@synindex fn cp
@synindex vr cp
@synindex pg cp
-@dircategory Emacs
-@direntry
-* Emacs MIME: (emacs-mime). The MIME de/composition library.
-@end direntry
-@iftex
-@finalout
-@end iftex
-@setchapternewpage odd
-
-@ifnottex
+@copying
This file documents the Emacs MIME interface functionality.
Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003
Free Software Foundation, Inc.
+@quotation
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.1 or
any later version published by the Free Software Foundation; with no
Documentation License. If you want to distribute this document
separately from the collection, you can do so by adding a copy of the
license to the document, as described in section 6 of the license.
-@end ifnottex
+@end quotation
+@end copying
-@tex
+@dircategory Emacs
+@direntry
+* Emacs MIME: (emacs-mime). Emacs MIME de/composition library.
+@end direntry
+@iftex
+@finalout
+@end iftex
+@setchapternewpage odd
@titlepage
@title Emacs MIME Manual
@author by Lars Magne Ingebrigtsen
@page
-
@vskip 0pt plus 1filll
-Copyright @copyright{} 1998, 1999, 2000, 2001, 2002, 2003 Free Software
-Foundation, Inc.
-
-Permission is granted to copy, distribute and/or modify this document
-under the terms of the GNU Free Documentation License, Version 1.1 or
-any later version published by the Free Software Foundation; with the
-Invariant Sections being none, with the Front-Cover texts being ``A GNU
-Manual'', and with the Back-Cover Texts as in (a) below. A copy of the
-license is included in the section entitled ``GNU Free Documentation
-License'' in the Emacs manual.
-
-(a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify
-this GNU Manual, like GNU software. Copies published by the Free
-Software Foundation raise funds for GNU development.''
-
-This document is part of a collection distributed under the GNU Free
-Documentation License. If you want to distribute this document
-separately from the collection, you can do so by adding a copy of the
-license to the document, as described in section 6 of the license.
+@insertcopying
@end titlepage
-@page
-
-@end tex
@node Top
@top Emacs MIME
@menu
* Decoding and Viewing:: A framework for decoding and viewing.
-* Composing:: MML; a language for describing @acronym{MIME} parts.
+* Composing:: @acronym{MML}; a language for describing @acronym{MIME} parts.
* Interface Functions:: An abstraction over the basic functions.
* Basic Functions:: Utility and basic parsing functions.
* Standards:: A summary of RFCs and working documents used.
@vindex mm-external-terminal-program
The program used to start an external terminal.
+@item mm-enable-external
+@vindex mm-enable-external
+Indicate whether external @acronym{MIME} handlers should be used.
+
+If @code{t}, all defined external @acronym{MIME} handlers are used. If
+@code{nil}, files are saved to disk (@code{mailcap-save-binary-file}).
+If it is the symbol @code{ask}, you are prompted before the external
+@acronym{MIME} handler is invoked.
+
+When you launch an attachment through mailcap (@pxref{mailcap}) an
+attempt is made to use a safe viewer with the safest options---this isn't
+the case if you save it to disk and launch it in a different way
+(command line or double-clicking). Anyhow, if you want to be sure not
+to launch any external programs, set this variable to @code{nil} or
+@code{ask}.
+
@end table
@node Files and Directories
Ready-made functions include
@table @code
+@item mm-file-name-delete-control
+@findex mm-file-name-delete-control
+Delete all control characters.
+
+@item mm-file-name-delete-gotchas
+@findex mm-file-name-delete-gotchas
+Delete characters that could have unintended consequences when used
+with flawed shell scripts, i.e. @samp{|}, @samp{>} and @samp{<}; and
+@samp{-}, @samp{.} as the first character.
+
@item mm-file-name-delete-whitespace
@findex mm-file-name-delete-whitespace
Remove all whitespace.
Replace whitespace with underscores. Set the variable
@code{mm-file-name-replace-whitespace} to any other string if you do
not like underscores.
-
@end table
The standard Emacs functions @code{capitalize}, @code{downcase},
@cindex MML
@cindex MIME Meta Language
-Creating a @acronym{MIME} message is boring and non-trivial. Therefore, a
-library called @code{mml} has been defined that parses a language called
-MML (@acronym{MIME} Meta Language) and generates @acronym{MIME} messages.
