netsetup.sh

#!/bin/bash
PAC="http://192.168.3.2/proxy.pac"
function networkService() {
    services=$(networksetup -listnetworkserviceorder | grep 'Hardware Port')
    while read line; do
        sname=$(echo $line | awk -F  "(, )|(: )|[)]" '{print $2}')
        sdev=$(echo $line | awk -F  "(, )|(: )|[)]" '{print $4}')
        #echo "Current service: $sname, $sdev, $currentservice"
        if [ -n "$sdev" ]; then
            ifconfig $sdev 2>/dev/null | grep 'status: active' > /dev/null 2>&1
            rc="$?"
            if [ "$rc" -eq 0 ]; then
                currentservice="$sname"
                break
            fi
        fi
    done <<< "$(echo "$services")"

    if [ -n $currentservice ]; then
        echo $currentservice
    else
        echo false
    fi
}
service=$(networkService)
state=$(networksetup -getautoproxyurl $service |grep Enabled |awk -F "(, )|(: )|[)]" '{print $2}')
if [ "$state" = "Yes" ]; then
    networksetup -setautoproxystate $service off
    echo "turned auto proxy off"
else
    networksetup -setautoproxyurl $service $PAC
    echo "set autoproxy url of $service to $PAC "
fi