GetCRC

Dim RealCRC As String * 8
  RealCRC = CStr(Hex$(GetCrc32(lCrc32Value)))
 
 'This is to just infom you that your crc has been generated. 
 'you can remove this msgbox
  MsgBox "This is the CRC32 that was generated for the file " _
  & "you askd for: " & RealCRC, vbInformation, "CRC Completed"
 'end of msgbox
    
  GetCRCforFile = RealCRC
  Exit Function
Err:
  MsgBox "An error has been Reported by GOP CRC Wizard v1.00" _
  & vbCrLf & vbCrLf & _
  "Message Generated By : Function GetCRCforFile()", _
   vbCritical, "GOP CRC Wizard v1.00"
End Function

Option Explicit
 Option Compare Text
 '// Then declare this array variable Crc32Table
  Private Crc32Table(255) As Long
 '// Then all we have to do is writing public functions like these...

Public Function InitCrc32(Optional ByVal Seed As Long = _
       &HEDB88320, Optional ByVal Precondition As Long = _
       &HFFFFFFFF) As Long
 '// Declare counter variable iBytes, counter variable iBits, 
 'value variables lCrc32 and lTempCrc32
  Dim iBytes As Integer, iBits As Integer, lCrc32 As Long, _
      lTempCrc32 As Long
 '// Turn on error trapping
  On Error Resume Next
 '// Iterate 256 times
  For iBytes = 0 To 255
     '// Initiate lCrc32 to counter variable
      lCrc32 = iBytes
     '// Now iterate through each bit in counter byte
      For iBits = 0 To 7
         '// Right shift unsigned long 1 bit
          lTempCrc32 = lCrc32 And &HFFFFFFFE
          lTempCrc32 = lTempCrc32 \ &H2
          lTempCrc32 = lTempCrc32 And &H7FFFFFFF
         '// Now check if temporary is less than zero and then
         'mix Crc32 checksum with Seed Value
          If (lCrc32 And &H1) <> 0 Then
             lCrc32 = lTempCrc32 Xor Seed
          Else
             lCrc32 = lTempCrc32
          End If
       Next
      '// Put Crc32 checksum value in the holding array
       Crc32Table(iBytes) = lCrc32
    Next
   '// After this is done, set function value to the 
   'precondition value
    InitCrc32 = Precondition
End Function

'// The function above is the initializing function, now we 
 'have to write the computation function

Public Function AddCrc32(ByVal Item As String, _
       ByVal CRC32 As Long) As Long
 '// Declare following variables
  Dim bCharValue As Byte, iCounter As Integer, lIndex As Long
  Dim lAccValue As Long, lTableValue As Long
 '// Turn on error trapping
  On Error Resume Next
 '// Iterate through the string that is to be 
 'checksum-computed
  For iCounter = 1 To Len(Item)
     '// Get ASCII value for the current character
      bCharValue = Asc(Mid$(Item, iCounter, 1))
     '// Right shift an Unsigned Long 8 bits
      lAccValue = CRC32 And &HFFFFFF00
      lAccValue = lAccValue \ &H100
      lAccValue = lAccValue And &HFFFFFF
     '// Now select the right adding value from the holding table
      lIndex = CRC32 And &HFF
      lIndex = lIndex Xor bCharValue
      lTableValue = Crc32Table(lIndex)
     '// Then mix new Crc32 value with previous accumulated Crc32 value
      CRC32 = lAccValue Xor lTableValue
  Next
 '// Set function value the the new Crc32 checksum
  AddCrc32 = CRC32
End Function

'// At last, we have to write a function so that we can get 
 'the Crc32 checksum value at any time

Public Function GetCrc32(ByVal CRC32 As Long) As Long
 '// Turn on error trapping
  On Error Resume Next
 '// Set function to the current Crc32 value
  GetCrc32 = CRC32 Xor &HFFFFFFFF
End Function

'// To Test the Routines Above...

Public Function Compute(ToGet As String) As String
    Dim lCrc32Value As Long
    On Error Resume Next
    lCrc32Value = InitCrc32()
    lCrc32Value = AddCrc32(ToGet, lCrc32Value)
    Compute = Hex$(GetCrc32(lCrc32Value))
End Function

'Example  :   
'mvarFILECRC = GetCRCforFile("c:\myapppath\myapp.exe")

Just add CRCfile.bas into your project and run the function 
as described and your set!!!

This is a CRC32 generator for a file inputted. 
it is easy to use and the funtion's use it like this:

Example  :   
mvarFILECRC = GetCRCforFile("c:\myapppath\myapp.exe")

Code generated by GOP and function used from Append 
CRC32 to end of file by Detonate

Public Function GetCRCforFile(TheFile As String) As String
On Error GoTo Err:
'you must speify the complete file and directory

'the file is in.

