--- /dev/null
+<?xml version="1.0" standalone="no"?>
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.1//EN"
+ "http://www.oasis-open.org/docbook/xml/4.1/docbook.dtd">
+
+<refentry id="mimedecode.py">
+
+<refmeta>
+ <refentrytitle>mimedecode.py</refentrytitle>
+ <manvolnum>1</manvolnum>
+</refmeta>
+
+<refnamediv>
+ <refname>mimedecode.py</refname>
+ <refpurpose>decode MIME message</refpurpose>
+</refnamediv>
+
+<refsynopsisdiv>
+ <cmdsynopsis>
+ <command>mimedecode.py</command>
+ <arg choice="opt">
+ <option>-h|--help</option>
+ </arg>
+ <arg choice="opt">
+ <option>-V|--version</option>
+ </arg>
+ <arg choice="opt">
+ <option>-cCDP</option>
+ </arg>
+ <arg choice="opt">
+ <option>-f charset</option>
+ </arg>
+ <arg choice="opt">
+ <option>-d header</option>
+ </arg>
+ <arg choice="opt">
+ <option>-p header:param</option>
+ </arg>
+ <arg choice="opt">
+ <option>-beit mask</option>
+ </arg>
+ <arg choice="opt">filename</arg>
+ </cmdsynopsis>
+</refsynopsisdiv>
+
+
+<refsect1>
+<title>DESCRIPTION</title>
+<para>
+ Mail users, especially in non-English countries, often find that mail
+messages arrived in different formats, with different content types, in
+different encodings and charsets. Usually it is good because it allows to use
+an appropriate format/encoding/whatever. Sometimes, though, some unification is
+desirable. For example, one may want to put mail messages into an archive,
+make HTML indices, run search indexer, etc. In such situations converting
+messages to text in one character set and skipping some binary attachments is
+much desirable.
+</para>
+
+<para>
+ Here is the solution - mimedecode.py!
+</para>
+
+<para>
+ It is a program to decode MIME messages. The program expects one input file
+(either on the command line or on stdin) which is treated as an RFC822 message,
+and decoded to stdout. If the file is not an RFC822 message it is just piped to
+stdout as is. If the file is a simple RFC822 message it is just decoded as one
+part. If it is a MIME message with multiple parts ("attachments") all parts are
+decoded recursively. Decoding can be controlled by the command-line options.
+</para>
+
+<para>
+ First, Subject and Content-Disposition headers are examined. If any of those
+exists, it is decoded according to RFC2047. Content-Disposition header is not
+decoded - only its "filename" parameter. Encoded header parameters violate
+the RFC, but widely deployed anyway, especially in the M$ Ophice GUI (often
+referred as "Windoze") world, where programmers are often ignorant lamers who
+never even heard about RFCs. Correct parameter encoding specified by RFC2231.
+This program decodes RFC2231-encoded parameters, too.
+</para>
+
+<para>
+ Then the body of the message (or the current part) is decoded. Decoding
+starts with looking at header Content-Transfer-Encoding. If the header
+specifies non-8bit encoding (usually base64 or quoted-printable), the body
+converted to 8bit. Then, if its content type is multipart (multipart/related or
+multipart/mixed, e.g) every part is recursively decoded. If it is not
+multipart, mailcap database is consulted to find a way to convert the body to
+plain text. (I have no idea how mailcap could be configured on said M$ Ophice
+GUI, please don't ask me; real OS users can consult my example at
+http://phd.pp.ru/Software/dotfiles/mailcap.html). The decoding process uses
+first copiousoutput filter it can find. If there is no any filter the body just
+passed unconverted.
+</para>
+
+<para>
+ Then Content-Type header consulted for charset. If it is not equal to
+current default charset the body text recoded. Finally message headers and body
+flushed to stdout.
+</para>
+</refsect1>
+
+
+<refsect1>
+<title>OPTIONS</title>
+<variablelist>
+ <varlistentry>
+ <term>-h</term>
+ <term>-help</term>
+ <listitem>
+ <para>
+ Print brief usage help and exit.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>-V</term>
+ <term>--version</term>
+ <listitem>
+ <para>
+ Print version and exit.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>-c</term>
+ <listitem>
+ <para>
+ Recode different character sets in message body to current default
+ charset; this is the default.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>-C</term>
+ <listitem>
+ <para>
+ Do not recode character sets in message body.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>-f charset</term>
+ <listitem>
+ <para>
+ Force this charset to be the current default charset instead of
+ sys.getdefaultencoding().
