Print Function - Mikrotik Script
How to Print Function on RouterOS

As stated in Lua documentation, 'print' command is not available in RouterOS compared to standard Lua release. This example will show you how to get back 'print' command

# Print function
function print (...)
   local strPrintResult = ""
   if ... then
      local targs = {...}
      for i,v in ipairs(targs) do
        strPrintResult = strPrintResult .. tostring(v) .. "  "
      end
      strPrintResult = strPrintResult .. "\r\n"
      io.write(strPrintResult)
   end
end

Now you can include this custom function to other scripts and use this cool custom print function :)
You can also modify this function to write messages in RouterOS log.