Reading file as HEX

[vbNeo]

How do I read a file and get it's HEX values? Is it possible to get this in a string?

Cheers!

[ranma_at]

I m not sure what you re after, if you just need to convert text into string that `s easy.

Option Explicit   
 
Private m_InitHex as Boolean   
Private m_ByteToHex(0 To 255, 0 To 1) as Byte   
Private m_HexToByte(48 To 70, 48 To 70) as Byte   
 
Private Declare Sub FillMemory Lib "kernel32.dll" Alias "RtlFillMemory" (Destination as Any, ByVal Length as Long, ByVal Fill as Byte)   
 
Function HexToStr(HexText as String, Optional ByVal Separators as Long = 1) as String   
 
  Dim a as Long   
  Dim Pos as Long   
  Dim PosAdd as Long   
  Dim ByteSize as Long   
  Dim HexByte() as Byte   
  Dim ByteArray() as Byte   
 
  'Initialize the hex routine
  If (Not m_InitHex) Then Call InitHex   
 
  'The destination string is half
  'the size of the source string
  'when the separators are removed
  If (Len(HexText) = 2) Then   
    ByteSize = 1   
  Else   
    ByteSize = ((Len(HexText) + 1) \ (2 + Separators))   
  End If   
  ReDim ByteArray(0 To ByteSize - 1)   
 
  'Convert every HEX code to the
  'equivalent ASCII character
  PosAdd = 2 + Separators   
  HexByte() = StrConv(HexText, vbFromUnicode)   
  For a = 0 To (ByteSize - 1)   
    ByteArray(a) = m_HexToByte(HexByte(Pos), HexByte(Pos + 1))   
    Pos = Pos + PosAdd   
  Next   
 
  'Now finally convert the byte
  'array to the return string
  HexToStr = StrConv(ByteArray, vbUnicode)   
 
End Function   
Private Sub InitHex()   
 
  Dim a as Long   
  Dim b as Long   
  Dim HexBytes() as Byte   
  Dim HexString as String   
 
  'The routine is initialized
  m_InitHex = True   
 
  'Create a string with all hex values
  HexString = String$(512, "0")   
  For a = 1 To 255   
    Mid$(HexString, 1 + a * 2 + -(a < 16)) = Hex(a)   
  Next   
  HexBytes = StrConv(HexString, vbFromUnicode)   
 
  'Create the Str->Hex array
  For a = 0 To 255   
    m_ByteToHex(a, 0) = HexBytes(a * 2)   
    m_ByteToHex(a, 1) = HexBytes(a * 2 + 1)   
  Next   
 
  'Create the Str->Hex array
  For a = 0 To 255   
    m_HexToByte(m_ByteToHex(a, 0), m_ByteToHex(a, 1)) = a   
  Next   
 
End Sub   
Function StrToHex(text as String, Optional Separator as String = " ") as String   
 
  Dim a as Long   
  Dim Pos as Long   
  Dim Char as Byte   
  Dim PosAdd as Long   
  Dim ByteSize as Long   
  Dim ByteArray() as Byte   
  Dim ByteReturn() as Byte   
  Dim SeparatorLen as Long   
  Dim SeparatorChar as Byte   
 
  'Initialize the hex routine
  If (Not m_InitHex) Then Call InitHex   
 
  'Initialize variables
  SeparatorLen = Len(Separator)   
 
  'Create the destination bytearray, this
  'will be converted to a string later
  ByteSize = (Len(text) * 2 + (Len(text) - 1) * SeparatorLen)   
  ReDim ByteReturn(ByteSize - 1)   
  Call FillMemory(ByteReturn(0), ByteSize, Asc(Separator))   
 
  'We convert the source string into a
  'byte array to speed this up a tad
  ByteArray() = StrConv(text, vbFromUnicode)   
 
  'Now convert every character to
  'it's equivalent HEX code
  PosAdd = 2 + SeparatorLen   
  For a = 0 To (Len(text) - 1)   
    ByteReturn(Pos) = m_ByteToHex(ByteArray(a), 0)   
    ByteReturn(Pos + 1) = m_ByteToHex(ByteArray(a), 1)   
    Pos = Pos + PosAdd   
  Next   
 
  'Convert the bytearray to a string
  StrToHex = StrConv(ByteReturn(), vbUnicode)   
 
End Function

[phinds]

it's not clear what it is you want to do, but I'd suggest you check out the "binary" option in the open statement

[vbNeo]

What I need to do is extract a hex digit from a file(00 00 00 11), this digit changes from file to file, I do however have the address, which is 14(00 00 00 E0), so my idea was to convert it to a string, then parse it trhough... But I really can't get it to work - is there another, better way to do it ?

