#!/bin/bash

iws() {
	iwlist wlan0 scan | while read q
	do	if [ "${q:0:7}" = 'ESSID:"' ]
		then	q="${q:7}"; e="${q%\"}"
		#	echo "iws-i: e='$e'" >&2
		elif [ "${q:0:8}" = "Quality:" ]
		then	q="${q:8}"; q="${q%%/*}"
		#	echo "iws-i: q='$q'" >&2
			echo "$q $e"
		#	echo "q=$q e=$e" >&2
		fi
	done | sort -n | tail -1 | cut -d\  -f2-
}

l="/var/log/wlan0-wln"
date +%F\ %T >> "$l"
e=$(iws 2>> "$l")
echo "iws: e='$e'" >> "$l"
#e="${e:-_none_}"

while read k v
do	echo "k='$k' v='$v'" >> "$l"
	case "$e" in
	$k) [ "$e" ] && echo "$v" && echo "e=$e i=$v" >> "$l"; e="";;
	esac
done