Thread: Huge memory leak

I'm getting a large memory leak in my code, its even causing my program to shutdown after a little bit and I'm having trouble finding what is wrong. I ran rational purifyplus on it and it gave me the distinct location but I don't see the problem. Here's some code:

Calling Code:

Code:

std::string str = "";
str += ZPacketData->GetData()->back()->GetMACAddress(TRUE);

GetMACAddress: (where the memory leak supposedly happens)

Code:

std::string ZeroPacket::GetMACAddress(BOOL IsSource)
{
	std::string strReturn = "";
	char cBuff[20];
	char* pChar;

	if( IsSource )
		pChar = (char*)(m_Data);
	else
		pChar = (char*)(m_Data+6);

	for( int i=0; i<6; i++ )
	{
		sprintf(cBuff, ("02x:"), *(BYTE*)pChar++);
		strReturn += cBuff;
	}

	return strReturn;
}

The code is pretty straightforward and I'm assuming it has something to do with std::string. Also, PurifyPlus is stating that the leak is on the heap, but I didn't allocated anything to the heap except for m_Data. Any Ideas?

Code:

sprintf(cBuff, ("02x:"), *(BYTE*)pChar++);

The above line is wrong -- where is the '%'?

Code:

sprintf(cBuff, ("%02x:"), (unsigned)*(BYTE*)pChar++);

Not sure if it will help or not, but you might try typcasting to unsigned int.

yea, I fixed that heh. Still causes a leak tho so I'm switching over to MFC and hopefully CString will return properly