#!/bin/sh
#
# authorize_email
#
# AUTHOR:
#   Dan Harkless                                                    <opensource@
#   http://harkless.org/dan/software/                              harkless.org>
#
# COPYRIGHT:
#   This file is Copyright (C) 1998 by Dan Harkless, and is released under the
#   GNU General Public License <http://www.gnu.org/copyleft/gpl.html>.
#
# USAGE:
#   % authorize_email <from_email_address> <forward_to_account>
# 
# EXAMPLE:
#   % authorize_email MyFriend@aol.com dan-pop
# 
# DESCRIPTION:
#   A script to be called automatically from your MH/nmh .maildelivery file to
#   allow someone at a specific email address to email you without having to go
#   through any challenge-response process.  Adds the email address in $1 to the
#   list of people who are authorized to email you and delivers the message on
#   stdin to another of your accounts, $2.  This script could be modified fairly
#   easily to work with procmail instead of MH's slocal.
#
#   To use this script, your .maildelivery file must contain a section bounded
#   by the lines "# Allow email BEGIN" and "# Allow email END".  authorize_email
#   will add authorized email addresses alphabetically to this section.
#
# DATE        MODIFICATION
# ==========  ==================================================================
# 1998-06-27  Previous copy of .maildelivery should be .prev, not ".bak".
# 1997-11-04  Put MH/nmh library path in MH_LIB variable for easy customization.
# 1997-06-18  Output variable number of TABs for pretty formatting.
# 1997-05-29  Original.

set -x  # turn on trace mode so we can put the output of this script in a log

# You may need to change this on your system!
MH_LIB=/usr/local/lib/nmh

# We use relative paths below, so make sure we're in our home directory.
# We might not be if we're being run interactively for debugging purposes.
cd

# Wait for any other authorize_email invocations to finish.
while [ -f authorize.lock ]; do
  sleep 10
done

# Lock.
trap 'rm -f authorize.lock maildelivery.new maildelivery.sort' 0 1 2 3 15
touch authorize.lock

# Add to the list of people allowed to email.
begin=`fgrep -n "Allow email BEGIN" .maildelivery | head -1 | cut -d: -f1`
end=`fgrep -n "Allow email END" .maildelivery | head -1 | cut -d: -f1`
head -$begin .maildelivery > maildelivery.new
begin=`expr $begin + 1`
lines=`expr $end - $begin`
tail +$begin .maildelivery | head -$lines > maildelivery.sort
email=`bin/email_address "$1"`
length=`echo $email | awk '{print length}'`
if [ $length -gt 18 ]; then
  tabs='	'
elif [ $length -gt 10 ]; then
  tabs='		'
elif [ $length -gt 2 ]; then
  tabs='			'
else
  tabs='				'
fi
echo 'From '$email"$tabs"'^ ? "'$MH_LIB/rcvdist $2'"' \
     >> maildelivery.sort
sort maildelivery.sort | uniq >> maildelivery.new
tail +$end .maildelivery >> maildelivery.new
mv .maildelivery .maildelivery.prev
mv maildelivery.new .maildelivery

# Distribute the mail to a non-tainted account (it's on stdin).
$MH_LIB/rcvdist $2