Appending Text to a File in VB .NET

[joopdog]

I want to be able to append text in the middle of a text file instead of at the end. What the below code does it searches for the [BrandIcons1] line, then it should immediately append text directly below [BrandIcons1]. But it appends at the end of the file.

I’m using vb.net 2003. There’s gotta be a way to do this.

Here’s what I have so far:

Private Sub btnWriteToFile_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnWriteToFile.Click
        Dim oFile As System.IO.File
        Dim oRead As System.IO.StreamReader
        Dim oWrite As System.IO.StreamWriter
        Dim FILE_NAME As String = "C:\Program Files\WCS\Mobility\Config\mobility1.ini"
        Dim FILE_COPY As String = "C:\Program Files\WCS\Mobility\Config\mobility2.ini"
        Dim LineIn As String
 
        If oFile.Exists(FILE_NAME) = True Then
            oFile.Copy(FILE_NAME, FILE_COPY, True)
            '
            ' Open and read an exisiting file
            oRead = oFile.OpenText(FILE_NAME)
            While oRead.Peek <> -1
                LineIn = oRead.ReadLine()
                If LineIn = "[BrandIcons1]" Then
                    oRead.Close()
 
                    MsgBox(LineIn & " Found.")
                    ' Write to an existing file
                    oWrite = oFile.AppendText(FILE_NAME)
 
                    oWrite.WriteLine("[BrandIcons]")
                    oWrite.WriteLine("BE18=as1.bmp")
                    oWrite.WriteLine("BE01=bu4.bmp")
                    oWrite.WriteLine("BE02=")
                    oWrite.WriteLine("---------")
                    oWrite.Flush()
                    oWrite.Close()
                    Exit While
                End If
            End While
            MsgBox("Done!")
        Else
            MsgBox("File Does Not Exist: " & vbCrLf _
              & FILE_NAME)
        End If
        Me.Close() 'End the program and close the form
    End Sub

The file to append Mobility1.ini

[MOBILITY]
back drive=d
standard header 1=Digital Matrix, Inc.
standard header 2=Budweiser
standard header 3=Holiday, CA
Last Backup Drive=d
dBev Compatibility=F
Sell Items Not In Product List=T
Auto Lost Placement Enabled=F
Auto Lost Placement Days=365
Use IBS Interface=F
Use IBS For Survey=F
Use IBS For WEARS=F
IBS Application Path=
IBS Window Title=IBS
Expired License Popup Msg Enabled=T

[BrandIcons1]
<append text information here>

[TCOMM]
host name=w55511
host ip=192.168.1.2
host login=wcs
host password=qjris
RAS Entry=Mobility
RAS phone number=555-1212
RAS login=np
RAS password=nkfl
RAS timeout=120
max tcomm number=99

Any help would be appreciated.

[grilkip]

Hi joop (fellow dutchman?)

I think you only have two choices.

1> Read the entire file to memory and write it back to disk with the new text inserted.
2> Create a tempfile with the new text in it and then replace the original.

[jonwondering]

When you open text with .AppendText(), it doesn't matter where you are located. The function will open the file and move to the location at the very end. You can solve the problem grilkip's way:

Read in the file until you find whatever you need, then write the new information, and only then read in the rest of the original file.
Once you have this new file, you can write it back replacing the old one.

[joopdog]

Your idea worked!

You can see the above mobility.ini file. There are four sections to the file.
[MOBILITY]
[TCOMM]
[BrandIcons]
[Wears Item Ranges]

I needed to place the text information under [BrandIcons] and not disturb the other information of this file (mobility.ini).

I extracted each line of the file and placed them in an array. Then copied each line back into another file, followed by the text lines I needed to be inserted, and then continued on copying lines of the text file.

Here the code. It’s not a clean code, but it works:

