#! /bin/sh
### BEGIN INIT INFO
# Provides:          Snort
# Required-Start:    $local_fs $remote_fs $syslog $network mysql
# Required-Stop:     $local_fs $remote_fs $syslog $network mysql
# Default-Start:     2 3 4 5
# Default-Stop:      S 0 1 6
# Short-Description: Init script to start the Snort daemon
# Description:       Provides Snort service on startup and terminates
#                    on shutdown. Snort is an IDS or IPS. This script
#                    assumes that snort is installed in /usr/sbin and
#                    that it's main snort.conf file is in /etc/snort.
#                    The service will be started as a daemon, listening
#                    on eth0 and will also start quietly. If you require
#                    something other than this, you will have to edit
#                    the script accordingly.
#                    USE AT YOUR OWN RISK, YMMV. THIS SCRIPT COMES WITH
#                    ABSOLUTELY NO WARRANTY WHATSOEVER.
# License:           GPLv2 see http://www.gnu.org/licenses/gpl-2.0.txt
### END INIT INFO

# Author: Nigel Houghton <nigel.houghton@sourcefire.com>

PATH=/usr/sbin:/usr/bin:/sbin:/bin
DESC="Snort service for IDS or IPS"
NAME=snort
CONFIG="/etc/snort/snort.conf"
INTERFACE="eth0"
DAEMON=/usr/sbin/$NAME
DAEMON_ARGS="-c $CONFIG -i $INTERFACE -qD"
PIDFILE=/var/run/$NAME.pid
SCRIPTNAME=/etc/init.d/$NAME

# Exit if the package is not installed
[ -x "$DAEMON" ] || exit 1

# Read configuration variable file if it is present
[ -r /etc/default/$NAME ] && . /etc/default/$NAME

# Load the VERBOSE setting and other rcS variables
[ -f /etc/default/rcS ] && . /etc/default/rcS

# Define LSB log_* functions.
# Depend on lsb-base (>= 3.0-6) to ensure that this file is present.
. /lib/lsb/init-functions

#
# Function that starts the daemon/service
#
do_start()
{
# Return
#   0 if daemon has been started
#   1 if daemon was already running
#   2 if daemon could not be started
start-stop-daemon --start --quiet --pidfile $PIDFILE --exec $DAEMON --test > /dev/null \
 || return 1
start-stop-daemon --start --quiet --pidfile $PIDFILE --exec $DAEMON -- \
 $DAEMON_ARGS \
 || return 2
}

#
# Function that stops the daemon/service
#
do_stop()
{
# Return
#   0 if daemon has been stopped
#   1 if daemon was already stopped
#   2 if daemon could not be stopped
#   other if a failure occurred
  start-stop-daemon --stop --quiet --retry=TERM/30/KILL/5 --pidfile $PIDFILE --name $NAME
RETVAL="$?"
[ "$RETVAL" = 2 ] && return 2
start-stop-daemon --stop --quiet --oknodo --retry=0/30/KILL/5 --exec $DAEMON
[ "$?" = 2 ] && return 2
# Many daemons don't delete their pidfiles when they exit.
if [ -f "$PIDFILE" ]; then
   rm -f $PIDFILE
  fi
return "$RETVAL"
}

#
# Function that sends a SIGHUP to the daemon/service
#
do_reload() {
start-stop-daemon --stop --signal 1 --quiet --pidfile $PIDFILE --name $NAME
return 0
}

case "$1" in
 start)
[ "$VERBOSE" != no ] && log_daemon_msg "Starting $DESC" "$NAME"
do_start
case "$?" in
 0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
 2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
esac
;;
 stop)
[ "$VERBOSE" != no ] && log_daemon_msg "Stopping $DESC" "$NAME"
do_stop
case "$?" in
 0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
 2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
esac
;;
 restart|force-reload)
log_daemon_msg "Restarting $DESC" "$NAME"
do_stop
case "$?" in
  0|1)
 do_start
 case "$?" in
  0) log_end_msg 0 ;;
  1) log_end_msg 1 ;; # Old process is still running
  *) log_end_msg 1 ;; # Failed to start
 esac
 ;;
  *)
   # Failed to stop
 log_end_msg 1
 ;;
esac
;;
 *)
echo "Usage: $SCRIPTNAME {start|stop|restart|force-reload}" >&2
exit 3
;;
esac

:

You may use it at your own risk :D Some things may need to be changed before it will work for your system and you should use the update-rc.d command to put the links in the right places for you after installation into /etc/init.d/.

p.s. Don't forget to chmod 0700 /etc/init.d/snortstart after you install it.