* 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}.
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.
+@findex unify-8859-on-decoding-mode
+ 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
+@code{unify-8859-on-decoding-mode} enables a mode that ``unifies'' the
+Latin alphabets when decoding text. This works by converting all
+non-@acronym{ASCII} Latin-@var{n} characters to either Latin-1 or
+Unicode characters. This way it is easier to use various
+Latin-@var{n} alphabets together. (In a future Emacs version we hope
+to move towards full Unicode support and complete unification of
+character sets.)
+
+@vindex enable-character-translation
+ If you set the variable @code{enable-character-translation} to
+@code{nil}, that disables all character translation (including
+@code{unify-8859-on-decoding-mode}).
+
@node Recognize Coding
@section Recognizing Coding Systems
decoded correctly when you visit those files if you suppress the
escape sequence detection.
-@vindex coding
- You can specify the coding system for a particular file using the
-@w{@samp{-*-@dots{}-*-}} construct at the beginning of a file, 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
-@code{file-coding-system-alist}.
-
- If you add the character @samp{!} at the end of the coding system
-name, it disables any character translation while decoding the file.
-For instance, it effectively cancels the effect of
-@code{unify-8859-on-decoding-mode}. This is useful when you need to
-make sure that the character codes in the Emacs buffer will not
-according to user settings; for instance, for the sake of strings in
-Emacs Lisp source files.
-
@vindex auto-coding-alist
@vindex auto-coding-regexp-alist
@vindex auto-coding-functions
pattern, are decoded correctly. One of the builtin
@code{auto-coding-functions} detects the encoding for XML files.
+@vindex 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
+@code{nil}.
+
+@vindex 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).
+
+@node Specify Coding
+@section 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
@key{RET} r @var{coding-system} @key{RET}}. To see what coding system
mnemonic letter near the left edge of the mode line (@pxref{Mode
Line}), or type @kbd{C-h C @key{RET}}.
-@findex unify-8859-on-decoding-mode
- The command @code{unify-8859-on-decoding-mode} enables a mode that
-``unifies'' the Latin alphabets when decoding text. This works by
-converting all non-@acronym{ASCII} Latin-@var{n} characters to either
-Latin-1 or Unicode characters. This way it is easier to use various
-Latin-@var{n} alphabets together. In a future Emacs version we hope
-to move towards full Unicode support and complete unification of
-character sets.
+@vindex coding
+ You can specify the coding system for a particular file in the file
+itself, using the @w{@samp{-*-@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
+@code{file-coding-system-alist}.
+
+ If you add the character @samp{!} at the end of the coding system
+name in @code{coding}, it disables any character translation while
+decoding the file. For instance, it effectively cancels the effect of
+@code{unify-8859-on-decoding-mode}. 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.
+
+@node Output Coding
+@section Choosing Coding Systems for Output
@vindex 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} and uses that coding
-system, by default, for operations that write from this buffer into a
-file. This includes the commands @code{save-buffer} and
-@code{write-region}. If you want to write files from this buffer using
-a different coding system, you can specify a different coding system for
-the buffer using @code{set-buffer-file-coding-system} (@pxref{Text
-Coding}).
-
- You can insert any possible character into any Emacs buffer, but
-most coding systems can only handle some of the possible characters.
-This means that it is possible for you to 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 @code{iso-8859-2} and add some Russian words to it.
-When you save the buffer, Emacs cannot use the current value of
+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
+@code{set-buffer-file-coding-system} (@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
+@code{iso-8859-2} and add some Russian words to it. When you save
+that buffer, Emacs cannot use the current value of
@code{buffer-file-coding-system}, because the characters you added
cannot be encoded by that coding system.
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. (If you do
-want to use the most-preferred coding system, you can still type its
-name in response to the question.)
+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.)
@vindex sendmail-coding-system
When you send a message with Mail mode (@pxref{Sending Mail}), Emacs has
if that is non-@code{nil}. If all of these three values are @code{nil},
Emacs encodes outgoing mail using the Latin-1 coding system.
-@vindex 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
-@code{nil}.
-
-@vindex 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).
-
@node Text Coding
@section Specifying a Coding System for File Text
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