net-notifyd

#!/bin/bash
# net-notifyd v0.02 last mod 2011/11/29
# Latest version at <http://github.com/ryran/b19scripts>
# Copyright 2011 Ryan Sawhill <ryan@b19.org>
#
#    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 3 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 <gnu.org/licenses/gpl.html> for more details.
#-------------------------------------------------------------------------------
# This simple script is designed to be run automatically when a user logs into
# their desktop. (In fedora open 'gnome-session-properties' & add it; log out.)
# It then sleeps in the background, waiting to receive a message from root via a
# fifo in /tmp. If it receives a keyword that it knows about, it displays a
# preset message to the user in the GUI, via the notify-send command.
#
# Perhaps it is obvious, but the idea here is that a SA could ssh into systems
# with a for loop and drop a keyword to the pipe, ensuring that a message
# would get displayed to the currently logged-in user, without having to worry
# about who they are.
#
# Explicit instructions:
# After running this script (preferably via gnome-session-properties), run:
#     echo warning > /tmp/net-notifyd
# either as yourself or as root to test it. As you can see below, "logout" is
# another keyword I created a message for. The daemon ignores anything else.
#
# I just named this in a hurry, so I haven't done any research on similarly-
# named projects. Let me know if you've got a better idea.
# Also, if you've got suggestions on implementation, I'm all ears!

fifo=/tmp/$(basename $0)
rm $fifo 2>/dev/null
mkfifo -m 600 $fifo
trap "rm $fifo 2>/dev/null" EXIT

PARSE_command() {
  if [[ $net_command = logout ]]; then
    notify-send -u critical "Admin Says:" "Reboot required. If you don't log out in the next 120 seconds, you will lose your unsaved work."
  elif [[ $net_command = warning ]]; then
    notify-send -u critical "Admin Says:" "Just a warning. In 10 minutes we're going to need to reboot your PC."
  fi
}

LISTEN_net() {
  net_command=$(<$fifo)
  PARSE_command
  LISTEN_net
}

LISTEN_net