some file related

1. drop empty files from folder

string[] files = Directory.GetFiles(dirName);
foreach (string file in files)
{
    FileInfo fi = new FileInfo(file);
    if (fi.Length == 0)
        fi.Delete();
}

2. append text to file

string msg = "some text";
bool   append = True;

using (TextWriter tw = new StreamWriter(file, append))
    tw.WriteLine(msg);
  .. or ..
using (StreamWriter sw = File.AppendText(file))
    sw.WriteLine(msg);
  .. or ..
File.AppendAllText(file, msg + "\n");