/mobfarm/turtles

local input="bottom"
local attackInterval=1

function doAttack()
    print("Switching to Attack Mode")

    while(rs.getInput(input)) do
        turtle.attack(attackInterval)
        sleep(attackInterval)
    end

    print("Switching to Passive Mode")
end

while(true) do
    if(rs.getInput(input)) then
        doAttack()
    end

    os.pullEvent("redstone")
end