iwlist helper

This script filter helpful output from iwlist.
Use it this way:

# show-wifi wlan0 VOO_HOMESPOT last

#!/bin/sh

device=${1-wlan0}
essid=${2-}
last=${3}

filter()
{
    if [ -n "$essid" ] ; then
        grep -B 3 $essid | grep -v ^--
    else
        cat
    fi
}

iwlist $device scanning $last | egrep "ESSID:|Address:|Quality=|Channel:" | filter