how can i open 2 file?

let's say i have a .dat file and .hdr file .... i have to compare both of them .... how can i open both of them at the same time and then compare them ? do you think is it prossible? pls help me?

Are they the same format? You could check the size, which would be quick, but if it's binary on one file, and text on the other, you can't.

You can even use Windows Internal command fc. You should use Shell to execute this command.

The only condition here is that the files should be text files.

This is a quick and dirty FileCompare. It works with text and binary files as well.
Just call it with two valid filenames.
It reads both files consecutively into strings and compares them afterwards.

Code:

---

Private Function FileComp(File1 As String, File2 As String) As Boolean
  Dim s1$, s2$, f%
  f = FreeFile
  Open File1 For Binary As #f: s1 = Space$(LOF(f)): Get #f, , s1: Close f
  Open File2 For Binary As #f: s2 = Space$(LOF(f)): Get #f, , s2: Close f
  FreeFile f
  FileComp = s1 = s2
End Function

---

If you want to do some fancy comparing and keep both files open, the code would look like:

Code:

---

Private Function FileComp2(File1 As String, File2 As String) As Boolean
  Dim f1%, f2%
  f1 = FreeFile: Open File1 For Binary As #f1
  f2 = FreeFile: Open File2 For Binary As #f2
  'now both files are open to do your reading and comparing
  Close #f2: FreeFile f2
  Close #f1: FreeFile f1
End Function

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From an old project, fast and efficient, note that you may want to change the buffer size.

Note that this function just tell if the two files are differents. If you want to compare the datas and tells the difference or something, this code would be a good frame to start on:

Code:

---

Private Function filesAreDuplicate(strFile1 As String, strFile2 As String)

    ' Open both file and compare them
    Const BUFFERSIZE = 10240
    Dim file1 As Integer
    Dim file2 As Integer
    Dim lngRemaining1 As Long
    Dim lngRemaining2 As Long
    Dim lngRemaining As Long
    Dim bolFilesAreDuplicate As Boolean
    Dim bolFinish As Boolean
    Dim buffer1 As String
    Dim buffer2 As String
   
    buffer1 = Space$(BUFFERSIZE)
    buffer2 = Space$(BUFFERSIZE)
   
    file1 = FreeFile
    Open strFile1 For Binary Access Read As #file1
   
    file2 = FreeFile
    Open strFile2 For Binary Access Read As #file2
   
    lngRemaining1 = LOF(file1)
    lngRemaining2 = LOF(file2)
   
    If lngRemaining1 <> lngRemaining2 Then
        bolFilesAreDuplicate = False
    Else
        bolFilesAreDuplicate = True
    End If
   
    lngRemaining = lngRemaining1
   
    While bolFinish = False And bolFilesAreDuplicate = True And _
        EOF(file1) = False And EOF(file2) = False
       
        If lngRemaining < BUFFERSIZE Then
            buffer1 = Space$(lngRemaining)
            buffer2 = Space$(lngRemaining)
        End If
   
        Get #file1, , buffer1
        Get #file2, , buffer2
        DoEvents
       
        If buffer1 <> buffer2 Then
            bolFilesAreDuplicate = False
        End If
       
        lngRemaining = lngRemaining - Len(buffer1)
       
        If lngRemaining = 0 Then
            bolFinish = True
        End If
    Wend
 
    filesAreDuplicate = bolFilesAreDuplicate
   
    Close #file2
    Close #file1
   
End Function

---

JeffB

thank you... really appreciate it.....