#!/usr/bin/perl
# user_monitor.pl v0.4 :: keep track on who's logged in
# Written by Stephan Schmieder <http://www.unix-geek.info>, 2003
# Usage: ./user-monitor.pl&

use strict;
use warnings;
use diagnostics;
use Net::SMTP;

#<configuration>
my $smtp_server='localhost';
my $mail_to     ='root';
my $mail_from   ='root@localhost.localnet';
my $subject     ='[localhost.localnet] user monitor';
#</configuration>

my @old_users=split(/\n/, qx/who/);
while(sleep(1))
{
        my @users=split(/\n/, qx/who/);
        if(@users ne @old_users)
        {
                my $smtp = Net::SMTP->new($smtp_server);
                die "Couldn't connect to server" unless $smtp;
                $smtp->mail( $mail_from );
                $smtp->to( $mail_to );
                $smtp->data();
                $smtp->datasend("Subject: $subject\n\n");
                foreach my $user (@users)
                {
                        $smtp->datasend("$user\n");
                }
                $smtp->dataend();
                $smtp->quit();
        }
        @old_users=@users;
}