#!/usr/bin/perl

# 120 column format
$wfrom = 25;
$wtocc = 25;
$wsubj = 44;

# 80 column format
# $wfrom = 16;
# $wtocc = 16;
# $wsubj = 22;

@mname = ("Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec");
@mnum{@mname} = ("01" .. "12");

if ($ARGV[0] =~ /^-n$/) { $number = 1; shift }
if ($ARGV[0] =~ /^-(\d+)$/) { $tail = $1; shift }

chop ($user = `whoami`);
my $file = shift || "/usr/mail/$user";
open MAIL, "< $file" or die "$0: can't read $file: $!\n";

$/ = "\nFrom ";

while(<MAIL>)
{ #next unless /^From /;
  s/\n\n.*/\n/s;
  my %headers = map /^([\w\-]+)\s*:\s*(.*)$/, split "\n";

  my ($mday,$mname,$year,$time)
   = $headers{'Date'} =~ /(\d+)\s+(\w+)\s+(\d+)\s+(\d+:\d+(:\d+)?)/;
  my $date = sprintf("%04d-%02d-%02d %s", $year, $mnum{$mname}, $mday, $time);

  push @list, sprintf("%-19s %$wfrom.${wfrom}s => %-$wtocc.${wtocc}s %-$wsubj.${wsubj}s\n", $date,
    $headers{'From'} || $headers{'Sender'},
    $headers{'To'} || $headers{'Cc'},
    $headers{'Subject'});
}

if ($number)
{ $width = length(@list);
  @list = map { sprintf "%${width}s ".substr($_,0,-($width+2))."\n", ++$counter } @list;
}

$tail ||= @list;
print @list[-$tail..-1];