Socket

一、Server

 int server_fd,client_fd;

 // 地址蔟、socket类型、通信协议
 server_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
 if (server_fd < 0) {
     printf("socket error\n");
     return -1;
    }

 struct sockaddr_in addr,clientAddr;
 bzero(&addr,sizeof(addr));

 addr.sin_family = AF_INET;
 addr.sin_port = htons(7787);
 addr.sin_addr.s_addr = INADDR_ANY; // inet_addr("127.0.0.0")

 // 地址绑定
 bind(server_fd, (struct sockaddr_in *)&addr, sizeof(struct sockaddr_in));

 // 100 最大连接数,监听连接请求--监听队列长度为 100
 listen(server_fd, 100);

 // 阻塞，直到有客户端连接
 int s_size = sizeof(struct sockaddr_in);
 client_fd = accept(server_fd, (struct sockaddr_in *)&clientAddr, &s_size);
 if (client_fd >= 0) {
     printf("connect client:%s\n",inet_ntoa(clientAddr.sin_addr));
 }

二、Client

 int fd;

 // 网络层协议： 决定抵制类型（ipv4、ipv6）AF_INET AF_INET6
 // socket类型：SOCK_STREAM SOCK_DGRAM
 // 运输层协议： IPPROTO_TCP IPPROTO_UDP
 fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
 if (fd <= 0) {
     perror("open socket error\n");
     return -1;
 }

 struct sockaddr_in addr;
 bzero(&addr,sizeof(addr));

 addr.sin_family = AF_INET;
 addr.sin_port = htons(8088);
 addr.sin_addr.s_addr = inet_addr("127.0.0.1");

 // connect 成功返回0
 if (connect(fd, (struct sockaddr_in *)&addr, sizeof(addr)) < 0) {
     perror("connect error\n");
     return -1;
 }