# pm-jaube-prg-ifile -- Interface to ifile program
# $Id: pm-jaube-prg-ifile.rc,v 1.8 2004/12/15 21:07:07 jaalto Exp $
#
#   File id
#
#       .Copyright (C)  Jari Aalto
#       .$Keywords:     procmail, subroutine, UBE, spam, filter $
#
#       This code is free software in terms of GNU Gen. pub. Lic. v2 or later
#       Refer to http://www.gnu.org/copyleft/gpl.html
#
#   Warning
#
#       Put all your Unsolicited Bulk Emacil (aka spam) filters towards the
#       end of your `~/.procmailrc'. The idea is that valid messages are filed
#       first (mailing lists, your work and private mail, bounces) and only
#       the uncategorized messages are checked last.
#
#       YOU CANNOT USE THIS PROCMAIL SUBROUTINE UNLESS YOU HAVE TRAINED THE
#       BAYESIAN PROGRAM FIRST!
#
#       To train:
#
#           $ rm ~/.idata                       # delete database
#           $ echo herbalife | ifile -i spam    # initialize database
#           $ ifile -h -i good good.msg ...
#           $ ifile -h -i spam spam.msg ...
#
#   Overview of features
#
#       o   Implements interface to http://freshmeat.net/projects/ifile
#           project.
#       o   variable `ERROR' is set to the result of ifile check. This
#           usually holds the "folder" name the ifile was trained at the
#           time. E.g. if the folder used for training Unsolicited Bulk
#           Email was "ifile -i spam", then the return value is "spam".
#       o   Results are available by default in header `X-Spamifile'.
#
#   Description
#
#       There are several Bayesian based statistical analysis programs that
#       study the message's tokens and then classify it into two categories:
#       good or bad, or if you like, ham and spam. All the Bayesian programs
#       are not the same, so if you want to achive magic 99.99% probability
#       the only methodology to do that is to chain several programs in
#       serially. There is no single program that can solve the UBE detection.
#       This procmail subroutine implements call interface to program
#       `ifile', which must already have been installed.
#
#   About bouncing message back
#
#       The general consensus is, that you should not send bounces. The UBE
#       sender is not there, because the address forged. Do not increase
#       the network traffic; you will not do any good to anybody by
#       bouncing messgas -- you just increase mail traffic even more.
#       Instead save the messages to folders and periodically periodically
#       check their contents.
#
#   Required settings
#
#       If `ifile' program is available, define this variable in your
#       `~/.procmailrc'. Use absolute path to make the external shell
#       quick; it'll save server load considerably.
#
#           JA_UBE_IFILE_PRG = /usr/bin/ifile
#
#       If you _do_ _not_ have program installed, do not leave the
#       variable lying aroung, because it will keep this subroutine active.
#       Calling a non existing program is not a good idea, so it better to
#       empty the variable if the program is not available.
#
#   Required settings
#
#       None. No dependencies to other procmail modules.
#
#   Call arguments (variables to set before calling)
#
#       o   JA_UBE_IFILE_PRG, path to the program
#       o   JA_UBE_IFILE_HEADER, the header name where the results
#           are put. If not defined, no header is added.
#           Defaults to `X-Spam-Ifile-Status'
#       o   JA_UBE_IFILE_FORCE, if set to _yes_ then call program no matter
#           what. Normally if there already is header,
#           it is assumed that the message has already been checked
#           and no new checking is needed.
#
#   Return values
#
#       o   ERROR, is set to the return value of `ifile' program.
#
#       If header output is enabled, it will contain the folder name
#       `ifile' thinks the message belongs to. Assuming that trained
#       folders used for messages were *spam* and *good*, then the headers
#       read:
#
#           X-Spam-Ifile-Status: spam
#           X-Spam-Ifile-Status: good
#
#   Usage example
#
#           PMSRC                  = $HOME/procmail # procmail recipe dir
#
#           <other checks, mailing lists, work mail etc.>
#
#           JA_UBE_IFILE_PRG       = "/usr/bin/nice -n 5 /usr/bin/ifile"
#           INCLUDERC              = $PMSRC/pm-jaube-prg-ifile.rc
#
#           #   The ERROR will contains reason if program classified
#           #   the message into "bad" category.
#
#           :0 :
#           * ! ERROR ?? ^^^^
#           junk.mbox
#
#   File layout
#
#       The layout of this file is managed by Emacs packages tinyprocmail.el
#       and tinytab.el for the 4 tab text placement.
#       See project http://tiny-tools.sourceforge.net/
#
#   Change Log
#
#       None

dummy = "
========================================================================
pm-jaube-prg-ifile.rc: init:"

# ................................................... User variables ...

#   You must define program path, because we don't know
#   if it has been installed in this system or not

JA_UBE_IFILE_PRG           = ${JA_UBE_IFILE_PRG:-""}

#  No user options cannot be passed to ifile, because the output would
#  change. This variable is not used.
# JA_UBE_IFILE_PRG_OPT       = ${JA_UBE_IFILE_PRG_OPT:-""}

#   The header name with no colon at the end. If this variable
#   is empty, then external formail call is saved - results can still
#   be checked from variable ERROR.

JA_UBE_IFILE_HEADER = ${JA_UBE_IFILE_HEADER:-\
"X-Spam-Ifile-Status"}

# Should we check even if there already was header
# JA_UBE_IFILE_HEADER ?

JA_UBE_IFILE_FORCE = ${JA_UBE_IFILE_FORCE:-"no"}

# ............................................................ do it ...

ERROR   # Kill variable

:0
*                   JA_UBE_IFILE_PRG     ?? [a-z]
*$ ! 9876543210^0  ^$JA_UBE_IFILE_HEADER
*    9876543210^0   JA_UBE_IFILE_FORCE   ?? yes
{
    :0 w : ifile$LOCKEXT
    jaubeIfileFolder=|$JA_UBE_IFILE_PRG --strip-header --query --concise

    :0
    * ! jaubeIfileFolder ?? ^^^^
    {
        ERROR = $jaubeIfileFolder

        :0 fhw
        * ! JA_UBE_IFILE_HEADER ?? ^^^^
        | ${FORMAIL:-formail} -I "$JA_UBE_IFILE_HEADER: $jaubeIfileFolder"
    }
}

dummy = "pm-jaube-prg-ifile.rc: end: $ERROR"

# End of file