##2.6 epoll服務器 ###2.6.1 服務端 ```cpp #include <stdio.h> #include <stdlib.h> #include <ctype.h> #include <string.h> #include <unistd.h> #include <sys/types.h> #include <sys/socket.h> #include <arpa/inet.h> #include <sys/epoll.h> #define SERVER_PORT (7778) #define EPOLL_MAX_NUM (2048) #define BUFFER_MAX_LEN (4096) char buffer[BUFFER_MAX_LEN]; void str_toupper(char *str) { int i; for (i = 0; i < strlen(str); i ++) { str[i] = toupper(str[i]); } } int main(int argc, char **argv) { int listen_fd = 0; int client_fd = 0; struct sockaddr_in server_addr; struct sockaddr_in client_addr; socklen_t client_len; int epfd = 0; struct epoll_event event, *my_events; // socket listen_fd = socket(AF_INET, SOCK_STREAM, 0); // bind server_addr.sin_family = AF_INET; server_addr.sin_addr.s_addr = htonl(INADDR_ANY); server_addr.sin_port = htons(SERVER_PORT); bind(listen_fd, (struct sockaddr*)&server_addr, sizeof(server_addr)); // listen listen(listen_fd, 10); // epoll create epfd = epoll_create(EPOLL_MAX_NUM); if (epfd < 0) { perror("epoll create"); goto END; } // listen_fd -> epoll event.events = EPOLLIN; event.data.fd = listen_fd; if (epoll_ctl(epfd, EPOLL_CTL_ADD, listen_fd, &event) < 0) { perror("epoll ctl add listen_fd "); goto END; } my_events = malloc(sizeof(struct epoll_event) * EPOLL_MAX_NUM); while (1) { // epoll wait int active_fds_cnt = epoll_wait(epfd, my_events, EPOLL_MAX_NUM, -1); int i = 0; for (i = 0; i < active_fds_cnt; i++) { // if fd == listen_fd if (my_events[i].data.fd == listen_fd) { //accept client_fd = accept(listen_fd, (struct sockaddr*)&client_addr, &client_len); if (client_fd < 0) { perror("accept"); continue; } char ip[20]; printf("new connection[%s:%d]\n", inet_ntop(AF_INET, &client_addr.sin_addr, ip, sizeof(ip)), ntohs(client_addr.sin_port)); event.events = EPOLLIN | EPOLLET; event.data.fd = client_fd; epoll_ctl(epfd, EPOLL_CTL_ADD, client_fd, &event); } else if (my_events[i].events & EPOLLIN) { printf("EPOLLIN\n"); client_fd = my_events[i].data.fd; // do read buffer[0] = '\0'; int n = read(client_fd, buffer, 5); if (n < 0) { perror("read"); continue; } else if (n == 0) { epoll_ctl(epfd, EPOLL_CTL_DEL, client_fd, &event); close(client_fd); } else { printf("[read]: %s\n", buffer); buffer[n] = '\0'; #if 1 str_toupper(buffer); write(client_fd, buffer, strlen(buffer)); printf("[write]: %s\n", buffer); memset(buffer, 0, BUFFER_MAX_LEN); #endif /* event.events = EPOLLOUT; event.data.fd = client_fd; epoll_ctl(epfd, EPOLL_CTL_MOD, client_fd, &event); */ } } else if (my_events[i].events & EPOLLOUT) { printf("EPOLLOUT\n"); /* client_fd = my_events[i].data.fd; str_toupper(buffer); write(client_fd, buffer, strlen(buffer)); printf("[write]: %s\n", buffer); memset(buffer, 0, BUFFER_MAX_LEN); event.events = EPOLLIN; event.data.fd = client_fd; epoll_ctl(epfd, EPOLL_CTL_MOD, client_fd, &event); */ } } } END: close(epfd); close(listen_fd); return 0; } ``` ###2.6.2 客戶端 ```cpp #include <stdio.h> #include <stdlib.h> #include <string.h> #include <strings.h> #include <sys/types.h> #include <sys/socket.h> #include <arpa/inet.h> #include <unistd.h> #include <fcntl.h> #define MAX_LINE (1024) #define SERVER_PORT (7778) void setnoblocking(int fd) { int opts = 0; opts = fcntl(fd, F_GETFL); opts = opts | O_NONBLOCK; fcntl(fd, F_SETFL); } int main(int argc, char **argv) { int sockfd; char recvline[MAX_LINE + 1] = {0}; struct sockaddr_in server_addr; if (argc != 2) { fprintf(stderr, "usage ./client <SERVER_IP>\n"); exit(0); } // 創建socket if ( (sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) { fprintf(stderr, "socket error"); exit(0); } // server addr 賦值 bzero(&server_addr, sizeof(server_addr)); server_addr.sin_family = AF_INET; server_addr.sin_port = htons(SERVER_PORT); if (inet_pton(AF_INET, argv[1], &server_addr.sin_addr) <= 0) { fprintf(stderr, "inet_pton error for %s", argv[1]); exit(0); } // 鏈接服務端 if (connect(sockfd, (struct sockaddr*) &server_addr, sizeof(server_addr)) < 0) { perror("connect"); fprintf(stderr, "connect error\n"); exit(0); } setnoblocking(sockfd); char input[100]; int n = 0; int count = 0; // 不斷的從標準輸入字符串 while (fgets(input, 100, stdin) != NULL) { printf("[send] %s\n", input); n = 0; // 把輸入的字符串發送 到 服務器中去 n = send(sockfd, input, strlen(input), 0); if (n < 0) { perror("send"); } n = 0; count = 0; // 讀取 服務器返回的數據 while (1) { n = read(sockfd, recvline + count, MAX_LINE); if (n == MAX_LINE) { count += n; continue; } else if (n < 0){ perror("recv"); break; } else { count += n; recvline[count] = '\0'; printf("[recv] %s\n", recvline); break; } } } return 0; } ```