1. local function write_log(content)
    2.     local file_name = "/tmp/debug.txt"
    3.     content = content or "content as nil"
    4.     local timestemp = os.date("%Y-%m-%d %H:%M:%S")
    5.     content = timestemp .. " : " .. content
    6.     local file = io.open(file_name, "a")
    7.     if not file then
    8.         return "can\'t open file \"" .. file_name .. "\""
    9.     end
    10.     file:write(debug.traceback(content,2))
    11.     file:write("\n")
    12.     file:close()
    13.     return nil
    14. end