Windows系统下c++具体代码实现采用非阻塞模式实现面向连接的 socket 编程

以下是Windows系统下C语言非阻塞模式实现面向连接的socket编程的示例代码：

1. 创建socket

int sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock == INVALID_SOCKET) {
    printf("Error creating socket: %d\n", WSAGetLastError());
    WSACleanup();
    return 1;
}

2. 设置非阻塞模式

unsigned long mode = 1;
int result = ioctlsocket(sock, FIONBIO, &mode);
if (result != NO_ERROR) {
    printf("Error setting non-blocking mode: %d\n", WSAGetLastError());
    closesocket(sock);
    WSACleanup();
    return 1;
}

3. 连接服务器

struct sockaddr_in server_address;
memset(&server_address, 0, sizeof(server_address));
server_address.sin_family = AF_INET;
server_address.sin_port = htons(port);
InetPton(AF_INET, server_ip, &server_address.sin_addr);

result = connect(sock, (struct sockaddr*)&server_address, sizeof(server_address));
if (result == SOCKET_ERROR && WSAGetLastError() != WSAEWOULDBLOCK) {
    printf("Error connecting to server: %d\n", WSAGetLastError());
    closesocket(sock);
    WSACleanup();
    return 1;
}

4. 使用select函数等待连接完成

fd_set write_fds;
FD_ZERO(&write_fds);
FD_SET(sock, &write_fds);

struct timeval timeout;
timeout.tv_sec = 5;
timeout.tv_usec = 0;

result = select(0, NULL, &write_fds, NULL, &timeout);
if (result == 0) {
    printf("Connection timed out.\n");
    closesocket(sock);
    WSACleanup();
    return 1;
} else if (result == SOCKET_ERROR) {
    printf("Error waiting for connection: %d\n", WSAGetLastError());
    closesocket(sock);
    WSACleanup();
    return 1;
}

5. 发送数据

const char* message = "Hello, server!";
result = send(sock, message, strlen(message), 0);
if (result == SOCKET_ERROR) {
    printf("Error sending data: %d\n", WSAGetLastError());
    closesocket(sock);
    WSACleanup();
    return 1;
}

6. 接收数据

char buffer[1024];
result = recv(sock, buffer, sizeof(buffer), 0);
if (result == SOCKET_ERROR) {
    printf("Error receiving data: %d\n", WSAGetLastError());
    closesocket(sock);
    WSACleanup();
    return 1;
} else {
    buffer[result] = '\0';
    printf("Received data: %s\n", buffer);
}

7. 关闭socket

closesocket(sock);
WSACleanup();