File Content Search

[amolt]

Hi all,

expecting some ideas to create an application which search for the contents in a file.
Microsoft Windows Search 4.0 or the Search included in Windows 7 does the same.
I have already implemented the Windows Search so I am not looking for the Windows Search implementation.
Any way to create a program using VB6.0 ?

[SamOscarBrown]

Once you open your file, use instr() function

[SamOscarBrown]

Here's a quick example to find the FIRST occurrence of a string within a text file. You can modify to find more occurrences easily.

Private Sub Command6_Click()
Dim mySearchText As String, x As Integer
 Dim fnum As Integer, myFileContents As String
 mySearchText = "Fred"
    fnum = FreeFile
    Open App.Path & "\test.txt" For Input As fnum
    myFileContents = Input(LOF(fnum), fnum)
    Close fnum
    x = InStr(1, myFileContents, mySearchText)
    If x > 0 Then
        MsgBox Mid(myFileContents, x, Len(mySearchText))
    End If
End Sub

[DataMiser]

If what you are asking is how to search through a lot of files and folders of files then you should be aware that using something like Instr() on each file will be extremely slow compared to windows search which uses indexing.

[fafalone]

I'd recommend the file search class from this:

http://leandroascierto.com/blog/clase-para-buscar/

The function it uses to search files seems pretty quick; it uses API and byte arrays... much faster than user regular vb instr code. And it will work with large files.

If you can get past the language barrier, there's some truly amazing code on that site. vbAccelerator level stuff using simple class modules instead of nightmarish user control active x crap.

Private Function FindWordInFile(ByVal sPath As String, ByVal sWord As String, Optional ByVal bUnicode As Boolean) As Boolean
    Dim bArray() As Byte
    Dim lRet As Long
    Dim hFile As Long
    Dim sFind() As Byte
    Dim s As String
    Dim t As Long
    Dim i As Long
    Dim FileSize As Currency
    Dim tLI As LARGE_INTEGER
    Dim LenBuffer As Long
    Dim CurPos As Currency

    sWord = UCase(sWord)
    If bUnicode Then sWord = StrConv(sWord, vbUnicode)
    sFind = StrConv(sWord, vbFromUnicode)

    hFile = CreateFile(sPath, GENERIC_READ, FILE_SHARE_READ, ByVal 0&, OPEN_EXISTING, 0, 0)
    
    If hFile <> INVALID_HANDLE_VALUE Then
    
        
        tLI.LowPart = GetFileSize(hFile, tLI.HighPart)
    
        LenBuffer = &H2800 ' 10 KB
    
        FileSize = LargeIntToCurrency(tLI.LowPart, tLI.HighPart)
        
        If FileSize < UBound(sFind) Then GoTo OutSearch
    
        If LenBuffer > FileSize Then LenBuffer = FileSize
    
        ReDim bArray(LenBuffer - 1)
 
        Do
            ReadFile hFile, bArray(0), UBound(bArray) + 1, lRet, 0&
            
            If lRet = 0 Then Exit Do
            
            CurPos = CurPos + lRet

            If lRet < LenBuffer Then
                ReDim Preserve bArray(lRet)
            End If

            If InBytes(bArray, sFind) <> -1 Then
                FindWordInFile = True
                Exit Do
            End If
            
            If CurPos = FileSize Then Exit Do
            
            tLI = CurrencyToLargeInt(CurPos - UBound(sFind) + 1)
            
            SetFilePointer hFile, tLI.LowPart, tLI.HighPart, FILE_BEGIN
                        
            If c_bCancel Then GoTo OutSearch
        Loop
        
OutSearch:
        
        CloseHandle hFile

    End If
End Function


Private Function InBytes(ByRef bvSource() As Byte, ByRef bvMatch() As Byte) As Long

    Dim i       As Long
    Dim j       As Long
    Dim lChr    As Byte
    Dim LenMach As Long
 
    LenMach = UBound(bvMatch)
    
    lChr = bvMatch(0)
    
    If LenMach > 0 Then
    
        For i = 0 To UBound(bvSource) - LenMach
      
            If (lChr = aUChars(bvSource(i))) Then

                j = LenMach - 1
    
                Do
                    If bvMatch(j) <> aUChars(bvSource(i + j)) Then GoTo NotEqual
                    j = j - 1
                Loop While j
                
                InBytes = i
                
                Exit Function
    
            End If
NotEqual:
        
        Next
    
    Else
        For i = 0 To UBound(bvSource)
            If (lChr = aUChars(bvSource(i))) Then
                InBytes = i
                Exit Function
            End If
        Next
    End If

    InBytes = -1
End Function

[amolt]

Hi to all,
Thanks for the replies.

Sam, yes it is easy to look with InStr within a single file or few bunch of files as well if the file size also comparatively less.
As DataMiser got the point the InStr will be extremely slow in the case of lot of files in a folder or folders.

As Windows Search uses indexing of files and look for a string in to it.
The basic problem of using Windows Search as facing is it can not index the mapped drives path or a URL path.
As in the case of a reporting application where we need to provide a string search in report contents and display the resultant files.
Here if the report creation path is not local or placed on NAS or any other shared folder on other server, then it is quite impossible to use Windows Search for such locations.
So rather than implementing the Windows Search I am thinking to develop some application which follows some Windows Search techniques like creating Indexes or may be anyother way where we can search on any given path.

[amolt]

#fafalone a great link you given. Thanks to you.
Will trying to work around with it.

Any ideas, for creating the index of files.

[fafalone]

I didn't think Windows Search indexed the content of the files? Not sure how you would do that without just copying it.

[amolt]

Windows Search indexed locations are configured from control panel item "IndexingOptions" if you are using Windows 7 u can see it there. For WinXP systems we need to install Windows Search 4.0