sendmail/contrib/qtool.pl

#!/usr/bin/env perl
##
## Copyright (c) 1998-2002 Proofpoint, Inc. and its suppliers.
##  All rights reserved.
##
## $Id: qtool.pl,v 8.32 2013-11-22 20:51:18 ca Exp $
##
use strict;
use File::Basename;
use File::Copy;
use File::Spec;
use Fcntl qw(:flock :DEFAULT);
use Getopt::Std;

##
## QTOOL
##  This program is for moving files between sendmail queues. It is
## pretty similar to just moving the files manually, but it locks the files
## the same way sendmail does to prevent problems.
##
##  NOTICE: Do not use this program to move queue files around
## if you use sendmail 8.12 and multiple queue groups. It may interfere
## with sendmail's internal queue group selection strategy and can cause
## mail to be not delivered.
##
##  The syntax is the reverse of mv (ie. the target argument comes
## first). This lets you pick the files you want to move using find and
## xargs.
##
##  Since you cannot delete queues while sendmail is running, QTOOL
## assumes that when you specify a directory as a source, you mean that you
## want all of the queue files within that directory moved, not the
## directory itself.
##
##  There is a mechanism for adding conditionals for moving the files.
## Just create an Object with a check_move(source, dest) method and add it
## to the $conditions object. See the handling of the '-s' option for an
## example.
##

##
## OPTION NOTES
##
## The -e option:
##  The -e option takes any valid perl expression and evaluates it
##  using the eval() function. Inside the expression the variable
##  '$msg' is bound to the ControlFile object for the current source
##  queue message. This lets you check for any value in the message
##  headers or the control file. Here's an example:
##
##  ./qtool.pl -e '$msg{num_delivery_attempts} >= 2' /q1 /q2
##
##  This would move any queue files whose number of delivery attempts
##  is greater than or equal to 2 from the queue 'q2' to the queue 'q1'.
##
##  See the function ControlFile::parse for a list of available
##  variables.
##

my %opts;
my %sources;
my $dst_name;
my $destination;
my $source_name;
my $source;
my $result;
my $action;
my $new_condition;
my $qprefix;
my $queuegroups = 0;
my $conditions = new Compound();
my $fcntl_struct = 's H60';
my $fcntl_structlockp = pack($fcntl_struct, Fcntl::F_WRLCK,
    "000000000000000000000000000000000000000000000000000000000000");
my $fcntl_structunlockp = pack($fcntl_struct, Fcntl::F_UNLCK,
    "000000000000000000000000000000000000000000000000000000000000");
my $lock_both = -1;

Getopt::Std::getopts('bC:de:Qs:', \%opts);

sub move_action
{
    my $source = shift;
    my $destination = shift;

    $result = $destination->add($source);
    if ($result)
    {
        print("$result.\n");
    }
}

sub delete_action
{
    my $source = shift;

    return $source->delete();
}

sub bounce_action
{
    my $source = shift;

    return $source->bounce();
}

$action = \&move_action;
if (defined $opts{d})
{
    $action = \&delete_action;
}
elsif (defined $opts{b})
{
    $action = \&bounce_action;
}

if (defined $opts{s})
{
    $new_condition = new OlderThan($opts{s});
    $conditions->add($new_condition);
}

if (defined $opts{e})
{
    $new_condition = new Eval($opts{e});
    $conditions->add($new_condition);
}

if (defined $opts{Q})
{
    $qprefix = "hf";
}
else
{
    $qprefix = "qf";
}

if ($action == \&move_action)
{
    $dst_name = shift(@ARGV);
    if (!-d $dst_name)
    {
        print("The destination '$dst_name' must be an existing " .
              "directory.\n");
        usage();
        exit;
    }
    $destination = new Queue($dst_name);
}

# determine queue_root by reading config file
my $queue_root;
{
    my $config_file = "/etc/mail/sendmail.cf";
    if (defined $opts{C})
    {
        $config_file = $opts{C};
    }

    my $line;
    open(CONFIG_FILE, $config_file) or die "$config_file: $!";

