text files

[Guest herewegoagain]

Hi all...

I am looking for an online tutorial or code sample that will allow me to edit a text file within a vb.net program. Such as if the line begins with "MBS" then that line would get deleted? Can anyone help?

[Volte]

Well, there is a basic tutorial on EliteVB about reading files. I suggest you read that tutorial,

as well as reading the MSDN that came with your VS.NET. Look

up StreamReader and StreamWriter to learn how to

read and write text files.

 

There are basically two ways to do what you want. You could either:

 

1) open two streams simultaneously (one reading your source file,

one writing to a temp file), and reading line-by-line through the

source file, while writing to the temp file if the line doesn't start

with 'MBS'

 

2) read the lines into an array, and just loop through the array and overwrite the file with no temp files needed.

 

The following code does the latter:

        'Open the file you want
       Dim sr As IO.StreamReader = New IO.StreamReader( _
                           New IO.FileStream("c:\somefile.txt", _
                                             IO.FileMode.Open))

       'Read in the entire file, close the file
       Dim strFile As String
       strFile = sr.ReadToEnd()
       sr.Close()

       'Split it into its individual lines
       Dim strSplit() As String
       strSplit = strFile.Split(ControlChars.Lf)

       'Open the file for writing, clearing it
       Dim sw As IO.StreamWriter = New IO.StreamWriter( _
                           New IO.FileStream("c:\somefile.txt", _
                           IO.FileMode.Create))

       'Set the newline character to a LineFeed alone (because
       'the CarriageReturn is left over from the old file)
       sw.NewLine = ControlChars.Lf

       'Loop through the array of lines and write to the
       'temp file -- if it starts with MBS, don't write
       Dim i As Integer
       For i = 0 To strSplit.GetUpperBound(0)
           If Not strSplit(i).StartsWith("MBS") Then
               sw.WriteLine(strSplit(i))
           End If
       Next

       'Close the file
       sw.Close()

[Guest herewegoagain]

Thank you and one more thing

 

Is it possible with this code where it says:

For i = 0 To strSplit.GetUpperBound(0)

If Not strSplit(i).StartsWith("MBS") Then

sw.WriteLine(strSplit(i))

End If

that it could also be if it starts with "MBS" and ends with "sbm"

[wyrd]

Of course, just replace

 

If Not strSplit(i).StartsWith("MBS") Then

 

with

 

If (Not strSplit(i).StartsWith("MBS")) Or (strSplit(i).StartsWith("MBS") And strSplit(i).EndsWith("sbm")) Then

[Guest herewegoagain]

This group rocks.....

 

Thank you......