套接字非阻塞设置

1. #include <sys/socket.h>
2. #include <fcntl.h>
3. #include <netinet/in.h>
4. 
5. int main()
6. {
7. int socketfd = socket(AF_INET, SOCK_STREAM, 0);
8. 
9. struct sockaddr_in servaddr;
10.     servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
11.     servaddr.sin_family = AF_INET;
12.     servaddr.sin_port = htons(9999);
13. 
14. int flags = fcntl(socketfd, F_GETFL, 0);
15.     flags |= O_NONBLOCK;
16. fcntl(socketfd, F_SETFL, flags);
17}