!7

// works with certain versions of vnstat. Try apt-get install vnstat

module EstimatedMonthlyTraffic > DynBigNumber {
  switchable S vnstatInterface; // set this to the interface name if output is empty otherwise 
  
  start {
    dm_reloadOnFieldChange vnstatInterface();
    doEvery(0.0, 10*60.0, r {
      if (!isOnPATH('vnstat))
        setValue("vnstat not installed");
      else
        setValue(regexpReplaceWithNothing(",\\d+",
          parse_vnstat(backtick("vnstat" + (empty(vnstatInterface) ? "" : " -i " + vnstatInterface))).thisMonthEstimated));
    });
  }
}