Looking at the binary

[Pumices]

ok, how would I look take a file... any file and look at the binary code in vb? Everything exist in binary atleast on the harddrive if nothing else and I just need to access the raw binary data. Is there anyway I can do this? Thanks

 

[chiph]

Umm, use the BinaryReader class?

Dim binReader As New BinaryReader(File.Open(fileName, FileMode.Open))
Try
   Dim b As Byte
   While(True)
      b = binReader.ReadByte
      ' Do something with the byte
   Wend
Catch ex As EndOfStreamException
End Try

Chip H.


____________________________________________________________________
If you want to get the best response to a question, please read FAQ222-2244 first

 

[Pumices]

That is close to what I needed but it is returning numbers other than 0 and 1 it is returning numbers like 80, 124, 86, etc. What I want to be able to do is take the binary from a large file and save the binary into a text file as quickly as possible. I want to then be able to reconstruct the file using that binary code at a later time. Thank you for your help so far and I hope this helps to better explain my problem. Thank you again

 

[earthandfire]

If you want to see the binary representation of the bytes you could use something like this:

    Dim MyByte As Byte
    Dim s As String = ""
    Dim bitset As Boolean
    For a As Integer = 7 To 0 Step -1
      bitset = (MyByte And CByte(Math.Pow(2, a))) = CByte(Math.Pow(2, a))
      If bitset Then
        s += "1"
      Else
        s += "0"
      End If

Hope this helps.

 

[Pumices]

Yes, that does help and thank you but just one more thing. If I save the binary to a text file. How would I reverse that process to recreate the file and if I did would the file be unaltered. Thank you so much for your help you guys have been incredibly helpful up to this point.

 

[earthandfire]

One problem - the string will have the value in "reverse" order:

"00000001" = 1
"10000000" = 128

As your text file size should be an exact multiple of eight - there are a number of options, however (the slowest) but easiest would be to read the file one byte at a time:

Each byte represents the ASCII representation of a bit i.e.

48 = "0"
49 = "1"

you will need to maintain a position index (from 7 to 0) and a byte variable

typed not tested

Dim ResultByte As Byte
Dim StringBit As Byte

'assumes the following is within a while not end of file loop

ResultByte = 0
For a As Integer = 7 To 0 Step -1
  'read a byte from input file into StringBit
  StringBit -=48
  ResultByte +=  StringBit * CByte(Math.Pow(2,a))
Next a
'write the byte ResultByte to the output file

At the end of this the ouptput file should be the same as the original input file

Hope this helps.

 

[Pumices]

Thank you very much that was exactly what I needed to know. Thank you for all the help you have made my day... or night.

 

[chiph]

That is close to what I needed but it is returning numbers other than 0 and 1 it is returning numbers like 80, 124, 86, etc.

Well, yeah. They are byte values, after all. Anything between 0..255 is valid, and is a correct representation of what is stored on disk.

Most people don't care about the actual bit patterns, as they can be gotten via simple powers-of-two manipulations like earthandfire did.

Chip H.


____________________________________________________________________
If you want to get the best response to a question, please read FAQ222-2244 first