Re: Problems in checking data from recv function

From:

"Ben Voigt [C++ MVP]" <rbv@nospam.nospam>

Newsgroups:

microsoft.public.vc.language

Date:

Wed, 6 Feb 2008 12:56:34 -0600

Message-ID:

<uIJZwGPaIHA.1532@TK2MSFTNGP04.phx.gbl>

"Christian" <voodoo81people@gmail.com> wrote in message
news:0094cbdf-afd8-4992-922d-3ee9e1c975cc@s8g2000prg.googlegroups.com...

Hi
I'm writing a server for Pocket PC without a GUI.I'm using winsock2.h
in Visual Studio 2005
Here is it the code:
[code]
string comm = ""; // type basic_string
char cResponseBuffer[20] = "";
int nBytesReceived = 0;
nBytesReceived = recv(sIncomingSocket, &cResponseBuffer[20], 20, 0);
DEBUGMSG(TRUE, (TEXT("Received %u bytes\n"),nBytesReceived));

comm.append(cResponseBuffer);

In addition to the bug Igor found, this line is not adding nBytesReceived as
it should, but instead searching for a NUL character that may or may not
exist in the data. Use an append override with a length argument.

int lung = comm.length();
[/code]

Now in my test recv returns N bytes different from zero (this would
mean that has received client's data) but when I append the buffer to
the comm string,the final string is empty as if cResponseBuffer itself
would be empty. How is it possibile? Smarter way to retrive and check
data? I only have to do some comparison between strings sent by the
client and string in the server like:

[code]
if(comm.compare("getttnversion") == 0){
temp = true;
}
[/code]

Thanks for helping me.