#!/usr/bin/lua

function pairsByKeys (t, f)
      local a = {}
      for n in pairs(t) do table.insert(a, n) end
      table.sort(a, f)
      local i = 0      -- iterator variable
      local iter = function ()   -- iterator function
        i = i + 1
        if a[i] == nil then return nil
        else return a[i], t[a[i]]
        end
      end
      return iter
    end

local f = io.popen("/usr/bin/ntpq -c readlist")
local line
ntp = {}

while true do
    line = f:read("*l") -- read output of command
    if line == nil then break end
    local pl = line
    if string.find(line, "version=") then
        ntp["version"] = string.match(line, "version=\"[^\"]+\"")
        ntp["version"] = string.gsub(ntp["version"], "version=\"([^\"]+)\"", "%1")
    end
    if string.find(line, "processor=") then
        ntp["processor"] = string.match(line, "processor=\"[^\"]+\"")
        ntp["processor"] = string.gsub(ntp["processor"], "processor=\"([^\"]+)\"", "%1")
    end
    if string.find(line, "system=") then
         ntp["system"] = string.match(line, "system=\"[^\"]+\"")
         ntp["system"] = string.gsub(ntp["system"], "system=\"([^\"]+)\"", "%1")
    end
    if string.find(line, "reftime=") then
         ntp["reftime"] = string.match(line, "reftime=%x%x%x%x%x%x%x%x%.%x%x%x%x%x%x%x%x%s+%w+,[^,]+")
         ntp["reftime"] = string.gsub(ntp["reftime"], "reftime=(%x%x%x%x%x%x%x%x%.%x%x%x%x%x%x%x%x)%s+(%w+),%s+(.+)", "%2 %3 (%1)")
    end
    if string.find(line, "clock=") then
         ntp["clock"] = string.match(line, "clock=%x%x%x%x%x%x%x%x%.%x%x%x%x%x%x%x%x%s+%w+,[^,]+")
         ntp["clock"] = string.gsub(ntp["clock"], "clock=(%x%x%x%x%x%x%x%x%.%x%x%x%x%x%x%x%x)%s+(%w+),%s+(.+)", "%2 %3 (%1)")
    end
    if string.find(line, "precision=") then
         ntp["precision"] = string.match(line, "precision=[^,]+")
         ntp["precision"] = string.gsub(ntp["precision"], "precision=([^,]+)", "%1")
    end
    if string.find(line, "rootdelay=") then
         ntp["rootdelay"] = string.match(line, "rootdelay=[^,]+")
         ntp["rootdelay"] = string.gsub(ntp["rootdelay"], "rootdelay=([^,]+)", "%1")
    end
    if string.find(line, "rootdispersion=") then
         ntp["rootdispersion"] = string.match(line, "rootdispersion=[^,]+")
         ntp["rootdispersion"] = string.gsub(ntp["rootdispersion"], "rootdispersion=([^,]+)", "%1")
    end
    if string.find(line, "leap=") then
         ntp["leap"] = string.match(line, "leap=[^,]+")
         ntp["leap"] = string.gsub(ntp["leap"], "leap=([^,]+)", "%1")
    end
    if string.find(line, "stratum=") then
         ntp["stratum"] = string.match(line, "stratum=[^,]+")
         ntp["stratum"] = string.gsub(ntp["stratum"], "stratum=([^,]+)", "%1")
    end
    if string.find(line, "peer=") then
         ntp["peer"] = string.match(line, "peer=[^,]+")
         ntp["peer"] = string.gsub(ntp["peer"], "peer=([^,]+)", "%1")
    end
    if string.find(line, "refid=") then
         ntp["refid"] = string.match(line, "refid=[^,]+")
         ntp["refid"] = string.gsub(ntp["refid"], "refid=([^,]+)", "%1")
    end
    if string.find(line, "poll=") then
         ntp["poll"] = string.match(line, "poll=[^,]+")
         ntp["poll"] = string.gsub(ntp["poll"], "poll=([^,]+)", "%1")
    end
    if string.find(line, "offset=") then
         ntp["offset"] = string.match(line, "offset=[^,]+")
         ntp["offset"] = string.gsub(ntp["offset"], "offset=([^,]+)", "%1")
    end
    if string.find(line, "frequency=") then
         ntp["frequency"] = string.match(line, "frequency=[^,]+")
         ntp["frequency"] = string.gsub(ntp["frequency"], "frequency=([^,]+)", "%1")
    end
    if string.find(line, "jitter=") then
         ntp["jitter"] = string.match(line, "jitter=[^,]+")
         ntp["jitter"] = string.gsub(ntp["jitter"], "jitter=([^,]+)", "%1")
    end
    if string.find(line, "noise=") then
         ntp["noise"] = string.match(line, "noise=[^,]+")
         ntp["noise"] = string.gsub(ntp["noise"], "noise=([^,]+)", "%1")
    end
    if string.find(line, "stability=") then
         ntp["stability"] = string.match(line, "stability=[^,]+")
         ntp["stability"] = string.gsub(ntp["stability"], "stability=([^,]+)", "%1")
    end
    if string.find(line, "tai=") then
         ntp["tai"] = string.match(line, "tai=[^,]+")
         ntp["tai"] = string.gsub(ntp["tai"], "tai=([^,]+)", "%1")
    end
    if string.find(line, "state=") then
         ntp["state"] = string.match(line, "state=[^,]+")
         ntp["state"] = string.gsub(ntp["state"], "state=([^,]+)", "%1")
    end
end

for k,v in pairsByKeys(ntp) do
    print(string.format("<tr><td>%s</td><td>%s</td></tr>", k, v))
end

f:close()