+Creating a @acronym{MIME} message is boring and non-trivial. Therefore,
+a library called @code{mml} has been defined that parses a language
+called @acronym{MML} (@acronym{MIME} Meta Language) and generates
+@acronym{MIME} messages.
@findex mml-generate-mime
The main interface function is @code{mml-generate-mime}. It will
string containing the @acronym{MIME} message.
@menu
-* Simple MML Example:: An example MML document.
-* MML Definition:: All valid MML elements.
-* Advanced MML Example:: Another example MML document.
+* Simple MML Example:: An example @acronym{MML} document.
+* MML Definition:: All valid @acronym{MML} elements.
+* Advanced MML Example:: Another example @acronym{MML} document.
* Encoding Customization:: Variables that affect encoding.
* Charset Translation:: How charsets are mapped from @sc{mule} to @acronym{MIME}.
-* Conversion:: Going from @acronym{MIME} to MML and vice versa.
+* Conversion:: Going from @acronym{MIME} to @acronym{MML} and vice versa.
* Flowed text:: Soft and hard newlines.
@end menu
@node MML Definition
@section MML Definition
-The MML language is very simple. It looks a bit like an SGML
+The @acronym{MML} language is very simple. It looks a bit like an SGML
application, but it's not.
-The main concept of MML is the @dfn{part}. Each part can be of a
+The main concept of @acronym{MML} is the @dfn{part}. Each part can be of a
different type or use a different charset. The way to delineate a part
is with a @samp{<#part ...>} tag. Multipart parts can be introduced
with the @samp{<#multipart ...>} tag. Parts are ended by the
but that's not necessary unless the value contains white space. So
@samp{filename=/home/user/#hello$^yes} is perfectly valid.
-The following parameters have meaning in MML; parameters that have no
-meaning are ignored. The MML parameter names are the same as the
+The following parameters have meaning in @acronym{MML}; parameters that have no
+meaning are ignored. The @acronym{MML} parameter names are the same as the
@acronym{MIME} parameter names; the things in the parentheses say which
header it will be used in.
The size (in octets) of the part (@code{Content-Disposition}).
@item sign
-What technology to sign this MML part with (@code{smime}, @code{pgp}
+What technology to sign this @acronym{MML} part with (@code{smime}, @code{pgp}
or @code{pgpmime})
@item encrypt
-What technology to encrypt this MML part with (@code{smime},
+What technology to encrypt this @acronym{MML} part with (@code{smime},
@code{pgp} or @code{pgpmime})
@end table
+Parameters for @samp{text/plain}:
+
+@table @samp
+@item format
+Formatting parameter for the text, valid values include @samp{fixed}
+(the default) and @samp{flowed}. Normally you do not specify this
+manually, since it requires the textual body to be formatted in a
+special way described in RFC 2646. @xref{Flowed text}.
+@end table
+
Parameters for @samp{application/octet-stream}:
@table @samp
As an example, if you do not want to have ISO-8859-1 characters
quoted-printable encoded, you may add @code{(iso-8859-1 . 8bit)} to
this variable. You can override this setting on a per-message basis
-by using the @code{encoding} MML tag (@pxref{MML Definition}).
+by using the @code{encoding} @acronym{MML} tag (@pxref{MML Definition}).
@item mm-coding-system-priorities
@vindex mm-coding-system-priorities
Prioritize coding systems to use for outgoing messages. The default
is @code{nil}, which means to use the defaults in Emacs. It is a list of
-coding system symbols (aliases of coding systems does not work, use
-@kbd{M-x describe-coding-system} to make sure you are not specifying
-an alias in this variable). For example, if you have configured Emacs
+coding system symbols (aliases of coding systems are also allowed, use
+@kbd{M-x describe-coding-system} to make sure you are specifying correct
+coding system names). For example, if you have configured Emacs
to prefer UTF-8, but wish that outgoing messages should be sent in
ISO-8859-1 if possible, you can set this variable to
-@code{(iso-latin-1)}. You can override this setting on a per-message
-basis by using the @code{charset} MML tag (@pxref{MML Definition}).
