Question

I created a named pipe using WCF and C#, and a client to connect to it so that I know that it is working correctly. Now I’m trying to create a c++ client. So far I have been able to get the name of the pipe, connect to it, and write some data to it. When I try to read from it I’m getting error code 998 Invalid access to memory location. Here is the code I’m using:

HANDLE hPipe = CreateFile(pipeName.c_str(), GENERIC_WRITE | GENERIC_READ, 2, NULL, OPEN_EXISTING, NULL, NULL);
BOOL bWrite = WriteFile(hPipe, &message, size, &bytesWritten, NULL);
LPVOID buffer = 0;
DWORD bytesRead;
BOOL bRead = ReadFile(hPipe, buffer, 10, &bytesRead, NULL);

I’m not sure what I’m doing wrong.

Answer 1

No memory has been allocated for buffer, it is currently a null pointer, and the code is requesting that 10 bytes of data be read into an array that does not exist. From ReadFile():

lpBuffer [out]

A pointer to the buffer that receives the data read from a file or device.

To rectify:

char buffer[10];