Read Number of lines in Large Text File VB6

Question

I have text File of Size 230MB. I want to Count Number of Lines OF that File.

I tried \"Scripting.FileSystemOblect\" but it goes out Of

Answer 1

Normal Windows line breaks are CRLF, so you can count the LFs and add 1 to the count in cases where the last line of your files doesn't have one after it.

In true VB (i.e. VB5, VB6, etc.) you can make use of the byte-oriented String operations to speed many tasks. If we can assume the text files contain ANSI then this is pretty fast:

Option Explicit

Private Sub Main()
    Const BUFSIZE As Long = 100000
    Dim T0 As Single
    Dim LfAnsi As String
    Dim F As Integer
    Dim FileBytes As Long
    Dim BytesLeft As Long
    Dim Buffer() As Byte
    Dim strBuffer As String
    Dim BufPos As Long
    Dim LineCount As Long

    T0 = Timer()
    LfAnsi = StrConv(vbLf, vbFromUnicode)
    F = FreeFile(0)
    Open "big.txt" For Binary Access Read As #F
    FileBytes = LOF(F)
    ReDim Buffer(BUFSIZE - 1)
    BytesLeft = FileBytes
    Do Until BytesLeft = 0
        If BufPos = 0 Then
            If BytesLeft < BUFSIZE Then ReDim Buffer(BytesLeft - 1)
            Get #F, , Buffer
            strBuffer = Buffer 'Binary copy of bytes.
            BytesLeft = BytesLeft - LenB(strBuffer)
            BufPos = 1
        End If
        Do Until BufPos = 0
            BufPos = InStrB(BufPos, strBuffer, LfAnsi)
            If BufPos > 0 Then
                LineCount = LineCount + 1
                BufPos = BufPos + 1
            End If
        Loop
    Loop
    Close #F
    'Add 1 to LineCount if last line of your files do not
    'have a trailing CrLf.
    MsgBox "Counted " & Format$(LineCount, "#,##0") & " lines in" & vbNewLine _
         & Format$(FileBytes, "#,##0") & " bytes of text." & vbNewLine _
         & Format$(Timer() - T0, "0.0#") & " seconds."
End Sub

Given a 7,000,000 line file of 293MB it only takes 0.7 seconds here. But note that I had not rebooted to ensure that the file wasn't cached when I ran that test. Without caching (i.e. after a reboot) I'd expect it to take as long as 5 times that.

Converting to handle Unicode text files is fairly simple. Just replace the B-functions by the non-B equivalents, make sure you set BUFSIZE to a multiple of 2, and search for vbLf instead of an ANSI LF byte.