[Jacob Roman]

'This is a little dangerous cause this is one good step
'away to attatching a virus to the files.

Option Explicit

Dim Byte_Array() as Byte

Private Sub File_Disassemble(File_Path As String, Get_Bytes() As Byte)



'Tear apart the file by the byte!!!

Dim Current_Line As Long

Open File_Path For Binary Access Read As #1

While Not EOF(1)

ReDim Preserve Get_Bytes(Current_Line) As Byte

Get #1, , Get_Bytes(Current_Line)

Current_Line = Current_Line + 1

Wend

Close #1

End Sub

Private Sub File_Reassemble(File_Path As String, Set_Bytes() As Byte)

'Puts the file back together.
'Works on all file extentions, including exes!

Dim Current_Line As Long

Dim Byte_String As String

Open File_Path For Output As #1

For Current_Line = 0 To UBound(Set_Bytes) - 1

Byte_String = Byte_String & Chr(Set_Bytes(Current_Line))

Next Current_Line

Print #1, Byte_String

Close #1

End Sub

[Merri]

'in a module
Public Function GetByteFromFile(ByVal Filename As String, ByVal FilePosition As Long) As Byte
    Dim FileNumber As Byte, Temp As Byte
    FileNumber = FreeFile
    On Error Goto ErrorHandler
    Open Filename For Binary Access Read As #FileNumber
        Seek #FileNumber, FilePosition
        Get #FileNumber, , Temp
    Close #FileNumber
    GetByteFromFile = Temp
ErrorHandler:
End Function

Then you can use Hex$() to convert it to a hex. Also, I posted this code yesterday, it reads all the data in a file and shows it as hex (separated by spaces):

'in a module
Public Function OpenFileAsHex(ByVal Filename As String) As String
    Dim ReadBuffer() As Byte, ReturnBuffer() As Byte
    Dim FileNumber As Byte, A As Long, B As Long
    FileNumber = FreeFile
    'open file
    Open Filename For Binary Access Read As #FileNumber
        'prepare a read buffer
        ReDim Preserve ReadBuffer(LOF(FileNumber) - 1)
        'prepare a return buffer
        ReDim Preserve ReturnBuffer(LOF(FileNumber) * 3 - 1)
        'read all data
        Get #FileNumber, , ReadBuffer
    Close #FileNumber
    'convert numbers to 0 - F
    For A = 0 To UBound(ReturnBuffer) Step 3
        'divide by three (\ is faster than /)
        B = A \ 3
        '&H30 = 48, which is the character code for 0
        'the code before it rips the four upper bits (value will be 0 - 15)
        ReturnBuffer(A) = ((ReadBuffer(B) And &HF0) \ &H10) Or &H30
        'rip the four lower bits and and add 48
        ReturnBuffer(A + 1) = (ReadBuffer(B) And &HF) Or &H30
        'space character to divide the hex values from each other
        ReturnBuffer(A + 2) = &H20
        'then check if character code is bigger than the code for number 9
        'and add seven if it is so 10 will be A and 11 B and so on
        If ReturnBuffer(A) > 57 Then ReturnBuffer(A) = ReturnBuffer(A) + 7
        If ReturnBuffer(A + 1) > 57 Then ReturnBuffer(A + 1) = ReturnBuffer(A + 1) + 7
    Next A
    'convert to string
    OpenFileAsHex = StrConv(ReturnBuffer, vbUnicode)
End Function

Usage:

Text1.Text = OpenFileAsHex("c:\autoexec.bat")


If you want to get a specific hex from the string, you can look it with logic Mid$(Text1.Text, Position * 3, 2). The code is rather fast once you compile it

[Siu Yan]

I've asked a similar question a few days ago.

Take a look at

http://www.vbforums.com/showthread.p...ght=binary+hex

My one is to read a binary file and change into Hex code.

