#!/bin/sh

IFACE=$1

ip link set $IFACE up

SCAN=$( \

iwlist $IFACE scan 2>&1 | grep -v "^$IFACE" | grep -v "^$" | \

    sed -e "s/^\ *//" \

        -e "s/^Cell [0-9]\+ - /#/" \

        -e "s/^#Address: /#AP=/" \

        -e "s/^Quality:\([0-9]\+\)\/.*$/QUALITY=\1/" \

        -e "s/^.*Channel \([0-9]\+\).*$/CHANNEL=\1/" \

        -e "s/^ESSID:/ESSID=/" \

        -e "s/^Mode:/MODE=/" \

        -e "s/^Encryption key:/ENC=/" \

        -e "s/^[^#].*:.*//" | \

    tr "\n#" "|\n" \

)

ip link set $IFACE down

which=""

while read glob scheme; do

    AP=""; QUALITY=""; CHANNEL=""; ESSID=""; MODE=""; ENC=""

    for i in $SCAN ; do

        for j in $(echo $i | sed -e "s/|/ /g" ) ; do

            case $j in

                AP=*)

                    AP=${j#AP=}

                    ;;

                QUALITY=*)

                    QUALITY=${j#QUALITY=}

                    ;;

                CHANNEL=*)

                    CHANNEL=${j#CHANNEL=}

                    ;;

                ESSID=*)

                    ESSID=${j#ESSID=}

                    ;;

                MODE=*)

                    MODE=${j#MODE=}

                    ;;

                ENC=*)

                    ENC=${j#ENC=}

                    ;;

            esac

        done

        case "$AP,$ESSID,$ENC,$MODE,$CHANNEL" in

            $glob)

                echo $scheme

                exit 0

                ;;

        esac

    done

done

exit 1