Visual Basic

Dave Kreskowiak wrote:

Standard question #2. What does the code look like that you're using to get the file into the memory stream?

Private Function DecryptFile(ByVal strInputFile As String, _<br />
                                     ByVal bytKey() As Byte, _<br />
                                     ByVal bytIV() As Byte) As String<br />
<br />
        Dim strBuilder As New StringBuilder<br />
        Dim mem As MemoryStream = New MemoryStream()<br />
      'Setup file streams to handle input and output.<br />
            fsInput = New System.IO.FileStream(strInputFile, FileMode.Open, _FileAccess.Read)<br />
            mem.SetLength(0)<br />
            'Declare variables for decrypt process.<br />
            Dim bytBuffer(4096) As Byte 'holds a block of bytes for processing<br />
            Dim lngBytesProcessed As Long = 0 'running count of bytes processed<br />
            Dim lngFileLength As Long = fsInput.Length 'the input file's length<br />
            Dim intBytesInCurrentBlock As Integer 'current bytes being processed<br />
            Dim csCryptoStream As CryptoStream<br />
            'Declare your CryptoServiceProvider.<br />
            Dim cspRijndael As New System.Security.Cryptography.RijndaelManaged<br />
<br />
            csCryptoStream = New CryptoStream(mem, _<br />
                      cspRijndael.CreateDecryptor(bytKey, bytIV), _<br />
                      CryptoStreamMode.Write)<br />
<br />
            'Use While to loop until all of the file is processed.<br />
            While lngBytesProcessed < lngFileLength<br />
                'Read file with the input filestream.<br />
                intBytesInCurrentBlock = fsInput.Read(bytBuffer, 0, 4096)<br />
                'Write output file with the cryptostream.<br />
                csCryptoStream.Write(bytBuffer, 0, intBytesInCurrentBlock)<br />
                'Update lngBytesProcessed<br />
                lngBytesProcessed = lngBytesProcessed + CLng(intBytesInCurrentBlock)<br />
<br />
            End While<br />
<br />
            Dim result As Byte() = mem.ToArray()<br />
           <br />
 Dim valu As String = System.Text.Encoding.ASCII.GetString(result)<br />

MartyK2007 wrote:

is there a way of telling if a file has finished being copied to a subdir

Dave Kreskowiak wrote:

wait an appropriate amount of time for the files to be completely written

Dave Kreskowiak wrote:

Also, if the other process opens the file, writes some data

Dave Kreskowiak wrote:

It should maintain the lock so the data can be backed out or rewritten

MartyK2007 wrote:

can you define and appropriate amount of time.

MartyK2007 wrote:

Also does having 10 files mean the codes waits 10 periods or waits 1 period and hopes all 10 files have finished copying.

MartyK2007 wrote:

In theory that wont happen in my scenario

MartyK2007 wrote:

that implies that some thought has been given by our unix team to crashes etc and that they have coded something like that - for which I am doubtfull.

MartyK2007 wrote:

You dont have a decent "Pattern" for doing this anywhere do you??

• FTP (or file-copy) the big data file into the folder (e.g. "MyData20070821_1.dta").
• FTP a zero-sized flag file with the same basename (e.g. "MyData20070821_1.flg").