#!/usr/bin/env python

"""Unpack a MIME message into a directory of files."""

import os

import sys

import email

import errno

import mimetypes

from optparse import OptionParser

def main():

    parser = OptionParser(usage="""\

Unpack a MIME message into a directory of files.

Usage: %prog [options] msgfile

""")

    parser.add_option('-d', '--directory',

                      type='string', action='store',

                      help="""Unpack the MIME message into the named

                      directory, which will be created if it doesn't already

                      exist.""")

    opts, args = parser.parse_args()

    if not opts.directory:

        parser.print_help()

        sys.exit(1)

    try:

        msgfile = args[0]

    except IndexError:

        parser.print_help()

        sys.exit(1)

    try:

        os.mkdir(opts.directory)

    except OSError, e:

        # Ignore directory exists error

        if e.errno <> errno.EEXIST:

            raise

    fp = open(msgfile)

    msg = email.message_from_file(fp)

    fp.close()

    counter = 1

    for part in msg.walk():

        # multipart/* are just containers

        if part.get_content_maintype() == 'multipart':

            continue

        # Applications should really sanitize the given filename so that an

        # email message can't be used to overwrite important files

        filename = part.get_filename()

        if not filename:

            ext = mimetypes.guess_extension(part.get_content_type())

            if not ext:

                # Use a generic bag-of-bits extension

                ext = '.bin'

            filename = 'part-%03d%s' % (counter, ext)

        counter += 1

        fp = open(os.path.join(opts.directory, filename), 'wb')

        fp.write(part.get_payload(decode=True))

        fp.close()

if __name__ == '__main__':

    main()