#!/usr/bin/perl
#
# $Id: fm,v 1.33 2003/08/01 02:10:56 jmates Exp $
#
# The author disclaims all copyrights and releases this script into the
# public domain.
#
# Run perldoc(1) on this file for additional documentation.
#
######################################################################
#
# REQUIREMENTS

require 5;

use strict;

######################################################################
#
# MODULES

use Carp;
use Getopt::Std;

# for the format() and write() reports
use FileHandle;

# file locking related modules
use Fcntl qw(:DEFAULT :flock);
use IO::Handle;

######################################################################
#
# VARIABLES

my $VERSION;
($VERSION = '$Revision: 1.33 $ ') =~ s/[^0-9.]//g;

my (
  %opts,           $procmailrc, $logfile, $days_of_week,
  $months_of_year, $backup,     @data,    %folders,
  %folder_sizes,   $oldest,     $newest,  $total_messages,
  $total_size,     $machine,    $summary, $reverse,
  $zap
);

# where to look for the procmailrc...
$procmailrc = $ENV{'HOME'} . '/.procmailrc';

# for matching date field in from line
$days_of_week   = '(Sun|Mon|Tue|Wed|Thu|Fri|Sat)';
$months_of_year = '(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)';

# prefs for the humanize file size routine
my %global_prefs = (

  # include decimals in output? (e.g. 25.8 K vs. 26 K)
  'decimal' => 0,

  # include .0 in decmail output?
  'decimal_zero' => 0,

  # what to divide file sizes down by
  'factor' => 1024,

  # percentage above which will be bumped up
  # (e.g. 999 bytes -> 1 K as within 5% of 1024)
  # set to undef to turn off
  'fudge' => 0.98,

  # lengths above which decimals will not be included
  # for better readability
  'max_human_length' => 2,

  # list of suffixes for human readable output
  'suffix' => ['B', 'K', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'],
);

######################################################################
#
# MAIN

# parse command-line options
getopts('h?srzb:m:', \%opts);

help() if exists $opts{'h'} or exists $opts{'?'};

# extract backup option, if any
$backup = $opts{'b'} if exists $opts{'b'};

# whether to zap logfile
$zap = 1 if exists $opts{'z'};

# summary only? (no message log)
$summary = 1 if exists $opts{'s'};

# reverse sort message log?
$reverse = 1 if exists $opts{'r'};

# "machine" output style required?
$machine = $opts{'m'} if exists $opts{'m'};

# first, we find out where the logfile is (command line or automagic)
if (@ARGV) {
  $logfile = shift;
} else {
  $logfile = get_logfile_loc($procmailrc);
}

# parse through the logfile, feeding various global variables
parse_logfile();

# see whether there is any new mail to report about...
unless (keys %folders) {
  print "No new mail.\n";
  exit;
}

# and print off a pretty little report for fun
print_report();

# see if machine-style output format is required
print_machine($machine) if defined $machine;

######################################################################
#
# SUBROUTINES

# dumps a pretty report to STDOUT...
sub print_report {
  my ($subject, $from, $folder, $size, $date);

  print "Email report from $oldest to $newest\n\n";

  # use format to easily line up everything the way I want...

  # disable notion of "pages" in resulting format
  format_lines_per_page STDOUT 99999999;

  # perl doesn't like format_formfeed on a per-handle basis, ergo:
  $^L = '';

  format STDOUT_TOP = 
 Count  Destination                                               Size
----------------------------------------------------------------------
.
  format STDOUT = 
@>>>>>  @<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<   @>>>>>>>>>>>
commify($folders{$_}), $_, humanize($folder_sizes{$_})
.

  for (sort { $a cmp $b } keys %folders) {
    write;
  }

  # hack to get a "footer" for the above summary including totals...
  format_name STDOUT "FOOTER";

  format FOOTER =
----------------------------------------------------------------------
@>>>>>                                                    @>>>>>>>>>>>
commify($total_messages), humanize($total_size)

