Create Named Pipe C++ 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.