1MIME::WordDecoder(3) User Contributed Perl Documentation MIME::WordDecoder(3)
2
6 MIME::WordDecoder - decode RFC 2047 encoded words to a local
7 representation
8
10 See MIME::Words for the basics of encoded words. See "DESCRIPTION" for
11 how this class works.
12 use MIME::WordDecoder;
14 ### Get the default word-decoder (used by unmime()):
17 $wd = default MIME::WordDecoder;
18 ### Get a word-decoder which maps to ISO-8859-1 (Latin1):
20 $wd = supported MIME::WordDecoder "ISO-8859-1";
21 ### Decode a MIME string (e.g., into Latin1) via the default decoder:
24 $str = $wd->decode('To: =?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?= <keld>');
25 ### Decode a string using the default decoder, non-OO style:
27 $str = unmime('To: =?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?= <keld>');
28
30 A MIME::WordDecoder consists, fundamentally, of a hash which maps a
31 character set name (US-ASCII, ISO-8859-1, etc.) to a subroutine which
32 knows how to take bytes in that character set and turn them into the
33 target string representation. Ideally, this target representation
34 would be Unicode, but we don't want to overspecify the translation that
35 takes place: if you want to convert MIME strings directly to Big5,
36 that's your own decision.
37 The subroutine will be invoked with two arguments: DATA (the data in
39 the given character set), and CHARSET (the upcased character set name).
40 For example:
42 ### Keep 7-bit characters as-is, convert 8-bit characters to '#':
44 sub keep7bit {
45 local $_ = shift;
46 tr/\x00-\x7F/#/c;
47 $_;
48 }
49 Here's a decoder which uses that:
51 ### Construct a decoder:
53 $wd = MIME::WordDecoder->new({'US-ASCII' => "KEEP", ### sub { $_[0] }
54 'ISO-8859-1' => \&keep7bit,
55 'ISO-8859-2' => \&keep7bit,
56 'Big5' => "WARN",
57 '*' => "DIE"});
58 ### Convert some MIME text to a pure ASCII string...
60 $ascii = $wd->decode('To: =?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?= <keld>');
61 ### ...which will now hold: "To: Keld J#rn Simonsen <keld>"
63
65 default [DECODER]
66 Class method. Get/set the default DECODER object.
67 supported CHARSET, [DECODER]
69 Class method. If just CHARSET is given, returns a decoder object
70 which maps data into that character set (the character set is
71 forced to all-uppercase).
72 $wd = supported MIME::WordDecoder "ISO-8859-1";
74 If DECODER is given, installs such an object:
76 MIME::WordDecoder->supported("ISO-8859-1" =>
78 (new MIME::WordDecoder::ISO_8859 "1"));
79 You should not override this method.
81 new [\@HANDLERS]
83 Class method, constructor. If \@HANDLERS is given, then @HANDLERS
84 is passed to handler() to initiallize the internal map.
85 handler CHARSET=>\&SUBREF, ...
87 Instance method. Set the handler SUBREF for a given CHARSET, for
88 as many pairs as you care to supply.
89 When performing the translation of a MIME-encoded string, a given
91 SUBREF will be invoked when translating a block of text in
92 character set CHARSET. The subroutine will be invoked with the
93 following arguments:
94 DATA - the data in the given character set.
96 CHARSET - the upcased character set name, which may prove useful
97 if you are using the same SUBREF for multiple CHARSETs.
98 DECODER - the decoder itself, if it contains configuration information
99 that your handler function needs.
100 For example:
102 $wd = new MIME::WordDecoder;
104 $wd->handler('US-ASCII' => "KEEP");
105 $wd->handler('ISO-8859-1' => \&handle_latin1,
106 'ISO-8859-2' => \&handle_latin1,
107 '*' => "DIE");
108 Notice that, much as with %SIG, the SUBREF can also be taken from a
110 set of special keywords:
111 KEEP Pass data through unchanged.
113 IGNORE Ignore data in this character set, without warning.
114 WARN Ignore data in this character set, with warning.
115 DIE Fatal exception with "can't handle character set" message.
116 The subroutine for the special CHARSET of 'raw' is used for raw
118 (non-MIME-encoded) text, which is supposed to be US-ASCII. The
119 handler for 'raw' defaults to whatever was specified for 'US-ASCII'
120 at the time of construction.
121 The subroutine for the special CHARSET of '*' is used for any
123 unrecognized character set. The default action for '*' is WARN.
124 decode STRING
126 Instance method. Decode a STRING which might contain MIME-encoded
127 components into a local representation (e.g., UTF-8, etc.).
128 unmime STRING
130 Function, exported. Decode the given STRING using the default()
131 decoder. See default().
132
134 MIME::WordDecoder::ISO_8859
135 A simple decoder which keeps US-ASCII and the 7-bit characters of
136 ISO-8859 character sets and UTF8, and also keeps 8-bit characters
137 from the indicated character set.
138 ### Construct:
140 $wd = new MIME::WordDecoder::ISO_8859 2; ### ISO-8859-2
141 ### What to translate unknown characters to (can also use empty):
143 ### Default is "?".
144 $wd->unknown("?");
145 ### Collapse runs of unknown characters to a single unknown()?
147 ### Default is false.
148 $wd->collapse(1);
149 According to http://czyborra.com/charsets/iso8859.html (ca.
151 November 2000):
152 ISO 8859 is a full series of 10 (and soon even more) standardized
154 multilingual single-byte coded (8bit) graphic character sets for
155 writing in alphabetic languages:
156 1. Latin1 (West European)
158 2. Latin2 (East European)
159 3. Latin3 (South European)
160 4. Latin4 (North European)
161 5. Cyrillic
162 6. Arabic
163 7. Greek
164 8. Hebrew
165 9. Latin5 (Turkish)
166 10. Latin6 (Nordic)
167 The ISO 8859 charsets are not even remotely as complete as the
169 truly great Unicode but they have been around and usable for quite
170 a while (first registered Internet charsets for use with MIME) and
171 have already offered a major improvement over the plain 7bit US-
172 ASCII.
173 Characters 0 to 127 are always identical with US-ASCII and the
175 positions 128 to 159 hold some less used control characters: the
176 so-called C1 set from ISO 6429.
177 MIME::WordDecoder::US_ASCII
179 A subclass of the ISO-8859-1 decoder which discards 8-bit
180 characters. You're probably better off using ISO-8859-1.
181
183 MIME::Tools
184
186 Eryq (eryq@zeegee.com), ZeeGee Software Inc (http://www.zeegee.com).
187 David F. Skoll (dfs@roaringpenguin.com) http://www.roaringpenguin.com
188perl v5.12.0 2008-06-30 MIME::WordDecoder(3)