.
  write;

  unless ($summary) {

    # select new format style
    format_name STDOUT "MESSAGE";
    format_top_name STDOUT "MESSAGE_TOP";

    # reset line count to force header
    format_lines_left STDOUT 0;

    my $order;
    if ($reverse) {
      $order = 'newest-at-top';
    } else {
      $order = 'oldest-at-top';
    }

    format MESSAGE_TOP =
Message Summaries by Date (@<<<<<<<<<<<<)                         Time
$order
----------------------------------------------------------------------
.

    format MESSAGE =
Subject:  ^<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<   @>>>>>>>
          $subject, $date
~         ^<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<...
          $subject
From:     ^<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
          $from
~         ^<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<...
          $from
To:       @<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<   @>>>>>>>
          $folder, $size

.

    @data = reverse(@data) if $reverse;

    for (@data) {

      # use strict complains if use funky calls, so de-ref 'em...
      $subject = $_->{'_subject'};
      $from    = $_->{'_from'};
      $folder  = $_->{'_folder'};
      $size    = $_->{'_size'};
      $date    = $_->{'_date'};

      # only show size if above certain amount (should be a constant,
      # or even better based on standard deviation above average size!)
      if ($size > 10000) {
        $size = humanize($size);
      } else {
        $size = undef;
      }

      # just HH:MM now, as that's all I need to see...
      my ($wday, $mon, $day, $time, $year) = split /\s+/, $date;

      $time =~ s/:\d+$//;

      $date = $time;

      write;
    }
  }
}

# machine-style output format (e.g. easily parsed by a machine)
sub print_machine {
  my $file_loc = shift;

  # open & aquire write lock on the file_loc
  open(FD, ">$file_loc") or die "Error opening $file_loc: $!\n";
  FD->autoflush(1);

  unless (flock(FD, LOCK_EX | LOCK_NB)) {
    warn "Waiting for write lock on $file_loc ...\n";
    flock(FD, LOCK_EX);
  }

  # delete file just to be sure
  seek(FD, 0, 0) or die "Problem seeking $file_loc: $!\n";
  truncate(FD, 0) or die "Problem truncating $file_loc: $!\n";

  my $oldfh = select(FD);

  # global info
  print "global\tstart\t",  $oldest,         "\n";
  print "global\tfinish\t", $newest,         "\n";
  print "global\tcount\t",  $total_messages, "\n";
  print "global\tsize\t",   $total_size,     "\n";

  # folder info
  for (sort { $a cmp $b } keys %folders) {
    print "folder\t", $_, "\t", $folders{$_}, "\t", $folder_sizes{$_}, "\n";
  }

  # message info
  my $t_count = 0;
  for (@data) {
    print "message", $t_count, "\tsubject\t", $_->{'_subject'}, "\n";
    print "message", $t_count, "\tfrom\t",    $_->{'_from'},    "\n";
    print "message", $t_count, "\tfolder\t",  $_->{'_folder'},  "\n";
    print "message", $t_count, "\tsize\t",    $_->{'_size'},    "\n";
    print "message", $t_count, "\tdate\t",    $_->{'_date'},    "\n";
    $t_count++;
  }

  select($oldfh);

  flock(FD, LOCK_UN);
  close(FD);
}

# parse procmail's logfile w/ locking using global variables
sub parse_logfile {
  my $count = -1;  # track where we are in array of anon hashes

  # open & aquire write lock on the logfile
  open(FD, "+< $logfile") or die "Error opening $logfile: $!\n";
  FD->autoflush(1);

  unless (flock(FD, LOCK_EX | LOCK_NB)) {
    warn "Waiting for write lock on $logfile ...\n";
    flock(FD, LOCK_EX);
  }

  # are we backing up the file?
  if ($backup) {
    open(BACK, ">$backup") or die "Error opening $backup: $!\n";
    BACK->autoflush(1);

    unless (flock(BACK, LOCK_EX | LOCK_NB)) {
      warn "Waiting for write lock on $logfile ...\n";
      flock(BACK, LOCK_EX);
    }

