Scan for wireless accesspoints, parse the output

so, iwlist throws its output in different order depending of the wifi nic, so we need to scan and parse, to see 3 columns: 

signal strength: encryption needed: ESSID
27:on:CASA
27:on:AP1133
30:on:CC5763
32:on:XX1330
36:off:gg54g

So, we wrote a script called "scan" that loops to all wlan interfaces and scans for APs.

#!/bin/bash

ifconfig -a  |grep -i wlan | awk '{ print $1 }'|while read i;do
        echo "#---- scanning on $i"
(       ifconfig $i up
        iwlist $i scan | egrep -i 'essid|freq|qual|encr' |nawk 'ORS=NR%4?" ":"\n"'| tr -s ' '| while read l;do
                AP=`echo "$l "|awk '{s=substr($0,index($0,"ESSID:")+7);print substr(s,1,index(s,"\"")-1)}'`
                EN=`echo "$l "|awk '{s=substr($0,index($0,"Encryption key:")+15);print substr(s,1,index(s," ")-1)}'`
                QU=`echo "$l "|awk '{s=substr($0,index($0,"Quality=")+8);print substr(s,1,index(s,"/")-1)}'`
                echo "$QU:$EN:$AP"
        done
) | sort -n
done

Posted by rdircio