#!/usr/bin/perl
#
# emaildir
#
# version 0.1, August 2000
#
# This script replaces e-mails in fields `From: ' and `Return-Path: ' of e-mail
# header. It's usefull when you have different local and remote e-mail.
# Input parameters are paths to two maildirs. This script reads messages from
# first maildir and writes to second.
#
# Replacements must be set in /etc/emaildir.loc2rem. There must be TWO e-mails 
# on each line separated by TABULATOR. Comments lines must begin with `#' char.
# Empty lines are supported.
#
# Script is distributed under the GNU General Public Licence.
#
# author:
#   Jiri VERUNEK <verunek@vol.cz> <jiri.verunek@seznam.cz>
#   http://verunek.host.sk
#   http://verunek.oceany.cz
#

sub createfilelist
{
  local($a);
  push(@dirlist, "");
  while (@dirlist."" > 0)
  {
    $curdirpath = pop(@dirlist);
    opendir(dir, @ARGV[0].$curdirpath);
    @curdir = readdir(dir);
    closedir(dir);
    for ($a = 0; $a < @curdir.""; ++$a)
    {
      if (-f @ARGV[0].$curdirpath.$curdir[$a])
      {
        push(@filelist, $curdirpath.$curdir[$a]);
      }
      elsif ((-d @ARGV[0].$curdirpath.$curdir[$a]) && ($curdir[$a] ne '.') && ($curdir[$a] ne '..'))
      {
        push(@dirlist, $curdirpath.$curdir[$a]."/");
      }
    }
  }
}

sub loademailfile
{
  open(emailfile, "/etc/emaildir.loc2rem");
  @email = <emailfile>;
  close(email);

  local($a);
  do
  {
    if (($email[$a] !~ /^#/) && ($email[$a] =~ /.\t./))
    {
      push(@emailrem, substr($email[$a], index($email[$a], "\t")+1));
      push(@emailloc, substr($email[$a], 0, index($email[$a], "\t")));
    }
    ++$a
  }
  until($a >= @email."");
  chop(@emailrem);
  undef @email;
}

sub replaceemail
{
  local($a);
  for ($a = 0; $a < @emailloc.""; ++$a)
  {
    $message[$_[0]] =~ s/$emailloc[$a]/$emailrem[$a]/;
  }
}

sub savemessage
{
  if (-f @ARGV[1].$messagepath)
  {
    print "ERROR: File @ARGV[1]$messagepath exists yet!\n"
  }
  elsif (open(file, ">@ARGV[1]$messagepath") == 1)
  {
    print file @message;
    close(file);
    unlink(@ARGV[0].$messagepath);
  }
  else
  {
    print "ERROR: File @ARGV[1]$messagepath cannot be created.\n"
  }
}

sub processthefiles
{
  while (@filelist."" > 0)
  {
    $messagepath = pop(@filelist);

    open(file, @ARGV[0].$messagepath);
    @message = <file>;
    close(file);

    $returnpath_ok = 0;
    $from_ok = 0;

    $messagelinenumber = 0;
    do
    {
      if ($message[$messagelinenumber] =~ /.@./)
      {
        if (($returnpath_ok == 0) && ($message[$messagelinenumber] =~ /^Return-Path: /))
        {
          $returnpath_ok = 1;
          &replaceemail($messagelinenumber);
        }
        elsif (($from_ok == 0) && ($message[$messagelinenumber] =~ /^From: /))
        {
          $from_ok = 1;
          &replaceemail($messagelinenumber);
        }
      }
      ++$messagelinenumber;
    }
    until ($messagelinenumber >= @message."") || (($returnpath_ok == 1) && ($from_ok == 1));
  &savemessage;
  }
}

# ===== MAIN PROGRAM =====

if ((@ARGV."" == 1) && (@ARGV[0] == "--help"))
{
  print "emaildir\n";
  print "version 0.1, August 2000\n\n";
  print "This script replaces e-mails in fields `From: ' and `Return-Path: ' of e-mail header. It's usefull when you have different local and remote e-mail. Input parameters are paths to two maildirs. This script reads messages from first maildir and writes to second.\n";
  print "Replacements must be set in /etc/emaildir.loc2rem. There must be TWO e-mails on each line separated by TABULATOR. Comments lines must begin with `#' char. Empty lines are supported.\n\n";
  print "license: GNU GPL\n\n";
  print "author:\n";
  print '   Jiri VERUNEK <verunek@mbox.vol.cz> <jiri.verunek@seznam.cz>'."\n";
  print '   http://www.oceany.cz/verunek'."\n";
}
elsif ((@ARGV."" != 2) || !(-d @ARGV[0]) || !(-d @ARGV[1]))
{
  print "Usage: emaildir DIR1 DIR2\n";
  print "  \"emaildir --help\" for help\n"
}
else
{
  if (@ARGV[0] !~ /.\/$/)
  {
    @ARGV[0] = @ARGV[0]."/";
  }
  if (@ARGV[1] !~ /.\/$/)
  {
    @ARGV[1] = @ARGV[1]."/";
  }

  &createfilelist;
  if (@filelist."" > 0)
  {
    &loademailfile;
    &processthefiles;
  }
}