    # zap contents of current backup file (just to be sure)
    seek(BACK, 0, 0) or die "Problem seeking $backup: $!\n";
    truncate(BACK, 0) or die "Problem truncating $backup: $!\n";
  }

  # parse the file
  while (<FD>) {

    # keep backup if necessary
    print BACK $_ if $backup;

    chomp;

    if (
m/^From\s+(.*?)\s+($days_of_week\s+$months_of_year\s+\d{1,2}\s\d\d:\d\d:\d\d\s\d\d\d\d)/o
     ) {

      # new From line matched, increment our position in @data array
      $count++;

      # and tack various info into anon hash in @data array...
      $data[$count]->{'_from'} = $1;
      $data[$count]->{'_date'} = $2;
    }
    if (m/^\s*Subject:\s+(.*)$/) {
      $data[$count]->{'_subject'} = $1;
    }
    if (my ($folder, $size) = m/^\s*Folder:\s+(.+?)\s+(\d+)$/) {
      $folder =~ s:/new.+::;

      $data[$count]->{'_folder'} = $folder;
      $data[$count]->{'_size'}   = $size;

      # keep separate track of folder locs for ease
      # of lookup at cost of more memory
      $folders{$folder}++;

      # and also amount of data gone to specific destinations
      $folder_sizes{$folder} += $size;

      # and some totals for fun
      $total_messages++;
      $total_size += $size;
    }
  }

  # this (optionally) erases the logfile
  if ($zap) {
    seek(FD, 0, 0) or die "Problem seeking $logfile: $!\n";
    truncate(FD, 0) or die "Problem truncating $logfile: $!\n";
  }

  # clean up all our locks/open files
  if ($backup) {
    flock(BACK, LOCK_UN);
    close(BACK);
  }

  flock(FD, LOCK_UN);
  close(FD);

  # finally, extract out the oldest & newest dates from
  # the data array using a lot of assumptions
  $oldest = $data[0]->{'_date'};
  $newest = $data[$#data]->{'_date'};
}

# automagically gets logfile location from .procmailrc file,
# single argument is path to the procmailrc file
sub get_logfile_loc {
  my $procmailrc = shift;

  my $logfile;

  open FILE, $procmailrc or die "Error opening $procmailrc: $!\n";

  while (<FILE>) {
    chomp;

    # not too sure about formatting allowed in .procmailrc...
    if (m/LOGFILE\s*=\s*(.*)$/) {
      my $logfile_loc = $1;

      # convert (potentially) shell-notational logfile loc
      # to a full pathname (e.g. $HOME/.pm_log -> /home/user/.pm_log)
      $logfile = `echo $logfile_loc`;
    }
  }
  close FILE;

  return $logfile;
}

# little generic add commas to data routine...
sub commify {
  my $text = reverse $_[0];
  $text =~ s/(\d\d\d)(?=\d)(?!\d*\.)/$1,/g;
  return scalar reverse $text;
}

# Inspired from GNU's df -h output, which fixes 133456345 bytes
# to be something human readable.
#
# takes a number, returns formatted string.  Also takes optional
# hash containing various defaults that affect output style.
sub humanize {
  my $num   = shift;  # could also take a array ref or hash ref to parse thru?
  my %prefs = @_;

  # inherit global prefs, but give preference to user supplied ones
  unless (keys %prefs) {
    %prefs = %global_prefs;
  } else {

    # benchmarking w/ 5.6.0 on Linux PPC & i386 showed this next
    # faster than direct merge method (p. 145 Perl Cookbook)
    while (my ($k, $v) = each(%global_prefs)) {
      $prefs{$k} = $v unless exists $prefs{$k};
    }
  }

  # some local working variables
  my $count  = 0;
  my $prefix = '';
  my $tmp    = '';

  # handle negatives
  if ($num < 0) {
    $num    = abs $num;
    $prefix = '-';
  }

  # reduce number to something readable by factor specified
  while ($num > $prefs{'factor'}) {
    $num /= $prefs{'factor'};
    $count++;
  }

