Working with binary data?

[Dan]

To all the gurus out there. I am writing a tool that
receives binary data from a network device. The data
arrives in a standard format which the vendor has
documented, e.g. byte 0 is the format version, 1-4 are
integers between 0 and 255, etc. At this point I just
want to format the data into something that can be read
by humans and write it to the console. I have seen some
other examples of how people acomplish this but none in
visual basic. There is a Perl example I ran across that
uses the unpack operation to change the binary data to
several strings. I have tried converting the data to a
string with different types of encoding. No luck with
that it just shows up as jibberish. I have included my
source so you can see what i'm after. Is there a
comperable operation to the Perl unpack or some little
hack routine that someone has written to make the binary
data useful? Thanks!

Dan

Imports System
Imports System.Net
Imports System.Net.Sock ets
Imports System.Text

Public Class NetFlowCollecto r

Private Shared UDPPort As Integer = 5000

Private Shared Sub StartListener()
Dim done As Boolean = False

Dim RemoteIpEndPoin t As New IPEndPoint(IPAd dress.Any,
0)
Dim UDPClient As New UdpClient(UDPPo rt)

Try
While Not done
Dim bytes As Byte() = UDPClient.Recei ve
(RemoteIpEndPoi nt)

Console.WriteLi ne(strData)
End While

Catch e As Exception
Console.WriteLi ne(e.ToString() )
End Try
End Sub

Public Overloads Shared Function Main(ByVal args() As
[String]) As Integer
Console.WriteLi ne("Listening for NetFlow data on UDP
{0}", UDPPort)
StartListener()

Return 0
End Function 'Main
End Class

[Brian]

Try the BitConverter class. You can pack and unpack bytes this way.

"Dan" <an*******@disc ussions.microso ft.com> wrote in message
news:03******** *************** *****@phx.gbl.. .

To all the gurus out there. I am writing a tool that
receives binary data from a network device. The data
arrives in a standard format which the vendor has
documented, e.g. byte 0 is the format version, 1-4 are
integers between 0 and 255, etc. At this point I just
want to format the data into something that can be read
by humans and write it to the console. I have seen some
other examples of how people acomplish this but none in
visual basic. There is a Perl example I ran across that
uses the unpack operation to change the binary data to
several strings. I have tried converting the data to a
string with different types of encoding. No luck with
that it just shows up as jibberish. I have included my
source so you can see what i'm after. Is there a
comperable operation to the Perl unpack or some little
hack routine that someone has written to make the binary
data useful? Thanks!

Dan

Imports System
Imports System.Net
Imports System.Net.Sock ets
Imports System.Text

Public Class NetFlowCollecto r

Private Shared UDPPort As Integer = 5000

Private Shared Sub StartListener()
Dim done As Boolean = False

Dim RemoteIpEndPoin t As New IPEndPoint(IPAd dress.Any,
0)
Dim UDPClient As New UdpClient(UDPPo rt)

Try
While Not done
Dim bytes As Byte() = UDPClient.Recei ve
(RemoteIpEndPoi nt)

Console.WriteLi ne(strData)
End While

Catch e As Exception
Console.WriteLi ne(e.ToString() )
End Try
End Sub

Public Overloads Shared Function Main(ByVal args() As
[String]) As Integer
Console.WriteLi ne("Listening for NetFlow data on UDP
{0}", UDPPort)
StartListener()

Return 0
End Function 'Main
End Class

[Dan]

Thanks for the reply. That seems to have me moving in
the right direction. Can you recommend the most
efficient way to feed that information "into" an say
ASCII? So right now I dump the info to the console and I
see:

00-34-00-00-00...

I assume that is hex which each group representing one
byte. I'm afraid that if i convert that data into a
string and then parse it out with a hex2decimal function
and then feed it to ascii that will be too slow. Thanks
again!

Dan

-----Original Message-----
Try the BitConverter class. You can pack and unpack

bytes this way.

[Brian]

This will do it.

