Section: User Contributed Perl Documentation (3)
Updated: 2006-03-17
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MIME::Words - deal with RFC-1522 encoded words  


Before reading further, you should see MIME::Tools to make sure that you understand where this module fits into the grand scheme of things. Go on, do it now. I'll wait.

Ready? Ok...

    use MIME::Words qw(:all);

    ### Decode the string into another string, forgetting the charsets:
    $decoded = decode_mimewords(
          'To: =?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?= <keld@dkuug.dk>',

    ### Split string into array of decoded [DATA,CHARSET] pairs:
    @decoded = decode_mimewords(
          'To: =?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?= <keld@dkuug.dk>',

    ### Encode a single unsafe word:
    $encoded = encode_mimeword("\xABFran\xE7ois\xBB");

    ### Encode a string, trying to find the unsafe words inside it: 
    $encoded = encode_mimewords("Me and \xABFran\xE7ois\xBB in town");



Fellow Americans, you probably won't know what the hell this module is for. Europeans, Russians, et al, you probably do. ":-)".

For example, here's a valid MIME header you might get:

      From: =?US-ASCII?Q?Keith_Moore?= <moore@cs.utk.edu>
      To: =?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?= <keld@dkuug.dk>
      CC: =?ISO-8859-1?Q?Andr=E9_?= Pirard <PIRARD@vm1.ulg.ac.be>
      Subject: =?ISO-8859-1?B?SWYgeW91IGNhbiByZWFkIHRoaXMgeW8=?=

The fields basically decode to (sorry, I can only approximate the Latin characters with 7 bit sequences /o and 'e):

      From: Keith Moore <moore@cs.utk.edu>
      To: Keld J/orn Simonsen <keld@dkuug.dk>
      CC: Andr'e  Pirard <PIRARD@vm1.ulg.ac.be>
      Subject: If you can read this you understand the example... cool!



decode_mimewords ENCODED, [OPTS...]
Function. Go through the string looking for RFC-1522-style ``Q'' (quoted-printable, sort of) or ``B'' (base64) encoding, and decode them.

In an array context, splits the ENCODED string into a list of decoded "[DATA, CHARSET]" pairs, and returns that list. Unencoded data are returned in a 1-element array "[DATA]", giving an effective CHARSET of "undef".

    $enc = '=?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?= <keld@dkuug.dk>';
    foreach (decode_mimewords($enc)) {
        print "", ($_[1] || 'US-ASCII'), ": ", $_[0], "\n";

In a scalar context, joins the ``data'' elements of the above list together, and returns that. Warning: this is information-lossy, and probably not what you want, but if you know that all charsets in the ENCODED string are identical, it might be useful to you. (Before you use this, please see ``unmime'' in MIME::WordDecoder, which is probably what you want.)

In the event of a syntax error, $@ will be set to a description of the error, but parsing will continue as best as possible (so as to get something back when decoding headers). $@ will be false if no error was detected.

Any arguments past the ENCODED string are taken to define a hash of options:

Name of the mail field this string came from. Currently ignored.
encode_mimeword RAW, [ENCODING], [CHARSET]
Function. Encode a single RAW ``word'' that has unsafe characters. The ``word'' will be encoded in its entirety.

    ### Encode "<<Franc,ois>>":
    $encoded = encode_mimeword("\xABFran\xE7ois\xBB");

You may specify the ENCODING ("Q" or "B"), which defaults to "Q". You may specify the CHARSET, which defaults to "iso-8859-1".

encode_mimewords RAW, [OPTS]
Function. Given a RAW string, try to find and encode all ``unsafe'' sequences of characters:

    ### Encode a string with some unsafe "words":
    $encoded = encode_mimewords("Me and \xABFran\xE7ois\xBB");

Returns the encoded string. Any arguments past the RAW string are taken to define a hash of options:

Encode all unsafe stuff with this charset. Default is 'ISO-8859-1', a.k.a. ``Latin-1''.
The encoding to use, "q" or "b". The default is "q".
Name of the mail field this string will be used in. Currently ignored.

Warning: this is a quick-and-dirty solution, intended for character sets which overlap ASCII. It does not comply with the RFC-1522 rules regarding the use of encoded words in message headers. You may want to roll your own variant, using "encoded_mimeword()", for your application. Thanks to Jan Kasprzak for reminding me about this problem.



Exports its principle functions by default, in keeping with MIME::Base64 and MIME::QuotedPrint.  


Eryq (eryq@zeegee.com), ZeeGee Software Inc (http://www.zeegee.com). David F. Skoll (dfs@roaringpenguin.com) http://www.roaringpenguin.com

All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

Thanks also to...

      Kent Boortz        For providing the idea, and the baseline 
                         RFC-1522-decoding code!
      KJJ at PrimeNet    For requesting that this be split into
                         its own module.
      Stephane Barizien  For reporting a nasty bug.



$Revision: 1.14 $ $Date: 2006/03/17 21:03:23 $




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