[RESOLVED] how to get crc from zip

[doberman2002]

i have the code to open zip and se its contents but how do i check each file crc?
am not at home now so please share what you can thank you.

[LaVolpe]

Computing the crc for a file is a well-established algorithm. You can many examples on this site. While your aware from home, you may want to try this google search: crc file site:vbforums.com

[doberman2002]

Computing the crc for a file is a well-established algorithm. You can many examples on this site. While your aware from home, you may want to try this google search: crc file site:vbforums.com

thanks

[wqweto]

JFYI, the original cZipArchive class has a public CalcCrc32Array function that is based on libdeflate's crc32_slice4 implementation and I'm 99% sure this can beat any VB6 implementation in benchmarking (left 1% for if Olaf chimes in:-)).

cheers,
</wqw>

[dilettante]

If you make use of zlibwapi.dll you can get the CRC along with the Name (and other things if you really want them) of each item.

Here's a wrapper class for the purpose.



You'll need a version of zlibwapi.dll in the EXE folder, or somewhere along the paths in the PATH environment variable, or a path spelled out in a manifest, etc. Somewhere that the DLL search can find it.

[Wolfgang Enzinger]

The easiest way that I'm aware of is described here.

Wolfgang

[doberman2002]

If you make use of zlibwapi.dll you can get the CRC along with the Name (and other things if you really want them) of each item.

Here's a wrapper class for the purpose.



You'll need a version of zlibwapi.dll in the EXE folder, or somewhere along the paths in the PATH environment variable, or a path spelled out in a manifest, etc. Somewhere that the DLL search can find it.

thank you so much.

[xiaoyao]

If you make use of zlibwapi.dll you can get the CRC along with the Name (and other things if you really want them) of each item.

Here's a wrapper class for the purpose.



You'll need a version of zlibwapi.dll in the EXE folder, or somewhere along the paths in the PATH environment variable, or a path spelled out in a manifest, etc. Somewhere that the DLL search can find it.

how to get file byte from DLL API?

LIKE THIS?
How to unpack a ZIP file using the library zlibwapi.dll ?-VBForums
https://www.vbforums.com/showthread....y-zlibwapi-dll

Sub GetFileList(FileList() As String) 
    Dim crc As Long
    Dim Path As String
    Dim Listc As New Collection
    FirstFile Path, crc
    Do While Len(Path)
        Listc.Add Path
        NextFile Path, crc
    Loop
    If Listc.Count > 0 Then
        ReDim FileList(Listc.Count - 1)
        Dim v
        Dim ID As Long
         ID = 0
        For Each v In Listc
            FileList(ID) = v
            ID = ID + 1
        Next
    Else
        ReDim FileList(-1 To -1)
    End If
End Sub

[HackerVlad]

Option Explicit
Private Declare Function RtlComputeCrc32 Lib "ntdll.dll" (ByVal dwInitial As Long, ByVal pData As Long, ByVal iLen As Long) As Long

Private Function Crc32Api(tBuff() As Byte) As Long
    Crc32Api = RtlComputeCrc32(0, VarPtr(tBuff(0)), UBound(tBuff) + 1)
End Function