HTP

[Merri]

Heh, I replied the same topic and the code I have above is much faster

[VB Client/Server]

'in a module
Public Function GetByteFromFile(ByVal Filename As String, ByVal FilePosition As Long) As Byte
    Dim FileNumber As Byte, Temp As Byte
    FileNumber = FreeFile
    On Error Goto ErrorHandler
    Open Filename For Binary Access Read As #FileNumber
        Seek #FileNumber, FilePosition
        Get #FileNumber, , Temp
    Close #FileNumber
    GetByteFromFile = Temp
ErrorHandler:
End Function

Then you can use Hex$() to convert it to a hex. Also, I posted this code yesterday, it reads all the data in a file and shows it as hex (separated by spaces):

'in a module
Public Function OpenFileAsHex(ByVal Filename As String) As String
    Dim ReadBuffer() As Byte, ReturnBuffer() As Byte
    Dim FileNumber As Byte, A As Long, B As Long
    FileNumber = FreeFile
    'open file
    Open Filename For Binary Access Read As #FileNumber
        'prepare a read buffer
        ReDim Preserve ReadBuffer(LOF(FileNumber) - 1)
        'prepare a return buffer
        ReDim Preserve ReturnBuffer(LOF(FileNumber) * 3 - 1)
        'read all data
        Get #FileNumber, , ReadBuffer
    Close #FileNumber
    'convert numbers to 0 - F
    For A = 0 To UBound(ReturnBuffer) Step 3
        'divide by three (\ is faster than /)
        B = A \ 3
        '&H30 = 48, which is the character code for 0
        'the code before it rips the four upper bits (value will be 0 - 15)
        ReturnBuffer(A) = ((ReadBuffer(B) And &HF0) \ &H10) Or &H30
        'rip the four lower bits and and add 48
        ReturnBuffer(A + 1) = (ReadBuffer(B) And &HF) Or &H30
        'space character to divide the hex values from each other
        ReturnBuffer(A + 2) = &H20
        'then check if character code is bigger than the code for number 9
        'and add seven if it is so 10 will be A and 11 B and so on
        If ReturnBuffer(A) > 57 Then ReturnBuffer(A) = ReturnBuffer(A) + 7
        If ReturnBuffer(A + 1) > 57 Then ReturnBuffer(A + 1) = ReturnBuffer(A + 1) + 7
    Next A
    'convert to string
    OpenFileAsHex = StrConv(ReturnBuffer, vbUnicode)
End Function

Usage:

Text1.Text = OpenFileAsHex("c:\autoexec.bat")


If you want to get a specific hex from the string, you can look it with logic Mid$(Text1.Text, Position * 3, 2). The code is rather fast once you compile it

Great code
But, can U make it afther load hex file in text box, save it again to binary ???

Usage:

Text1.Text = SaveFileAsBinary("c:\autoexec.bat")

B.R
VB Client/Server

[randem]

It seems no one knows about conversions anymore. It's a shame it's not taught anymore...


All files are binary. Hex, Oct, ASCII and EBCIDIC are just different ways to display it and for a processor to operate on it.

[Merri]

It seems people don't know too well about variable datatypes either or how character sets work and so on. Pretty important stuff for any programmer to know, really, otherwise it is just playing around with some code and saying "you can't do that!" or "I can't do that!" without knowing what the final compiled code actually does.

In the end thing are pretty simple, but understanding how you can handle it is a bit more difficult.


Anyways, my tip is: if you want to handle something, store it in memory in the most basic form it can be. Only change it to something else (ie. hex string) if you want to display it to the user. And only do it when you display it, and you don't need to convert everything at once. Also, when user inputs something, convert it internally into the most basic form. Think as if you have information layers:

• Visual layer: information the user sees
• Visual <-> data layer: interaction (conversions) between internal data and what the user sees
• Data layer: the actual data in a format that is easy and fast for a computer to handle
• Data <-> file layer: interaction (conversions) between internal data and a file format being used
• File layer: the final file that contains the data (be it encrypted, compressed or as-is and whatever it actually contains)

This is how all professional programs are done. To my eye it seems some programmers try to read a file and then try to handle it "directly", without making it easy to handle for a computer. If it isn't easy to handle for a computer, how can a programmer handle it any better? And the same for visual data: what is on a window isn't necessary easy to handle internally, even if it is easy for a user to handle.

The big five: USER <-CONVERSION-> COMPUTER <-CONVERSION-> STORAGE


Kind of a rant I guess, but maybe atleast one person finds this useful

[VB Client/Server]

I agree with U Merri,
but I dont know how to load few kb of binary data in internal memory, goto
xx address, erase 12 bytes, put new 12 bytes and save file again as binary.
Since I can only see where are thouse 12 bytes (24 HEX) and also copy another (24 HEX), when I convert it to HEX.
I would be very greatfull if U show me how this can be done using only
few lines of code.