Private Sub btnReadFileIntoMemory_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnReadFileIntoMemory.Click
        'http://www.builderau.com.au/program/windows/0,39024644,20267367,00.htm
        'http://www.seattlecentral.org/faculty/ymoh/mic110vb/sequential_file.htm
        '
        Dim oFile As System.IO.File
        Dim oRead As System.IO.StreamReader
        Dim oWrite As System.IO.StreamWriter
        Dim FILE_NAME As String = "C:\Program Files\WCS\Mobility\Config\mobility.ini"
        Dim FILE_COPY As String = "C:\Program Files\WCS\Mobility\Config\mobility2.ini"
        Dim FILE_BACK As String = "C:\Program Files\WCS\Mobility\Config\mobility3.txt"
        Dim strMobility(20) As String 'The lower bound is always 0 so this array contains 11 elements numbered 0 through 10. 
        Dim strTCOMM(15) As String
        Dim strWearsItem(10) As String
        Dim LineIn As String
        Dim intMobility As Integer, intTCOMM As Integer, intWearsItems As Integer
        Dim intCounter As Integer, i As Integer
        Dim intLineCounter As Integer
        '
        ' Backup the file
        oFile.Copy(FILE_NAME, FILE_BACK, True)
        'Create a COPY of the file to Append
        oWrite = oFile.CreateText(FILE_COPY)
        oWrite.Flush()
        oWrite.Close()
        ' Open and read an exisiting file
        '
        '-------------- [MOBILITY] -------------------- 
        oRead = oFile.OpenText(FILE_NAME)
        intLineCounter = 0
        ' Read each line of a TEXT file into memory
        While oRead.Peek <> -1
            LineIn = oRead.ReadLine()
            intCounter = intCounter + 1
            If LineIn = "[MOBILITY]" Then
                intLineCounter = intLineCounter + 1 ' Total number of line for [MOBILITY]
                strMobility(0) = LineIn
                For i = 1 To 20
                    intLineCounter = intLineCounter + 1
                    strMobility(i) = oRead.ReadLine()
                    If strMobility(i) = "" Then
                        Exit For
                    End If
                Next
            End If
        End While
        oRead.Close()
        intCounter = -1
        intLineCounter = intLineCounter - 3
        ' Write to an exisiting existing file
        oWrite = oFile.AppendText(FILE_COPY)
        Do While intCounter <= intLineCounter
            intCounter = intCounter + 1
            oWrite.WriteLine(strMobility(intCounter))
        Loop
        oWrite.WriteLine("")
        oWrite.Flush()
        oWrite.Close()
        '
        '-------------- [TCOMM] -------------------- 
        oRead = oFile.OpenText(FILE_NAME)
        intLineCounter = 0
        ' Read each line of a TEXT file into memory
        While oRead.Peek <> -1
            LineIn = oRead.ReadLine()
            intCounter = intCounter + 1
            If LineIn = "[TCOMM]" Then
                intLineCounter = intLineCounter + 1 ' Total number of line for [TCOMM]
                strTCOMM(0) = LineIn
                For i = 1 To 20
                    intLineCounter = intLineCounter + 1
                    strTCOMM(i) = oRead.ReadLine()
                    If strTCOMM(i) = "" Then
                        Exit For
                    End If
                Next
            End If
        End While
        oRead.Close()
        intCounter = -1
        intLineCounter = intLineCounter - 3
        ' Write to an exisiting existing file
        oWrite = oFile.AppendText(FILE_COPY)
        Do While intCounter <= intLineCounter
            intCounter = intCounter + 1
            oWrite.WriteLine(strTCOMM(intCounter))
        Loop
        oWrite.WriteLine("")
        oWrite.Flush()
        oWrite.Close()
        '
        '-------------- [BrandIcons] -------------------- 
        ' Write to an exisiting existing file
        ' <append text information here>
        oWrite = oFile.AppendText(FILE_COPY)
        oWrite.WriteLine("[BrandIcons]")
        oWrite.WriteLine("BE18=as1.bmp")
        oWrite.WriteLine("BE01=bu4.bmp")
        oWrite.WriteLine("BE02=")
        oWrite.WriteLine("")
        oWrite.Close()
        '
        '-------------- [Wears Item Ranges] -------------------- 
        oRead = oFile.OpenText(FILE_NAME)
        intLineCounter = 0
        ' Read each line of a TEXT file into memory
        While oRead.Peek <> -1
            LineIn = oRead.ReadLine()
            intCounter = intCounter + 1
            If LineIn = "[Wears Item Ranges]" Then
                intLineCounter = intLineCounter + 1 ' Total number of line for [WEARS]
                strWearsItem(0) = LineIn
                For i = 1 To 20
                    intLineCounter = intLineCounter + 1
                    strWearsItem(i) = oRead.ReadLine()
                    If strWearsItem(i) = "" Then
                        Exit For
                    End If
                Next
            End If
        End While
        oRead.Close()
        intCounter = -1
        intLineCounter = intLineCounter - 3
        ' Write to an exisiting existing file
        oWrite = oFile.AppendText(FILE_COPY)
        Do While intCounter <= intLineCounter
            intCounter = intCounter + 1
            oWrite.WriteLine(strWearsItem(intCounter))
        Loop
        oWrite.WriteLine("")
        oWrite.Flush()
        oWrite.Close()
        'Copy the file back to mobility.ini
        oFile.Copy(FILE_COPY, FILE_NAME, True)
        'DONE!
        MsgBox("Done!")
        ' not a clean code but it works.
    End Sub

Thanks for all your help.