Exe File encoding - http via vb.net

[Dave Kreskowiak]

Umm... There is NO encoding for any binary file. Encoding means "interpet the bytes as this", which will change how the bytes are interpreted, changing them when read. You absolutely do NOT want to change a single byte. You should be just sending the bytes, not creating a string out of them.

Asking questions is a skill CodeProject Forum Guidelines Google: C# How to debug code Seriously, go read these articles.
Dave Kreskowiak

[Lost User]

Dim MyString As String = Encoding.UTF8.GetString(bytes)

You just destroyed the content of the file. Any file that is non-text based is pure binary and should only be read and written as such.

[Lost User]

Bart van Tuijl wrote:

Dim MyString As String = Encoding.UTF8.GetString(bytes)

No, apply them bytes? That's what Dave says and he is right. Bytes are that. No encoding. Write them bytes directly.

Bastard Programmer from Hell :suss: "If you just follow the bacon Eddy, wherever it leads you, then you won't have to think about politics." -- Some Bell.

[Bart van Tuijl]

Okay I get how that should work. I'm not all to sure on how to achieve this and I've given it a shot but it dosn't work as expected all the downloaded file now says when opened in notepad is 77 Here's my attempt.

                With My404HtmlPage

                    .Append("HTTP/1.1 200 OK" & Environment.NewLine)
                    .Append("Content-Type:  application/octet-stream" & Environment.NewLine)
                    .Append("Content-Disposition: attachment; filename=" & Chr(34) & "Bilandted.exe" & Chr(34) & Environment.NewLine)
                    .Append(Environment.NewLine)

                    Dim array() As Byte = File.ReadAllBytes("C:\\Test\\TestFile.exe")
                    Using memory As MemoryStream = New MemoryStream(array)
                        Using reader As BinaryReader = New BinaryReader(memory)
                            .Append((reader.ReadByte()))
                        End Using
                    End Using

End With

Im thinking I need to do something with the byte length but have now landed outside of my field of knowledge?

[Richard Deeming]

What type is your My404HtmlPage variable? Hopefully, it should support writing more than one byte at a time... If not, you'll need to loop over the bytes and copy them all to the output one by one. NB: There's no need for the MemoryStream and BinaryReader, since you already have an array of the bytes you need to send.

Dim array() As Byte = File.ReadAllBytes("C:\Test\TestFile.exe")
For i As Integer = 0 To array.Length - 1
.Append(array(i))
Next

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"These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

[Bart van Tuijl]

There is indeed a lot of data now in the downloaded file but its still all in numbers (It dosent look like binary too me but more like decimal without the hyphens) what am I missing here I'm assuming that the browser would know how to handle this data and reproduce a valid file from it (perhaps I'm wrong)? also to answer the type of variable for My404HtmlPage is

Dim My404HtmlPage As New System.Text.StringBuilder()

which then is passed on to a variable named MyHtmlServerResponse as follows

MyHtmlServerResponse = (My404HtmlPage.ToString)

MyHtmlServerResponse is a string variable as can be seen below

Dim MyHtmlServerResponse As String

EDIT: Just as extra Info the actual sending is done through TCP/ IP as follows

For Each c As TcpClient In MyClientList

            If c Is MyClient Then
                Dim nns As NetworkStream = c.GetStream()
                nns.Write(Encoding.ASCII.GetBytes(MyHtmlServerResponse), 0, MyHtmlServerResponse.Length)

                MyClient.Dispose()

            End If

[jschell]

Bart van Tuijl wrote:

I'm in the process of building a HTML server using vb.ne

Reading through this and your other posts. You need to come to a full stop on your code and first learn how http and the browser works. And additionally what a 'binary' file is. ------------------------------------------ Binary file - if is an executable and you open it in notepad will always look like you found. Does not matter where it came from. Notepad takes data and then transforms it in to characters. That can only work if the data is in fact characters. A binary, especially an executable will never consist solely of characters. So of course notepad will never display it because it cannot. Notepad displays a '?' for data that is not actually characters. Some (most) executables will have data in them that you will be able to read. Doesn't mean the rest is wrong just that an executable has text in it. And all of that depends on what character set notepad expects to see (I suspect you might want to research that also.) You can experiment with this by using notepad to open various files on your computer. I suggest 1. Executable 2. Image file 3. Write your own program, put text in it (a string), compile it, then open that. Do NOT save anything in Notepad to those above files. Unless you want to destroy them (try it if you wish but only if you expect to lose it.) If you really want to modify a binary file manually then you need to find a 'hex editor'. If you want to do that then you will need to learn what 'hex' means. ------------------------------------------ A browser sends a request to a web server and the web server then responds to that request. You should learn about the HTTP protocol. Your browser will have a 'developer tool' which allows you to inspect both requests and responses. The HTTP protocol itself does not support file downloads in anyway. A specific request might result in some content which originates from files being downloaded. 1. A html response (from a request) might have tags in it which the browser which will then use to make another request to the web server, and the response body with have data which is an image. The request defines this not the HTTP protocol. Browsers used to support a 'ftp' protocol that allowed files to be downloaded. Rather than 'http' it started with 'ftp' However apparently newer versions (Chrome, Firefox) no longer support that at all.

[Lost User]

It does not matter what the content of the file looks like. If you do not understand how to handle binary data without corrupting it then you will never pass go or collect your $200. So stop trying to convdert the content into printable/displayable strings, that just destroys it (as I said in my previous message). You must read and write the content as pure binary bytes, nothing else.

[Richard Deeming]

Bart van Tuijl wrote:

also to answer the type of variable for My404HtmlPage is Dim My404HtmlPage As New System.Text.StringBuilder()

Well, there's your problem. You cannot treat binary data as a string!

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"These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

[Bart van Tuijl]

This My404HtmlPage being a string I had suspected, though Im at a dilemma because my http header information is sent as string and my file as bytes yet they belong to eachother. Is there a way I can convert my HTTP header to bytes and add my file to it as bytes and then send it or will that not work? (Sorry guys Im just a hobbyist so my knowledge is limited)

[jschell]

Yes as I suggested in my other post. You need to learn what hexadecimal is ('hex'). You need to get a hexadecimal editor (it will be called a hex editor.) You need to compile a SMALL project and then look at the exe (which is a binary file) using the hex editor. Not notepad. You need to then look at an image using a hex editor. You need to then find the specification ('spec') for that type of image and use the hex editor (not notepad) to figure out the parts of the image. I would also suggest that you write a program parse an image file. NOT display it. Just read it and print out the parts. 1. Read the file with a stream 2. Use the spec to figure out how to read the file. 3. Print out the various pieces. For example there is likely a size (x and y) so print that out as integers.