12 MIME: Decoding Internet Data
12.1 Message Decoding
procedure
(mime-analyze message-in [part?]) → message?
message-in : (or/c bytes? input-port) part? : any/c = #f
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.
struct
(struct message (version entity fields) #:extra-constructor-name make-message) version : real? entity : entity fields : (listof string?)
struct
(struct entity ( type subtype charset encoding disposition params id description other fields parts body) #:extra-constructor-name make-entity) type : symbol? subtype : symbol? charset : symbol? encoding : symbol? disposition : disposition? params : (listof (cons/c symbol? string?)) id : string? description : string? other : (listof string?) fields : (listof string?) parts : (listof message?) body : (or/c (output-port? . -> . void?) null?)
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] |
|
|
| [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).
struct
(struct disposition ( type filename creation modification read size params) #:extra-constructor-name make-disposition) type : symbol? filename : (or/c string? false/c) creation : (or/c string? false/c) modification : (or/c string? false/c) read : (or/c string? false/c) size : (or/c exact-nonnegative-integer? false/c) params : (listof (cons/c symbol? string?))
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.
12.2 Exceptions
struct
(struct mime-error exn:fail () #:extra-constructor-name make-mime-error)
struct
(struct unexpected-termination mime-error (msg) #:extra-constructor-name make-unexpected-termination) msg : string?
struct
(struct missing-multipart-boundary-parameter mime-error () #:extra-constructor-name make-missing-multipart-boundary-parameter)
struct
(struct malformed-multipart-entity mime-error (msg) #:extra-constructor-name make-malformed-multipart-entity) msg : string?
struct
(struct empty-mechanism mime-error () #:extra-constructor-name make-empty-mechanism)
struct
(struct empty-type mime-error () #:extra-constructor-name make-empty-type)
struct
(struct empty-subtype mime-error () #:extra-constructor-name make-empty-subtype)
struct
(struct empty-disposition-type mime-error () #:extra-constructor-name make-empty-disposition-type)
12.3 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) | package: compatibility-lib |
value
mime@ : unit?
12.4 MIME Signature
| (require net/mime-sig) | package: compatibility-lib |
signature
mime^ : signature
Includes everything exported by the net/mime module.