    ##  Notice: we can only break out of this loop (using last)
    ##  when both entries (queue directory and group group)
    ##  have been found.
    while ($line = <CONFIG_FILE>)
    {
        chomp $line;
        if ($line =~ m/^O QueueDirectory=(.*)/)
        {
            $queue_root = $1;
            if ($queue_root =~ m/(.*)\/[^\/]+\*$/)
            {
                $queue_root = $1;
            }
            # found also queue groups?
            if ($queuegroups)
            {
                last;
            }
        }
        if ($line =~ m/^Q.*/)
        {
            $queuegroups = 1;
            if ($action == \&move_action)
            {
                print("WARNING: moving queue files around " .
                      "when queue groups are used may\n" .
                      "result in undelivered mail!\n");
            }
            # found also queue directory?
            if (defined $queue_root)
            {
                last;
            }
        }
    }
    close(CONFIG_FILE);
    if (!defined $queue_root)
    {
        die "QueueDirectory option not defined in $config_file";
    }
}

while (@ARGV)
{
    $source_name = shift(@ARGV);
    $result = add_source(\%sources, $source_name);
    if ($result)
    {
        print("$result.\n");
        exit;
    }
}

if (keys(%sources) == 0)
{
    exit;
}

while (($source_name, $source) = each(%sources))
{
    $result = $conditions->check_move($source, $destination);
    if ($result)
    {
        $result = &{$action}($source, $destination);
        if ($result)
        {
            print("$result\n");
        }
    }
}

sub usage
{
    print("Usage:\t$0 [options] directory source ...\n");
    print("\t$0 [-Q][-d|-b] source ...\n");
    print("Options:\n");
    print("\t-b\t\tBounce the messages specified by source.\n");
    print("\t-C configfile\tSpecify sendmail config file.\n");
    print("\t-d\t\tDelete the messages specified by source.\n");
    print("\t-e [perl expression]\n");
    print("\t\t\tMove only messages for which perl expression\n");
    print("\t\t\treturns true.\n");
    print("\t-Q\t\tOperate on quarantined files.\n");
    print("\t-s [seconds]\tMove only messages whose queue file is older\n");
    print("\t\t\tthan seconds.\n");
}

##
## ADD_SOURCE -- Adds a source to the source hash.
##
##  Determines whether source is a file, directory, or id. Then it
##  creates a QueuedMessage or Queue for that source and adds it to the
##  list.
##
##  Parameters:
##      sources -- A hash that contains all of the sources.
##      source_name -- The name of the source to add
##
##  Returns:
##      error_string -- Undef if ok. Error string otherwise.
##
##  Notes:
##      If a new source comes in with the same ID as a previous
##      source, the previous source gets overwritten in the sources
##      hash. This lets the user specify things like * and it still
##      works nicely.
##

sub add_source
{
    my $sources = shift;
    my $source_name = shift;
    my $source_base_name;
    my $source_dir_name;
    my $data_dir_name;
    my $source_id;
    my $source_prefix;
    my $queued_message;
    my $queue;
    my $result;

    ($source_base_name, $source_dir_name) = File::Basename::fileparse($source_name);
    $data_dir_name = $source_dir_name;

    $source_prefix = substr($source_base_name, 0, 2);
    if (!-d $source_name && $source_prefix ne $qprefix &&
        $source_prefix ne 'df')
    {
        $source_base_name = "$qprefix$source_base_name";
        $source_name = File::Spec->catfile("$source_dir_name",
                           "$source_base_name");
    }
    $source_id = substr($source_base_name, 2);

    if (!-e $source_name)
    {
        $source_name = File::Spec->catfile("$source_dir_name", "qf",
                           "$qprefix$source_id");
        if (!-e $source_name)
        {
            return "'$source_name' does not exist";
        }
        $data_dir_name = File::Spec->catfile("$source_dir_name", "df");
        if (!-d $data_dir_name)
        {
            $data_dir_name = $source_dir_name;
        }
        $source_dir_name = File::Spec->catfile("$source_dir_name",
                               "qf");
    }

    if (-f $source_name)
    {
        $queued_message = new QueuedMessage($source_dir_name,
                            $source_id,
                            $data_dir_name);
        $sources->{$source_id} = $queued_message;
        return undef;
    }

    if (!-d $source_name)
    {
        return "'$source_name' is not a plain file or a directory";
    }