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>-d header</term>
+ <listitem>
+ <para>
+ Add the header to a list of headers to decode; initially the list
+ contains headers "From" and "Subject".
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>-D</term>
+ <listitem>
+ <para>
+ Clear the list of headers to decode (make it empty).
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>-p header:param</term>
+ <listitem>
+ <para>
+ Add the (header, param) pair to a list of headers' parameters to
+ decode; initially the list contains header "Content-Disposition",
+ parameter "filename".
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>-P</term>
+ <listitem>
+ <para>
+ Clear the list of headers' parameters to decode (make it empty).
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>-b mask</term>
+ <listitem>
+ <para>
+ Append mask to the list of binary content types; if the message to
+ decode has a part of this type the program will pass the part as is,
+ without any additional processing.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>-e mask</term>
+ <listitem>
+ <para>
+ Append mask to the list of error content types; if the message to
+ decode has a part of this type the program will raise ValueError.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>-i mask</term>
+ <listitem>
+ <para>
+ Append mask to the list of content types to ignore; if the message to
+ decode has a part of this type the program will not pass it, instead
+ a line "Message body of type `%s' skipped." will be issued.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>-t mask</term>
+ <listitem>
+ <para>
+ Append mask to the list of content types to convert to text; if the
+ message to decode has a part of this type the program will consult
+ mailcap database, find first copiousoutput filter and convert the
+ part.
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+
+<para>
+ The last 4 options (-beit) require more explanation. They allow a user
+to control body decoding with great flexibility. Think about said mail
+archive; for example, its maintainer wants to put there only texts, convert
+Postscript/PDF to text, pass HTML and images as is, and ignore everything
+else. Easy:
+</para>
+
+<para>
+<code language="shell">
+ mimedecode.py -t application/postscript -t application/pdf -b text/html
+ -b 'image/*' -i '*/*'
+</code>
+</para>
+
+<para>
+ When the program decodes a message (or its part), it consults
+Content-Type header. The content type is searched in all 4 lists, in order
+"text-binary-ignore-error". If found, appropriate action performed. If not
+found, the program search the same lists for "type/*" mask (the type of
+"text/html" is just "text"). If found, appropriate action performed. If not
+found, the program search the same lists for "*/*" mask. If found,
+appropriate action performed. If not found, the program uses default
+action, which is to decode everything to text (if mailcap specifies
+a filter).
+</para>
+
+<para>
+ Initially all 4 lists are empty, so without any additional parameters
+the program always uses the default decoding.
+</para>
+</refsect1>
+
+
+<refsect1>
+<title>ENVIRONMENT</title>
+<para>
+ LANG
+ LC_ALL
+ LC_CTYPE
+ Define current locale settings. Used to determine current default
+ charset (if your Python is properly installed and configured).
+</para>
+</refsect1>
+
+
+<refsect1>
+<title>BUGS</title>
+<para>
+ The program may produce incorrect MIME message. The purpose of the program
+is to decode whatever it is possible to decode, not to produce absolutely
+correct MIME output. The incorrect parts are obvious - decoded Subject headers
+and filenames. Other than that output is correct MIME message. The program does
+not try to guess whether the headers are correct. For example, if a message
+header states that charset is iso8859-5, but the body is actually in koi8-r -
+the program will recode the message to the wrong charset.
+</para>
+</refsect1>
+
+
+<refsect1>
+<title>AUTHOR</title>
+<para>
+ Oleg Broytmann <phd@phd.pp.ru>
+</para>
+</refsect1>
+
+
+<refsect1>
+<title>COPYRIGHT</title>
+<para>
+ Copyright (C) 2001-2004 PhiloSoft Design
+</para>
+</refsect1>
+
+
+<refsect1>
+<title>LICENSE</title>
+<para>
+ GNU GPL
+</para>
+</refsect1>
+
+
+<refsect1>
+<title>NO WARRANTIES</title>
+<para>
+ 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.
