socket进程间通信的一个一对多例子

//http://blog.csdn.net/ctrl_qun/article/details/52524086 //一对多服务器网络sock #include<stdio.h> #include<stdlib.h> #include<netinet/in.h> #include<sys/socket.h> #include<arpa/inet.h> #include<string.h> #include<unistd.h> #define BACKLOG 5 //完成三次握手但没有accept的队列的长度 #define CONCURRENT_MAX 8 //应用层同时可以处理的连接 #define SERVER_PORT 11332 #define BUFFER_SIZE 1024 #define QUIT_CMD ".quit" int client_fds[CONCURRENT_MAX]; int main(int argc, const char * argv[]) { char input_msg[BUFFER_SIZE]; char recv_msg[BUFFER_SIZE]; //本地地址 struct sockaddr_in server_addr; server_addr.sin_family = AF_INET; server_addr.sin_port = htons(SERVER_PORT); server_addr.sin_addr.s_addr = inet_addr("127.0.0.1"); bzero(&(server_addr.sin_zero), 8); //创建socket int server_sock_fd = socket(AF_INET, SOCK_STREAM, 0); if(server_sock_fd == -1) { perror("socket error"); return 1; } //绑定socket int bind_result = bind(server_sock_fd, (struct sockaddr *)&server_addr, sizeof(server_addr)); if(bind_result == -1) { perror("bind error"); return 1; } //listen if(listen(server_sock_fd, BACKLOG) == -1) { perror("listen error"); return 1; } //fd_set fd_set server_fd_set; int max_fd = -1; struct timeval tv; //超时时间设置 while(1) { tv.tv_sec = 20; tv.tv_usec = 0; FD_ZERO(&server_fd_set); FD_SET(STDIN_FILENO, &server_fd_set); if(max_fd <STDIN_FILENO) { max_fd = STDIN_FILENO; } //printf("STDIN_FILENO=%d\n", STDIN_FILENO); //服务器端socket FD_SET(server_sock_fd, &server_fd_set); // printf("server_sock_fd=%d\n", server_sock_fd); if(max_fd < server_sock_fd) { max_fd = server_sock_fd; } //客户端连接 for(int i =0; i < CONCURRENT_MAX; i++) { //printf("client_fds[%d]=%d\n", i, client_fds[i]); if(client_fds[i] != 0) { FD_SET(client_fds[i], &server_fd_set); if(max_fd < client_fds[i]) { max_fd = client_fds[i]; } } } int ret = select(max_fd + 1, &server_fd_set, NULL, NULL, &tv); if(ret < 0) { perror("select 出错\n"); continue; } else if(ret == 0) { printf("select 超时\n"); continue; } else { //ret 为未状态发生变化的文件描述符的个数 if(FD_ISSET(STDIN_FILENO, &server_fd_set)) { printf("发送消息：\n"); bzero(input_msg, BUFFER_SIZE); fgets(input_msg, BUFFER_SIZE, stdin); //输入“.quit"则退出服务器 if(strcmp(input_msg, QUIT_CMD) == 0) { exit(0); } for(int i = 0; i < CONCURRENT_MAX; i++) { if(client_fds[i] != 0) { printf("client_fds[%d]=%d\n", i, client_fds[i]); send(client_fds[i], input_msg, BUFFER_SIZE, 0); } } } if(FD_ISSET(server_sock_fd, &server_fd_set)) { //有新的连接请求 struct sockaddr_in client_address; socklen_t address_len; int client_sock_fd = accept(server_sock_fd, (struct sockaddr *)&client_address, &address_len); printf("new connection client_sock_fd = %d\n", client_sock_fd); if(client_sock_fd > 0) { int index = -1; for(int i = 0; i < CONCURRENT_MAX; i++) { if(client_fds[i] == 0) { index = i; client_fds[i] = client_sock_fd; break; } } if(index >= 0) { printf("新客户端(%d)加入成功 %s:%d\n", index, inet_ntoa(client_address.sin_addr), ntohs(client_address.sin_port)); } else { bzero(input_msg, BUFFER_SIZE); strcpy(input_msg, "服务器加入的客户端数达到最大值,无法加入!\n"); send(client_sock_fd, input_msg, BUFFER_SIZE, 0); printf("客户端连接数达到最大值，新客户端加入失败 %s:%d\n", inet_ntoa(client_address.sin_addr), ntohs(client_address.sin_port)); } } } for(int i =0; i < CONCURRENT_MAX; i++) { if(client_fds[i] !=0) { if(FD_ISSET(client_fds[i], &server_fd_set)) { //处理某个客户端过来的消息 bzero(recv_msg, BUFFER_SIZE); long byte_num = recv(client_fds[i], recv_msg, BUFFER_SIZE, 0); if (byte_num > 0) { if(byte_num > BUFFER_SIZE) { byte_num = BUFFER_SIZE; } recv_msg[byte_num] = '\0'; printf("客户端(%d):%s\n", i, recv_msg); } else if(byte_num < 0) { printf("从客户端(%d)接受消息出错.\n", i); } else { FD_CLR(client_fds[i], &server_fd_set); client_fds[i] = 0; printf("客户端(%d)退出了\n", i); } } } } } } return 0; }