in defining one fontset.
-
- For the other character sets, Emacs chooses a font based on
address@hidden It replaces @address@hidden with values
-that describe the character set. For the @acronym{ASCII} character font,
address@hidden@var{alias}} is replaced with @samp{ISO8859-1}.
-
- In addition, when several consecutive fields are wildcards, Emacs
-collapses them into a single wildcard. This is to prevent use of
-auto-scaled fonts. Fonts made by scaling larger fonts are not usable
-for editing, and scaling a smaller font is not useful because it is
-better to use the smaller font in its own size, which is what Emacs
-does.
-
- Thus if @var{fontpattern} is this,
-
address@hidden
--*-fixed-medium-r-normal-*-24-*-*-*-*-*-fontset-24
address@hidden example
-
address@hidden
-the font specification for @acronym{ASCII} characters would be this:
-
address@hidden
--*-fixed-medium-r-normal-*-24-*-ISO8859-1
address@hidden example
-
address@hidden
-and the font specification for Chinese GB2312 characters would be this:
-
address@hidden
--*-fixed-medium-r-normal-*-24-*-gb2312*-*
address@hidden example
-
- You may not have any Chinese font matching the above font
-specification. Most X distributions include only Chinese fonts that
-have @samp{song ti} or @samp{fangsong ti} in @var{family} field. In
-such a case, @address@hidden can be specified as below:
-
address@hidden
-Emacs.Fontset-0: -*-fixed-medium-r-normal-*-24-*-*-*-*-*-fontset-24,\
- chinese-gb2312:-*-*-medium-r-normal-*-24-*-gb2312*-*
address@hidden smallexample
-
address@hidden
-Then, the font specifications for all but Chinese GB2312 characters have
address@hidden in the @var{family} field, and the font specification for
-Chinese GB2312 characters has a wild card @samp{*} in the @var{family}
-field.
-
address@hidden create-fontset-from-fontset-spec
- The function that processes the fontset resource value to create the
-fontset is called @code{create-fontset-from-fontset-spec}. You can also
-call this function explicitly to create a fontset.
-
- @xref{Font X}, for more information about font naming in X.
-
address@hidden Undisplayable Characters
address@hidden Undisplayable Characters
-
- There may be a some address@hidden characters that your terminal cannot
-display. Most text-only terminals support just a single character
-set (use the variable @code{default-terminal-coding-system}
-(@pxref{Terminal Coding}) to tell Emacs which one); characters which
-can't be encoded in that coding system are displayed as @samp{?} by
-default.
-
- Graphical displays can display a broader range of characters, but
-you may not have fonts installed for all of them; characters that have
-no font appear as a hollow box.
-
- If you use Latin-1 characters but your terminal can't display
-Latin-1, you can arrange to display mnemonic @acronym{ASCII} sequences
-instead, e.g.@: @samp{"o} for o-umlaut. Load the library
address@hidden to do this.
-
address@hidden latin1-display
- If your terminal can display Latin-1, you can display characters
-from other European character sets using a mixture of equivalent
-Latin-1 characters and @acronym{ASCII} mnemonics. Customize the variable
address@hidden to enable this. The mnemonic @acronym{ASCII}
-sequences mostly correspond to those of the prefix input methods.
-
address@hidden Unibyte Mode
address@hidden Unibyte Editing Mode
-
address@hidden European character sets
address@hidden accented characters
address@hidden ISO Latin character sets
address@hidden Unibyte operation
- The ISO 8859 address@hidden character sets define character codes in
-the range 0240 to 0377 octal (160 to 255 decimal) to handle the
-accented letters and punctuation needed by various European languages
-(and some non-European ones). If you disable multibyte characters,
-Emacs can still handle @emph{one} of these character codes at a time.
-To specify @emph{which} of these codes to use, invoke @kbd{M-x
-set-language-environment} and specify a suitable language environment
-such as @address@hidden
-
- For more information about unibyte operation, see @ref{Enabling
-Multibyte}. Note particularly that you probably want to ensure that
-your initialization files are read as unibyte if they contain
address@hidden characters.
-
address@hidden unibyte-display-via-language-environment
- Emacs can also display those characters, provided the terminal or font
-in use supports them. This works automatically. Alternatively, on a
-graphical display, Emacs can also display single-byte characters
-through fontsets, in effect by displaying the equivalent multibyte
-characters according to the current language environment. To request
-this, set the variable @code{unibyte-display-via-language-environment}
-to a address@hidden value.
