Create Named Pipe C++ Windows - windows

Question

I am trying to create a simple comunication between 2 processes in C++ ( Windows ) like FIFO in linux.
This is my server:
int main()
{
HANDLE pipe = CreateFile(TEXT("\\\\.\\pipe\\Pipe"), GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);
ConnectNamedPipe(pipe, NULL);
while(TRUE){
string data;
DWORD numRead =1 ;
ReadFile(pipe, &data, 1024, &numRead, NULL);
cout << data << endl;
}
CloseHandle(pipe);
return 0;
}
And this is my client:
int main()
{
HANDLE pipe = CreateFile(TEXT("\\\\.\\pipe\\Pipe"), GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL);
ConnectNamedPipe(pipe, NULL);
string message = "TEST";
DWORD numWritten;
WriteFile(pipe, message.c_str(), message.length(), &numWritten, NULL);
return 0;
}
The code does't work , how can i fixed it to like FIFO ?

Answer 1

You cannot create a named pipe by calling CreateFile(..).
Have a look at the pipe examples of the MSDN. Since these examples are quite complex I've quickly written a VERY simple named pipe server and client.
int main(void)
{
HANDLE hPipe;
char buffer[1024];
DWORD dwRead;
hPipe = CreateNamedPipe(TEXT("\\\\.\\pipe\\Pipe"),
PIPE_ACCESS_DUPLEX,
PIPE_TYPE_BYTE | PIPE_READMODE_BYTE | PIPE_WAIT, // FILE_FLAG_FIRST_PIPE_INSTANCE is not needed but forces CreateNamedPipe(..) to fail if the pipe already exists...
1,
1024 * 16,
1024 * 16,
NMPWAIT_USE_DEFAULT_WAIT,
NULL);
while (hPipe != INVALID_HANDLE_VALUE)
{
if (ConnectNamedPipe(hPipe, NULL) != FALSE) // wait for someone to connect to the pipe
{
while (ReadFile(hPipe, buffer, sizeof(buffer) - 1, &dwRead, NULL) != FALSE)
{
/* add terminating zero */
buffer[dwRead] = '\0';
/* do something with data in buffer */
printf("%s", buffer);
}
}
DisconnectNamedPipe(hPipe);
}
return 0;
}
And here is the client code:
int main(void)
{
HANDLE hPipe;
DWORD dwWritten;
hPipe = CreateFile(TEXT("\\\\.\\pipe\\Pipe"),
GENERIC_READ | GENERIC_WRITE,
0,
NULL,
OPEN_EXISTING,
0,
NULL);
if (hPipe != INVALID_HANDLE_VALUE)
{
WriteFile(hPipe,
"Hello Pipe\n",
12, // = length of string + terminating '\0' !!!
&dwWritten,
NULL);
CloseHandle(hPipe);
}
return (0);
}
You should replace the name of the pipe TEXT("\\\\.\\pipe\\Pipe") by a #define which is located in a commonly used header file.