I have attach here 2kb binary file

please convert txt to bin

here is that file open with hex editor, already marked bytes need to be changed:

selected binary/hex data must be changed wit this data:

938690B56A43787384ADFCAF

Please help me solve this problem !

Public Function GetByteFromFile(ByVal Filename As String, ByVal FilePosition As Long) As Byte
    Dim FileNumber As Byte, Temp As Byte
    FileNumber = FreeFile
    On Error GoTo ErrorHandler
    Open Filename For Binary Access Read As #FileNumber
        Seek #FileNumber, FilePosition
        Get #FileNumber, , Temp
    Close #FileNumber
    GetByteFromFile = Temp
ErrorHandler:
End Function
Public Function OpenFileAsHex(ByVal Filename As String) As String
    Dim ReadBuffer() As Byte, ReturnBuffer() As Byte
    Dim FileNumber As Byte, A As Long, B As Long
    FileNumber = FreeFile
    'open file
    Open Filename For Binary Access Read As #FileNumber
        'prepare a read buffer
        ReDim Preserve ReadBuffer(LOF(FileNumber) - 1)
        'prepare a return buffer
        ReDim Preserve ReturnBuffer(LOF(FileNumber) * 3 - 1)
        'read all data
        Get #FileNumber, , ReadBuffer
    Close #FileNumber
    'convert numbers to 0 - F
    For A = 0 To UBound(ReturnBuffer) Step 3
        'divide by three (\ is faster than /)
        B = A \ 3
        '&H30 = 48, which is the character code for 0
        'the code before it rips the four upper bits (value will be 0 - 15)
        ReturnBuffer(A) = ((ReadBuffer(B) And &HF0) \ &H10) Or &H30
        'rip the four lower bits and and add 48
        ReturnBuffer(A + 1) = (ReadBuffer(B) And &HF) Or &H30
        'space character to divide the hex values from each other
        ReturnBuffer(A + 2) = &H20
        'then check if character code is bigger than the code for number 9
        'and add seven if it is so 10 will be A and 11 B and so on
        If ReturnBuffer(A) > 57 Then ReturnBuffer(A) = ReturnBuffer(A) + 7
        If ReturnBuffer(A + 1) > 57 Then ReturnBuffer(A + 1) = ReturnBuffer(A + 1) + 7
    Next A
    'convert to string
    OpenFileAsHex = StrConv(ReturnBuffer, vbUnicode)
End Function

Private Sub Form_Load()
On Error GoTo error
Text2.Text = OpenFileAsHex("c:\test.bin")
Dim sStr$
sStr = Text2.Text
sStr = Replace(sStr, " ", "")
Text2.Text = sStr
Exit Sub
error:
MsgBox "**** happens! Restart aplication and try again ! "
Exit Sub
End Sub

Private Sub Text1_Change()
On Error GoTo error
Dim sStr$
sStr = Text1.Text
sStr = Replace(sStr, " ", "")
Text1.Text = sStr
Exit Sub
error:
MsgBox "**** happens! Restart aplication and try again ! "
Exit Sub
End Sub

Private Sub Command4_Click()
Text2.SelStart = 10
    Text2.SelLength = 6
    Text2.SetFocus
  '  pause 2000
    'erasing selected text
    Text2.SelText = ""
    'copy text1 on place where is erased in text2
End Sub

so how to convert text2 to bin and save it to file?



B.R
VB Client/Server

I have solve my problem...

[vbNeo]

It seems people don't know too well about variable datatypes either or how character sets work and so on. Pretty important stuff for any programmer to know, really, otherwise it is just playing around with some code and saying "you can't do that!" or "I can't do that!" without knowing what the final compiled code actually does.

You really shouldn't judge the entire programming community just based on the users here at VBF .

I've learned a lot since I started using other languages than Visual Basic, and TBH, most of the people signed up at this forum are just like I was - I didn't have any idea about data types either, nor did I understand the principle of binary, and the way data is handled.

However, since I changed to Java(and later, C#), I've read a few books explaining a lot more than any tutorial could've, plus - I've grown.

So, it's true that most of the users here have no idea what a datatype actually is, or how data is handled by the computer - that doesn't mean they're dum, they just haven't found the right source of information yet.

To sum up; don't judge the entire programming community based on you're observations here at VBF .

Thanks for the replys! Although the question is somewhat obsolete as of 2004 .

[Merri]

Who said I talked about the entire programming community? That's quite a broad assumption But I won't go into this more than this; wrong thread, wrong forum.