StreamHelper.cs :  » Persistence-Frameworks » FileHelpers-Library » FileHelpers » C# / CSharp Open Source

#region "   Copyright 2005-07 to Marcos Meli - http://www.marcosmeli.com.ar" 

// Errors, suggestions, contributions, send a mail to: marcos@filehelpers.com.

#endregion

using System.IO;
using System.Text;

namespace FileHelpers{

#if NET_1_1 || MINI

  internal sealed class StreamHelper
  {
    private StreamHelper()
    {
    }

#else
  internal static class StreamHelper
  {
#endif
    internal static TextWriter CreateFileAppender(string fileName, Encoding encode, bool correctEnd)
    {
      return CreateFileAppender(fileName, encode, correctEnd, true);
    }

    internal static TextWriter CreateFileAppender(string fileName, Encoding encode, bool correctEnd, bool disposeStream)
    {
      TextWriter res;

      if (correctEnd)
      {
        FileStream fs = null;

        try
        {
          fs = new FileStream(fileName, FileMode.OpenOrCreate, FileAccess.ReadWrite);

          if (fs.Length >= 2)
          {
            fs.Seek(-2, SeekOrigin.End);

            if (fs.ReadByte() == 13)
            {
              if (fs.ReadByte() == 10)
              {
                int nowRead;
                do
                {
                  fs.Seek(-2, SeekOrigin.Current);
                  nowRead = fs.ReadByte();
                } while (nowRead == 13 || nowRead == 10);
              }
            }
            else
              fs.ReadByte();

            fs.WriteByte(13);
            fs.WriteByte(10);

          }

          res = new StreamWriter(fs, encode);

        }
        finally
        {
          if (disposeStream && fs != null)
            fs.Close();
        }
      }
      else
      {
        res = new StreamWriter(fileName, true, encode);
      }

      return res;
    }

  }
}