#!/opt/bin/perl
#
#########################################################################
#                                                                       #
#   Program for storing e-mail problem reports with automatic receipt   #
#                                                                       #
#########################################################################
#                                                                       #
#   Version 1.0     -   Written 01.08.95 by Steffen Beyer               #
#                                                                       #
#########################################################################
#                                                                       #
#   Copyright (C) 1995 by software design & management GmbH & Co. KG    #
#                                                                       #
#########################################################################
#
# Some important default settings:
#
$version = 'Version 1.0';
#
$self = $0;
#
if ($self =~ m!/([^/]+)$!) { $self = $1; }
#
# Define here the name of your mailbox (MUST be an ABSOLUTE path!!!):
#
$mailbox = '/u/sysadm/preport';
#
$lockfile = "$mailbox.lock";
#
$tempfile = "$mailbox.temp";
#
$wait = "true";
#
# Wait for semaphore:
#
while ($wait)
{
    #
    # Wait for semaphore to be released (if set):
    #
    while (-f $lockfile) { sleep(5); }
    #
    # When semaphore is gone, create own one:
    #
    unless (open(LOCKFILE, ">>$lockfile"))
    {
        unlink($lockfile);
        die "Can't open semaphore for writing: $!\n";
    }
    print LOCKFILE "$$\n";
    close(LOCKFILE);
    #
    # Check wether semaphore is our's or was created
    # in the meantime by another copy of this process
    #
    unless (open(LOCKFILE, "<$lockfile"))
    {
        unlink($lockfile);
        die "Can't open semaphore for reading: $!\n";
    }
    $_ = <LOCKFILE>;
    chop;
    close(LOCKFILE);
    #
    # Loop if semaphore isn't our's:
    #
    $wait = ($_ != $$);
    if ($wait)
    {
        warn "Semaphore access conflict detected!\n";
        warn "Waiting for other process to terminate.\n";
    }
}
#
# Append incoming mail to mailbox and determine the sender's e-mail address:
#
$subject = '';
$reply_address = '';
$real_address  = '';
$logic_address = '';
#
unless (open(MAILBOX, ">>$mailbox"))
{
    unlink($lockfile);
    die "Can't open mailbox for writing: $!\n";
}
#
while (<STDIN>)
{
    chop;
    print MAILBOX $_, "\n";
    if (($reply_address eq '') && (/^Reply-To:\s+(\S+@\S+)/))
    {
        $reply_address = $1;
    }
    if (($real_address eq '')  && (/^From:\s+(\S+@\S+)/))
    {
        $real_address  = $1;
    }
    if (($logic_address eq '') && (/^From\s+(\S+@\S+)/))
    {
        $logic_address = $1;
    }
    if (($subject eq '') && (/^Subject:\s+(.*)/))
    {
        $subject = $1;
    }
}
#
close(MAILBOX);
#
if ($reply_address eq $real_address)
{
    $real_address = '';
}
if (($reply_address eq $logic_address) || ($real_address eq $logic_address))
{
    $logic_address = '';
}
#
# If address was found and no error abort so far, send acknowledgement mail:
#
if (($reply_address ne '') || ($real_address ne '') || ($logic_address ne ''))
{
    unless (open(TEMPFILE, ">$tempfile"))
    {
        unlink($tempfile);
        unlink($lockfile);
        die "Can't open tempfile for writing: $!\n";
    }
    #
    print TEMPFILE "From: sysadm@bi.sdm.de\n";
    if ($reply_address ne '')
    {
        print TEMPFILE "To: $reply_address\n";
        if ($real_address ne '')
        {
            if ($logic_address ne '')
            {
                print TEMPFILE "Cc: $real_address, $logic_address\n";
            }
            else
            {
                print TEMPFILE "Cc: $real_address\n";
            }
        }
        else
        {
            if ($logic_address ne '')
            {
                print TEMPFILE "Cc: $logic_address\n";
            }
        }
    }
    elsif ($real_address ne '')
    {
        print TEMPFILE "To: $real_address\n";
        if ($logic_address ne '')
        {
            print TEMPFILE "Cc: $logic_address\n";
        }
    }
    else
    {
        print TEMPFILE "To: $logic_address\n";
    }
    print TEMPFILE <<"VERBATIM";
Subject: Bestaetigung: Problemreport erhalten!

Dein Problem-Report wurde registriert.
VERBATIM
    if ($subject ne '')
    {
        print TEMPFILE "Dein Subject war: $subject\n";
    }
    print TEMPFILE <<"VERBATIM";
Diese Bestaetigung wird automatisch verschickt.

Mit freundlichen Gruessen,
Eure System-Administration.
VERBATIM
    #
    close(TEMPFILE);
    #
    system("cat $tempfile | /opt/bin/sendmail -t");
    #
    unlink($tempfile);
}
#
# Release semaphore:
#
unlink($lockfile);
#
# Done.
#