MSDN Documentation

• CreateNamedPipe
• ConnectNamedPipe
• DisconnectNamedPipe
• CreateFile (client)
• ReadFile
• WriteFile
• SetNamedPipeHandleState

HANDLE CreateNamedPipe(
    LPCWSTR               lpName,
    DWORD                 dwOpenMode,
    DWORD                 dwPipeMode,
    DWORD                 nMaxInstances,
    DWORD                 nOutBufferSize,
    DWORD                 nInBufferSize,
    DWORD                 nDefaultTimeOut,
    LPSECURITY_ATTRIBUTES lpSecurityAttributes
);

BOOL ConnectNamedPipe(
    HANDLE       hNamedPipe,
    LPOVERLAPPED lpOverlapped
);

Parameter	Description
lpName	The unique pipe name, e.g., \\\\.\\pipe\\MyPipe.
dwOpenMode	Pipe open mode flags (e.g., PIPE_ACCESS_DUPLEX).
dwPipeMode	Data flow mode (e.g., PIPE_TYPE_MESSAGE).
nMaxInstances	Maximum number of simultaneous instances (use PIPE_UNLIMITED_INSTANCES).
nOutBufferSize	Size of the output buffer in bytes.
nInBufferSize	Size of the input buffer in bytes.
nDefaultTimeOut	Default timeout, in milliseconds.
lpSecurityAttributes	Security descriptor for the pipe (optional).

On success, returns a handle to the server end of the pipe. On failure, returns INVALID_HANDLE_VALUE. Use GetLastError for extended error information.

• Named pipes can be used for local IPC or remote communication across a network.
• Pipe instances can be created dynamically; the server typically creates a new instance after each successful connection.
• When PIPE_TYPE_MESSAGE is used, data is delivered as discrete messages; otherwise, it behaves as a byte stream.
• Security attributes control who can access the pipe. Use SECURITY_DESCRIPTOR to restrict access.

#include <windows.h>
#include <iostream>

int main()
{
    const wchar_t* pipeName = L"\\\\.\\pipe\\SamplePipe";

    HANDLE hPipe = CreateNamedPipeW(
        pipeName,
        PIPE_ACCESS_DUPLEX,
        PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE | PIPE_WAIT,
        PIPE_UNLIMITED_INSTANCES,
        512, 512,
        0,
        nullptr);

    if (hPipe == INVALID_HANDLE_VALUE) {
        std::cerr << "CreateNamedPipe failed: " << GetLastError() << '\n';
        return 1;
    }

    std::wcout << L"Waiting for client connection..." << std::endl;
    BOOL connected = ConnectNamedPipe(hPipe, nullptr) ?
                     TRUE : (GetLastError() == ERROR_PIPE_CONNECTED);

    if (!connected) {
        std::cerr << "ConnectNamedPipe failed: " << GetLastError() << '\n';
        CloseHandle(hPipe);
        return 1;
    }

    const wchar_t* msg = L"Hello from server!";
    DWORD bytesWritten;
    WriteFile(hPipe, msg, (DWORD)(wcslen(msg) * sizeof(wchar_t)), &bytesWritten, nullptr);

    wchar_t buffer[128];
    DWORD bytesRead;
    ReadFile(hPipe, buffer, sizeof(buffer), &bytesRead, nullptr);
    buffer[bytesRead / sizeof(wchar_t)] = L'\0';
    std::wcout << L"Received: " << buffer << std::endl;

    DisconnectNamedPipe(hPipe);
    CloseHandle(hPipe);
    return 0;
}

• Pipe Operations
• CreateNamedPipeA
• ConnectNamedPipe
• CreateFile (client)