data file help
 

i need to be able to add data to my .dat file without deleting my old data during a program run can anyone help me?

Re: data file help
 

If this is a console app (DOS program) or UNIX program that outputs to standard output, you could redirect the output to your data file

program.exe >> datafile.dat


If this is a Windows program, you can use CreateFile with the following arguments

HANDLE hFile = INVALID_HANDLE_VALUE;

hFile = CreateFile("yourfile.dat", 

  GENERIC_READ | GENERIC_WRITE, 

  0, // no file sharing

  NULL, // no security descriptor

  OPEN_ALWAYS, // creates if not found

  FILE_ATTRIBUTE_NORMAL,

  NULL); // No template handle

This returns a HANDLE that you can pass to ReadFile and WriteFile

Using SetFilePointer if you need to position to any part of the file.

if (hFile != INVALID_HANDLE_VALUE)

{

  DWORD bytesWritten;

  if (FALSE == WriteFile(hFile,

    dataBuffer, // data to write

    dataBufferSize,

    &bytesWritten,

    NULL))  // not using overlapped I/O

  {

    MessageBox(GetActiveWindow(),

      "Error", "Error", MB_ICONSTOP);

  }

  // will want to verify 

  // bytesWritten == dataBufferSize

}

Be sure to close the file with

CloseHandle(hFile);

Hope this helps.