TCP string functions

[Snarg]

I have never posted something like this before so please keep the flames to a minimum. I would like to give the vast majority of the credit to Larry. I only came upon this idea by browsing what he has posted. These are a variation of some of the functions he has posted. Any errors in these functions are soley mine and mine alone.

These functions will add a measure of data integrity to TCP. A simple checksum is added to the beginning of every packet sent. This checksum is verified when a packet is received to ensure the whole packet has been received.

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;===============================================================================
;
;Description:   Sends data via TCP. It can be any type of non-binary data. A
;                length identifier is added to the beginning of the packet to
;                ensure all the data is present on the receiving end.
;
;Parameter(s):  $vData - Accepts any type of formated data.
;                 $iSocket - The connected socket identifier (SocketID) as returned by TCPConnect.
;
;Requirement(s):A TCP connection.
;
;Author:        Snarg  - Supa(dot)Snarg(at)gmail(dot)com
;                (I would like to give the vast majority of the credit to Larry)
;
;===============================================================================
Func _TCPSendText ($iSocket, $vData)
    
    Local $vBuffer = ""
    $vBuffer = StringLen ($vData) & "," & $vData
    TCPSend ($iSocket, $vBuffer)
    
EndFunc

;===============================================================================
;
;Description:     Recieves a data packet via TCP. It can be any type of non-binary
;                 data. A length identifier is checked at the start of the packet
;                 to ensure all the data has been recieved.
;
;Parameter(s):    $iSocket - The connected socket identifier (SocketID) as returned by TCPAccept or
;                 TCPConnect.
;
;Requirement(s):  A TCP connection.
;
;Return Value:    $vBuffer - Data recieved on the TCP connection.
;
;Author:          Snarg  - Supa(dot)Snarg(at)gmail(dot)com
;                 (I would like to give the vast majority of the credit to Larry)
;
;===============================================================================

Func _TCPReciveText ($iSocket)
    Local $vBuffer = ""
    Local $iBytes = -1
    
    While 1
        $vBuffer &= TCPRecv ($iSocket, 1024)
        If $iBytes = -1 And StringInStr ($vBuffer, ",") Then
            $iBytes = StringLeft ($vBuffer, StringInStr ($vBuffer, ",")-1)
            $vBuffer = StringTrimLeft ($vBuffer, StringInStr ($vBuffer, ","))
        Else
            If StringLen ($vBuffer) = $iBytes Then ExitLoop
        EndIf
    WEnd
    
    Return $vBuffer
EndFuncoÝ÷ ØLZ^±«­¢+ØíáµÁ±½}Q
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P.S.: Don't copy/paste from this post, the formatting is horrible. Please download the attached file.

Edit: You would think I am capable of spelling 'TCP'...

Edit: Removed the examples from the .au3 file.

TCP_Text.au3

Edited November 26, 2006 by Snarg

[arcker]

mmm interesting, you came at the the good time for me

your integrity control is a really good idea, and simple

thx

edit :

in all of my programs that uses TCP, I use the if @error then exitloop (like in Larry's funcs) when i use tcprecv, why you don't use it here

Edited November 25, 2006 by arcker

[nitekram]

Examples:

;Example of _TCPSendText:

Dim $sMyVariable = 76
Dim $vMyData = "This is some data. Is has letters, numbers (1,2,3,4,5,6...), special characters _
        !@#$%^&* and can also contain variables. The variable is = " & $sMyVariable

TCPStartUp ()
$iSocket = TCPConnect (127.0.0.1, 3333)
_TCPSendText ($iSocket, $vMyData)
TCPShutDown ()

;Example of _TCPReciveText:

Dim $vMyData = ""

TCPStartUp ()
$iListen = TCPListen (127.0.0.1, 3333)
$iSocket = TCPAccept ($iListen)
$vMyData = _TCPReciveText ($iSocket)
MsgBox (0, "Recieved Data", "The data recieved is: " & $vMyData)
TCPShutdown ()

P.S.: Don't copy/paste from this post, the formatting is horrible. Please download the attached file.

Edit: You would think I am capable of spelling 'TCP'...

I find some errors in your download file - missing quotes.

[Snarg]

in all of my programs that uses TCP, I use the if @error then exitloop (like in Larry's funcs) when i use tcprecv, why you don't use it here

Because I am not quite certain how to do it. (I don't like smileys so imagine me with an embarassed face)

I find some errors in your download file - missing quotes.

Could you please point out where? I just downloaded it and it looks fine.

[nitekram]

Because I am not quite certain how to do it. (I don't like smileys so imagine me with an embarassed face)

Could you please point out where? I just downloaded it and it looks fine.

Sorry - just got back - it looks like your string $vMyData is missing quotes and both your local IP's 127.0.0.1 - don't they need to be quoted?

[Snarg]

Sorry - just got back - it looks like your string $vMyData is missing quotes and both your local IP's 127.0.0.1 - don't they need to be quoted?

I removed the examples from the .au3 file, they should not have been there in the first place. I also fixed $vMyData. As for the TCP functions, unless something has changed in the newest beta, quote marks are not required.

[Snarg]

in all of my programs that uses TCP, I use the if @error then exitloop (like in Larry's funcs) when i use tcprecv, why you don't use it here

Ok, I took a better look at the help file seeing how @error would work into this. According to the help file, @error returns the following for TCPRecv: Returns "" and set @error according to Windows API WSAGetError return. So, if I were to modify the function like the example below, I think it would fail. (I am not at my regular computer or I would test it to find out.) Once the buffer was empty, @error would be set to "". However, the conditions wouldn't complete and, it looks like, $vBuffer would never be returned. You could make a conditional @error, something like: If @error = WSAGetError Then Return 0

Only problem with that is, I really don't know what WSAGetError is.

So, to sum it up, if there is a better way to do this I am more then willing to learn. Please show me the light.

Func _TCPReciveText ($iSocket)
    Local $vBuffer = ""
    Local $iBytes = -1
    
    While 1
        $vBuffer &= TCPRecv ($iSocket, 1024)
    If @error Then Return 0
        If $iBytes = -1 And StringInStr ($vBuffer, ",") Then
            $iBytes = StringLeft ($vBuffer, StringInStr ($vBuffer, ",")-1)
            $vBuffer = StringTrimLeft ($vBuffer, StringInStr ($vBuffer, ","))
        Else
            If StringLen ($vBuffer) = $iBytes Then ExitLoop
        EndIf
    WEnd
    
    Return $vBuffer
EndFunc

[nitekram]

I removed the examples from the .au3 file, they should not have been there in the first place. I also fixed $vMyData. As for the TCP functions, unless something has changed in the newest beta, quote marks are not required.

I have looked at this beta help file online and it used quotes. Can you link me to other help file?

[Snarg]

I have looked at this beta help file online and it used quotes. Can you link me to other help file?

$iSocket = TCPConnect (127.0.0.1, 3333) ;What I usedoÝ÷ Ù0
çyËH

TCPListen ( IPAddr, port [, MaxPendingConnection] ); From the helpfile located here.