test.lua

#!/usr/bin/lua
require "socket"
io.stdout:setvbuf "no"

prev_total = 0
prev_idle = 0

function round(number, decimal)
  local multiplier = 10^(decimal or 0)
  return math.floor(number * multiplier + 0.5) / multiplier
end

function sleep(sec)
  socket.select(nil,nil,sec)
end

function getpct()
  file = assert(io.open("/proc/stat", "r"))

  --- Get the cpu line and insert each space-seperated value into a table
  for line in file:lines() do
    sfound = string.find(line, "cpu ", 1)
    if sfound ~= nil then
      cpu = {}
      for word in line:gmatch("%S+") do
	table.insert(cpu,word)
      end
      table.remove(cpu,1)
    end
  end

  -- No need to keep this fd open any longer than we need to...
  file:close()

  -- Get the idle cpu time (the 5th number in the series of 10)
  idle = cpu[4]

  -- Calculate the total cpu time
  total = 0
  for row,cpuval in ipairs(cpu) do
    total = total + cpuval
  --  print("Loop run, total = ", total, " cpuval = ", cpuval)
  end
  
  -- Calculate the CPU usage since we last checked
  diff_idle  = idle - prev_idle
  diff_total = total - prev_total
  diff_usage = (1000 * (diff_total - diff_idle) / diff_total + 5) / 10

  -- Remember the total and idle CPU times for the next check
  prev_total = total
  prev_idle = idle


  return round(diff_usage, 0)
end

function gdbar(pct,fgcolor,bgcolor,x_dimension,y_dimension,maxpct)
  gdbar_diff  = maxpct / x_dimension
  gdbar_div   = pct / gdbar_diff
  gdbar_rdiv  = round(gdbar_div)
  return("^fg(" .. fgcolor .. ")^r(" .. gdbar_rdiv .. "x" .. y_dimension .. ")^fg(" .. bgcolor .. ")^r(" .. x_dimension - gdbar_rdiv .. "x" .. y_dimension .. ")^fg()")
end

while true do
  date = os.date("%A, %b %d. %I:%M%p")
  cpu_pct = getpct()
  print("^i(/home/igneous/.dzen/bitmaps/xbm8x8/cpu.xbm) " .. gdbar(cpu_pct,"white","darkgrey",80,10,100))
  sleep(1)
end