+</para>
+</refsect1>
+
+
+<refsect1>
+<title>SEE ALSO</title>
+<para>
+ mimedecode.py home page: http://phd.pp.ru/Software/Python/#mimedecode
+</para>
+</refsect1>
+
+</refentry>
License: GPL
"""
-__version__ = "1.1.7"
+__version__ = "2.0.0"
+__copyright__ = "Copyright (C) 2001-2002 PhiloSoft Design"
import sys, os
-import mimetools
+import email
try:
from cStringIO import StringIO
me = os.path.basename(sys.argv[0])
+def version(exit=1):
+ sys.stdout.write("""\
+BroytMann mimedecode.py version %s, %s
+""" % (__version__, __copyright__))
+ if exit: sys.exit(0)
+
+
def usage(code=0):
+ version(0)
sys.stdout.write("""\
Usage: %s [-h|--help] [-V|--version] [-cCDP] [-f charset] [-d header] [-p header:param] [-beit mask] [filename]
""" % me)
sys.exit(code)
-def version():
- sys.stdout.write("""\
-BroytMann mimedecode.py version %s
-""" % __version__)
- sys.exit(0)
+def output(s, outfile = sys.stdout):
+ outfile.write(s)
-
-def output(s):
- sys.stdout.write(s)
-
-def output_headers(msg):
- if msg.unixfrom:
- output(msg.unixfrom)
- output("%s\n" % msg)
+def output_headers(msg, outfile = sys.stdout):
+ unix_from = msg.get_unixfrom()
+ if unix_from:
+ output(unix_from + os.linesep)
+ for key, value in msg.items():
+ output("%s: %s\n" % (key, value), outfile)
+ output("\n", outfile) # End of headers
def recode(s, charset):
def recode2(s, charset):
if charset and charset <> GlobalOptions.default_charset:
- charset = charset.lower()
s = recode(s, charset)
return s
-def getparam(msg, header, param):
- "Get parameter from the header; return the header without the parameter, parameter itself and rfc2231 flag"
-
- if not msg.has_key(header):
- return None, None, 0
+def _decode_header(s):
+ """Return a decoded string according to RFC 2047.
+ NOTE: This is almost the same as email.Utils.decode.
+ """
+ from types import ListType
+ import email.Header
- header = msg[header]
- parts = [part.strip() for part in header.split(';')]
-
- new_parts = [parts[0]] # The header itself
- del parts[0]
-
- new_value = None
- rfc2231_encoded = 0
-
- import re, rfc822
- rfc2231_continuation = re.compile("^%s\\*[0-9]+\\*?$" % param)
- rfc2231_header = []
+ L = email.Header.decode_header(s)
+ if not isinstance(L, ListType):
+ # s wasn't decoded
+ return s
- for part in parts:
- name, value = part.split('=', 1)
- # The code is incomplete. Continuations in rfc2231-encoded paramters
- # (header*1, header*2, etc) are not yet supported
- if (name == param) or (name == param + '*'):
- new_value = rfc822.unquote(value)
- rfc2231_encoded += (name <> param)
- elif rfc2231_continuation.match(name):
- rfc2231_header.append(rfc822.unquote(value))
- rfc2231_encoded = 1
+ rtn = []
+ for atom, charset in L:
+ if charset is None:
+ rtn.append(atom)
else:
- new_parts.append(part)
+ rtn.append(recode2(atom, charset))
+ rtn.append(' ')
+ del rtn[-1] # remove the last space
- if rfc2231_header:
- new_value = ''.join(rfc2231_header)
-
- if new_value is not None:
- return "; ".join(new_parts), new_value, rfc2231_encoded
-
- return None, None, 0
+ # Now that we've decoded everything, we just need to join all the parts
+ # together into the final string.
+ return ''.join(rtn)
def decode_header(msg, header):
if msg.has_key(header):
value = msg[header]
- new_value = decode_rfc2047(value)
- if value <> new_value: # do not bother to touch msg if not changed
- msg[header] = new_value
+ new_value = _decode_header(value)
+ if new_value <> value: # do not bother to touch msg if not changed
+ set_header(msg, header, new_value)
+
+
+def _decode_header_param(s):
+ return recode2(s[2], s[0])
def decode_header_param(msg, header, param):
"Decode mail header's parameter (if exists) and put it back, if it was encoded"
if msg.has_key(header):
- new_value, pstr, rfc2231_encoded = getparam(msg, header, param)
- if pstr is not None:
- if rfc2231_encoded:
- new_str = decode_rfc2231(pstr)
+ value = msg.get_param(param, header=header)
+ if value:
+ from types import TupleType
+ if isinstance(value, TupleType):
+ new_value = _decode_header_param(value)
else:
- new_str = decode_rfc2047(pstr)
- if pstr <> new_str: # do not bother to touch msg if not changed
- msg[header] = "%s; %s=\"%s\"" % (new_value, param, new_str)
-
-
-def decode_rfc2047(s):
- "Decode string according to rfc2047"
-
- parts = s.split() # by whitespaces
- new_parts = []
- got_encoded = 0
-
- for s in parts:
- l = s.split('?')