-
address@hidden @code{iso-ascii} library
- If your terminal does not support display of the Latin-1 character
-set, Emacs can display these characters as @acronym{ASCII} sequences which at
-least give you a clear idea of what the characters are. To do this,
-load the library @code{iso-ascii}. Similar libraries for other
address@hidden character sets could be implemented, but we don't have
-them yet.
-
address@hidden standard-display-8bit
address@hidden 8-bit display
- Normally non-ISO-8859 characters (decimal codes between 128 and 159
-inclusive) are displayed as octal escapes. You can change this for
-non-standard ``extended'' versions of ISO-8859 character sets by using the
-function @code{standard-display-8bit} in the @code{disp-table} library.
-
- There are two ways to input single-byte address@hidden
-characters:
-
address@hidden @bullet
address@hidden 8-bit input
address@hidden
-You can use an input method for the selected language environment.
address@hidden Methods}. When you use an input method in a unibyte buffer,
-the address@hidden character you specify with it is converted to unibyte.
-
address@hidden
-If your keyboard can generate character codes 128 (decimal) and up,
-representing address@hidden characters, you can type those character codes
-directly.
-
-On a graphical display, you should not need to do anything special to use
-these keys; they should simply work. On a text-only terminal, you
-should use the command @code{M-x set-keyboard-coding-system} or the
-variable @code{keyboard-coding-system} to specify which coding system
-your keyboard uses (@pxref{Terminal Coding}). Enabling this feature
-will probably require you to use @kbd{ESC} to type Meta characters;
-however, on a console terminal or in @code{xterm}, you can arrange for
-Meta to be converted to @kbd{ESC} and still be able type 8-bit
-characters present directly on the keyboard or using @kbd{Compose} or
address@hidden keys. @xref{User Input}.
-
address@hidden C-x 8
address@hidden @code{iso-transl} library
address@hidden compose character
address@hidden dead character
address@hidden
-For Latin-1 only, you can use the key @kbd{C-x 8} as a ``compose
-character'' prefix for entry of address@hidden Latin-1 printing
-characters. @kbd{C-x 8} is good for insertion (in the minibuffer as
-well as other buffers), for searching, and in any other context where
-a key sequence is allowed.
-
address@hidden 8} works by loading the @code{iso-transl} library. Once that
-library is loaded, the @key{ALT} modifier key, if the keyboard has
-one, serves the same purpose as @kbd{C-x 8}: use @key{ALT} together
-with an accent character to modify the following letter. In addition,
-if the keyboard has keys for the Latin-1 ``dead accent characters,''
-they too are defined to compose with the following character, once
address@hidden is loaded.
-
-Use @kbd{C-x 8 C-h} to list all the available @kbd{C-x 8} translations.
address@hidden itemize
-
address@hidden Charsets
address@hidden Charsets
address@hidden charsets
-
- Emacs groups all supported characters into disjoint @dfn{charsets}.
-Each character code belongs to one and only one charset. For
-historical reasons, Emacs typically divides an 8-bit character code
-for an extended version of @acronym{ASCII} into two charsets:
address@hidden, which covers the codes 0 through 127, plus another
-charset which covers the ``right-hand part'' (the codes 128 and up).
-For instance, the characters of Latin-1 include the Emacs charset
address@hidden plus the Emacs charset @code{latin-iso8859-1}.
-
- Emacs characters belonging to different charsets may look the same,
-but they are still different characters. For example, the letter
address@hidden with acute accent in charset @code{latin-iso8859-1}, used for
-Latin-1, is different from the letter @samp{o} with acute accent in
-charset @code{latin-iso8859-2}, used for Latin-2.
-
address@hidden list-charset-chars
address@hidden characters in a certain charset
address@hidden describe-character-set
- There are two commands for obtaining information about Emacs
-charsets. The command @kbd{M-x list-charset-chars} prompts for a name
-of a character set, and displays all the characters in that character
-set. The command @kbd{M-x describe-character-set} prompts for a
-charset name and displays information about that charset, including
-its internal representation within Emacs.
-
- To find out which charset a character in the buffer belongs to,
-put point before it and type @kbd{C-u C-x =}.
-
address@hidden
- arch-tag: 310ba60d-31ef-4ce7-91f1-f282dd57b6b3
address@hidden ignore
- [Emacs-diffs] Changes to mule.texi,
Glenn Morris <=