Custom script on pfsense 2.0.2

[ciambellone]

Hello World,
Please I want to know how to execute a custom script on pfsense.
I've found the following procedure:
http://forum.pfsense.org/index.php/topic,7228.0.html
and i would to know if It is right.
If no, how i can configure the script.
Please, if you can check my script, It bring down one network adapter of a particular host cannot answer to a ping.

#!/usr/local/etc/rc.d

timeout=5         # delay between checks
pingip='10.155.0.3'   # what to ping
iface="em3"
LOG_FILE="/var/log/"
isdown=0            # indicate whether the interface is up or down
                   # start assuming interface is up

while true; do
    LOG_TIME=`date +%b' '%d' '%T`
    if ping -q -c 2 "$pingip" >> /dev/null ; then      # ping is good - bring iface up
        if [ "$isdown" -ne 0 ] ; then
            ifup $iface && isdown=0
            printf "$LOG_TIME $0: Interface brought up: %s\n" "$iface" | tee -a $LOG_FILE
        fi
    else                                 # ping is bad - bring iface down
        beep -f 4000
        if [ "$isdown" -ne 1 ] ;  then
            ifdown $iface && isdown=1
            printf "$LOG_TIME $0: Interface brought down: %s\n" "$iface" | tee -a $LOG_FILE
        fi
    fi
    sleep "$timeout"
done

BEst regards.
Matteo