-
- if l[0] <> '=' or l[4] <> '=': # assert correct format
- new_parts.append(' ')
- new_parts.append(s) # if not encoded - just put it into output
- got_encoded = 0
- continue
-
- if not got_encoded:
- new_parts.append(' ') # no space between encoded parts, one space otherwise
- got_encoded = 1
-
- charset = l[1].lower()
- encoding = l[2].lower()
- s = l[3]
-
- if '*' in charset:
- charset, language = charset.split('*', 1) # language ignored
-
- infile = StringIO(s)
- outfile = StringIO()
-
- if encoding == "b":
- from base64 import decode
- elif encoding == "q":
- from quopri import decode
- else:
- raise ValueError, "wrong encoding `%s' (expected 'b' or 'q')" % encoding
-
- decode(infile, outfile)
- s = outfile.getvalue()
-
- if charset == GlobalOptions.default_charset:
- new_parts.append(s) # do not recode
- continue
-
- s = recode(s, charset)
- new_parts.append(s)
-
- if new_parts and new_parts[0] == ' ':
- del new_parts[0]
- return ''.join(new_parts)
-
-
-def decode_rfc2231(s):
- "Decode string according to rfc2231"
-
- charset, language, s = s.split("'", 2) # language ignored
-
- i = 0
- result = []
-
- while i < len(s):
- c = s[i]
- if c == '%': # hex
- i += 1
- c = chr(int(s[i:i+2], 16))
- i += 1
- result.append(c)
- i += 1
-
- s = ''.join(result)
- s = recode2(s, charset)
- return s
+ new_value = _decode_header(value)
+ if new_value <> value: # do not bother to touch msg if not changed
+ msg.set_param(param, new_value, header)
def decode_headers(msg):
for header, param in GlobalOptions.decode_header_params:
decode_header_param(msg, header, param)
- if header.lower() == "content-type" and msg.has_key(header):
- # reparse type
- msg.typeheader = msg[header]
- msg.parsetype() # required for plist...
- msg.parseplist() #... and reparse decoded plist
-def set_content_type(msg, newtype, charset=None):
- plist = msg.getplist()
- if plist:
- if charset:
- newplist = []
- for p in plist:
- if p.split('=')[0] == "charset":
- p = "charset=%s" % charset
- newplist.append(p)
- plist = newplist
-
- elif charset:
- plist = ["charset=%s" % charset]
+def set_header(msg, header, value):
+ "Replace header"
+ if msg.has_key(header):
+ msg.replace_header(header, value)
else:
- plist = []
+ msg[header] = value
+
+
+def set_content_type(msg, newtype, charset=None):
+ msg.set_type(newtype)
+
+ if charset:
+ msg.set_param("charset", charset, "Content-Type")
- if plist and plist[0]: plist.insert(0, '')
- msg["Content-Type"] = "%s%s" % (newtype, ";\n ".join(plist))
caps = None # Globally stored mailcap database; initialized only if needed
if caps is None:
caps = mailcap.getcaps()
- content_type = msg.gettype()
+ content_type = msg.get_content_type()
filename = tempfile.mktemp()
command = None
os.remove(filename)
set_content_type(msg, "text/plain")
- msg["X-MIME-Body-Autoconverted"] = "from %s to text/plain by %s id %s" % (content_type, host_name, command.split()[0])
-
- msg.maintype = "text"
- msg.subtype = "plain"
- msg.type = "text/plain"
+ msg["X-MIME-Autoconverted"] = "from %s to text/plain by %s id %s" % (content_type, host_name, command.split()[0])
return s
def recode_charset(msg, s):
"Recode charset of the message to the default charset"
- save_charset = charset = msg.getparam("charset")
+ save_charset = charset = msg.get_content_charset()
if charset and charset <> GlobalOptions.default_charset:
s = recode2(s, charset)
- content_type = msg.gettype()
+ content_type = msg.get_content_type()
set_content_type(msg, content_type, GlobalOptions.default_charset)
- msg["X-MIME-Charset-Autoconverted"] = "from %s to %s by %s id %s" % (save_charset, GlobalOptions.default_charset, host_name, me)
+ msg["X-MIME-Autoconverted"] = "from %s to %s by %s id %s" % (save_charset, GlobalOptions.default_charset, host_name, me)
return s
-def totext(msg, infile):
- "Convert infile (StringIO) content to text"
+def totext(msg, instring):
