##### addrlistlookup.rc
#
# Resource file for procmail.
# Looks up whether an email address in the current msg is found in a list.
# The email headers which are searched are currently:
#   From:, Reply-To:, "From ", Return-Path:
# The address list is in a file which can have comments, and is translated into
# a procmail-readable file. This happens automatically the first time it is
# used after each change.
# The addresses in the list are case-insensitive, and use extended regular
# expressions. They are anchored on both sides to something appropriate for an
# email address.
# 
# Uses GNU /usr/bin/test, and egrep. Contains shell code.
# I don't really like the whole concept very much yet, so it's likely to change.
# It doesn't allow to specify which mail headers to examine - would that be
# useful?
#
# Variables, in (set before calling):
#   ADDRESSLIST		The file with the list of email addresses to look up in.
#			A copy without comments is created as $ADDRESSLIST.pm,
#			so procmail needs write access to the directory it's in.
# Variables, returned:
#   INLIST		Set to "1" if email is from this list, unset otherwise.
#
# Run with e.g.:
#   ADDRESSLIST="filewithlistofaddresses"
#   INCLUDERC=yourpath/addrlistlookup.rc
#   :0
#   * INLIST ?? ^^1^^
#   { ... }
# in your $HOME/.procmailrc.
#
# The latest version is always available from:
# http://volker.dnsalias.net/soft/procmail/
#
# Copyright (C) by Volker Kuhlmann <VolkerKuhlmann@GMX.de>
# Released under the terms of the GNU General Public License (GPL) Version 2.
# See http://www.gnu.org/ for details.
#
# Volker Kuhlmann
#   22 Sep; 30 Oct; 6 Nov 2002
#   16 May 2003
#   5 Jan; 3 Mar 2004
#   24 May 2005
#

## Init
INLIST=

## Address list lookup
# (Recipe is executed if exit code is 0)
# (Solaris 2.7 grep does not have "-f patternfile", using egrep -f)
# (Solaris 2.7 egrep -f gives syntax error for empty line in pattern file)
# (Solaris 2.7 fgrep -i -f: the -i doesn't always work, using egrep)
# (Conclusion: Solaris 2.7 = POS)
# First check if the address list file has been modified, and if yes rewrite
# the stripped copy of it.
# Headers to examine: add Sender: ?
:0
* $ ! ADDRESSLIST ?? ^^^^
* $ ? test -f "$ADDRESSLIST"
* $ ? ( \
      /usr/bin/test "$ADDRESSLIST" -nt "$ADDRESSLIST".pm \
	  -o ! -e "$ADDRESSLIST".pm \
		&& sed '/^$/d; /^[#%!]/d; s/.*/(^|[^a-z0-9_.-])&($|[^a-z0-9_.-])/;' \
			<"$ADDRESSLIST" >"$ADDRESSLIST".pm; \
      formail -zxFrom: -zxReply-To: -zx"From " -zxReturn-Path: \
	      | egrep -i -f "$ADDRESSLIST".pm \
      )
{ INLIST=1 }

# Damn, this effectively creates a substring search, unless all email addresses
# in the input are already anchored
#		&& egrep -v '^[ 	]*($|[#%!])' \
#			"$ADDRESSLIST" >"$ADDRESSLIST".pm; \

#		&& sed '/^$/d; /^[#%!]/d; s/.*/(^|[^a-z])&($|[^a-z])/;' \
#			<"$ADDRESSLIST" >"$ADDRESSLIST".pm; \

##### EOF addrlistlookup.rc