+@code{(iso-8859-1)}. You can override this setting on a per-message
+basis by using the @code{charset} @acronym{MML} tag (@pxref{MML Definition}).
@item mm-content-transfer-encoding-defaults
@vindex mm-content-transfer-encoding-defaults
(digitally signed messages require 7bit encoding). Besides the normal
@acronym{MIME} encodings, @code{qp-or-base64} may be used to indicate that for
each case the most efficient of quoted-printable and base64 should be
-used. You can override this setting on a per-message basis by using
-the @code{encoding} MML tag (@pxref{MML Definition}).
+used.
+
+@code{qp-or-base64} has another effect. It will fold long lines so that
+MIME parts may not be broken by MTA. So do @code{quoted-printable} and
+@code{base64}.
+
+Note that it affects body encoding only when a part is a raw forwarded
+message (which will be made by @code{gnus-summary-mail-forward} with the
+arg 2 for example) or is neither the @samp{text/*} type nor the
+@samp{message/*} type. Even though in those cases, you can override
+this setting on a per-message basis by using the @code{encoding}
+@acronym{MML} tag (@pxref{MML Definition}).
@item mm-use-ultra-safe-encoding
@vindex mm-use-ultra-safe-encoding
@section Charset Translation
@cindex charsets
-During translation from MML to @acronym{MIME}, for each @acronym{MIME} part which
-has been composed inside Emacs, an appropriate charset has to be chosen.
+During translation from @acronym{MML} to @acronym{MIME}, for each
+@acronym{MIME} part which has been composed inside Emacs, an appropriate
+charset has to be chosen.
@vindex mail-parse-charset
If you are running a non-@sc{mule} Emacs, this process is simple: If the
Customization}).
The charset to be used can be overridden by setting the @code{charset}
-MML tag (@pxref{MML Definition}) when composing the message.
+@acronym{MML} tag (@pxref{MML Definition}) when composing the message.
The encoding of characters (quoted-printable, 8bit etc) is orthogonal
to the discussion here, and is controlled by the variables
@section Conversion
@findex mime-to-mml
-A (multipart) @acronym{MIME} message can be converted to MML with the
-@code{mime-to-mml} function. It works on the message in the current
-buffer, and substitutes MML markup for @acronym{MIME} boundaries.
-Non-textual parts do not have their contents in the buffer, but instead
-have the contents in separate buffers that are referred to from the MML
-tags.
+A (multipart) @acronym{MIME} message can be converted to @acronym{MML}
+with the @code{mime-to-mml} function. It works on the message in the
+current buffer, and substitutes @acronym{MML} markup for @acronym{MIME}
+boundaries. Non-textual parts do not have their contents in the buffer,
+but instead have the contents in separate buffers that are referred to
+from the @acronym{MML} tags.
@findex mml-to-mime
-An MML message can be converted back to @acronym{MIME} by the
+An @acronym{MML} message can be converted back to @acronym{MIME} by the
@code{mml-to-mime} function.
These functions are in certain senses ``lossy''---you will not get back
emacs, Emacs Manual}) when encoding a message, and the
``format=flowed'' Content-Type parameter when decoding a message.
-On encoding text, lines terminated by soft newline characters are
-filled together and wrapped after the column decided by
-@code{fill-flowed-encode-column}. This variable controls how the text
-will look in a client that does not support flowed text, the default
-is to wrap after 66 characters. If hard newline characters are not
-present in the buffer, no flow encoding occurs.
+On encoding text, regardless of @code{use-hard-newlines}, lines
+terminated by soft newline characters are filled together and wrapped
+after the column decided by @code{fill-flowed-encode-column}.
+Quotation marks (matching @samp{^>* ?}) are respected. The variable
+controls how the text will look in a client that does not support
+flowed text, the default is to wrap after 66 characters. If hard
+newline characters are not present in the buffer, no flow encoding
+occurs.
On decoding flowed text, lines with soft newline characters are filled
together and wrapped after the column decided by
@code{fill-flowed-display-column}. The default is to wrap after
@code{fill-column}.
