Custom Mob Loot for Minecraft

function string.split(str, spl)
    if spl == nil then
        spl = "%s"
    end
    local tab = {}
    for s in string.gmatch(str, "([^"..spl.."]+)") do
        table.insert(tab, s)
    end
    return tab
end

mobcount = 0
mobs = {}
local lts = fs.list("plugins/loottables")
for _,entity in pairs(lts) do
    local mob = {}
    mob["Name"] = entity
    mob["Data"] = {}
    local file = fs.open("plugins/loottables/"..entity,"r")
    local line = file.readLine()
    while line do
        local dets = string.split(line, " ")
        local data = {}
        data["Item"] = dets[1]
        data["Count"] = tonumber(dets[2])
        data["Meta"] = tonumber(dets[3])
        data["Chance"] = tonumber(dets[4])
        table.insert(mob["Data"], data)
        line = file.readLine()
    end
    mobs[entity] = mob
    mobcount = mobcount + 1
    print("Loaded Entity #"..mobcount..": "..entity)
end
print("Loaded "..mobcount.." mobs")

parallel.waitForAny(function()
    local c = 0
    while true do
        if c > 10000 then
            c = 0
            sleep(0)
        else
            c = c + 1
        end

        for _,tag in pairs(mobs) do
            if commands.exec("testfor @e[type="..tag["Name"]..",tag=!enhanced]") then
                commands.exec("effect @e[type="..tag["Name"]..",tag=!enhanced] invisibility 100 0 true")
                local sumScript = ""
                local sumScript2 = ""
                local unused = 5
                for _,i in pairs(tag["Data"]) do
                    unused = unused - 1
                    sumScript = sumScript.."{Count:"..i["Count"]..",id:\""..i["Item"].."\"},"
                    sumScript2 = sumScript2..i["Chance"].."F,"
                end
                for i = 1,unused do
                    sumScript = sumScript.."{},"
                    sumScript2 = sumScript2.."1F,"
                end
                sumScript = sumScript:sub(1,-2)
                sumScript2 = sumScript2:sub(1,-4)
                commands.exec("execute @e[type="..tag["Name"]..",tag=!enhanced] ~ ~ ~ /summon "..tag["Name"].." ~ ~ ~ {ArmorItems:["..sumScript.."],ArmorDropChances:["..sumScript2.."],Tags:[\"enhanced\"]}")
                commands.exec("gamerule doMobLoot false")
                commands.exec("kill @e[type="..tag["Name"]..",tag=!enhanced]")
                commands.exec("gamerule doMobLoot true")
            end
        end
    end
end,function()
    print("Press any key to cancel")
    os.pullEvent("key")
end)