#!/usr/local/bin/perl

# From: print out one line for each mail message in the system mailbox
#       indicating who the mail is from and the subject
#
#       Written by Dave Ratner
#
#	This program is shareware.  It can be freely distributed
#	as long as my name and this notice remains as is.


$debug = 0;

#
# Parse options
#	-d debug
#
while ($#ARGV >= 0) {
    if ($ARGV[0] eq '-d') {
	$debug++;
	shift(@ARGV);
    } else {
	last;
    };
};

#
# Find that system mailbox
#
if ($#ARGV >= 0) {
    $mbox = shift @ARGV;
} else {
    $mbox = "/var/spool/mail/$ENV{'LOGNAME'}";
    # $mbox = "/usr/spool/mail/$ENV{'LOGNAME'}"
}
die "You have no mail\n"
    if ( ! -s $mbox);
open(MBOX, "< $mbox") || die "Can't open $mbox: $!\n";


#
# Get the from and subject lines
#
sub getmessage {
    local ($from, $subject, $header);

    # Check the line we saved from the last email message
    $header = $getmessage_savedline;
    if ($header =~ s/^Subject: //) {
	$subject = $header;
    } elsif ($header =~ s/^From: //) {
	$from = $header;
    }
    
    #
    # Read the header looking for "From:" and "Subject:"
    #
    while (<MBOX>) {
	$header = $_;
	if ($header =~ s/^Subject: //) {
	    $subject = $header;
	} elsif ($header =~ s/^From: //) {
	    $from = $header;
	}
	last if (/^$/);
    };

    #
    # If we are at the end of the file, exit early
    #
    return () if (!defined($from) && !defined($subject));

    #
    # Skip the message body
    #
    while (<MBOX>) {
	last if (/^From /);
    };

    # save the first line of the next email header
    $getmessage_savedline = $_;

    # remove newlines
    chop $from;
    chop $subject;

    # edit the from line so if they have a name and email address, we
    # just use the name
    #
    # NEEDSWORK: this section can be condensed 
    #
    # sometimes its "name <email address>"
    # sometimes its "email address (name)"
    # sometimes its just "email address"
    $from =~ s/<.*@.*>//;  # filter out email addr from "name <email address>"
    $from =~ s/"//g;  # filter out quotes from around name, if present.
    if ($from !~ /^.*@[^(]*$/) { # if not just an email address
	# filter out email addr from "addr (name)" and remove the parens
	$from =~ s/^.*@[^(]*// && $from =~ s/[()]//g;
    }

    # some subject lines have unnecessary whitespace at the beginning
    $subject =~ /^\s*(.*)$/ && ($subject = $1);

    return ($from, $subject);
}


#
# Mainline
#
$message_number = 0;
#
# Loop until no more messages
#
while (($from, $subject) = &getmessage) {
    if ($debug) {
	print "\nMessage " . $message_number++ . "\n";
	print "******\n" . $header . "*****\n";
    }

    $subject = "<none>" if (!defined($subject));

    #
    # Print the data; prune "from" to 18 characters so everything lines up
    # since from is 18 characters, max subject line should be 55 (assume
    # a standard 80 column window)
    #
    printf("%-18.18s \t %.55s\n", $from, $subject);

}

exit 0;