-
+@table @code
+@item mm-fill-flowed
+@vindex mm-fill-flowed
+If non-@code{nil} a format=flowed article will be displayed flowed.
+@end table
@node Interface Functions
@item mail-encode-encoded-word-region
@findex mail-encode-encoded-word-region
Encode the non-@acronym{ASCII} words in the region. For instance,
-@samp{Naïve} is encoded as @samp{=?iso-8859-1?q?Na=EFve?=}.
+@samp{Na@"{@dotless{i}}ve} is encoded as @samp{=?iso-8859-1?q?Na=EFve?=}.
@item mail-encode-encoded-word-buffer
@findex mail-encode-encoded-word-buffer
@example
(mail-encode-encoded-word-string
- "This is naïve, baby")
+ "This is na@"{@dotless{i}}ve, baby")
@result{} "This is =?iso-8859-1?q?na=EFve,?= baby"
@end example
@example
(mail-decode-encoded-word-string
"This is =?iso-8859-1?q?na=EFve,?= baby")
-@result{} "This is naïve, baby"
+@result{} "This is na@"{@dotless{i}}ve, baby"
@end example
@end table
The following variables are tweakable:
@table @code
-@item rfc2047-default-charset
-@vindex rfc2047-default-charset
-Characters in this charset should not be decoded by this library.
-This defaults to @code{iso-8859-1}.
-
@item rfc2047-header-encoding-alist
@vindex rfc2047-header-encoding-alist
This is an alist of header / encoding-type pairs. Its main purpose is
The keys can either be header regexps, or @code{t}.
-The values can be either @code{nil}, in which case the header(s) in
-question won't be encoded, or @code{mime}, which means that they will be
-encoded.
+The values can be @code{nil}, in which case the header(s) in question
+won't be encoded, @code{mime}, which means that they will be encoded, or
+@code{address-mime}, which means the header(s) will be encoded carefully
+assuming they contain addresses.
@item rfc2047-charset-encoding-alist
@vindex rfc2047-charset-encoding-alist
Quoted-Printable-like encoding) and @code{B} (base64). This alist
specifies which charset should use which encoding.
-@item rfc2047-encoding-function-alist
-@vindex rfc2047-encoding-function-alist
+@item rfc2047-encode-function-alist
+@vindex rfc2047-encode-function-alist
This is an alist of encoding / function pairs. The encodings are
@code{Q}, @code{B} and @code{nil}.
-@item rfc2047-q-encoding-alist
-@vindex rfc2047-q-encoding-alist
-The @code{Q} encoding isn't quite the same for all headers. Some
-headers allow a narrower range of characters, and that is what this
-variable is for. It's an alist of header regexps / allowable character
-ranges.
-
@item rfc2047-encoded-word-regexp
@vindex rfc2047-encoded-word-regexp
When decoding words, this library looks for matches to this regexp.
+@item rfc2047-encode-encoded-words
+@vindex rfc2047-encode-encoded-words
+The boolean variable specifies whether encoded words
+(e.g. @samp{=?hello?=}) should be encoded again.
+
@end table
Those were the variables, and these are this functions:
@findex rfc2047-decode-string
Decode a string and return the results.
+@item rfc2047-encode-parameter
+@findex rfc2047-encode-parameter
+Encode a parameter in the RFC2047-like style. This is a replacement for
+the @code{rfc2231-encode-string} function. @xref{rfc2231}.
+
+When attaching files as @acronym{MIME} parts, we should use the RFC2231
+encoding to specify the file names containing non-@acronym{ASCII}
+characters. However, many mail softwares don't support it in practice
+and recipients won't be able to extract files with correct names.
+Instead, the RFC2047-like encoding is acceptable generally. This
+function provides the very RFC2047-like encoding, resigning to such a
+regrettable trend. To use it, put the following line in your
+@file{~/.gnus.el} file:
+
+@lisp
+(defalias 'mail-header-encode-parameter 'rfc2047-encode-parameter)
+@end lisp
+
@end table
@c mode: texinfo
@c coding: iso-8859-1
@c End:
+
+@ignore
+ arch-tag: c7ef2fd0-a91c-4e10-aa52-c1a2b11b1a8d
+@end ignore
projects / gnus / blobdiff