#!/usr/bin/perl

#
# a simple vacation script
#

use strict;
use Time::localtime;

# ----- some global vars - set up to fit your needs

my $message 	   = $ENV{'HOME'} . "/" . ".vacation.msg";
my $dbfile 	   = $ENV{'HOME'} . "/" . ".vacation.db";
my $check_sig 	   = 1;				# check for signature in $HOME?
my $version 	   = "vacation.pl (c) 2001 by lf, v. 160801-1815";
my $reply_interval = 60; 			# max reply interval (minutes)
my $sendmail       = "/usr/sbin/sendmail";	# path to sendmail prog/wrapper
my $hostname_file  = "/etc/hostname";		# file containing hostname
my @weekdays = qw (Sun Mon Tue Wed Thu Fri Sat);
my @months = qw (Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec);

# ----- set host's name, if needed

if ( (-e $hostname_file) and (!$ENV{'HOSTNAME'}) ) {
  open (HN, "<$hostname_file");
  $ENV{'HOSTNAME'} = <HN>;
  chomp $ENV{'HOSTNAME'};
  close (HN);
}

# ----- check for existing message file

if (!-e $message) {
  print "Die Datei $message existiert noch nicht!\n";
  exit (1);
}

# ----- read the mail header from std input

local $/ = "";

my $header = <STDIN>;

undef $/;

# ----- preformatting of header

my @header = split /\n(?!\s)/, $header;
foreach (@header) {
  if (/.*\n.*/) {
    $_ =~ s/\n\s+/ /g;
  }
}

# ----- read headers into hash

my %hash = ();

foreach (@header) {
  my ($label, $value) = split /:\s*/, $_, 2;
  $hash{$label} = $value;
}

# ----- check if auto-reply was already sent within interval

open (STATUS, "<$dbfile");
my @status = split /\n/, <STATUS>;
close (STATUS);

@status = reverse @status;

foreach (@status) {
  my ($rdate, $rrecip) = split /;/, $_;
  if ($rrecip =~ /$hash{'From'}/) {
    my $diff = abs ( time() - $rdate );
    exit (1) if ($diff < ($reply_interval * 60));
    last;
  }
}

# ----- prevent bogus and useless replies

exit (1) if ( ($hash{'X-Loop'}) or ($hash{'Precedence'} =~ /(bulk|junk|list)/) );
exit (1) if ( (!$hash{'From'}) or ($hash{'From'} =~ /(daemon|postmaster|mailer-daemon|mailer)/i) );

# ----- Reply-To overrides To address

$hash{'From'} = $hash{'Reply-To'} if $hash{'Reply-To'};

# ----- get some date and Message ID for replying

my $message_id = time () . "\%vacation\@" . $ENV{'HOSTNAME'};
#my $date = localtime ( time() );
my $tm = localtime ( time() );
my $date = sprintf ("%s, %02d %s %04d %02d:%02d:%02d +0100",
  $weekdays[$tm->wday], $tm->mday, $months[$tm->mon + 1],
  $tm->year + 1900, $tm->hour, $tm->min, $tm->sec);

# ----- read the message file

open (MSGFILE, "<$message");
my @message = <MSGFILE>;
close (MSGFILE);

# ----- open sendmail pipe

$ENV{'PATH'} = "";
open (SMPIPE, "| $sendmail -t");

# ----- evaluate message

my $eval = "print SMPIPE <<\"...\";\n";
   $eval .= $_ foreach (@message);
   $eval .= "...";

eval ($eval);

# ----- append signature, if requested and sig file set up

if ( ($check_sig) and (-e "$ENV{'HOME'}/.signature") ) {
  print SMPIPE "\n\n--  \n";
  open (SIG, "<$ENV{'HOME'}/.signature");
  print SMPIPE <SIG>;
  close (SIG);
}

close (SMPIPE);

# ----- write to vacation status file

open (STATUS, ">>$dbfile");
print STATUS time () . ";" . $hash{'From'} . "\n";
close (STATUS);