    $queue = new Queue($source_name);
    $result = $queue->read();
    if ($result)
    {
        return $result;
    }

    while (($source_id, $queued_message) = each(%{$queue->{files}}))
    {
        $sources->{$source_id} = $queued_message;
    }

    return undef;
}

##
## LOCK_FILE -- Opens and then locks a file.
##
##  Opens a file for read/write and uses flock to obtain a lock on the
##  file. The flock is Perl's flock which defaults to flock on systems
##  that support it. On systems without flock it falls back to fcntl
##  locking.  This script will also call fcntl explicitly if flock
##      uses BSD semantics (i.e. if both flock() and fcntl() can successfully
##      lock the file at the same time)
##
##  Parameters:
##      file_name -- The name of the file to open and lock.
##
##  Returns:
##      (file_handle, error_string) -- If everything works then
##          file_handle is a reference to a file handle and
##          error_string is undef. If there is a problem then
##          file_handle is undef and error_string is a string
##          explaining the problem.
##

sub lock_file
{
    my $file_name = shift;
    my $result;

    if ($lock_both == -1)
    {
        if (open(DEVNULL, '>/dev/null'))
        {
            my $flock_status = flock(DEVNULL, Fcntl::LOCK_EX | Fcntl::LOCK_NB);
            my $fcntl_status = fcntl (DEVNULL, Fcntl::F_SETLK, $fcntl_structlockp);
            close(DEVNULL);

            $lock_both = ($flock_status && $fcntl_status);
        }
        else
        {
            # Couldn't open /dev/null.  Windows system?
            $lock_both = 0;
        }
    }


    $result = sysopen(FILE_TO_LOCK, $file_name, Fcntl::O_RDWR);
    if (!$result)
    {
        return (undef, "Unable to open '$file_name': $!");
    }

    $result = flock(FILE_TO_LOCK, Fcntl::LOCK_EX | Fcntl::LOCK_NB);
    if (!$result)
    {
        return (undef, "Could not obtain lock on '$file_name': $!");
    }

    if ($lock_both)
    {
        my $result2 = fcntl (FILE_TO_LOCK, Fcntl::F_SETLK, $fcntl_structlockp);
        if (!$result2)
        {
            return (undef, "Could not obtain fcntl lock on '$file_name': $!");
        }
    }

    return (\*FILE_TO_LOCK, undef);
}

##
## UNLOCK_FILE -- Unlocks a file.
##
##  Unlocks a file using Perl's flock.
##
##  Parameters:
##      file -- A file handle.
##
##  Returns:
##      error_string -- If undef then no problem. Otherwise it is a
##          string that explains problem.
##

sub unlock_file
{
    my $file = shift;
    my $result;

    $result = flock($file, Fcntl::LOCK_UN);
    if (!$result)
    {
        return "Unlock failed on '$result': $!";
    }
    if ($lock_both)
    {
        my $result2 = fcntl ($file, Fcntl::F_SETLK, $fcntl_structunlockp);
        if (!$result2)
        {
            return (undef, "Fcntl unlock failed on '$result': $!");
        }
    }

    return undef;
}

##
## MOVE_FILE -- Moves a file.
##
##  Moves a file.
##
##  Parameters:
##      src_name -- The name of the file to be move.
##      dst_name -- The name of the place to move it to.
##
##  Returns:
##      error_string -- If undef then no problem. Otherwise it is a
##          string that explains problem.
##

sub move_file
{
    my $src_name = shift;
    my $dst_name = shift;
    my $result;

    $result = File::Copy::move($src_name, $dst_name);
    if (!$result)
    {
        return "File move from '$src_name' to '$dst_name' failed: $!";
    }

    return undef;
}


##
## CONTROL_FILE - Represents a sendmail queue control file.
##
##  This object represents represents a sendmail queue control file.
##  It can parse and lock its file.
##


package ControlFile;

sub new
{
    my $this = shift;
    my $class = ref($this) || $this;
    my $self = {};
    bless $self, $class;
    $self->initialize(@_);
    return $self;
}

sub initialize
{
    my $self = shift;
    my $queue_dir = shift;
    $self->{id} = shift;

