Script to Change IP of a cpanel domain

ALGORITHM

1) Get the word count(TLN) of /root/bobcares/iplist_username.txt file
2) Get the current ip of domain(CIP) from /root/bobcares/current_ip_username.txt
3) Find the line number(CLN) of CIP in /root/bobcares/iplist_username.txt
4) If CLN -eq WC_ ;then
set CLN=1
save CLN
take the first ip in IPlIST
assign ip to domain
sent alert to email address

else
CLN=CLN+1
Take the ip on line $CLN from IPlIST
save CLN
assign ip to domain
sent alert to email address
fi
5) End

    #!/bin/bash
    # Created by Bobcares
    # USERNAME : cpanel username
    # IPLIST: List of IPs that will be assigned to the domain(each IP's will be listed in
    # CUR_IP: Contains the current IP assigned to the domain
    #

    CHANGEIP=/usr/local/cpanel/bin/setsiteip
    USERNAME=username
    IPLIST=/root/bobcares/iplist_username.txt
    CUR_IP=/root/bobcares/current_ip_username.txt

    ##REMOVE EMPTY LINES FROM FILE
    sed -i "/^$/d" iplist_username.txt

    #Current IP
    CIP=$(cat ${CUR_IP})
    #Total line count
    TLN=$(wc -l ${IPLIST}|cut -d" " -f1)
    #Current line number
    CLN=$(grep -n ${CIP} ${IPLIST}|cut -d: -f1)

    echo -e "$CLN\n$TLN\n$CIP"

    if [ $CLN -eq $TLN ]; then
    CLN=1
    echo ${CLN} > ${CUR_IP}
    sed -n 1p ${IPLIST} > ${CUR_IP}
    CIP=$(cat ${CUR_IP})
    $CHANGEIP -u ${USERNAME} ${CIP} > ~/report_username.txt
    ret=$?
    echo -e "CLN=1\nRET=${ret}"
    else
    CLN=$((CLN+1))
    echo ${CLN} > ${CUR_IP}
    sed -n "${CLN}"p ${IPLIST} > ${CUR_IP}
    CIP=$(cat ${CUR_IP})
    $CHANGEIP -u ${USERNAME} ${CIP} > ~/report_username.txt
    ret=$?
    echo -e "CLN=${CLN}\nRET=${ret}"
    fi

    ####SEND ALERT####
    ALERTEMAIL_=user8@hotmail.com

    if [ $ret -eq 0 ];then
    exit 0
    #msg="IP CHANGED SUCCESSFULLY NEW IP=${CIP}"
    #echo "NOTIFICATION FROM `hostname`"| mail -s "${msg}" ${ALERTEMAIL_}
    else
    msg="IP CHANGED FAILURE IP TRIED=${CIP}"
    content=$(cat ~/report.txt)
    echo "$content" |mail -s "${msg}" ${ALERTEMAIL_}
    fi
    #######
    ##END
    #######