#!/bin/sh
iwlist scan 2>/dev/null | awk '
function flush()
{
    printf("%3s %-32s %2s %9s dBm %s\n", cell, essid, chan, signal, crypt)
    cell = "?"
    essid = "?"
    signal = "?"
    crypt = "?"
    chan = "?"
}

/^ *Cell/ {
    if (cell != "")
	flush()
    match($0, /[0-9]+/)
    cell = substr($0, RSTART, RLENGTH)
}
/^ *ESSID:/ {
    match($0, /"[^"]*"/)
    essid = substr($0, RSTART+1, RLENGTH-2)
}
/^ *Quality/ {
    match($0, /Signal level[=:][^ ]* /)
    signal = substr($0, RSTART+13, RLENGTH-14)
    match($0, /Noise level[=:][^ ]* /)
    signal = signal "/" substr($0, RSTART+12, RLENGTH-13)
}
/^ *Encryption key:off/ {
    crypt = "open"
}
/^ *Encryption key:on/ {
    crypt = "WEP"
}
/^ *IE: WPA/ {
    crypt = "WPA"
}
/^ *Extra:wpa_ie/ {
    crypt = "WPA"
}
/^ *Frequency:/ {
    match($0, /Channel [0-9]*/)
    chan = substr($0, RSTART+8, RLENGTH-8)
}
END {
    if (cell != "")
	flush()
}'