#!/bin/sh
#-------------------------------------------------------------------------
# A simple shell script to allow the starting/stopping/restarting of the
# black_hole_http_server.pl script that was written by Sean Burke. This
# Black-hole server can then be used by John LoVerso's ad-blocking file,
# called 'no-ads.pac', for browsers that need some sort of response.
# Note: no-ads.pac can be found here:
#  <http://www.schooner.com/~loverso/no-ads/>;
#
#
# Instructions:
# -------------
# 1) First download the perl script from here:
#     <http://www.speech.cs.cmu.edu/~sburke/pub/black_hole_http_server.pl>
#
# 2) Then rename it to 'blackhole' and save it in /usr/local/bin. Make sure
#    the x bit is set to allow execution of the perl script. To make sure,
#    run this command as root: chmod a+x /usr/local/bin/blackhole
#
# 3) Save this shell script as 'bhpd' and place it anywhere in your path,
#    such as'/usr/local/bin/bhpd'. Now you can start the server by running
#    this command, 'bhpd start'. To stop the server, run this command,
#    'bhpd stop'. To restart it, run 'bhpd restart'. You will need to make
#    sure it is executable, also (chmod a+x /usr/local/bin/bhpd).
#
# NOTE: For users of Slackware or a BSD, you can name this shell script
#       'rc.bhpd' and drop it in the /etc/rc.d/ directory. Then add these
#       lines in /etc/rc.d/rc.local:
#
#       # Start the Black-hole proxy server
#       if [ -x /usr/rc.d/rc.bhpd  ] ; then
#         /etc/rc.d/rc.bhpd start
#       fi
#
#       Now you can activate or deactivate the starting of the server by
#       simply changing the executable bit. To allow the server to start
#       during boot, use the command 'chmod a+x /usr/rc.d/rc.bhpd'. To
#       prevent the server from starting during boot, run this command,
#       'chmod a-x /usr/rc.d/rc.bhpd'.
#
#      The above lines will also work in a user's ~/.bashrc script or
#      equivalent if they can't use it as a system wide startup script. Then
#      whenever the user log ons, the black-hole server will start up
#      automatically. It will still require root priveleges to stop the
#      server, though.
#
#-------------------------------------------------------------------------
# Start bhpd:
bhpd_start() {
  if [ -x /usr/local/bin/blackhole ]; then
    echo "Starting Black-hole proxy server..."
    ( /usr/local/bin/blackhole ) &
  fi
}

# Stop bhpd:
bhpd_stop() {
  echo "Stopping Black-hole proxy server..."
  killall blackhole
}

# Restart bhpd:
bhpd_restart() {
  bhpd_stop
  sleep 1
  bhpd_start
}

case "$1" in
'start')
  bhpd_start
  ;;
'stop')
  bhpd_stop
  ;;
'restart')
  bhpd_restart
  ;;
*)
  echo "usage $0 start|stop|restart"
esac