(oc)rplm.lua

--
-- Robot Power Level Monitor
--
-- Author: Sharidan
--     www.sharidan.dk
--
--[[
local event = require("event")
local pmtid, lc = 0, 0
local function setLight(nc)
  if (nc ~= lc) then
    require("robot").setLightColor(nc)
    lc = tonumber(nc)
  end
end
local function checkPower()
  local pct, nc = require("computer").energy()/(require("computer").maxEnergy()/100), 0
  if (pct >= 35) then
    setLight(0x00ff00)
  elseif (pct >= 20 and pct < 35) then
    setLight(0xffff33)
  elseif (pct >= 10 and pct < 20) then
    setLight(0xffa000)
  elseif (pct < 10) then
    setLight(0xff4040)
  end
end
function start()
  setLight(0x60c0ff)
  if (pmtid == 0) then
    pmtid = event.timer(5, checkPower, math.huge)
  end
end
function stop()
  if (pmtid > 0) then
    event.cancel(pmtid)
    pmtid = 0
  end
  setLight(0x60c0ff)
end
]]--
local function install()
  local sp = os.getenv("PWD")
  local fs = require("filesystem")
  if (fs.exists(sp.."rplm.lua")) then
    if (fs.exists("/etc/rc.d/rplm.lua")) then
      return false, "rplm already installed."
    else
      local sf = io.open(sp.."rplm.lua", "r")
      if (sf) then
        local tf = io.open("/etc/rc.d/rplm.lua", "w")
        if (tf) then
          local running, wc = true, false
          while running do
            local l = sf:read("*l")
            if (l == "--[[") then
              wc = true
            elseif (l == "]]--") then
              wc = nil
              running = nil
            elseif (string.sub(l, 1, 2) == "--" and not wc) then
              tf:write(l.."\n")
            elseif (wc) then
              tf:write(l.."\n")
            end
          end
          tf:close()
          sf:close()
          return true, ""
        end
      end
    end
  else
    return false, "rplm not found!\nPlease change to directory containing installer and try again."
  end
end
local function uninstall()
  local rc, fs = require("rc"), require("filesystem")
  if (rc) then
    local result, reason = rc.runCommand("rplm", "stop")
    result, reason = rc.runCommand("rplm", "disable")
    if (result) then
      if (fs.exists("/etc/rc.d/rplm.lua")) then
        fs.remove("/etc/rc.d/rplm.lua")
        return true, ""
      end
    else
      return false, reason
    end
  else
    return false, "rc not accessible!"
  end
end

local function showUsage()
  print("Robot Power Level Monitor")
  print("rplm -i/-u")
  print("  -i : install daemon")
  print("  -u : uninstall daemon")
end

local function checkRun(a)
  local bot = require("robot")
  if (bot) then
    if (a == "-i") then
      local s, r = install()
      if (s) then
        local rc = require("rc")
        if (rc) then
          s, r = rc.runCommand("rplm", "enable")
          s, r = rc.runCommand("rplm", "start")
        end
        print("rplm installed.")
      else
        print("rplm install failed:")
        print(r)
      end
    elseif (a == "-u") then
      local s, r = uninstall()
      if (s) then
        print("rplm uninstalled.")
      else
        print("rplm uninstall failed:")
        print(r)
      end
    else
      showUsage()
    end
  else
    showUsage()
  end
end

local args = {...}
if (#args == 1) then
  checkRun(string.lower(args[1]))
else
  showUsage()
end