    $self->{file_name} = $queue_dir . '/' . $qprefix . $self->{id};
    $self->{headers} = {};
}

##
## PARSE - Parses the control file.
##
##  Parses the control file. It just sticks each entry into a hash.
##  If a key has more than one entry, then it points to a list of
##  entries.
##

sub parse
{
    my $self = shift;
    if ($self->{parsed})
    {
        return;
    }
    my %parse_table =
    (
        'A' => 'auth',
        'B' => 'body_type',
        'C' => 'controlling_user',
        'D' => 'data_file_name',
        'd' => 'data_file_directory',
        'E' => 'error_recipient',
        'F' => 'flags',
        'H' => 'parse_header',
        'I' => 'inode_number',
        'K' => 'next_delivery_time',
        'L' => 'content-length',
        'M' => 'message',
        'N' => 'num_delivery_attempts',
        'P' => 'priority',
        'Q' => 'original_recipient',
        'R' => 'recipient',
        'q' => 'quarantine_reason',
        'r' => 'final_recipient',
        'S' => 'sender',
        'T' => 'creation_time',
        'V' => 'version',
        'Y' => 'current_delay',
        'Z' => 'envid',
        '!' => 'deliver_by',
        '$' => 'macro'
    );
    my $line;
    my $line_type;
    my $line_value;
    my $member_name;
    my $member;
    my $last_type;

    open(CONTROL_FILE, "$self->{file_name}");
    while ($line = <CONTROL_FILE>)
    {
        $line_type = substr($line, 0, 1);
        if ($line_type eq "\t" && $last_type eq 'H')
        {
            $line_type = 'H';
            $line_value = $line;
        }
        else
        {
            $line_value = substr($line, 1);
        }
        $member_name = $parse_table{$line_type};
        $last_type = $line_type;
        if (!$member_name)
        {
            $member_name = 'unknown';
        }
        if ($self->can($member_name))
        {
            $self->$member_name($line_value);
        }
        $member = $self->{$member_name};
        if (!$member)
        {
            $self->{$member_name} = $line_value;
            next;
        }
        if (ref($member) eq 'ARRAY')
        {
            push(@{$member}, $line_value);
            next;
        }
        $self->{$member_name} = [$member, $line_value];
    }
    close(CONTROL_FILE);

    $self->{parsed} = 1;
}

sub parse_header
{
    my $self = shift;
    my $line = shift;
    my $headers = $self->{headers};
    my $last_header = $self->{last_header};
    my $header_name;
    my $header_value;
    my $first_char;

    $first_char = substr($line, 0, 1);
    if ($first_char eq "?")
    {
        $line = (split(/\?/, $line,3))[2];
    }
    elsif ($first_char eq "\t")
    {
        if (ref($headers->{$last_header}) eq 'ARRAY')
        {
            $headers->{$last_header}[-1] =
                $headers->{$last_header}[-1] . $line;
        }
        else
        {
            $headers->{$last_header} = $headers->{$last_header} .
                           $line;
        }
        return;
    }
    ($header_name, $header_value) = split(/:/, $line, 2);
    $self->{last_header} = $header_name;
    if (exists $headers->{$header_name})
    {
        $headers->{$header_name} = [$headers->{$header_name},
                        $header_value];
    }
    else
    {
        $headers->{$header_name} = $header_value;
    }
}

sub is_locked
{
    my $self = shift;

    return (defined $self->{lock_handle});
}

sub lock
{
    my $self = shift;
    my $lock_handle;
    my $result;

    if ($self->is_locked())
    {
        # Already locked
        return undef;
    }

    ($lock_handle, $result) = ::lock_file($self->{file_name});
    if (!$lock_handle)
    {
        return $result;
    }

