Counting Records In Large Files The Easy Way
The other day I needed to be able to tell how many records were in some text files. In .NET, this seems pretty easy -- you can just read in the file and count the lines: Dim count = File.ReadAllLines(filename).Length But this can take a long time if the files are really big. And the files I was working with had millions of records. They also happened to be fixed length records. So all I had to do was find the total size of the file & the length of one record and then divide the former by the latter. Private Function GetRecordCount(filename As String) As Long Dim lineLength = File.ReadLines(filename).First().Length lineLength += 2 ' Add 2 bytes for CrLf Dim fi = New FileInfo(filename) Dim count As Long = fi.Length / lineLength Return count End Function;