Visual Basic

    Imports System.IO
    Imports System.Text
 
    Dim srcFile As New StreamReader("SourceFile.txt")
    Dim newFile As New StreamWriter("NewFile.txt")
    Dim inText As String
    Dim intLineCount As Integer = 1
 
    inText = srcFile.ReadLine()
    While Not inText Is Nothing
        If intLineCount <> 2 Then
            newFile.WriteLine(inText)
        Else
            newFile.WriteLine("New Text To Replace Line 2")
        End If
    End While
    srcFile.Close()
    newFile.Close()
 
    File.Delete("SourceFile.txt")
    File.Move("NewFile.txt", "SourceFile.txt")

<br />
Private Sub TextLineWriter(ByVal fileName As String, ByVal lineNumberToReplace As Integer, ByVal textToWrite As String)<br />
        Dim inFile As IO.StreamReader = IO.File.OpenText(fileName)<br />
        Dim tempString(-1) As String<br />
        Dim i As Byte<br />
<br />
        'read the file given and save each line into a new array element string<br />
        Do Until inFile.Peek = -1<br />
            ReDim Preserve tempString(tempString.Length)<br />
            tempString(tempString.Length - 1) = inFile.ReadLine<br />
        Loop<br />
        inFile.Close()<br />
<br />
        'determine if supplied 'numberToReplace' is valid with the current file,<br />
        'and correct the problem if so<br />
        If lineNumberToReplace - 1 > tempString.Length - 1 Then<br />
            lineNumberToReplace = tempString.Length<br />
        ElseIf lineNumberToReplace - 1 < 1 Then<br />
            lineNumberToReplace = 1<br />
        End If<br />
<br />
        'write the 'textToWrite' at the line number given<br />
        tempString(lineNumberToReplace - 1) = textToWrite<br />
<br />
        'create same file as given (overwriting it) and rewrite the entire file<br />
        Dim outFile As IO.StreamWriter = IO.File.CreateText(fileName)<br />
        For i = 0 To tempString.Length - 1<br />
            outFile.WriteLine(tempString(i))<br />
        Next<br />
        outFile.Close()<br />
    End Sub<br />