Dim b As BitConverter
Dim test(5) As Byte

test(0) = 72
test(1) = 69
test(2) = 76
test(3) = 76
test(4) = 79

Dim str As String = Encoding.ASCII. GetString(test, 0, test.Length)
Debug.WriteLine (str)
"Dan" <an*******@disc ussions.microso ft.com> wrote in message
news:01******** *************** *****@phx.gbl.. .

Thanks for the reply. That seems to have me moving in
the right direction. Can you recommend the most
efficient way to feed that information "into" an say
ASCII? So right now I dump the info to the console and I
see:

00-34-00-00-00...

I assume that is hex which each group representing one
byte. I'm afraid that if i convert that data into a
string and then parse it out with a hex2decimal function
and then feed it to ascii that will be too slow. Thanks
again!

Dan

-----Original Message-----
Try the BitConverter class. You can pack and unpack

bytes this way.

I'm going to have to beg forgiveness but I think you are
missing something in your example. You have Dim b As
BitCoverter but I don't see b referenced anywhere else in
the example. I think that is what i'm missing.

Thanks,

Dan

-----Original Message-----
This will do it.

Dim b As BitConverter
Dim test(5) As Byte

test(0) = 72
test(1) = 69
test(2) = 76
test(3) = 76
test(4) = 79

Dim str As String = Encoding.ASCII. GetString(test, 0, test.Length)Debug.WriteLin e(str)
"Dan" <an*******@disc ussions.microso ft.com> wrote in messagenews:01******* *************** ******@phx.gbl. ..

Thanks for the reply. That seems to have me moving in
the right direction. Can you recommend the most
efficient way to feed that information "into" an say
ASCII? So right now I dump the info to the console and I see:

00-34-00-00-00...

I assume that is hex which each group representing one
byte. I'm afraid that if i convert that data into a
string and then parse it out with a hex2decimal function and then feed it to ascii that will be too slow. Thanks again!

Dan

>-----Original Message-----
>Try the BitConverter class. You can pack and unpack

bytes this way.

.

[Brian]

That was a mistake, I just forgot to erase it. Here's a clearer example:

'-- Declare your array
Dim temp() As Byte

'-- This is your recieved Integer (just a test)
Dim k As Integer = 311875

'-- Convert the Integer to a byte array
temp = BitConverter.Ge tBytes(k)

'-- Now, get the string representation
Dim str As String = Encoding.ASCII. GetString(temp, 0, temp.Length)

Debug.WriteLine (str)
<an*******@disc ussions.microso ft.com> wrote in message
news:02******** *************** *****@phx.gbl.. .

I'm going to have to beg forgiveness but I think you are
missing something in your example. You have Dim b As
BitCoverter but I don't see b referenced anywhere else in
the example. I think that is what i'm missing.

Thanks,

Dan

-----Original Message-----
This will do it.

Dim b As BitConverter
Dim test(5) As Byte

test(0) = 72
test(1) = 69
test(2) = 76
test(3) = 76
test(4) = 79

Dim str As String = Encoding.ASCII. GetString(test, 0,

test.Length)

Debug.WriteLin e(str)
"Dan" <an*******@disc ussions.microso ft.com> wrote in

message

news:01******* *************** ******@phx.gbl. ..

Thanks for the reply. That seems to have me moving in
the right direction. Can you recommend the most
efficient way to feed that information "into" an say
ASCII? So right now I dump the info to the console and I see:

00-34-00-00-00...

I assume that is hex which each group representing one
byte. I'm afraid that if i convert that data into a
string and then parse it out with a hex2decimal function and then feed it to ascii that will be too slow. Thanks again!

Dan
>-----Original Message-----
>Try the BitConverter class. You can pack and unpack
bytes this way.

.

[Dan]

BTW

When I am running my last bit of code:

Console.WriteLi ne(BitConverter .ToUInt16(bytDa ta, 0))

The result is 256. When I look at the watch window I see:

Byte0 0
Byte1 1
Byte2 0
Byte3 24
etc.

