Vb6: Need some help with a loop

Question

So I have a loop that's supposed to do three things, go through a text file line by line, the text file contains pathnames and filenames(C:\Folder\file1.txt) If the line contains a certain string, it then copies a file to that location, renames it to what it is named in the text file, and then replaces a string within the copied file(still with me?). If not it goes on to the next line. I thought this would be fairly straight forward but I doesn't seem to be working, I'm currently unable to even compile as I'm getting errors saying the loop's syntax is wrong. Any help would be appreciated, here's the entire function's code:

Private Sub Command2_Click()

Dim LineData As String 
Dim FileHandle As Integer


FileHandle = FreeFile
Open "C:\textfile.txt" For Input As #FileHandle

Do While Not EOF(FileHandle)
Line Input #FileHandle, LineData
If InStr(LineData, ".log") Then
FileCopy "C:\thefile.log",LineData
Open LineData For Input As #3
 #3 = Replace$(#3, "abc", "xyz")
Else
End If  
Loop
Close #FileHandle
Close #3






 MsgBox "Copy, Replace, Complete!"

End Sub

Thanks in Advance!

Answer 1

One problem I see is that you're opening filehandle, then #3, but you close them in the same order, and you should be closing #3, then filehandle.

What I see happening is that filehandle is opened, then it searches for a line that contains ".log", then it does something - so far, so good. However, it then opens #3, does something else, and then loops. It needs to close #3 when it's done with it.

Moving "Close #3" up 4 lines (to the next statement after the "#3 = Replace..." should do what you expect and should compile okay.

Answer 2

I don't believe

#3 = Replace$(#3, "abc", "xyz")

is valid. You will need to read the contents of that file in, preferable line by line (or some sensible chunk at a time), do your replacement, then write it back out to a new file. As you are copying the file anyway I would suggest reading it from the source location, and writing the new version to the location that the file would have been copied to anyway.

for example...

Private Sub Command2_Click()
 Dim LineData As String
 Dim FileHandle As Integer
 Dim sourceHandle as Integer
 Dim destHandle as Integer
 dim temp as string
 FileHandle = FreeFile
 Open "C:\textfile.txt" For Input As #FileHandle
 Do While Not EOF(FileHandle)
  Line Input #FileHandle, LineData
  If InStr(LineData, ".log") Then
   sourceHandle=FreeFile
   Open "C:\thefile.log" For Input as #sourceHandle
   destHandle=FreeFile
   Open LineData For Output as #destHandle
   Do while Not EOF(sourceHandle)
    Line Input #sourceHandle,temp
    temp=replace$(temp,"abc","xyz")
    Print #destHandle,temp
   Loop
   Close #destHandle
   Close #sourceHandle
  End If
 Loop
Close #FileHandle
MsgBox "Copy, Replace, Complete!"
End Sub

Sorry if there are any errors, this isn't tested as I don't have a VB IDE installed on this computer.

Answer 3

#3 = Replace$... is your problem line... fixing that and other stuff results in this:

Private Sub Command2_Click()
  Dim LineData As String
  Dim FileHandle As Integer
  Dim Buffer As String
  FileHandle = FreeFile
  Open "C:\thefile.log" For Binary Access Read As #FileHandle
  Buffer = Space(LOF(FileHandle))
  Get #FileHandle, , Buffer
  Buffer = Replace(Buffer, "abc", "xyz")
  Close #FileHandle
  FileHandle = FreeFile
  Open "C:\textfile.txt" For Input As #FileHandle
  Do Until EOF(FileHandle)
    Line Input #FileHandle, LineData
    If InStr(LineData, ".log") Then
      Open LineData For Output As #3
      Print #3, Buffer;
      Close #3
    End If
  Loop
  Close #FileHandle
  MsgBox "Copy, Replace, Complete!"
End Sub

If you prefer minimalism and short code you could go with this instead:

Private Sub Command2_Click()
  ''// This code requires a reference to Microsoft Scripting runtime (Project -> References)
  Dim FSO As New Scripting.FileSystemObject
  Dim Files() As String
  Dim File As String
  Dim Data As String
  Data = Replace(FSO.OpenTextFile("C:\thefile.log").ReadAll(), "abc", "xyz")
  Files = Split(FSO.OpenTextFile("C:\textfile.txt").ReadAll(), vbCrLf)
  For Each File In Files
    If InStr(File, ".log") > 0 Then FSO.CreateTextFile(File, True).Write Data
  Next
  MsgBox "Copy, Replace, Complete!"
End Sub

Answer 4

I'd like to suggest a different approach to you. I've done something like this except I knew before hand I was making a copy, and my method was to open the source and a new target (copy). I then read the source file line by line make the needed changes to the variable I read the line into before writing it back out to the copy. My files were never more than a couple of k and this was plenty quick enough and eliminates one of your loops. You would have to have a variable inside your loop to tell you what to rename the file to once done, or delete the file if you did not find the line you were looking for and do not need the copy.