1MIME::EncWords(3) User Contributed Perl Documentation MIME::EncWords(3)
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6 MIME::EncWords - deal with RFC 2047 encoded words (improved)
7
9 MIME::EncWords is aimed to be another implimentation of MIME::Words so
10 that it will achieve more exact conformance with RFC 2047 (formerly RFC
11 1522) specifications. Additionally, it contains some improvements.
12 Following synopsis and descriptions are inherited from its inspirer,
13 then added descriptions on improvements (**) or changes and
14 clarifications (*).
15 Before reading further, you should see MIME::Tools to make sure that
17 you understand where this module fits into the grand scheme of things.
18 Go on, do it now. I'll wait.
19 Ready? Ok...
21 use MIME::EncWords qw(:all);
23 ### Decode the string into another string, forgetting the charsets:
25 $decoded = decode_mimewords(
26 'To: =?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?= <keld@dkuug.dk>',
27 );
28 ### Split string into array of decoded [DATA,CHARSET] pairs:
30 @decoded = decode_mimewords(
31 'To: =?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?= <keld@dkuug.dk>',
32 );
33 ### Encode a single unsafe word:
35 $encoded = encode_mimeword("\xABFran\xE7ois\xBB");
36 ### Encode a string, trying to find the unsafe words inside it:
38 $encoded = encode_mimewords("Me and \xABFran\xE7ois\xBB in town");
39
41 Fellow Americans, you probably won't know what the hell this module is
42 for. Europeans, Russians, et al, you probably do. ":-)".
43 For example, here's a valid MIME header you might get:
45 From: =?US-ASCII?Q?Keith_Moore?= <moore@cs.utk.edu>
47 To: =?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?= <keld@dkuug.dk>
48 CC: =?ISO-8859-1?Q?Andr=E9_?= Pirard <PIRARD@vm1.ulg.ac.be>
49 Subject: =?ISO-8859-1?B?SWYgeW91IGNhbiByZWFkIHRoaXMgeW8=?=
50 =?ISO-8859-2?B?dSB1bmRlcnN0YW5kIHRoZSBleGFtcGxlLg==?=
51 =?US-ASCII?Q?.._cool!?=
52 The fields basically decode to (sorry, I can only approximate the Latin
54 characters with 7 bit sequences /o and 'e):
55 From: Keith Moore <moore@cs.utk.edu>
57 To: Keld J/orn Simonsen <keld@dkuug.dk>
58 CC: Andr'e Pirard <PIRARD@vm1.ulg.ac.be>
59 Subject: If you can read this you understand the example... cool!
60 Supplement: Fellow Americans, Europeans, you probably won't know what
62 the hell this module is for. East Asians, et al, you probably do.
63 "(^_^)".
64 For example, here's a valid MIME header you might get:
66 Subject: =?EUC-KR?B?sNTAuLinKGxhemluZXNzKSwgwvzB9ri7seIoaW1w?=
68 =?EUC-KR?B?YXRpZW5jZSksILGzuLgoaHVicmlzKQ==?=
69 The fields basically decode to (sorry, I cannot approximate the non-
71 Latin multibyte characters with any 7 bit sequences):
72 Subject: ???(laziness), ????(impatience), ??(hubris)
74
76 decode_mimewords ENCODED, [OPTS...]
77 Function. Go through the string looking for RFC 2047-style "Q"
78 (quoted-printable, sort of) or "B" (base64) encoding, and decode
79 them.
80 In an array context, splits the ENCODED string into a list of
82 decoded "[DATA, CHARSET]" pairs, and returns that list. Unencoded
83 data are returned in a 1-element array "[DATA]", giving an
84 effective CHARSET of "undef".
85 $enc = '=?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?= <keld@dkuug.dk>';
87 foreach (decode_mimewords($enc)) {
88 print "", ($_[1] || 'US-ASCII'), ": ", $_[0], "\n";
89 }
90 ** However, adjacent encoded-words with same charset will be
92 concatenated to handle multibyte sequences safely.
93 ** Language information defined by RFC2231, section 5 will be
95 additonal third element, if any.
96 * Whitespaces surrounding unencoded data will not be stripped so
98 that compatibility with MIME::Words will be ensured.
99 In a scalar context, joins the "data" elements of the above list
101 together, and returns that. Warning: this is information-lossy,
102 and probably not what you want, but if you know that all charsets
103 in the ENCODED string are identical, it might be useful to you.
104 (Before you use this, please see "unmime" in MIME::WordDecoder,
105 which is probably what you want.) ** See also "Charset" option
106 below.
107 In the event of a syntax error, $@ will be set to a description of
109 the error, but parsing will continue as best as possible (so as to
110 get something back when decoding headers). $@ will be false if no
111 error was detected.
112 * Malformed encoded-words will be kept encoded. In this case $@
114 will be set.
115 Any arguments past the ENCODED string are taken to define a hash of
117 options. ** When Unicode/multibyte support is disabled (see
118 "USE_ENCODE" in MIME::Charset), these options will not have any
119 effects.
120 Charset **
122 Name of character set by which data elements in scalar context
123 will be converted. The default is no conversion. If this
124 option is specified as special value "_UNICODE_", returned
125 value will be Unicode string.
126 Note: This feature is still information-lossy, except when
128 "_UNICODE_" is specified.
129 Detect7bit **
131 Try to detect 7-bit charset on unencoded portions. Default is
132 "YES".
133 Mapping **
135 In scalar context, specify mappings actually used for charset
136 names. "EXTENDED" uses extended mappings. "STANDARD" uses
137 standardized strict mappings. Default is "EXTENDED".
