11 MIME: Decoding Internet Data

11.1 Message Decoding

If part? is #f, then message-in should start with the header for a full message; otherwise, message-in should start with the header for a part within a message.

Standard values for the type field include 'text, 'image, 'audio, 'video, 'application, 'message, and 'multipart.

Standard values for the subtype field depend on the type field, and include the following, but any subtype is allowed as a downcased version of the specification from the header.

'text		'plain		[RFC1521, NSB]
		'richtext		[RFC1521, NSB]
		'tab-separated-values		[Lindner]
'multipart		'mixed		[RFC1521, NSB]
		'alternative		[RFC1521, NSB]
		'digest		[RFC1521, NSB]
		'parallel		[RFC1521, NSB]
		'appledouble		[MacMime, Faltstrom]
		'header-set		[Crocker]
'message		'rfc822		[RFC1521, NSB]
		'partial		[RFC1521, NSB]
		'external-body		[RFC1521, NSB]
		'news		[RFC 1036, Spencer]
'application		'octet-stream		[RFC1521, NSB]
		'postscript		[RFC1521, NSB]
		'oda		[RFC1521, NSB]
		'atomicmail		[atomicmail, NSB]
		'andrew-inset		[andrew-inset, NSB]
		'slate		[slate, Crowley]
		'wita		[Wang Info Transfer, Campbell]
		'dec-dx		[Digital Doc Trans, Campbell]
		'dca-rft		[IBM Doc Content Arch, Campbell]
		'activemessage		[Shapiro]
		'rtf		[Lindner]
		'applefile		[MacMime, Faltstrom]
		'mac-binhex40		[MacMime, Faltstrom]
		'news-message-id		[RFC1036, Spencer]
		'news-transmission		[RFC1036, Spencer]
		'wordperfect5.1		[Lindner]
		'pdf		[Lindner]
		'zip		[Lindner]
		'macwriteii		[Lindner]
		'msword		[Lindner]
		'remote-printing		[RFC1486,MTR]
'image		'jpeg		[RFC1521, NSB]
		'gif		[RFC1521, NSB]
		'ief		[RFC1314]
		'tiff		[MTR]
'audio		'basic		[RFC1521, NSB]
'video		'mpeg		[RFC1521, NSB]
		'quicktime		[Lindner]

Standard values for the charset field include 'us-ascii, which is the default.

Standard values for the encoding field are '7bit, '8bit, 'binary, 'quoted-printable, and 'base64. The default is '7bit.

The params field contains a list of parameters from other MIME headers.

The id field is taken from the "Content-Id" header field.

The description field is taken from the "Content-description" header field.

The other field contains additional (non-standard) field headers whose field names start with "Content-".

The fields field contains additional field headers whose field names do not start with "Content-".

The parts contains sub-parts from multipart MIME messages. This list is non-empty only when type is 'multipart or 'message.

The body field represents the body as a function that consumes an output out and writes the decoded message to the port. If type is 'multipart or 'message., then body is '(). All of the standard values of encoding are supported. The procedure only works once (since the encoded body is pulled from a stream).

Standard values for the type field include 'inline and 'attachment.

The filename field is drawn from the "filename" parameter of the "Content-Disposition" header, if included in the message.

The creation, modification, and read fields represent file timestamps as drawn from the "creation-date", "modification-date", and "read-date" attributes of the "Content-Disposition" header, if included in the message.

The size field is drawn from the "size" parameter of the "Content-Disposition" header, if included in the message.

The params field stores any additional attribute bindings of the "Content-Disposition" header, if included in the message.

11.2 Exceptions

11.3 MIME Unit

mime@ and mime^ are deprecated. They exist for backward-compatibility and will likely be removed in the future. New code should use the net/mime module.

(require net/mime-unit)

11.4 MIME Signature

(require net/mime-sig)

Includes everything exported by the net/mime module.