C#

while(true)
{
  StringBuilder wholeText = "";
  String fileName = "file.txt";
  // create reader & open file
  Textreader tr = new StreamReader(fileName);

  // read a line of text
  String oneLine = tr.ReadLine();
  if(oneLine == null)
  {
     break;
  }
  else
  {
     doSomethingWith(oneLine);
  }

  while(String s = tr.ReadLine != null)
  {
     wholeText.add(String.Format("{0}\n",s);
  } 
  // close the stream
  tr.Close();

  //open the same file and write the text in there
  Textwriter tw = new StreamWriter(fileName);
  tw.write(wholeText.ToString());
  tw.Close();
}

private void TookMeLongEnough_Click(object sender, EventArgs e)
     {
         string[] lines = File.ReadAllLines(openFileDialog1.Tag.ToString());
         foreach (string line in lines)
         {
         SaveSessionTextBox.Text = fbd.SelectedPath +
             "\\" +
             i++ +
             "A" +
             i++ +
             DateTime.Now.Hour +
             DateTime.Now.Minute +
             DateTime.Now.Second +
             DateTime.Now.Millisecond +
             ".spr";
         }
     }

jas0n23 wrote:

openFileDialog1.Tag.ToString()

s=fbd.SelectedPath + "\\"+ i.ToString("N5")+ "_" + DateTime.Now.ToString("HHmmssfff")+".spr";
i++;