How can I check if a client disconnected through Winsock in C++?

Question

How can I check if a client disconnected through Winsock in C++?

Answer 1

Beej's Network Programming Guide

if you call recv in blocking mode and it returns with 0 bytes read, the socket has disconnected, else it wait for bytes to be received.

Look in this FAQ 2.12

example from select on this page.

int nRet;

if(( nRet = select( 0, &fdread, NULL, NULL, NULL )) == SOCKET_ERROR )
{
    // Error condition
    // Check WSAGetLastError
}

if( nRet > 0 )
{
    // select() will return value 1 because i m using only one socket
    // At this point, it should be checked whether the
    // socket is part of a set.

    if( FD_ISSET( s, &fdread ))
    {
        // A read event has occurred on socket s
    }
}