FIX-MIME-CHARSET(1)FIX-MIME-CHARSET(1)NAMEfix-mime-charset - fix incorrect charset specifications in MIME
messages
SYNOPSISfix-mime-charset [-BfLm?V] [-c charset] [-I charset,...] [-l language]
[-O charset,...] [--break-signature] [--charset=charset]
[--force-override] [--ignore-charsets=charset,...] [--lang=language]
[--mailbox] [--only-charsets=charset,...] [--show-langs] [--help]
[--usage] [--version] [file...]
DESCRIPTION
In non-English mailing lists (particularly in Russian) there is a big
problem with messages, where charset parameter of Content-Type header
is set incorrectly. Sometimes software is buggy, sometimes people
cannot set up their software properly, sometimes web-based email
clients do not implement charsets. While reading such a mail, one
should manually switch encoding in MUA back and forth. Incorrectly
encoded or plain 8-bit Subject field is another big problem. Such
fields often get corrupted while passing e-mail gateways.
This program can be used to solve these problems while used as mail
filter (in MTA, procmail(1) or similar program). It tries to detect
correct charset automatically (currently only Russian language KOI8-R,
Windows-1251 and UTF-8 charsets are detected) and fixes Content-Type
and Subject headers of the message or message subpart. fix-mime-
charset interprets multipart messages correctly and processes
text/plain subparts only. Attachments, other headers and body of the
message are not touched. fix-mime-charset correctly interprets quoted-
printable and base64 transfer-encodings. Program is written to be very
fast and use minimal amount of memory.
When no files are given in command line, the program reads input from
stdin. When several files are given, they are concatenated in the
order of appearance.
OPTIONS-B, --break-signature
Enable fixing charset information in multipart/signed messages.
Modication of Content-Type field in this case will result in
broken signature. You may enable this option if you prefer
readable text to verifyable signatures. In any case fix-mime-
charset will not modify the message if everything is correct.
By default, multipart/signed messages are leaved untouched.
-c, --charset=charset
Charset to be used when it cannot be determined automatically.
By default, in this case Content-Type field is leaved untouched.
If Content-Type field is absent, charset given in this option is
used (us-ascii by default). This behavior may be overriden by -f
switch.
-f, --force-override
Always override charset of Content-Type field. By default,
Content-Type field is leaved untouched if charset cannot be
determined automatically. When this option is used, charset
given by -c option overrides Content-Type field.
-I, --ignore-charsets=charset,...
Ignore messages with given charsets. us-ascii charset is assumed
when charset is not set in Content-Type field. Charsets in list
may be separated by space, comma, colon or semicolon. This option
can be repeated several times and lists are joined in this case.
-l, --lang=language
Set language for autodetection. language is two-letter ISO
639:1989 language code. fix-mime-charset-L gives list of all
available languages and language codes.
Default language is "ru" (Russian).
-L, --show-langs
Gives list of all available languages and language codes.
-m, --mailbox
Process input as Unix mailbox ("From " lines are used as message
delimiters). Without this option, input is considered to be an
individual message and messages should be passed to the filter
one-by-one.
-O, --only-charsets=charset,...
Process messages with given charsets only. us-ascii charset is
assumed when charset is not set in Content-Type field. Charsets
in list may be separated by space, comma, colon or semicolon.
This option can be repeated several times and lists are joined in
this case.
-?, --help
Print help message and exit.
--usage
Give a short usage message and exit.
-V, --version
Print version information and exit.
USAGE WITH PROCMAIL
Some people asked me for examples of using fix-mime-charset with
procmail(1). It is very easy - simply insert the following rule into
.procmailrc:
:0 f
| fix-mime-charset
Filtering rule is non-delivering in terms of procmail(1) and filtered
mail will be transferred to following rules.
It is equally easy to filter limited subset of messages:
:0
* <your filter here>
{
:0 f
| fix-mime-charset
<delivering rules here>
}
AUTHOR
Dmitry E. Melamud <balu@migdal.ru>
COPYRIGHT
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2 of the License, or any later
version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
SEE ALSOprocmail(1)v.0.5.3 2003-12-13 FIX-MIME-CHARSET(1)
