#!/usr/bin/lua

local invoker = require 'invoker'

local g_prefix = "/root/maps-info"
local g_apps = {
	"dy_rs485",
	"dy_modbus_tcp",
	"dy_protocol_parser",
}

local function os_date()
	local tim = os.time()
	local od = os.date("*t", time)
	if type(od) ~= "table" then return tostring(tim) end
	return string.format("%d%02d%02d-%02d%02d%02d",
		od.year or 0, od.month or 0, od.day or 0,
		od.hour or 0, od.min or 0, od.sec or 0)
end

local function dump_pid_maps(pid, appn)
	local mapfile = string.format("/proc/%s/maps", pid)
	local maps = invoker.readfile(mapfile, nil, 16384)
	if type(maps) ~= "string" or string.len(maps) == 0 then
		return false
	end

	local film = string.format("%s/%s/pid%s-%s.maps", g_prefix,
		appn, pid, os_date())
	local filp = io.open(film, "wb")
	if filp then
		filp:write(maps)
		filp:close(); filp = nil
		return true
	end
	return false
end

local function monitor_init()
	for _, appn in ipairs(g_apps) do
		local dirp = string.format("%s/%s", g_prefix, appn)
		io.stdout:write("creating directory " .. dirp .. "...\n")
		io.stdout:flush()
		invoker.invoke(invoker.NOSTDIO, "mkdir", "-p", dirp)
	end
	return true
end

local function collect_maps()
	for _, appn in ipairs(g_apps) do
		local eval, pids = invoker.invoke(invoker.OUTPUT, "pidof", appn)
		if eval ~= 0 or type(pids) ~= "string" then
			io.stderr:write(string.format("Error, cannot find PID for %s\n", appn))
			io.stderr:flush()
		else
			for lpid in string.gmatch(pids, "%d+") do
				dump_pid_maps(lpid, appn)
			end
		end
	end
end

monitor_init()
collect_maps()
os.exit(0)