Router Wifi Notification

#!/bin/sh

oldlist=/tmp/assoclist.old
newlist=/tmp/assoclist.new
touch $oldlist          # Create an empty file the first time through

while sleep 15
do
        for iface in $(nvram get wl_ifnames) $(nvram get wl0_vifs) $(nvram get wl1_vifs)
        do
                wl -i $iface assoclist >> $newlist
                sed -i "s/assoclist/$iface/g" $newlist
        done

        grep -vxFf $newlist $oldlist | while read macinfo
        do
                macaddr="${macinfo#* }"
                arpinfo="$(arp -a | grep -iF $macaddr | awk '{print $1 " " $2}')"
                logger -t wireless $macinfo $arpinfo "has disconnected."
                telegram-cli -WR -e "msg @mybot \"WiFi - $macinfo \n$arpinfo has disconnected.\" "
        done

        grep -vxFf $oldlist $newlist | while read macinfo
        do
                macaddr="${macinfo#* }"
                arpinfo="$(arp -a | grep -iF $macaddr | awk '{print $1 " " $2}')"
                logger -t wireless $macinfo $arpinfo "has connected."
                telegram-cli -WR -e "msg @mybot \"WiFi - $macinfo \n$arpinfo has connected.\" "

        done

        mv $newlist $oldlist
done