Sending plain text through socket

[xchewy]

Hi, I'm working with sockets in Symbian c++ and i managed to make the EchoEngine example to work and now my app connects and send data through the socket. The server side has to be a Java based server, and the connection is made, and it received the data but when it is shown on a console the message has strange characters almost like it was binary and not text, how can i send plain Text through the socket so the server can read the data?

thanks

[symbianyucca]

it is propably caused by wrong character encoding, so try sending normal ASCII text from the server, or use character converters for convertign the text.

[wizard_hu_]

If you are using "recent" S60 editions (perhaps S60 2nd FP2 and upwards), it should be possible to run your networking code in the emulator, where you can examine what you actually read from your socket using a debugger.

[xchewy]

if it is by wrong character encoding, how can i ensure the encoding i use in my Symbian c++ code, i write a TBuf8 into the socket, but it seems to treat it as binary data not text data, how can i set the ascii encoding in the c++ code side, the java needs to read text even UTF8 its ok, but text.

it is propably caused by wrong character encoding, so try sending normal ASCII text from the server, or use character converters for convertign the text.

[nigel.brown]

Through your socket you are sending binary. "Octets" as they are called in the RFCs. One of the things you can push down this binary tube is ascii text. There are variations (http://en.wikipedia.org/wiki/Plain_text or use google) but the key thing is that the code that is reading the socket is using the same format as the code writing to the socket.

For example, one thing that might get confused is the line endings. Some systems use character 0x0d for this and some 0x0a. Bizarrely, some will even use both 0x0d 0x0a.

The socket doesn't care what it is transmitting, it just does its best to get it there.

Look at what you are receiving in a hex editor (or in a debugger or packet sniffer as suggested previously) and you should be able to work out what is going on.

[symbianyucca]

ok, I misunderstood that your receiving and at phone gets it wrong. anyway, normal byte-buffer text should be ASCII encoded in symbina side.

[xchewy]

Hi, i've been testing my java server for the incoming data, and it always show
HEX{[01][01][00][00][00][01][00][00][01][01][00][01][01][01][0f]}

this is the hex value of each byte , but doesn't matter what i choose to send '000000000000000' or 'abcdefghijklmno' it sends the same data in the socket. in my server if i connect to it using putty for example and i send 'hello' it shows 'hello' the same with the strings above, i just dont get it. i connect to the server, and send a TBuf<15> , its quite simple but it doesnt work, encoding?mmm dont think so, because i append a '\n' after after the string i want to send so the java server knows it ends and it recognize the '\n' on the data it receives.

what i intent to do is send data i shown o some labels so it has to be or numbers or letters no special characters besides '\n' if someone knows why it happens please tell me

the code seems like

TBuf<17> originalBuf( _L("abcdefghijklmno") );
iEchoEngine->Write(originalBuf);

and Write method call this

void CEchoWrite::IssueWrite(const TDes &aText)
// Write a data to a stream socket
{
TBuf<2> eolT (_L("\n"));
// Set up buffer
iBuffer.SetLength(0);
iBuffer.Append(aText);
iBuffer.Append(eolT);
iEchoSocket->Write(iBuffer, iStatus);
// Request timeout
iTimer->After(iTimeOut);
SetActive();
iWriteStatus = ESending;
};

[nigel.brown]

What is the definition of your Write function?
It looks like you are passing the address or pointer of something, rather than a reference.
Also, you are using TBuf instead of TBuf8. So, I would expect it to be wrong for that reason, but not give the values you have shown.

If you have a log file, or can use a debugger, look at the contents of iBuffer just before you send it.

[muaz111111]

Huy,

i have the same problem. my server is in c#. my symbian code is working correctly on emulator but when i installed it on n72 then it sends garbage and my server didnot receive correct data. i have used UTF8 on my server side, but it didnot work. i am using RBUF8. is there any solution...

regards

[nigel.brown]

There's always a solution.

You need to look at your data at each stage on its merry journey to see which bit is not as you expect.
1. Print it to a file just before you send it.
2. Look at it in transit using a packet sniffer.
3. Log the raw data at the other end.

I expect you are not sending exactly what you think, but you haven't given enough info to determine.

Also, remember, sockets have been used once or twice successfully, so it is probably not an issue with the sockets themselves.

[xchewy]

Hi Nigel, i found the problem and you gave me clues, i found that the first method i use to call to send my data was not declared with a parameter by reference, that was all, once i change it, i went smooth on my java server, i am testing it only on the emulator not on a real device, i hope to do it in a week, i knew the socket implementation has to be compatible with any socket you write on any other language, it must the that way. now i think you're rigth that the string i was getting 00100110001111 was more like the address in memory, it was a long time ago since i did something in C/C++ but with symbian c++ im starting to remember, thanks

[nigel.brown]

Good news.
The reason I spotted it was because I have done the same thing myself, more that once.

[paipeng]

void CEchoWrite::IssueWrite(const TDes &aText)
// Write a data to a stream socket
{
TBuf<2> eolT (_L("\n"));
// Set up buffer
iBuffer.SetLength(0);
iBuffer.Append(aText);
iBuffer.Append(eolT);
iEchoSocket->Write(iBuffer, iStatus);
// Request timeout
iTimer->After(iTimeOut);
SetActive();
iWriteStatus = ESending;
};

I think, you should use .Copy() than .Append(). Because the iBuffer must be TDes8, and the parameter aText is a 16Bit.

something like

TBuf8<2> eolT (_L8("\n"));
iBuffer.Zero();
iBuffer.Copy(aText);
iBuffer.Append(eolT);
....

[muaz111111]

Huy,

thanks for your response. i am using following code to send my string


void CMobiMessengerContainerView::SignIn()
{
GlobalData* aGlobalData = GetGlobalData();
TBuf<20> aTempBuf(20);
RBuf8 aQuery;
aQuery.CleanupClosePushL();
aQuery.CreateL(100);

aQuery.Append(SI_Catagory_Code());
aQuery.Append(Entity_Code());

iTextBoxID->GetText(aTempBuf);
aGlobalData->iSignInUser.Create(aTempBuf.Length());
aGlobalData->iSignInUser.Append(aTempBuf);
aQuery.Append(aTempBuf);
aQuery.Append(Entity_Code());

aTempBuf.Zero();
iSecretPassword->GetText(aTempBuf);
aQuery.Append(aTempBuf);
aQuery.Append(Entity_Code());

aQuery.Append(_L("Online"));
aQuery.Append(Entity_Code());

aGlobalData->iSocketEngine->WriteL((TDesC8)aQuery);

CleanupStack::PopAndDestroy();
}

const TDesC8& Entity_Code()
{
_LIT8(toReturn,"!#!");
return toReturn;
}

const TDesC8& SI_Catagory_Code()
{
_LIT8(toReturn,"#*SI");
return toReturn;
}

[nigel.brown]

aGlobalData->iSocketEngine->WriteL((TDesC8)aQuery);
looks wrong. What is the definition of WriteL? It should be passing by reference.
http://library.thinkquest.org/C01115...ual.php?tid=51
http://library.thinkquest.org/C01115...ual.php?tid=52
Print "aQuery" and print the value you receive in "WriteL". I expect they are different.

Also, if you worry about the naming convention, the "a" in "aQuery" means it was passed as an argument. http://developer.symbian.com/wiki/pa...ion?pageId=530