#!/bin/sh
#
# $Id: mbox-to-maildir,v 1.2 2008/05/17 07:00:42 suter Exp $
# Copyright (C) 2003 Mark Suter <suter@humbug.org.au>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
# 
# 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.
# 
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
#
# [MJS 17 Jul 2002] Based on example in procmail(1)
# [MJS  5 Jun 2003] Reworked using "or die" technique
# [MJS 23 Apr 2004] Improvements during my 1.5GB transfer

## Our "die" function (think perl)
function die () { echo "$@" 1>&2 ; exit 1 ; }

## Set our PATH and test for needed binaries
export PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
hash test basename maildirmake lockfile mktemp cat true formail procmail || die $0: required binaries not present

## Check our first parameter (the mbox to read from)
MBOX="$1"
test -n "$MBOX"        || die Usage: $( basename $0 ) mbox maildir
test -f "$MBOX"        || die $0: File \"$MBOX\" is not a plain file.
test -r "$MBOX"        || die $0: File \"$MBOX\" is not readable.
test -s "$MBOX"        || die $0: File \"$MBOX\" is empty.

## Check our second parameter (the maildir to write to)
MAILDIR="$2"
test -e "$MAILDIR"     || maildirmake $MAILDIR || die $0: maildirmake failed.
test -d "$MAILDIR"     || die $0: Thing \"$MAILDIR\" is not a directory.
test -w "$MAILDIR"     || die $0: Maildir \"$MAILDIR\" is not writeable.
test -O "$MAILDIR"     || die $0: Maildir \"$MAILDIR\" not owned by effective uid.

## Generate our procmailrc file
rcfile=$(mktemp)       || die $0: mktemp failed.
cat > $rcfile <<EOF
DEFAULT="$MAILDIR/"
EOF

## Copy the data into a temporary file (locking in case it's our system mailbox)
tmpfile=$(mktemp)      || die $0: mktemp failed.
lockfile -ml           || die $0: Cannot lock your system mailbox.
cat "$MBOX" > $tmpfile || die $0: Cannot copy \$MBOX $MBOX.
true > "$MBOX"         || die $0: Cannot zero \$MBOX $MBOX - copy in $tmpfile.
lockfile -mu           || die $0: Cannot unlock your system mailbox - data in $tmpfile.

## Reprocess our copy via procmail
formail -s procmail $rcfile < $tmpfile || die $0: formail failed - data in $tmpfile.

## All successful, delete $tmpfile and exit
rm -f $tmpfile $rcfile || die $0: error deleting \$tmpfile $tmpfile
exit 0