Tnef

tnef - decode Microsoft's Transport Neutral Encapsulation Format

Beschreibung

TNEF ist ein Programm zur Dekomprimierung von MIME-Anhängen des Typs »application/ms-tnef«

• Dies ist ein typischer Microsoft-Anhang

Das Programm ermöglicht das Auspacken von in TNEF eingekapselten Anhängen

• Dies mildert die Notwendigkeit des Gebrauches von Microsoft Outlook, um diese Anhänge zu betrachten

Diese Handbuchseite dokumentiert den tnef-Filter

• tnef dekodiert E-Mail-Anhänge, die in Microsofts Transport Neutral Encapsulation Format (im Folgenden TNEF) kodiert sind, das Microsoft-E-Mail-Anhänge "umhüllt".

Leider sind diese "verpackten" Anhänge für jeden E-Mail-Client, der TNEF nicht versteht, unzugänglich.

• Glücklicherweise kann der tnef-Filter von jedem MIME-fähigen Client verwendet werden, um diese Anhänge zu entpacken.

Installation

# apt install tnef

Syntax

$ tnef [options] [FILE]
$ tnef {--help | --version}

Optionen

Option	Beschreibung
f FILE, --file=FILE	use FILE as input ('-' denotes stdin). When this option is omitted, tnef reads data from stdin.
C DIR, --directory=DIR	unpack file attachments into DIR.
x SIZE, --maxsize=SIZE	limit maximum size of extracted archive (bytes)
t, --list	list attached files, do not extract. For each file in the datafile the file name and full path will be printed. If the verbose option is also provided then this option acts as the --list-with-mime-types option and also prints the file length (in bytes) and the date of the file before the other data.
-list-with-mime-types	same as list option but also prints MIME type and content ID of each file after filename and file path.
w, --interactive, --confirmation	ask for confirmation for every action.
-overwrite	when extracting attachments, overwrite existing files.
-number-backups	when extracting attachments, if file FOO will be overwritten, create FOO.n instead.
-use-paths	honor file pathnames specified in the TNEF attachment. For security reasons, paths to attached files are ignored by default.
-save-body FILE	Save message body data found in the TNEF data. By default tnef only extracts the attached files and not the message body. There can be up to three message bodies in the file, plain text, HTML encoded, and RTF encoded. Which are saved is specified by the --body-pref option. By default the message bodies are written to a file named message with an extension based upon the type (txt, html, rtf).
-body-pref PREF	Specifies which of the possibly three message body formats will be saved. PREF can be up to three characters long and each character must be one of 'r', 'h', or 't' specifying RTF, HTML or text. The order is the order that the data will be checked, the first type found will be saved. If PREF is the special value of 'all' then any and all message body data found will be saved. The default is 'rht'.
-save-rtf FILE	DEPRECATED. Equivalent to --save-body=FILE --body-pref=r
h, --help	show usage message
V, --version	display version and copyright
v, --verbose	produce verbose output
-debug	enable debug output. (This will produce a very large amount of output.)

Anwendungen

tnef usage with a popular Unix mail client "mutt"

Step 1 — Configure ~/.mailcap

Mutt can't use tnef for its intended purpose until an appropriate content type definition exists in ~/.mailcap. Here's a sample definition:

application/ms-tnef; tnef -w %s

This mailcap entry says that whenever the MIME content type:

application/ms-tnef

is encountered, use this command to decode it:

tnef -w %s

The latter command string invokes tnef, specifying both the -w option and the attachment (created as a temporary file) as command line arguments.

Step 2 — Add The Filter To $PATH

Mutt can't invoke tnef if the filter isn't accessible via $PATH.

Step 3 — Test Mutt

Use mutt to read a message that includes a TNEF attachment. Mutt will note that an attachment of type "application/ms-tnef is unsupported".

Press the "v" key to open mutt's "view attachment" menu.

Move the cursor over the TNEF attachment and press the enter key to "view" the attachment. Mutt will launch tnef and invoke it using the command line syntax specified in ~/.mailcap (step 1). tnef then decodes all file(s) included in the TNEF attachment, prompting for confirmation prior to creating an individual file (refer to -w option above). -w is useful here because it gives the end user a chance to view the filename(s) included in the mail message.

Note that Mutt's attachment menu also supports a pipe option, which permits the user to pipe attachments to an external filter (how convenient). So, to list the contents of a TNEF attachment prior to decoding it, press the "|" key and enter this command:

tnef -t

KNOWN LIMITATIONS

tnef ignores the OEMCodePage data in the data file. It assumes Unicode data.

Siehe auch

1. metamail(1)
2. mailcap(4)
3. mutt(1)
4. other email clients

Links

Weblinks

1. https://www.dwheeler.com/essays/microsoft-outlook-tnef.html

Testfragen

Testfrage 1

Antwort1

Testfrage 2

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Testfrage 3

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Testfrage 4

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Testfrage 5

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