    $self->{lock_handle} = $lock_handle;

    return undef;
}

sub unlock
{
    my $self = shift;
    my $result;

    if (!$self->is_locked())
    {
        # Not locked
        return undef;
    }

    $result = ::unlock_file($self->{lock_handle});

    $self->{lock_handle} = undef;

    return $result;
}

sub do_stat
{
    my $self = shift;
    my $result;
    my @result;

    $result = open(QUEUE_FILE, $self->{file_name});
    if (!$result)
    {
        return "Unable to open '$self->{file_name}': $!";
    }
    @result = stat(QUEUE_FILE);
    if (!@result)
    {
        return "Unable to stat '$self->{file_name}': $!";
    }
    $self->{control_size} = $result[7];
    $self->{control_last_mod_time} = $result[9];
}

sub DESTROY
{
    my $self = shift;

    $self->unlock();
}

sub delete
{
    my $self = shift;
    my $result;

    $result = unlink($self->{file_name});
    if (!$result)
    {
        return "Unable to delete $self->{file_name}: $!";
    }
    return undef;
}


##
## DATA_FILE - Represents a sendmail queue data file.
##
##  This object represents represents a sendmail queue data file.
##  It is really just a place-holder.
##

package DataFile;

sub new
{
    my $this = shift;
    my $class = ref($this) || $this;
    my $self = {};
    bless $self, $class;
    $self->initialize(@_);
    return $self;
}

sub initialize
{
    my $self = shift;
    my $data_dir = shift;
    $self->{id} = shift;
    my $control_file = shift;

    $self->{file_name} = $data_dir . '/df' . $self->{id};
    return if -e $self->{file_name};
    $control_file->parse();
    return if !defined $control_file->{data_file_directory};
    $data_dir = $queue_root . '/' . $control_file->{data_file_directory};
    chomp $data_dir;
    if (-d ($data_dir . '/df'))
    {
        $data_dir .= '/df';
    }
    $self->{file_name} = $data_dir . '/df' . $self->{id};
}

sub do_stat
{
    my $self = shift;
    my $result;
    my @result;

    $result = open(QUEUE_FILE, $self->{file_name});
    if (!$result)
    {
        return "Unable to open '$self->{file_name}': $!";
    }
    @result = stat(QUEUE_FILE);
    if (!@result)
    {
        return "Unable to stat '$self->{file_name}': $!";
    }
    $self->{body_size} = $result[7];
    $self->{body_last_mod_time} = $result[9];
}

sub delete
{
    my $self = shift;
    my $result;

    $result = unlink($self->{file_name});
    if (!$result)
    {
        return "Unable to delete $self->{file_name}: $!";
    }
    return undef;
}


##
## QUEUED_MESSAGE - Represents a queued sendmail message.
##
##  This keeps track of the files that make up a queued sendmail
##  message.
##  Currently it has 'control_file' and 'data_file' as members.
##
##  You can tie it to a fetch only hash using tie. You need to
##  pass a reference to a QueuedMessage as the third argument
##  to tie.
##

package QueuedMessage;

sub new
{
    my $this = shift;
    my $class = ref($this) || $this;
    my $self = {};
    bless $self, $class;
    $self->initialize(@_);
    return $self;
}

sub initialize
{
    my $self = shift;
    my $queue_dir = shift;
    my $id = shift;
    my $data_dir = shift;

    $self->{id} = $id;
    $self->{control_file} = new ControlFile($queue_dir, $id);
    if (!$data_dir)
    {
        $data_dir = $queue_dir;
    }
    $self->{data_file} = new DataFile($data_dir, $id, $self->{control_file});
}

sub last_modified_time
{
    my $self = shift;
    my @result;
    @result = stat($self->{data_file}->{file_name});
    return $result[9];
}

sub TIEHASH
{
    my $this = shift;
    my $class = ref($this) || $this;
    my $self = shift;
    return $self;
}

sub FETCH
{
    my $self = shift;
    my $key = shift;

    if (exists $self->{control_file}->{$key})
    {
        return $self->{control_file}->{$key};
    }
    if (exists $self->{data_file}->{$key})
    {
        return $self->{data_file}->{$key};
    }

    return undef;
}

sub lock
{
    my $self = shift;

    return $self->{control_file}->lock();
}

sub unlock
{
    my $self = shift;

    return $self->{control_file}->unlock();
}

sub move
{
    my $self = shift;
    my $destination = shift;
    my $df_dest;
    my $qf_dest;
    my $result;

