1 <?xml version="1.0" standalone="no"?>
2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3 "file:///usr/share/xml/docbook/schema/dtd/4.5/docbookx.dtd">
5 <refentry id="mimedecode.py">
8 <title>mimedecode.py</title>
9 <productname>mimedecode.docbook</productname>
11 <firstname>Oleg</firstname>
12 <surname>Broytman</surname>
13 <email>phd@phdru.name</email>
17 <year>2001-2014</year>
18 <holder>PhiloSoft Design.</holder>
23 <refentrytitle>mimedecode.py</refentrytitle>
24 <manvolnum>1</manvolnum>
28 <refname>mimedecode.py</refname>
29 <refpurpose>decode MIME message</refpurpose>
34 <command>mimedecode.py</command>
36 <option>-h|--help</option>
39 <option>-V|--version</option>
42 <option>-cCDP</option>
45 <option>-f charset</option>
48 <option>-H|--host=hostname</option>
51 <option>-d header1[,header2,header3...]</option>
54 <option>-d *[,-header1,-header2,-header3...]</option>
57 <option>-p header1[,header2,header3,...]:param1[,param2,param3,...]</option>
60 <option>-p *[,-header1,-header2,-header3,...]:param1[,param2,param3,...]</option>
61 <option>-p header1[,header2,header3,...]:*[,-param1,-param2,-param3,...]</option>
62 <option>-p *[,-header1,-header2,-header3,...]:*[,-param1,-param2,-param3,...]</option>
65 <option>-r header1[,header2,header3...]</option>
68 <option>-r *[,-header1,-header2,-header3...]</option>
71 <option>-R header:param</option>
74 <option>--remove-params=header</option>
77 <option>-beit mask</option>
80 <option>-o output_file</option>
82 <arg choice="opt">input_file
83 <arg choice="opt">output_file</arg>
90 <title>DESCRIPTION</title>
92 Mail users, especially in non-English countries, often find that mail
93 messages arrived in different formats, with different content types, in
94 different encodings and charsets. Usually it is good because it allows to
95 use an appropriate format/encoding/whatever. Sometimes, though, some
96 unification is desirable. For example, one may want to put mail messages
97 into an archive, make HTML indices, run search indexer, etc. In such
98 situations converting messages to text in one character set and skipping
99 some binary attachments is much desirable.
103 Here is the solution - mimedecode.py!
107 This is a program to decode MIME messages. The program expects one input
108 file (either on command line or on stdin) which is treated as an RFC822
109 message, and decodes to stdout or an output file. If the file is not an
110 RFC822 message it is just copied to the output one-to-one. If the file is a
111 simple RFC822 message it is decoded as one part. If it is a MIME message
112 with multiple parts ("attachments") all parts are decoded. Decoding can be
113 controlled by command-line options.
117 First, for every part the program removes headers and parameters listed with
118 -r and -R options. Then, Subject and Content-Disposition headers (and all
119 headers listed with -d and -p options) are examined. If any of those exists,
120 they are decoded according to RFC2047. Content-Disposition header is not
121 decoded - only its "filename" parameter. Encoded header parameters violate
122 the RFC, but widely deployed anyway by ignorant coders who never even heard
123 about RFCs. Correct parameter encoding specified by RFC2231. This program
124 decodes RFC2231-encoded parameters, too.
128 Then the body of the message (or the current part) is decoded. Decoding
129 starts with looking at header Content-Transfer-Encoding. If the header
130 specifies non-8bit encoding (usually base64 or quoted-printable), the body
131 converted to 8bit. Then, if its content type is multipart (multipart/related
132 or multipart/mixed, e.g) every part is recursively decoded. If it is not
133 multipart, mailcap database is consulted to find a way to convert the body
134 to plain text. (I have no idea how mailcap can be configured on OSes other
135 than POSIX, please don't ask me; real OS users can consult my example at
136 <ulink url="http://phdru.name/Software/dotfiles/mailcap.html">http://phdru.name/Software/dotfiles/mailcap.html</ulink>).
137 The decoding process uses the first copiousoutput filter it can find. If
138 there are no filters the body just passed as is.
142 Then Content-Type header is consulted for charset. If it is not equal to the
143 current locale charset and recoding is allowed the body text is recoded.
144 Finally message headers and the body are flushed to stdout.
150 Please be warned that in the following options asterisk is a shell
151 metacharacter and should be escaped or quoted. Either write -d \*,-h1,-h2
152 or -d '*,-h1,-h2' or such.
157 <title>OPTIONS</title>
164 Print brief usage help and exit.
171 <term>--version</term>
174 Print version and exit.
183 Recode different character sets in message bodies to the current
184 default charset; this is the default.
193 Do not recode character sets in message bodies.
199 <term>-f charset</term>
202 Force this charset to be the current default charset instead of
209 <term>-H hostname</term>
210 <term>--host=hostname</term>
213 Use this hostname in X-MIME-Autoconverted headers instead of the
220 <term>-d header1[,header2,header3...]</term>
223 Add the header(s) to a list of headers to decode; initially the
224 list contains headers "From", "To", "Cc", "Reply-To",
225 "Mail-Followup-To" and "Subject".
