#!/usr/bin/perl
# Print a summary of mail messages.
# Usage:
#    mail_header mail_box_file
#
# For example, 
#   mail_header /usr/spool/mail/user_name
#
# If the mail_box_file is not set, the default is /usr/spool/mail/user_name
#
# The output is much like mail -H, but this program allows more control over
# what the output fields are.
#
# T. Metcalf 1996-03-15

#   Copyright (C) 1996 Thomas R. Metcalf
#
#   This software is provided "as is" and is subject to change without
#   notice.  No warranty of any kind is made with regard to this software,
#   including, but not limited to, the implied warranties of
#   merchantability and fitness for a particular purpose.  The author shall
#   not be liable for any errors or for direct, indirect, special,
#   incidental or consequential damages in connection with the furnishing,
#   performance, or use of this software:  use it at your own risk.
#
#    This program is free software; you can redistribute it and/or
#    modify it under the terms of the GNU General Public
#    License as published by the Free Software Foundation; either
#    version 2 of the License, or (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
#    General Public License for more details.
#
#    You should have received a copy of the GNU General Public
#    License along with this library; if not, write to the Free
#    Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#


if ($#ARGV >= 0) {
   $FILE = $ARGV[0];
} else {
   $FILE = "/var/mail/$ENV{'LOGNAME'}";
}
open(FILE, $FILE) || exit;

$message = 0;
$last_line_blank = 1;   # start of file treated as a blank line

while (<FILE>) {
   chop;
   # The start of a message is defined to be a line with format exactly like
   # From owner-wx-tropl@POSTOFFICE.CSO.UIUC.EDU Fri Mar 15 02:52:05 1996
   # or
   # From owner-wx-tropl@POSTOFFICE.CSO.UIUC.EDU Fri Mar 15 02:52 HST 1996
   # or
   # From owner-wx-tropl@POSTOFFICE.CSO.UIUC.EDU Fri Mar 15 02:52:05 HST 1996
   # or
   # From owner-wx-tropl Fri Mar 15 02:52:05 1996
   # etc.
   # preceded by either the start of the file or a blank line.
   # This seems to mimic the mail command pretty well.
   if (/^From\s+(\S+)(@(\S+)|)\s+((Sun|Mon|Tue|Wed|Thu|Fri|Sat)\s+(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\s+(\d+)\s+(\d{1,2}:\d{1,2}(:\d{1,2}|))\s+(\S*)\s*(\d{4,4}))\s*$/i && ($last_line_blank)) {
      if ($message > 0) { &OUTPUT();}
      &RESET();
      $from = $1.$2;
      $date = $4;
      $dow = $5;
      $mon = $6;
      $day = $7;
      $time = $8;
      $zone = $10;
      $year = $11;
   }
   ++$lines;
   if (/^Return-Path:\s+\<(\S+)(@(\S+)|)\>/i) {
      $from = $1.$2;
   }
   if (/^Subject:\s*(.*)/i) {$subject=$1;}
   if (/^$/) {$last_line_blank = 1;} else {$last_line_blank = 0;}
}
&OUTPUT();
exit;


sub RESET {
   ++$message;
   $from = "";
   $subject = "";
   $date = ""; 
   $dow = "";
   $mon = "";
   $day = "";
   $time = "";
   $zone = "";
   $year = "";
   $lines = 0;
}

sub OUTPUT {
   print "$message $from $date $lines $subject\n";
}