sys_service_printUnits

function string:split(s, delimiter)
    local result = {};
    for match in (s .. delimiter):gmatch("(.-)" .. delimiter) do
        table.insert(result, match);
    end
    return result;
end

function getMsgData(msg)
    local i, j = string.find(msg, ":")
    local tag = string.sub(msg, 1, i - 1)
    local pts = string:split(string.sub(msg, i + 1, -1), ",")
    return tag, pts
end

--syslib end

args = { ... }
local rootId = tonumber(args[1])
--to sys_service_printUnits
local monitor = peripheral.wrap("left") --find("monitor")
monitor.setTextScale(0.5)
rednet.open("back")
rednet.send(rootId, "@root:getUnitsData")
local done = false
while not done do
    local id, msg = rednet.receive()
    local i, j = string.find(msg, ":")
    if i ~= nil then
        local tag = string.sub(msg, 1, i - 1)
        local body = string.sub(msg, i + 1, -1)
        if tag == "action" then
            local pts = string:split(body, " ")
            print("" .. table.getn(pts))
            print("" .. body)
            monitor.clear()
            for i = 1, tonumber(table.getn(pts) / 3) do
                monitor.setCursorPos(1, i)
                monitor.write(pts[(i - 1) * 3 + 1] .. ": ")
                monitor.write(pts[(i - 1) * 3 + 2] .. " - ")
                monitor.write(pts[(i - 1) * 3 + 3])
            end
            sleep(1)
            rednet.send(rootId, "@root:getUnitsData")
        elseif tag == "@programs" then
            local tag, pts = getMsgData(msg)
            if pts[1] == "terminate" then
                done = true
            else print("unknown message: ", msg)
            end
        else
            print("unknown msg-tag: ", msg)
        end
    else print("unknown msg: ", msg)
    end
end