138 encode_mimeword RAW, [ENCODING], [CHARSET]
140 Function. Encode a single RAW "word" that has unsafe characters.
141 The "word" will be encoded in its entirety.
142 ### Encode "<<Franc,ois>>":
144 $encoded = encode_mimeword("\xABFran\xE7ois\xBB");
145 You may specify the ENCODING ("Q" or "B"), which defaults to "Q".
147 ** You may also specify it as ``special'' value: "S" to choose
148 shorter one of either "Q" or "B".
149 You may specify the CHARSET, which defaults to "iso-8859-1".
151 * Spaces will be escaped with ``_'' by "Q" encoding.
153 encode_mimewords RAW, [OPTS]
155 Function. Given a RAW string, try to find and encode all "unsafe"
156 sequences of characters:
157 ### Encode a string with some unsafe "words":
159 $encoded = encode_mimewords("Me and \xABFran\xE7ois\xBB");
160 Returns the encoded string.
162 ** RAW may be a Unicode string when Unicode/multibyte support is
164 enabled (see "USE_ENCODE" in MIME::Charset). Furthermore, RAW may
165 be a reference to that returned by "decode_mimewords" on array
166 context. In latter case "Charset" option (see below) will be
167 overridden (see also a note below).
168 Note: * When RAW is an arrayref, adjacent encoded-words (i.e.
170 elements having non-ASCII charset element) are concatenated. Then
171 they are split taking care of character boundaries of multibyte
172 sequences when Unicode/multibyte support is enabled. Portions for
173 unencoded data should include surrounding whitespace(s), or they
174 will be merged into adjoining encoded-word(s).
175 Any arguments past the RAW string are taken to define a hash of
177 options:
178 Charset
180 Encode all unsafe stuff with this charset. Default is
181 'ISO-8859-1', a.k.a. "Latin-1".
182 Detect7bit **
184 When "Encoding" option (see below) is specified as "a" and
185 "Charset" option is unknown, try to detect 7-bit charset on
186 given RAW string. Default is "YES". When Unicode/multibyte
187 support is disabled, this option will not have any effects (see
188 "USE_ENCODE" in MIME::Charset).
189 Encoding
191 The encoding to use, "q" or "b". ** You may also specify
192 ``special'' values: "a" will automatically choose recommended
193 encoding to use (with charset conversion if alternative charset
194 is recommended: see MIME::Charset); "s" will choose shorter one
195 of either "q" or "b". Note: * As of release 1.005, The default
196 was changed from "q" (the default on MIME::Words) to "a".
197 Field
199 Name of the mail field this string will be used in. ** Length
200 of mail field name will be considered in the first line of
201 encoded header.
202 Folding **
204 A Sequence to fold encoded lines. The default is "\n". If
205 empty string "" is specified, encoded-words exceeding line
206 length (see "MaxLineLen" below) will be split by SPACE.
207 Note: * Though RFC 5322 (formerly RFC 2822) states that the
209 lines in Internet messages are delimited by CRLF ("\r\n"), this
210 module chose LF ("\n") as a default to keep backward
211 compatibility. When you use the default, you might need
212 converting newlines before encoded headers are thrown into
213 session.
214 Mapping **
216 Specify mappings actually used for charset names. "EXTENDED"
217 uses extended mappings. "STANDARD" uses standardized strict
218 mappings. The default is "EXTENDED". When Unicode/multibyte
219 support is disabled, this option will not have any effects (see
220 "USE_ENCODE" in MIME::Charset).
221 MaxLineLen **
223 Maximum line length excluding newline. The default is 76.
224 Negative value means unlimited line length (as of release
225 1.012.3).
226 Minimal **
228 Takes care of natural word separators (i.e. whitespaces) in the
229 text to be encoded. If "NO" is specified, this module will
230 encode whole text (if encoding needed) not regarding
231 whitespaces; encoded-words exceeding line length will be split
232 based only on their lengths. Default is "YES" by which minimal
233 portions of text are encoded. If "DISPNAME" is specified,
234 portions including special characters described in RFC5322
235 (formerly RFC2822, RFC822) address specification (section 3.4)
236 are also encoded. This is useful for encoding display-name of
237 address fields.
238 Note: As of release 0.040, default has been changed to "YES" to
240 ensure compatibility with MIME::Words. On earlier releases,
241 this option was fixed to be "NO".
242 Note: "DISPNAME" option was introduced at release 1.012.
244 Replacement **
246 See "Error Handling" in MIME::Charset.
247 Configuration Files **
249 Built-in defaults of option parameters for "decode_mimewords" (except
250 'Charset' option) and "encode_mimewords" can be overridden by
251 configuration files: MIME/Charset/Defaults.pm and
252 MIME/EncWords/Defaults.pm. For more details read
253 MIME/EncWords/Defaults.pm.sample.
254
256 Consult $VERSION variable.
257 Development versions of this module may be found at
259 <http://hatuka.nezumi.nu/repos/MIME-EncWords/>.
260
262 MIME::Charset, MIME::Tools
263
265 The original version of function decode_mimewords() is derived from
266 MIME::Words module that was written by:
267 Eryq (eryq@zeegee.com), ZeeGee Software Inc
268 (http://www.zeegee.com).
269 David F. Skoll (dfs@roaringpenguin.com)
270 http://www.roaringpenguin.com
271 Other stuff are rewritten or added by:
273 Hatuka*nezumi - IKEDA Soji <hatuka(at)nezumi.nu>.
274 This program is free software; you can redistribute it and/or modify it
276 under the same terms as Perl itself.
277perl v5.34.0 2021-07-22 MIME::EncWords(3)