Dan

-----Original Message-----
That was a mistake, I just forgot to erase it. Here's a clearer example:
'-- Declare your array
Dim temp() As Byte

'-- This is your recieved Integer (just a test)
Dim k As Integer = 311875

'-- Convert the Integer to a byte array
temp = BitConverter.Ge tBytes(k)

'-- Now, get the string representation
Dim str As String = Encoding.ASCII. GetString(temp, 0, temp.Length)
Debug.WriteLin e(str)
<an*******@dis cussions.micros oft.com> wrote in message
news:02******* *************** ******@phx.gbl. ..

I'm going to have to beg forgiveness but I think you are missing something in your example. You have Dim b As
BitCoverter but I don't see b referenced anywhere else in the example. I think that is what i'm missing.

Thanks,

Dan

>-----Original Message-----
>This will do it.
>
>Dim b As BitConverter
>Dim test(5) As Byte
>
> test(0) = 72
> test(1) = 69
> test(2) = 76
> test(3) = 76
> test(4) = 79
>
>Dim str As String = Encoding.ASCII. GetString(test, 0,

test.Length)

>Debug.WriteLin e(str)
>
>
>"Dan" <an*******@disc ussions.microso ft.com> wrote in

message

>news:01******* *************** ******@phx.gbl. ..
>> Thanks for the reply. That seems to have me moving in >> the right direction. Can you recommend the most
>> efficient way to feed that information "into" an say
>> ASCII? So right now I dump the info to the console

and I

>> see:
>>
>> 00-34-00-00-00...
>>
>> I assume that is hex which each group representing one >> byte. I'm afraid that if i convert that data into a
>> string and then parse it out with a hex2decimal

function

>> and then feed it to ascii that will be too slow.

Thanks

>> again!
>>
>> Dan
>>
>>
>> >-----Original Message-----
>> >Try the BitConverter class. You can pack and unpack
>> bytes this way.
>>
>
>
>.
>

.

[Brian]

Bytes Contents
0-1 Version ---------> Short Data Type (Int16)
2-3 Count ---------> Short Data Type (Int16)
4-7 Uptime ----------> Integer Data Type (Int32)
8-11 Seconds ----------> Integer Data Type (Int32)
12-16 uSeconds --------> Integer DataType (Int32)


"Dan" <an*******@disc ussions.microso ft.com> wrote in message
news:07******** *************** *****@phx.gbl.. .

BTW

When I am running my last bit of code:

Console.WriteLi ne(BitConverter .ToUInt16(bytDa ta, 0))

The result is 256. When I look at the watch window I see:

Byte0 0
Byte1 1
Byte2 0
Byte3 24
etc.

Dan

-----Original Message-----
That was a mistake, I just forgot to erase it. Here's a

clearer example:

'-- Declare your array
Dim temp() As Byte

'-- This is your recieved Integer (just a test)
Dim k As Integer = 311875

'-- Convert the Integer to a byte array
temp = BitConverter.Ge tBytes(k)

'-- Now, get the string representation
Dim str As String = Encoding.ASCII. GetString(temp, 0,

temp.Length)

Debug.WriteLin e(str)
<an*******@dis cussions.micros oft.com> wrote in message
news:02******* *************** ******@phx.gbl. ..

I'm going to have to beg forgiveness but I think you are missing something in your example. You have Dim b As
BitCoverter but I don't see b referenced anywhere else in the example. I think that is what i'm missing.

