UDP在多个端口上接收数据

您要么需要每个端口一个线程，要么需要一种机制(例如select，poll)来告诉哪个套接字有等待读取的数据.在后一种情况下，一旦知道哪些套接字具有待处理的数据，就可以然后在该特定套接字上调用recvfrom以获取所需的数据，例如:// set up select parametersfd_set socks;FD_ZERO(&socks);FD_SET(socket_fd, &socks);FD_SET(socket_fd2, &socks);// find out which sockets are read - NB: it might be both!int nsocks = max(socket_fd, socket_fd2) + 1;if (select(nsocks, &socks, (fd_set *)0, (fd_set *)0, 0) >= 0) { if (FD_ISSET(socket_fd, &socks) { // handle socket 1 recvfrom(socket_fd, ...); } if (FD_ISSET(socket_fd2, &socks) { // handle socket 2 recvfrom(socket_fd2, ...); }}注意:这只是一个粗略而现成的示例-实际代码将进行错误检查等.Is it possible to receive data with recvfrom on 2 ports? I have a port which I use for user requests and another port for chat messages. Is it possible to bind two sockets, with different ports and receive data with one recvfrom()?RegardsEDITDoes this code work?int socket_fd,socket_fd2;struct sockaddr_in addr, chat_addr;addr.sin_family = AF_INET;addr.sin_port = htons(1234);addr.sin_addr.s_addr = inet_addr("127.0.0.1");chat_addr.sin_family = AF_INET;chat_addr.sin_port = htons(4321);chat_addr.sin_addr.s_addr = inet_addr("127.0.0.1");bind(socket_fd2, (struct sockaddr *) &chat_addr, sizeof(struct sockaddr_in));bind(socket_fd, (struct sockaddr *) &addr, sizeof(struct sockaddr_in));So I want to receive data on two different ports. 解决方案 No, it's not possible to read from both sockets using a single call to recvfrom, since that function only takes a single socket file descriptor parameter.You either need a thread per port, or a mechanism (e.g. select, poll) to tell which sockets have data waiting to be read.In the latter case, once you know which sockets have pending data you can then call recvfrom on that specific socket to get the data you need, e.g.:// set up select parametersfd_set socks;FD_ZERO(&socks);FD_SET(socket_fd, &socks);FD_SET(socket_fd2, &socks);// find out which sockets are read - NB: it might be both!int nsocks = max(socket_fd, socket_fd2) + 1;if (select(nsocks, &socks, (fd_set *)0, (fd_set *)0, 0) >= 0) { if (FD_ISSET(socket_fd, &socks) { // handle socket 1 recvfrom(socket_fd, ...); } if (FD_ISSET(socket_fd2, &socks) { // handle socket 2 recvfrom(socket_fd2, ...); }}NB: this is just a rough and ready sample - real code would have error checking, etc. 这篇关于UDP在多个端口上接收数据的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！