    $result = $self->lock();
    if ($result)
    {
        return $result;
    }

    $qf_dest = File::Spec->catfile($destination, "qf");
    if (-d $qf_dest)
    {
        $df_dest = File::Spec->catfile($destination, "df");
        if (!-d $df_dest)
        {
            $df_dest = $destination;
        }
    }
    else
    {
        $qf_dest = $destination;
        $df_dest = $destination;
    }

    if (-e File::Spec->catfile($qf_dest, "$qprefix$self->{id}"))
    {
        $result = "There is already a queued message with id '$self->{id}' in '$destination'";
    }

    if (!$result)
    {
        $result = ::move_file($self->{data_file}->{file_name},
                      $df_dest);
    }

    if (!$result)
    {
        $result = ::move_file($self->{control_file}->{file_name},
                      $qf_dest);
    }

    $self->unlock();

    return $result;
}

sub parse
{
    my $self = shift;

    return $self->{control_file}->parse();
}

sub do_stat
{
    my $self = shift;

    $self->{control_file}->do_stat();
    $self->{data_file}->do_stat();
}

sub setup_vars
{
    my $self = shift;

    $self->parse();
    $self->do_stat();
}

sub delete
{
    my $self = shift;
    my $result;

    $result = $self->{control_file}->delete();
    if ($result)
    {
        return $result;
    }
    $result = $self->{data_file}->delete();
    if ($result)
    {
        return $result;
    }

    return undef;
}

sub bounce
{
    my $self = shift;
    my $command;

    $command = "sendmail -qI$self->{id} -O Timeout.queuereturn=now";
#   print("$command\n");
    system($command);
}

##
## QUEUE - Represents a queued sendmail queue.
##
##  This manages all of the messages in a queue.
##

package Queue;

sub new
{
    my $this = shift;
    my $class = ref($this) || $this;
    my $self = {};
    bless $self, $class;
    $self->initialize(@_);
    return $self;
}

sub initialize
{
    my $self = shift;

    $self->{queue_dir} = shift;
    $self->{files} = {};
}

##
## READ - Loads the queue with all of the objects that reside in it.
##
##  This reads the queue's directory and creates QueuedMessage objects
##  for every file in the queue that starts with 'qf' or 'hf'
##  (depending on the -Q option).
##

sub read
{
    my $self = shift;
    my @control_files;
    my $queued_message;
    my $file_name;
    my $id;
    my $result;
    my $control_dir;
    my $data_dir;

    $control_dir = File::Spec->catfile($self->{queue_dir}, 'qf');

    if (-e $control_dir)
    {
        $data_dir = File::Spec->catfile($self->{queue_dir}, 'df');
        if (!-e $data_dir)
        {
            $data_dir = $self->{queue_dir};
        }
    }
    else
    {
        $data_dir = $self->{queue_dir};
        $control_dir = $self->{queue_dir};
    }

    $result = opendir(QUEUE_DIR, $control_dir);
    if (!$result)
    {
        return "Unable to open directory '$control_dir'";
    }

    @control_files = grep { /^$qprefix.*/ && -f "$control_dir/$_" } readdir(QUEUE_DIR);
    closedir(QUEUE_DIR);
    foreach $file_name (@control_files)
    {
        $id = substr($file_name, 2);
        $queued_message = new QueuedMessage($control_dir, $id,
                            $data_dir);
        $self->{files}->{$id} = $queued_message;
    }

    return undef;
}


##
## ADD_QUEUED_MESSAGE - Adds a QueuedMessage to this Queue.
##
##  Adds the QueuedMessage object to the hash and moves the files
##  associated with the QueuedMessage to this Queue's directory.
##

sub add_queued_message
{
    my $self = shift;
    my $queued_message = shift;
    my $result;

