Super Basic Bigger Reactor Monitor Minecraft

allNames = peripheral.getNames()

function getReactorName()
    for x = 1, #allNames do
        if string.match(allNames[x], "_Reactor_") then
            return allNames[x]
        end
    end
end

reactorName = getReactorName()

if reactorName == nil then
    write("Can't find 'Bigger Reactors' reactor")
    exit()
else
    write("Found reactor\n")
end

reactor = peripheral.wrap(reactorName)

function monitorPower()
    while true do
        currentRodPercent = reactor.getControlRod(0).level()
        batteryLevel = reactor.battery().stored() / reactor.battery().capacity()
        batteryLevelRounded = batteryLevel * 100
        batteryLevelRounded = math.floor(batteryLevelRounded)

        if batteryLevelRounded > 90 then
            reactor.setActive(false)
            write("Battery level over 90%, reactor off.\n")
        else
           reactor.setActive(true)
           write("Battery level: " .. batteryLevelRounded .. "%\n")
        end

        sleep(30)
    end
end

monitorPower()