Listing 2 check-pppoe.sh shell procedure

#!/bin/bash
#
# Copyright Dick Munroe, munroe@csworks.com, 2005 all rights reserved.
#
# Use of this program is granted under the Gnu Public LIcense provided 
# this copyright remains in place.
#

PATH=/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin

scriptName=${0##/*/}
scriptBaseName=${scriptName%%.*}

. /etc/$scriptBaseName/$scriptBaseName.conf

#
# Give the system some "time" to get ppp up.  It may take longer than 
# the default cycle and we don't want to get two ppp interface started.
#

sleep $SYSTEMSTARTUP

#
# Try a simple ppp restart.  Power cyclying and other things are external
# to this logic.  Call this only if the PPP interface really IS down.
#

function restartPPPoE()
{
    I=0

    while [ $I -lt $TRY ]
    do
    poff -r $DSL_PROVIDER 2>/dev/null || pon $DSL_PROVIDER

        sleep $PPP_PAUSE

    ifconfig $PPP >/dev/null 2>&1

    theStatus=$?

    #
    # Bail if the interface is there
    #

    if [ $theStatus -eq 0 ]
    then
        return 0
    fi

    I=$(($I + 1))
    done

    return 1
}

#
# Record the pid in the run file
#

echo $$ >/var/run/$scriptBaseName.pid

powercycletime=$POWERCYCLETIME

while [ 1 -eq 1 ]
do
    sleep $CYCLETIME

    ifconfig $PPP >/dev/null 2>&1
    theStatus=$?

    if [ $theStatus -ne 0 ]
    then
    logger -p local2.warn $PPP has dropped, attempting restart
    restartPPPoE 
    theStatus=$?
    if [ $theStatus -ne 0 ]
    then
        #
        # got here and the easy way didn't work, try cycling power, 
        # then restarting it.
        #

        logger -p local2.warn Cycling power on X10 interface $HOUSECODE.

        br $HOUSECODE off

        sleep $HOUSECODE_OFF_PAUSE

        br $HOUSECODE on

        sleep $HOUSECODE_ON_PAUSE

        logger -p local2.warn $PPP still down after power cycle, \
          attempting restart.

        restartPPPoE

        theStatus=$?
        if [ $theStatus -eq 0 ]
        then
        powercycletime=$POWERCYCLETIME
        logger -p local2.info $PPP is back up.
        else
        logger -p local2.emerg $PPP is not back up after $TRY, \
          powercycle, $TRY attempts.
        powercycletime=$(($powercycletime + $POWERCYCLETIMEINCREMENT))
        if [ $powercycletime -gt $POWERCYCLETIMEMAXIMUM ]
        then
            powercycletime=$POWERCYCLETIMEMAXIMUM
        fi

        sleep ${powercycletime}s
        fi
    else
        powercycletime=$POWERCYCLETIME
        logger -p local2.info $PPP is back up.
    fi
    fi
done