procmail giving “no match” on content-type

问题:

I am trying to have procmail decode a base64 encoded attachment. To begin with I am following a simple recipe, found here:

http://www.linuxquestions.org/questions/linux-software-2/procmailrc-decode-data-from-base64-encoded-emails-trying-to-decode-with-uudeview-933670/

However, it appears procmail cannot find the match:

procmail: [7459] Mon Aug 10 10:54:43 2015
procmail: Assigning "LOGFILE=/home/myself/procmail.log"
procmail: Opening "/home/myself/procmail.log"
procmail: Assigning "LOGABSTRACT=yes"
procmail: Assigning "LINEBUF=65535"
procmail: No match on "^Content-Type: *text/plain"
procmail: Locking "/home/myself/scratch/prc.out.lock"
procmail: Assigning "LASTFOLDER=/home/myself/scratch/prc.out"
procmail: Opening "/home/myself/scratch/prc.out"
procmail: Acquiring kernel-lock
procmail: Unlocking "/home/myself/scratch/prc.out.lock"
Subject: FMSG:219
Folder: /home/myself/scratch/prc.out                     8312
[168]%

My ~/.procmailrc is very simple:

SHELL=/bin/sh
PATH=/bin:/usr/bin/:/sbin:/usr/sbin:$PATH
MAILDIR=$HOME/scratch   # this is a symlink to a scratch disk
DEFAULT=$HOME/scratch/prc.out
VERBOSE=yes
LOGFILE=/home/myself/procmail.log
LOGABSTRACT=yes
LINEBUF=65535

:0
* ^Content-Type: *text/plain
{
        :0 fbw
        * ^Content-Transfer-Encoding: *base64
        | $HOME/mmencode -u -b

        :0 Afhw
        | formail -I "Content-Transfer-Encoding: 8bit"
}

and this is the start of the mail file:

Return-Path: <unknown>
Delivered-To: unknown
From: <user1>
To: ole <user2>
Date: Mon, 20 Jul 2015 14:46:49 +0200
Subject: FMSG:219
Message-ID:  <[e-mail]>
Accept-Language: en-US
Content-Language: en-US
Content-Type: multipart/mixed;
boundary="_002_6959f239a4d111111111111111111111111111111oletestl_"
MIME-Version: 1.0

--_002_6959f239a4d111111111111111111111111111111oletestl_
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable


--_002_6959f239a4d111111111111111111111111111111oletestl_
Content-Type: application/x-ole-envelope; name="20150720"
Content-Description: ole envelope
Content-Disposition: attachment; filename="20150720"; size=5528;
creation-date="Mon, 20 Jul 2015 12:46:52 GMT";
modification-date="Mon, 20 Jul 2015 12:46:52 GMT"
Content-Transfer-Encoding: base64

SDRzSUFBQUFBQUFBQzYxWFdZK2pXTEordnBiOEgxTDEwZzhvaDgxZ3V6dXJSb2ZGZ0EzWWJHWVp6
UU83d1d4bU1kaS8vaDY3DQpNcnV5ZW5wNjVrbzNKU3NoNG9zNHNaOUFrUlQrOVJpM1hWWlh2Nzdn
THQzOUFsMTVsVm5vQmg4TS8vL0hIS3ZqblA0NzRQMkZtdjJ0NDlpSDYzb2h2NkhzamYvdC9IVUZS

...

--_002_6959f239a4d6959f239a4d111111111111111111111111111111oletestl_

If I try to match on "Content-Type: multipart/mixed" I do in fact get a match:

procmail: Match on "^Content-Type: multipart/mixed;"
procmail: No match on "^Content-Transfer-Encoding: *base64"

but then not on the following ones... :(

Similar with an attempt on

procmail: No match on "^Content-Type: application/x-ole-envelope"

What am I missing?

Thanks

回答1:

There is no match in the message header on the regex. If you want to find a match in the body (including, but by no means limited to, MIME body part headers), use a B flag; but proper MIME support is going to be a lot more complex than that, and is next to impossible to do in Procmail alone.

The recipe you are copying is very specifically for normalizing single-part text/plain messages, not multiparts.

Your question is very general, so I can only suggest alternatives in broad terms. Maybe pipe the message to something like munpack, possibly based on some regex criteria which may well be possible to express in Procmail; but for anything more sophisticated, maybe pipe to a specialized Python (or Perl, or Ruby, etc) script.