Thanks,

Dan
>-----Original Message-----
>This will do it.
>
>Dim b As BitConverter
>Dim test(5) As Byte
>
> test(0) = 72
> test(1) = 69
> test(2) = 76
> test(3) = 76
> test(4) = 79
>
>Dim str As String = Encoding.ASCII. GetString(test, 0,
test.Length)
>Debug.WriteLin e(str)
>
>
>"Dan" <an*******@disc ussions.microso ft.com> wrote in
message
>news:01******* *************** ******@phx.gbl. ..
>> Thanks for the reply. That seems to have me moving in >> the right direction. Can you recommend the most
>> efficient way to feed that information "into" an say
>> ASCII? So right now I dump the info to the console
and I
>> see:
>>
>> 00-34-00-00-00...
>>
>> I assume that is hex which each group representing one >> byte. I'm afraid that if i convert that data into a
>> string and then parse it out with a hex2decimal
function
>> and then feed it to ascii that will be too slow.
Thanks
>> again!
>>
>> Dan
>>
>>
>> >-----Original Message-----
>> >Try the BitConverter class. You can pack and unpack
>> bytes this way.
>>
>
>
>.
>

.

[Brian]

Here are the values of the first two pair of bytes when packed into a Int16.

Byte0 0
Byte1 1----------- = 256 (first 2 bytes)

Byte2 0
Byte3 24---------- = 6144(second 2 bytes)

"Dan" <an*******@disc ussions.microso ft.com> wrote in message
news:07******** *************** *****@phx.gbl.. .

BTW

When I am running my last bit of code:

Console.WriteLi ne(BitConverter .ToUInt16(bytDa ta, 0))

The result is 256. When I look at the watch window I see:

Byte0 0
Byte1 1
Byte2 0
Byte3 24
etc.

Dan

-----Original Message-----
That was a mistake, I just forgot to erase it. Here's a

clearer example:

'-- Declare your array
Dim temp() As Byte

'-- This is your recieved Integer (just a test)
Dim k As Integer = 311875

'-- Convert the Integer to a byte array
temp = BitConverter.Ge tBytes(k)

'-- Now, get the string representation
Dim str As String = Encoding.ASCII. GetString(temp, 0,

temp.Length)

Debug.WriteLin e(str)
<an*******@dis cussions.micros oft.com> wrote in message
news:02******* *************** ******@phx.gbl. ..

I'm going to have to beg forgiveness but I think you are missing something in your example. You have Dim b As
BitCoverter but I don't see b referenced anywhere else in the example. I think that is what i'm missing.

Thanks,

Dan
>-----Original Message-----
>This will do it.
>
>Dim b As BitConverter
>Dim test(5) As Byte
>
> test(0) = 72
> test(1) = 69
> test(2) = 76
> test(3) = 76
> test(4) = 79
>
>Dim str As String = Encoding.ASCII. GetString(test, 0,
test.Length)
>Debug.WriteLin e(str)
>
>
>"Dan" <an*******@disc ussions.microso ft.com> wrote in
message
>news:01******* *************** ******@phx.gbl. ..
>> Thanks for the reply. That seems to have me moving in >> the right direction. Can you recommend the most
>> efficient way to feed that information "into" an say
>> ASCII? So right now I dump the info to the console
and I
>> see:
>>
>> 00-34-00-00-00...
>>
>> I assume that is hex which each group representing one >> byte. I'm afraid that if i convert that data into a
>> string and then parse it out with a hex2decimal
function
>> and then feed it to ascii that will be too slow.
Thanks
>> again!
>>
>> Dan
>>
>>
>> >-----Original Message-----
>> >Try the BitConverter class. You can pack and unpack
>> bytes this way.
>>
>
>
>.
>

.

[Dan]

I see exactly what you are talking about with the bytes
and the values that I see when I convert to .ToInt16. I
am clearly misunderstandin g why though. The numbers 1
and 24 are the expected results. If I see this:

Byte0 0
Byte1 1----------- = 256 (using .ToInt16)

Byte2 0
Byte3 24---------- = 6144(using .ToInt16)

Then what type of operation is taking place, or needs to
take place to get the expected results of 1 and 24. If i
take the numbers that I get 256 and 6144 and do some math
I get:

Int(256/256) = 1
Int(6114/256) = 24

Is there some 'factor' that needs to be applied to get
the expected results after using .ToIntXX?

Thanks again!
Dan