Dim lCrc32Value As Long
Dim CRCStr As String * 8
Dim FL As Long 'file length
On Error Resume Next
Dim FileStr$
FL = FileLen(TheFile)
FileStr$ = String(FL, 0)

Open TheFile For Binary As #1
Get #1, 1, FileStr$
Close #1

lCrc32Value = InitCrc32()
lCrc32Value = AddCrc32(FileStr$, lCrc32Value)

Dim RealCRC As String * 8
RealCRC = CStr(Hex$(GetCrc32(lCrc32Value)))

'This is to just infom you that your crc has been generated.

'you can remove this msgbox

MsgBox "This is the CRC32 that was generated for the file " _
& "you askd for: " & RealCRC, vbInformation, "CRC Completed"
'end of msgbox

GetCRCforFile = RealCRC
Exit Function
Err:
MsgBox "An error has been Reported by GOP CRC Wizard v1.00" _
& vbCrLf & vbCrLf & _
"Message Generated By : Function GetCRCforFile()", _
vbCritical, "GOP CRC Wizard v1.00"
End Function

Option Explicit
Option Compare Text
'// Then declare this array variable Crc32Table

Private Crc32Table(255) As Long
'// Then all we have to do is writing public functions like these...

Public Function InitCrc32(Optional ByVal Seed As Long = _
&HEDB88320, Optional ByVal Precondition As Long = _
&HFFFFFFFF) As Long
'// Declare counter variable iBytes, counter variable iBits,

'value variables lCrc32 and lTempCrc32

Dim iBytes As Integer, iBits As Integer, lCrc32 As Long, _
lTempCrc32 As Long
'// Turn on error trapping

On Error Resume Next
'// Iterate 256 times

For iBytes = 0 To 255
'// Initiate lCrc32 to counter variable

lCrc32 = iBytes
'// Now iterate through each bit in counter byte

For iBits = 0 To 7
'// Right shift unsigned long 1 bit

lTempCrc32 = lCrc32 And &HFFFFFFFE
lTempCrc32 = lTempCrc32 \ &H2
lTempCrc32 = lTempCrc32 And &H7FFFFFFF
'// Now check if temporary is less than zero and then

'mix Crc32 checksum with Seed Value

If (lCrc32 And &H1) <> 0 Then
lCrc32 = lTempCrc32 Xor Seed
Else
lCrc32 = lTempCrc32
End If
Next
'// Put Crc32 checksum value in the holding array

Crc32Table(iBytes) = lCrc32
Next
'// After this is done, set function value to the

'precondition value

InitCrc32 = Precondition
End Function

'// The function above is the initializing function, now we

'have to write the computation function

Public Function AddCrc32(ByVal Item As String, _
ByVal CRC32 As Long) As Long
'// Declare following variables

Dim bCharValue As Byte, iCounter As Integer, lIndex As Long
Dim lAccValue As Long, lTableValue As Long
'// Turn on error trapping

On Error Resume Next
'// Iterate through the string that is to be

'checksum-computed

For iCounter = 1 To Len(Item)
'// Get ASCII value for the current character

bCharValue = Asc(Mid$(Item, iCounter, 1))
'// Right shift an Unsigned Long 8 bits

lAccValue = CRC32 And &HFFFFFF00
lAccValue = lAccValue \ &H100
lAccValue = lAccValue And &HFFFFFF
'// Now select the right adding value from the holding table

lIndex = CRC32 And &HFF
lIndex = lIndex Xor bCharValue
lTableValue = Crc32Table(lIndex)
'// Then mix new Crc32 value with previous accumulated Crc32 value

CRC32 = lAccValue Xor lTableValue
Next
'// Set function value the the new Crc32 checksum

AddCrc32 = CRC32
End Function

'// At last, we have to write a function so that we can get

'the Crc32 checksum value at any time

Public Function GetCrc32(ByVal CRC32 As Long) As Long
'// Turn on error trapping

On Error Resume Next
'// Set function to the current Crc32 value

GetCrc32 = CRC32 Xor &HFFFFFFFF
End Function

'// To Test the Routines Above...

Public Function Compute(ToGet As String) As String
Dim lCrc32Value As Long
On Error Resume Next
lCrc32Value = InitCrc32()
lCrc32Value = AddCrc32(ToGet, lCrc32Value)
Compute = Hex$(GetCrc32(lCrc32Value))
End Function

'Example :

'mvarFILECRC = GetCRCforFile("c:\myapppath\myapp.exe")

Just add CRCfile.bas into your project and run the function
as described and your set!!!

This is a CRC32 generator for a file inputted.
it is easy to use and the funtion's use it like this:

Example :
mvarFILECRC = GetCRCforFile("c:\myapppath\myapp.exe")

Code generated by GOP and function used from Append
CRC32 to end of file by Detonate