    $result = $queued_message->move($self->{queue_dir});
    if ($result)
    {
        return $result;
    }

    $self->{files}->{$queued_message->{id}} = $queued_message;

    return $result;
}

##
## ADD_QUEUE - Adds another Queue's QueuedMessages to this Queue.
##
##  Adds all of the QueuedMessage objects in the passed in queue
##  to this queue.
##

sub add_queue
{
    my $self = shift;
    my $queue = shift;
    my $id;
    my $queued_message;
    my $result;

    while (($id, $queued_message) = each %{$queue->{files}})
    {
        $result = $self->add_queued_message($queued_message);
        if ($result)
        {
            print("$result.\n");
        }
    }
}

##
## ADD - Adds an item to this queue.
##
##  Adds either a Queue or a QueuedMessage to this Queue.
##

sub add
{
    my $self = shift;
    my $source = shift;
    my $type_name;
    my $result;

    $type_name = ref($source);

    if ($type_name eq "QueuedMessage")
    {
        return $self->add_queued_message($source);
    }

    if ($type_name eq "Queue")
    {
        return $self->add_queue($source);
    }

    return "Queue does not know how to add a '$type_name'"
}

sub delete
{
    my $self = shift;
    my $id;
    my $queued_message;

    while (($id, $queued_message) = each %{$self->{files}})
    {
        $result = $queued_message->delete();
        if ($result)
        {
            print("$result.\n");
        }
    }
}

sub bounce
{
    my $self = shift;
    my $id;
    my $queued_message;

    while (($id, $queued_message) = each %{$self->{files}})
    {
        $result = $queued_message->bounce();
        if ($result)
        {
            print("$result.\n");
        }
    }
}

##
## Condition Class
##
##  This next section is for any class that has an interface called
##  check_move(source, dest). Each class represents some condition to
##  check for to determine whether we should move the file from
##  source to dest.
##


##
## OlderThan
##
##  This Condition Class checks the modification time of the
##  source file and returns true if the file's modification time is
##  older than the number of seconds the class was initialized with.
##

package OlderThan;

sub new
{
    my $this = shift;
    my $class = ref($this) || $this;
    my $self = {};
    bless $self, $class;
    $self->initialize(@_);
    return $self;
}

sub initialize
{
    my $self = shift;

    $self->{age_in_seconds} = shift;
}

sub check_move
{
    my $self = shift;
    my $source = shift;

    if ((time() - $source->last_modified_time()) > $self->{age_in_seconds})
    {
        return 1;
    }

    return 0;
}

##
## Compound
##
##  Takes a list of Move Condition Classes. Check_move returns true
##  if every Condition Class in the list's check_move function returns
##  true.
##

package Compound;

sub new
{
    my $this = shift;
    my $class = ref($this) || $this;
    my $self = {};
    bless $self, $class;
    $self->initialize(@_);
    return $self;
}

sub initialize
{
    my $self = shift;

    $self->{condition_list} = [];
}

sub add
{
    my $self = shift;
    my $new_condition = shift;

    push(@{$self->{condition_list}}, $new_condition);
}

sub check_move
{
    my $self = shift;
    my $source = shift;
    my $dest = shift;
    my $condition;
    my $result;

    foreach $condition (@{$self->{condition_list}})
    {
        if (!$condition->check_move($source, $dest))
        {
            return 0;
        }
    }

    return 1;
}

##
## Eval
##
##  Takes a perl expression and evaluates it. The ControlFile object
##  for the source QueuedMessage is available through the name '$msg'.
##

package Eval;

sub new
{
    my $this = shift;
    my $class = ref($this) || $this;
    my $self = {};
    bless $self, $class;
    $self->initialize(@_);
    return $self;
}

sub initialize
{
    my $self = shift;

    $self->{expression} = shift;
}

sub check_move
{
    my $self = shift;
    my $source = shift;
    my $dest = shift;
    my $result;
    my %msg;

    $source->setup_vars();
    tie(%msg, 'QueuedMessage', $source);
    $result = eval($self->{expression});

    return $result;
}