accept() - winsock2.h

The accept() function permits an incoming connection attempt on a socket.

Syntax

SOCKET accept(
  _In_    SOCKET          s,
  _Out_   struct sockaddr *addr,
  _Inout_ int             *addrlen
);

Example

#ifndef UNICODE
#define UNICODE
#endif

#include <winsock2.h>
#include <stdio.h>
#include <windows.h>

// Need to link with Ws2_32.lib
#pragma comment(lib, "Ws2_32.lib")

int wmain(void)
{

    //----------------------
    // Initialize Winsock.
    WSADATA wsaData;
    int iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
    if (iResult != NO_ERROR) {
        wprintf(L"WSAStartup failed with error: %ld
", iResult);
        return 1;
    }
    //----------------------
    // Create a SOCKET for listening for
    // incoming connection requests.
    SOCKET ListenSocket;
    ListenSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (ListenSocket == INVALID_SOCKET) {
        wprintf(L"socket failed with error: %ld
", WSAGetLastError());
        WSACleanup();
        return 1;
    }
    //----------------------
    // The sockaddr_in structure specifies the address family,
    // IP address, and port for the socket that is being bound.
    sockaddr_in service;
    service.sin_family = AF_INET;
    service.sin_addr.s_addr = inet_addr("127.0.0.1");
    service.sin_port = htons(27015);

    if (bind(ListenSocket,
             (SOCKADDR *) & service, sizeof (service)) == SOCKET_ERROR) {
        wprintf(L"bind failed with error: %ld
", WSAGetLastError());
        closesocket(ListenSocket);
        WSACleanup();
        return 1;
    }
    //----------------------
    // Listen for incoming connection requests.
    // on the created socket
    if (listen(ListenSocket, 1) == SOCKET_ERROR) {
        wprintf(L"listen failed with error: %ld
", WSAGetLastError());
        closesocket(ListenSocket);
        WSACleanup();
        return 1;
    }
    //----------------------
    // Create a SOCKET for accepting incoming requests.
    SOCKET AcceptSocket;
    wprintf(L"Waiting for client to connect...
");

    //----------------------
    // Accept the connection.
    AcceptSocket = accept(ListenSocket, NULL, NULL);
    if (AcceptSocket == INVALID_SOCKET) {
        wprintf(L"accept failed with error: %ld
", WSAGetLastError());
        closesocket(ListenSocket);
        WSACleanup();
        return 1;
    } else
        wprintf(L"Client connected.
");

    // No longer need server socket
    closesocket(ListenSocket);

    WSACleanup();
    return 0;
}

Output / Return Value

Limitations

Supports Windows 8.1,Windows Vista, Windows server 2003 (Desktop and Windows Store App)

Alternatives / See Also

Reference