[RESOLVED] Delete data from end of file

[Bohlas_DuBhunkus]

Hello

I have JPG images with data stored at the end of them. My goal is to simply remove this data from the end of the file. The extra data is in plain text. The JPG images can still be viewed as normal with this data in them.

The plain text in the end of the file starts with the beginning mark of
"--------data---------", a line break, and then the data. Then there is
the end mark of the string
"-------enddata-------"

How can I remove all of this this data without destroying the file? Is there a way to do it without completely copying the file?

[Pradeep1210]

I think something like this should do:

Dim FileData As String
FileData = IO.File.ReadAllText("C:\myfile.jpg")
If FileData.Contains("--------data---------") Then
    FileData = FileData.Substring(FileData.IndexOf("--------data---------"))
End If
IO.File.WriteAllText("C:\myfile1.jpg", FileData)

[Bohlas_DuBhunkus]

Thanks for the reply, but it doesn't do what I need.

While your post successfully replaces the JPG with just the text, I was looking to delete the text from the JPG while preserving the JPG data in the file. My biggest issue is that the data somehow changes in the process leaving a unusable JPG file.

Any more tips would be great!

[Pradeep1210]

Thanks for the reply, but it doesn't do what I need.

While your post successfully replaces the JPG with just the text, I was looking to delete the text from the JPG while preserving the JPG data in the file. My biggest issue is that the data somehow changes in the process leaving a unusable JPG file.

Any more tips would be great!

If you remove that text using notepad (or any other text editor), does it work?

[Bohlas_DuBhunkus]

No. Using notepad and saving somehow kills the file.

I figured out how to get what I need done. Heres the code. Thanks to the original author of the byte/string conversion functions.

Public Sub DeleteINFO(ByVal InputtedFileName As String)
' Sepp is the ---------metadatastart---------- string (simply run through the string to byte array function
        Dim Sepp As String = "45,45,45,45,45,45,45,45,45,45,109,101,116,97,100,97,116,97,115,116,97,114,116,45,45,45,45,45,45,45,45,45,45,45"
        Dim EntireFileBytes() As Byte = My.Computer.FileSystem.ReadAllBytes(InputtedFileName)
        Dim EntireFileText As String = ArrayToString(EntireFileBytes)
 
            EntireFileText = Strings.Left(EntireFileText, InStr(EntireFileText, Sepp))
            My.Computer.FileSystem.WriteAllBytes(InputtedFileName, StringToArray(EntireFileText), False)
 
    End Sub
 
'--------------------------------------------------------------
' byte array to string, and string to byte array functions
    Private Shared Function ArrayToString(ByVal bytes() As Byte, Optional ByVal format As String = Nothing) As String
        If bytes.Length = 0 Then Return String.Empty
        Dim sb As New System.Text.StringBuilder(bytes.Length * 4)
        For Each b As Byte In bytes
            sb.Append(b.ToString)
            sb.Append(",")
        Next
        sb.Length -= 1
        Return sb.ToString()
    End Function
 
    Private Shared Function StringToArray(ByVal s As String, Optional ByVal style As System.Globalization.NumberStyles = Nothing) As Byte()
        If s.Length = 0 Then Return New Byte() {}
        Dim values() As String = s.Split(","c)
        Dim bytes(values.Length - 1) As Byte
        For index As Integer = 0 To values.Length - 1
            bytes(index) = Byte.Parse(values(index), style)
        Next
        Return bytes
    End Function