#!/bin/bash

# scan - a simple wifi scanner

# Copyright 2011 Dave Woodfall <dave@dawoodfall.net>
# All rights reserved.
#
# Redistribution and use of this script, with or without modification, is
# permitted provided that the following conditions are met:
#
# 1. Redistributions of this script must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ''AS IS'' AND ANY EXPRESS OR IMPLIED
# WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
# EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
# OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
# OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
# ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

# It takes only one argument and that is the interface. If that isn't done
# it defaults to wlan0
#
# keys 1 - 0 will print full info on a cell:
# 1 - cell 01
# 2 - cell 02 etc
#
# q = quit
#
# It will work as user but for best results run as root. See man iwlist for
# why.

function init {
    trap "cleanup" EXIT HUP INT ABRT QUIT SEGV TERM KILL
    GREP_OPTIONS=""
    clear
    cyan=''
    bcyan=''
    bred=''
    bgreen=''
    byellow=''
    bblue=''
    bwhite=""
    white=""
    normal='\017'
    blank=".............................................................."
    blank=${blank//./\\040}
    c1=$cyan
    c2=$bwhite
    IFACE=$1
    [[ -z $IFACE ]] && IFACE=wlan0
}

function cleanup {
    echo "     "
    exit 0
}

function display_cell {
    cell=$1
    scan=$(/sbin/iwlist $IFACE scan)
    let start=$(echo "$scan" | grep -n "Cell $cell" | cut -d: -f1)-1
    let end=$(echo "$scan" | grep -n "Cell 0$((cell+1))" | cut -d: -f1)-1
    if [ $start -eq -1 ]; then
        return
    fi
    if [ $end -eq -1 ]; then
        let end=$(echo "$scan" | wc -l)
    fi
    clear
    echo -en $bwhite
    echo "$scan" | head -n $end | tail -n $((end-start))
    read -sn1
    clear
}

function main {
    while true
    do
        tput cup 0 0
        scan=$(/sbin/iwlist $IFACE scan | sed "
        /wlan0/d
        /Cipher/d
        /Extra/d
        /uthentication/d
        /^[ ]\{10\}/ s/^[ ]\{10\}//g
        /Cell.*$/ s/Cell.*$/ ${bwhite}&/g
        /Cell.*$/N; s/\n */ /g
        /Address:\ / s/Address:\ /Address:/g
        /Address:\ / s/Address:/$c1&$c2/g
        /ESSID:/ s/ESSID:/$c1&$c2/g
        /ESSID:/ s/ESSID.*$/&              /g
        /Protocol.*$/d
        /Mode.*$/N;s/\n */ /g
        /Mode.*$/ s/Mode.*$/ &              /g
        /Mode:/ s/Mode:/$c1&$c2/g
        /Frequency:/ s/Frequency:/${c1}Frequency:$c2/g
        /Encryption key:on/ s/Encryption key:on/ ${c1}Encryption key:${c2}on/g
        /Encryption key:off/ s/Encryption key:off/ ${c1}Encryption key:${bred}off/g
        /Quality=/ s/Quality=/${c1}Quality=$c2/g
        /Quality=/ s/Quality=.*$/ &             /g
        / Signal level=/ s/ Signal level=/${c1}Signal level=$c2/g
        /IE:.*$/ s/IE:.*$/ &                          /g
        /IE: .*$/ s/IE: /${c1}IE:$c2/g
        /Mb\/s/d" | sed -n " 
        /Encryption key.*$/ !{
        p
        }
        /Encryption key.*$/ {
        h
        n
        G
        p
        }
           ")
        echo -e "$scan\n"
        let rows=$(stty size | cut -f1 -d' ')
        let lines=$(echo "$scan" | wc -l)
        if [ $lines -lt $rows ]; then
            for (( a=$((lines+3)); a<=$rows; a++))
            do 
                echo -e "$blank"
            done
        fi
        tput cup 0 0
        read -sn1 -t1 option
        case $option in
            'r')
            clear
            ;;
            '1')
            display_cell "01"
            ;;
            '2')
            display_cell "02"
            ;;
            '3')
            display_cell "03"
            ;;
            '4')
            display_cell "04"
            ;;
            '5')
            display_cell "05"
            ;;
            '6')
            display_cell "06"
            ;;
            '7')
            display_cell "07"
            ;;
            '8')
            display_cell "08"
            ;;
            '9')
            display_cell "09"
            ;;
            '0')
            display_cell "10"
            ;;
            'q')
            cleanup
            ;;
            *)
            ;;
        esac
    done
}

init $1
main