231 <term>-d *[,-header1,-header2,-header3...]</term>
234 This variant completely changes headers decoding. First, the list of
235 headers to decode is cleared. Then all the headers are decoded
236 except the given list of exceptions (headers listed with '-'). In
237 this mode it would be meaningless to give more than one -d options
238 but the program doesn't enforce it.
247 Clear the list of headers to decode (make it empty).
253 <term>-p header1[,header2,header3,...]:param1[,param2,param3,...]</term>
256 Add the parameters(s) to a list of headers parameters to decode;
257 the parameters will be decoded only for the given header(s).
258 Initially the list contains header "Content-Type", parameter "name";
259 and header "Content-Disposition", parameter "filename".
265 <term>-p *[,-header1,-header2,-header3,...]:param1[,param2,param3,...]</term>
268 Add the parameters(s) to a list of headers parameters to decode;
269 the parameters will be decoded for all headers except the given
276 <term>-p header1[,header2,header3,...]:*[,-param1,-param2,-param3,...]</term>
279 Decode all parameters except listed for the given list of headers.
285 <term>-p *[,-header1,-header2,-header3,...]:*[,-param1,-param2,-param3,...]</term>
288 Decode all parameters except listed for all headers (except listed).
297 Clear the list of headers parameters to decode (make it empty).
303 <term>-r header1[,header2,header3...]</term>
306 Add the header(s) to a list of headers to remove completely;
307 initially the list is empty.
313 <term>-r *[,-header1,-header2,-header3...]</term>
316 Remove all headers except listed.
322 <term>-R header:param</term>
325 Add the pair (header, param) to a list of headers parameters to
326 remove; initially the list is empty.
332 <term>--remove-params=header</term>
335 Add the header to a list of headers from which all parameters will
336 be removed; initially the list is empty.
345 Append mask to the list of binary content types; if the message to
346 decode has a part of this type the program will pass the part as is,
347 without any additional processing.
356 Append mask to the list of error content types; if the message to
357 decode has a part of this type the program fails with ValueError.
366 Append mask to the list of content types to ignore; if the message to
367 decode has a part of this type the program will not pass it, instead
368 a line "Message body of type `%s' skipped." will be issued.
377 Append mask to the list of content types to convert to text; if the
378 message to decode has a part of this type the program will consult
379 mailcap database, find first copiousoutput filter and convert the
386 <term>-o output_file</term>
389 Useful to set the output file in case of redirected stdin:
390 <programlisting language="sh">mimedecode.py -o output_file < input_file
391 cat input_file | mimedecode.py -o output_file</programlisting>
398 The 4 list options (-beit) require more explanation. They allow a user to
399 control body decoding with great flexibility. Think about said mail archive;
400 for example, its maintainer wants to put there only texts, convert
401 Postscript/PDF to text, pass HTML and images as is, and ignore everything
407 mimedecode.py -t application/postscript -t application/pdf -b text/html
408 -b 'image/*' -i '*/*'
413 When the program decodes a message (non-MIME or a non-multipart subpart of a
414 MIME message), it consults Content-Type header. The content type is searched
415 in all 4 lists, in order "text-binary-ignore-error". If found, appropriate
416 action performed. If not found, the program search the same lists for
417 "type/*" mask (the type of "text/html" is just "text"). If found,
418 appropriate action performed. If not found, the program search the same
419 lists for "*/*" mask. If found, appropriate action performed. If not found,
420 the program uses default action, which is to decode everything to text (if
421 mailcap specifies a filter).
425 Initially all 4 lists are empty, so without any additional parameters
426 the program always uses the default decoding.
432 <title>ENVIRONMENT</title>
434 <varlistentry><term>LANG</term></varlistentry>
435 <varlistentry><term>LC_ALL</term></varlistentry>
436 <varlistentry><term>LC_CTYPE</term></varlistentry>
439 Define current locale settings. Used to determine current default charset (if
440 your Python is properly installed and configured).
448 The program may produce incorrect MIME message. The purpose of the program
449 is to decode whatever it is possible to decode, not to produce absolutely
450 correct MIME output. The incorrect parts are obvious - decoded
451 From/To/Cc/Reply-To/Mail-Followup-To/Subject headers and filenames. Other
452 than that output is correct MIME message. The program does not try to guess
453 whether the headers are correct. For example, if a message header states
454 that charset is iso8859-5, but the body is actually in utf-8 the program
455 will recode the message with the wrong charset.
461 <title>AUTHOR</title>
463 <firstname>Oleg</firstname>
464 <surname>Broytman</surname>
465 <email>phd@phdru.name</email>
471 <title>COPYRIGHT</title>
473 Copyright (C) 2001-2014 PhiloSoft Design.
479 <title>LICENSE</title>
487 <title>NO WARRANTIES</title>
489 This program is distributed in the hope that it will be useful, but WITHOUT
490 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
491 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
498 <title>SEE ALSO</title>
500 mimedecode.py home page:
501 <ulink url="http://phdru.name/Software/Python/#mimedecode">http://phdru.name/Software/Python/#mimedecode</ulink>