現(xiàn)在的解決方法

// server端是否斷開(kāi)連接
bool is_server_disconnected(int client_socket)
{
    // 非阻塞
    set_flag(client_socket, O_NONBLOCK);
    char buffer[10];
    int length = recv(client_socket, buffer, 10, 0);
    clr_flag(client_socket, O_NONBLOCK);
    return length == 0;
}

把client_socket設(shè)置成了非阻塞，然后recv如果返回0了，說(shuō)明remote socket is closed.

When a stream socket peer has performed an orderly shutdown, the
return value will be 0 (the traditional "end-of-file" return).

Linux man

其他方法

tcp斷開(kāi)暫借不考慮，不知道有沒(méi)有更簡(jiǎn)單更好的方法？？