Project 004 : WLAN scanner - raster data acquisition

#!/bin/bash

test "$USER" != 'root' && { echo 'Starte bitte das Script als root.' ; exit ; }

readonly radius=20

echo 'Signalqualität   Signalpegel'
for((x=40;$x<200;x+=20))
do
  for((y=40;$y<200;y+=20))
  do
    dx=$(( $x + $radius ))
    dy=$(( $y + $radius ))
    convert raumplan.png -fill none -stroke red -strokewidth 2 -draw "circle $x,$y $dx,$dy" tmp-raumplan.png
    feh -B white -F tmp-raumplan.png
    value=`iwlist wlan0 scan | grep -B 3 'ESSID:"ebo-wlan' | grep 'Quality=' | sed 's/=/ | /g;s/\// |/;' | cut -f2,4 -d'|' | sort -nr | head -n1`
    echo "$x $y ${value}"
    echo "$x $y ${value}" >> wlan-raster-note.dat
  done
done