  # optionally fudge "near" values up to next higher level
  if (defined $prefs{'fudge'}) {
    if ($num > ($prefs{'fudge'} * $prefs{'factor'})) {
      $count++;
      $num /= $prefs{'factor'};
    }
  }

  # no .[1-9] decimal on longer numbers for easier reading
  # only show decimal if prefs say so
  if (length sprintf("%.f", $num) > $prefs{'max_human_length'}
    || !$prefs{'decimal'}) {

    $tmp = sprintf("%.0f", $num);

    } else {
    $tmp = sprintf("%.1f", $num);

    # optionally hack trailing .0 as is not needed
    $tmp =~ s/\.0$// unless $prefs{'decimal_zero'};
  }

  # return number with proper style applied
  return $prefix . $tmp . $prefs{'suffix'}->[$count];
}

# a generic help blarb
sub help {
  print <<"HELP";
Usage: $0 [options] [LOGFILE]

Procmail logfile parser and reporter.

Options for version $VERSION:
  -h/-?  Display this message

  -s     Summary mode only, don't print listing of messages.
  -r     Reverse sort newest messages to top of message list.

  -b xx  Make a backup of the LOGFILE, where xx is the (optional) target.
  -z     Truncate logfile after parsing it.

  -m xx  Export "machine" style output to file xx.

Run perldoc(1) on this script for additional documentation.

HELP
  exit;
}

__END__

=head1 NAME

fm - procmail logfile parser and reporter.

=head1 SYNOPSIS

Pretty simple, just run:

  $ fm

=head1 DESCRIPTION

=head2 Overview

fm is a procmail(1) logfile parser that shows you how many messages
of what size went where based on the contents of your procmail
logfile.

=head2 Normal Usage

  $ fm [options] [LOGFILE]

See L<"OPTIONS"> for details on the command line switches supported.

If you omit the logfile, fm will attempt to determine its location
from your ~/.procmailrc file.

Certain preferences must currently be set inside the script itself,
such as the options on the humanization of bytes.  This might be
constrewed as a bug.

=head1 OPTIONS

This script currently supports the following command line switches:

=over 4

=item B<-h>, B<-?>

Prints a brief usage note about the script.

=item B<-s>

Print only the count and size summary of the logfile.

By default, a listing of individual messages follows the leading count
summary, which might take up more screen space for quick mail summary
checks.

=item B<-r>

Reverse sort the individual message listings.

Setting the reverse mode prints the message listings in a
newest-at-top format instead of the default format which has the most
recent messages down at the bottom of the file.

=item B<-b> I<backup-file>

Save a backup of the LOGFILE to location I<backup-file>.

By default, no backups of the logfile are made.

=item B<-z>

Zap the logfile.

By default, the logfile is preserved.  Set the zap option to empty out
the current logfile.

=item B<-m> I<machine-data>

Save a machine-style output to the file I<machine-data>.

=back

=head1 EXAMPLES

If you want backups and to zero the manually located logfile once done:

  $ fm -zb ~/.pm_logfile.old

From cron, that would be something like:

  15 6 * * * /usr/local/bin/fm -zb .pm_logfile.old | mail $USER

=head1 BUGS

=head2 Reporting Bugs

Newer versions of this script may be available from:

http://sial.org/code/perl/

If the bug is in the latest version, send a report to the author.
Patches that fix problems or add new features are welcome.

=head2 Known Issues

Various other tweaks/massive rewrite might be prudent at some point,
but hey, it gets the job done.

=head1 SEE ALSO

perl(1), procmail(1), procmailrc(5)

=head1 AUTHOR

Jeremy Mates, http://sial.org/contact/

=head1 COPYRIGHT

The author disclaims all copyrights and releases this script into the
public domain.

=head1 VERSION

  $Id: fm,v 1.33 2003/08/01 02:10:56 jmates Exp $

=head1 SCRIPT CATEGORIES

Mail

=cut