+ "Convert instring content to text"
- if msg.getmaintype() == "multipart": # Recursively decode all parts of the multipart message
- newfile = StringIO("%s\n%s" % (msg, infile.getvalue()))
+ if msg.is_multipart(): # Recursively decode all parts of the multipart message
+ newfile = StringIO(str(msg))
+ newfile.seek(0)
decode_file(newfile)
return
# Decode body and recode charset
- s = decode_body(msg, infile.getvalue())
+ s = decode_body(msg, instring)
if GlobalOptions.recode_charset:
s = recode_charset(msg, s)
output(s)
-def decode_part(msg, infile):
+def decode_part(msg):
"Decode one part of the message"
- encoding = msg.getencoding()
- outfile = StringIO()
+ decode_headers(msg)
+ encoding = msg["Content-Transfer-Encoding"]
- if encoding in ('', '7bit', '8bit', 'binary'):
- mimetools.copyliteral(infile, outfile)
+ if encoding in (None, '', '7bit', '8bit', 'binary'):
+ outstring = str(msg.get_payload())
else: # Decode from transfer ecoding to text or binary form
- mimetools.decode(infile, outfile, encoding)
- msg["Content-Transfer-Encoding"] = "8bit"
+ outstring = str(msg.get_payload(decode=1))
+ set_header(msg, "Content-Transfer-Encoding", "8bit")
msg["X-MIME-Autoconverted"] = "from %s to 8bit by %s id %s" % (encoding, host_name, me)
- decode_headers(msg)
-
# Test all mask lists and find what to do with this content type
-
- for content_type in msg.gettype(), msg.getmaintype()+"/*", "*/*":
+ masks = []
+ ctype = msg.get_content_type()
+ if ctype:
+ masks.append(ctype)
+ mtype = msg.get_content_maintype()
+ if mtype:
+ masks.append(mtype + '/*')
+ masks.append('*/*')
+
+ for content_type in masks:
if content_type in GlobalOptions.totext_mask:
- totext(msg, outfile)
+ totext(msg, outstring)
return
elif content_type in GlobalOptions.binary_mask:
output_headers(msg)
- output(outfile.getvalue())
+ output(outstring)
return
elif content_type in GlobalOptions.ignore_mask:
output_headers(msg)
raise ValueError, "content type `%s' prohibited" % content_type
# Neither content type nor masks were listed - decode by default
- totext(msg, outfile)
+ totext(msg, outstring)
-def decode_file(infile, seekable=1):
+def decode_file(infile):
"Decode the entire message"
- m = mimetools.Message(infile)
- boundary = m.getparam("boundary")
+ msg = email.message_from_file(infile)
+ boundary = msg.get_boundary()
- if not boundary:
- if not m.getheader("Content-Type"): # Not a message, just text - copy it literally
- output(infile.read())
+ if msg.is_multipart():
+ decode_headers(msg)
+ output_headers(msg)
- else: # Simple one-part message - decode it
- decode_part(m, infile)
+ if msg.preamble: # Preserve the first part, it is probably not a RFC822-message
+ output(msg.preamble) # Usually it is just a few lines of text (MIME warning)
- else: # MIME message - decode all parts; may be recursive
- decode_headers(m)
- output_headers(m)
-
- import multifile
- mf = multifile.MultiFile(infile, seekable)
- mf.push(boundary)
+ for subpart in msg.get_payload():
+ output("\n--%s\n" % boundary)
+ decode_part(subpart)
- if not seekable: # Preserve the first part, it is probably not a RFC822-message
- output(mf.read()) # Usually it is just a few lines of text (MIME warning)
+ output("\n--%s--\n" % boundary)
- while 1:
- m = mimetools.Message(mf)
- decode_part(m, mf)
+ if msg.epilogue:
+ output(msg.epilogue)
- if not mf.next():
- break
- output("\n--%s\n" % boundary)
+ else:
+ if msg.has_key("Content-Type"): # Simple one-part message - decode it
+ decode_part(msg)
- mf.pop()
- output("\n--%s--\n" % boundary)
+ else: # Not a message, just text - copy it literally
+ output(str(msg))
class GlobalOptions:
if __name__ == "__main__":
arguments = init()
- seekable = 0
if len(arguments) == 0:
infile = sys.stdin
elif len(arguments) <> 1:
infile = sys.stdin
else:
infile = open(arguments[0], 'r')
- seekable = 1
- decode_file(infile, seekable)
+ decode_file(infile)