Im stumped with some array issue thingy....

[Jay King]

Ok what I'm doing is loading the first 32 bytes of a file looking for a
string then I start over again and from the last position (minus a few
bytes ) I start searching again. My problem is that it errors the second
time around claiming it (the file io object) cant load the next 32 bytes
into the array as if its already filled or some idiotic thing... HELP!

Here is my code. Use any file for testing longer then 64 bytes

Imports System.IO

Imports System.Text.ASCIIEncoding

Module Module1

Const strtBlock = "MADk" & Chr(80)

Const endBlock = "SCDlt"

Sub Main()

Console.WriteLine("Simcity 4 .dat file parter, Copyright 2003 CPG")

Console.WriteLine("Enter the name of the .dat file you wish to split")

Dim filename As String

filename = Console.ReadLine()

Console.WriteLine("About to process file...")

Dim fs As New FileStream(filename, FileMode.Open)

Dim datfile As IO.BinaryReader

Dim tempByte() As Byte '= New Byte(32) {}

Dim tempString As String

Dim index As Integer = 1

Dim count As Integer = 32

Dim stringExists As Integer ' non zero if true

10: Threading.Thread.CurrentThread.Sleep(New TimeSpan(10)) 'Sleep for 10
ticks (100 nano seconds * 10, 1,000 nanoseconds)

'tempByte = New Byte(32) {} 'Create new array of 32 bytes

tempByte = getbytearray()

datfile = New IO.BinaryReader(fs)

If (datfile.BaseStream.Length - index) < 32 Then count =
(datfile.BaseStream.Length - index) - 32 'Making sure count is never longer
then length of file.

datfile.Read(tempByte, index, count)

tempString = ASCII.GetChars(tempByte) 'Turn my byte array into a string

Erase tempByte

Console.WriteLine(tempString)

stringExists = InStr(tempString, strtBlock, CompareMethod.Binary)

If stringExists = 0 Then

If count < 32 Then

Console.WriteLine("End Searching file")

Console.Read()

End

End If

index = index + (32 - 5)

GoTo 10

Else 'I have found the start Block

Console.WriteLine("Found Start Block @" & index + stringExists) 'Tell user
you have found start byte.

End If

End Sub

Function getbytearray() As Byte()

Dim tempByte() As Byte = New Byte(32) {}

Return tempByte

End Function

End Module

[iGadget]

On Sat, 18 Jan 2003 05:18:21 -0500, Jay King wrote:

> Ok what I'm doing is loading the first 32 bytes of a file looking for a
> string then I start over again and from the last position (minus a few
> bytes ) I start searching again. My problem is that it errors the second
> time around claiming it (the file io object) cant load the next 32 bytes
> into the array as if its already filled or some idiotic thing... HELP!

In the line
datfile.Read(tempByte, index, count)
the index variable contains the position in the array that you want to
read into, not the position in the input file.

You need to use something like

Dim datfile As IO.BufferedStream
datfile = New BufferedStream(fs)
..
datfile.Seek(index, SeekOrigin.Begin)
datfile.Read(tempByte, 0, count)

Cheers,
Jason

[Jay King]

Sweet Thanks!

"iGadget" <igadget_@hotmail.com> wrote in message
news:w4n9e6r8ndiy$.bda43ym6lzdy$.dlg@40tude.net...
| On Sat, 18 Jan 2003 05:18:21 -0500, Jay King wrote:
|
| > Ok what I'm doing is loading the first 32 bytes of a file looking for a
| > string then I start over again and from the last position (minus a few
| > bytes ) I start searching again. My problem is that it errors the
second
| > time around claiming it (the file io object) cant load the next 32 bytes
| > into the array as if its already filled or some idiotic thing... HELP!
|
| In the line
| datfile.Read(tempByte, index, count)
| the index variable contains the position in the array that you want to
| read into, not the position in the input file.
|
| You need to use something like
|
| Dim datfile As IO.BufferedStream
| datfile = New BufferedStream(fs)
| .
| datfile.Seek(index, SeekOrigin.Begin)
| datfile.Read(tempByte, 0, count)
|
| Cheers,
| Jason