TextStream - reading special characters

I am trying to get TextStream to read a log file (text) with a special character in it. The special character is the hex null (00). A typical textreader (wordpad) represents it as a square. This character is randomly placed throughout the log file. The problem is whenever TextStream reads this characters it interprets it as a "endofstream" and stops reading. I am not concerned about the character it can me replaced with a space. I have tried both the ReadAll and the ReadLine but all fails. Is there anyway around this Is there some other way besides the "textstream" to read a text file as a string Is there a way to filter the file first and delete the character Help!

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TextStream - reading special characters

Viktor_BVP

Works like a charm!!!! Thanks for the help!!
James L VanDusen

Maybe something like this would work for you:

    Private Sub ReplaceNulls(ByVal bytes() As Byte)
        For byteNo As Integer = 0 To bytes.Length - 1
            ' Replace all NULLs with spaces...
            If bytes(byteNo) = 0 Then
                bytes(byteNo) = Microsoft.VisualBasic.Asc(" "c)
            End If
        Next
    End Sub

    Sub Main()
        Dim bytes() As Byte
        Using fileToRead As New System.IO.FileStream("FileWithFunkyNulls.txt", IO.FileMode.Open)
            Using reader As New System.IO.BinaryReader(fileToRead)
                ' Read all data into a temporary buffer so we can replace NULLs with
                ' spaces... This may not be feasible if the logfile is very big...
                bytes = reader.ReadBytes(fileToRead.Length)
                ReplaceNulls(bytes)
            End Using
        End Using

        ' Get the string from the ASCII encoded byte buffer now that we have removed
        ' all the NULLs from the buffer
        Dim resultingString As String = System.Text.Encoding.ASCII.GetString(bytes)

        Console.WriteLine(resultingString)
    End Sub

Best regards,
Johan Stenberg
ha ha

Hrm compiler warnings are your friend. ReplaceNulls shouldn't be a function, it should be a Sub, and the compiler is absolutely correct about warning me that I'm not returning anything.

I'm sorry for any confusion I may have caused.

Best regards,
Johan Stenberg
Mage

How do you open the file Which character encoding is the file using ASCII UTF8 Are you sure you open the file with the appropriate encoding

I just tried a little ASCII encoded file with a couple of NULL (0x00) characters in them and it works as expected (the NULLs get removed since they aren't valid ASCII code points)

What you could do is open the file as a binary file (techincally it isn't really a pure text file since it contains NULL characters), read the file as a stream of bytes, replace all instances of 0x00 with a valid code point (i.e. 0x20 - space - for ASCII) and then use the appropriate System.Encoding.GetString(byte()) method to get the string...

For info on how to read a binary file, see http://msdn.microsoft.com/library/default.asp url=/library/en-us/cpguide/html/cpconReadingWritingToNewlyCreatedDataFile.asp

Best regards,
Johan Stenberg
applechen
Mr Stenberg,

Thanks so much for the help. I am glad to hear there is a way around my problem. I understand your solution however I can't make it work.  I am going to have to ask you to spoon feel me the answer.

I created a binary file (test.txt) and inserted the null value. I refered to the help file you sent me and did some cut and pasting. The only output I received was a series of numbers ...not hex..not anything I recognize.

You said that you wrote some code that work fine with the null value. Could you post it And by the way, the file uses ASCII encoding and I use Wordpad to open it

Thanks again for your help!

This following is the code I ran:

Public Class Form1
    Private Const FILE_NAME As String = "c:\Test.txt"

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Dim fs = New System.IO.FileStream(FILE_NAME, System.IO.FileMode.Open, System.IO.FileAccess.Read)
        Dim r As New System.IO.BinaryReader(fs)
        Dim i As Integer
        For i = 0 To 10
            Console.WriteLine(r.ReadInt32())
        Next i
    End Sub
End Class
NormLane
Mr Stenberg, thank you so much for your time and help but when I ran your code I received an error. If it is something I am doing wrong please let me know. Just to let you know, I renamed my test file to "FileWithFunkyNulls" (cool name by the way). This is the error I received:

Warning 1 Function 'ReplaceNulls' doesn't return a value on all code paths. A null reference exception could occur at run time when the result is used. \Form1.vb 9 5 WindowsApplication2

Again, Thanks for your time!!!
TextStream - reading special characters

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