读取大文本文件VB6中的行数

Question

我有文件大小230MB的文件.我想计算该文件的行数.

我尝试过" Scripting.FileSystemOblect"但是内存不足.

请帮忙.

谢谢.

Answer 1

正常的Windows换行符是CRLF,因此您可以计算LF并在文件的最后一行之后没有一个的情况下将计数加1.

在真正的VB(即VB5,VB6等)中,您可以使用面向字节的String操作来加速许多任务.如果我们可以假设文本文件包含ANSI,那么这很快:

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

鉴于7,000,000行文件293MB,这里只需0.7秒.但请注意,我没有重新启动以确保在运行该测试时文件未被缓存.没有缓存(即重启后),我希望它只需要5倍.

转换为处理Unicode文本文件非常简单.只需用非B等效项替换B函数,确保将BUFSIZE设置为2的倍数,并搜索vbLf而不是ANSI LF字节.