Search a string from text file & Return the Line Number using VBA

I used a spin off of Me How's code example to go through a list of ~10,000 files searching for a string. Plus, since my html files have the potential to contain the string on several lines, and I wanted a staggered output, I changed it up a bit and added the cell insertion piece. I'm just learning, but this did exactly what I needed and I hope it can help others.

Public Sub ReadTxtFile()

    Dim start As Date
    start = Now

    Dim oFSO As Object
    Set oFSO = CreateObject("Scripting.FileSystemObject")

    Dim oFS As Object

    Dim filePath As String

    Dim a, b, c, d, e As Integer
    a = 2
    b = 2
    c = 3
    d = 2
    e = 1

    Dim arr() As String

    Do While Cells(d, e) <> vbNullString

            filePath = Cells(d, e)

            ReDim arr(5000) As String
            Dim i As Long
            i = 0

            If oFSO.FileExists(filePath) Then

                On Error GoTo Err

                Set oFS = oFSO.OpenTextFile(filePath)
                Do While Not oFS.AtEndOfStream
                    arr(i) = oFS.ReadLine
                    i = i + 1
                Loop
                oFS.Close
            Else
                MsgBox "The file path is invalid.", vbCritical, vbNullString
                Exit Sub
            End If

            For i = LBound(arr) To UBound(arr)
                If InStr(1, arr(i), "Clipboard", vbTextCompare) Then
                    Debug.Print i + 1, arr(i)
                    Cells(a + 1, b - 1).Select
                    Selection.Insert Shift:=xlDown
                    Cells(a, b).Value = i + 1
                    Cells(a, c).Value = arr(i)
                    a = a + 1
                    d = d + 1
                End If
            Next
            a = a + 1
            d = d + 1
    Loop

    Debug.Print DateDiff("s", start, Now)

    Exit Sub

Err:
    MsgBox "Error while reading the file.", vbCritical, vbNullString
    oFS.Close
    Exit Sub

End Sub

the following fragment could be repalaced like:

 Dim arr() As String
    Dim i As Long
    i = 0

    If oFSO.FileExists(filePath) Then

        On Error GoTo Err

        Set oFS = oFSO.OpenTextFile(filePath)
        Do While Not oFS.AtEndOfStream
        ReDim Preserve arr(0 To i)
            arr(i) = oFS.ReadLine                        'to save line's content to array
            'If Len(oFSfile.ReadLine) = 0 Then Exit Do   'to get number of lines only
            i = i + 1
        Loop
        oFS.Close
    Else
        MsgBox "The file path is invalid.", vbCritical, vbNullString
        Exit Sub
    End If

Here's another method that should work fairly quickly. It uses the shell to execute the FINDSTR command. If you find the cmd box flickers, do an internet search for how to disable it. There are two options provided: one will return the line number followed by a colon and the text of the line containing the keyword. The other will just return the line number.

Not sure what you want to do with the results, so I just have them in a message box.

Option Explicit
'Set reference to Windows Script Host Object Model
Sub FindStrings()
    Const FindStr As String = "Pune"
    Const FN As String = "C:\users\ron\desktop\LineNumTest.txt"
    Dim WSH As WshShell
    Dim StdOut As Object
    Dim S As String

Set WSH = New WshShell

Set StdOut = WSH.Exec("cmd /c findstr /N " & FindStr & Space(1) & FN).StdOut
Do Until StdOut.AtEndOfStream
    S = S & vbCrLf & StdOut.ReadLine
    'If you want ONLY the line number, then
    'S = S & vbCrLf & Split(StdOut.ReadLine, ":")(0)
Loop
S = Mid(S, 2)

MsgBox (S)

End Sub