epoll服务端和客户端示例代码

epoll 服务端demo

#include <stdio.h>
#include <sys/epoll.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <fcntl.h>
#include <unistd.h>
#include <netdb.h>
#include <errno.h>
#include <ctype.h>
#include <string.h>#define MAX_EVENTS 20
#define BUFFER_LEN 512
#define IP_ADDR "192.168.1.3"
#define SERVER_PORT 8081static int set_socket_non_blocking(int f) {int flags, s;flags = fcntl(f, F_GETFL, 0);if (-1 == flags) {perror("get fd status error");return -1;}flags |= O_NONBLOCK;s = fcntl(f, F_SETFL, flags);if (s == -1){perror("set fd status error");return -1;}return 0;
}int main() {int listenfd = 0, epfd = 0;int result = 0;struct epoll_event ev, events[MAX_EVENTS];struct sockaddr_in server_addr = {0};listenfd = socket(AF_INET, SOCK_STREAM, 0);if (-1 == listenfd) {perror("open listen socket");return -1;}int on = 1;result = setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));if (-1 == result) {perror("set socket");return -1;}server_addr.sin_family = AF_INET;inet_aton(IP_ADDR, &(server_addr.sin_addr));server_addr.sin_port = htons(SERVER_PORT);result = bind(listenfd, (const struct sockaddr*)&server_addr, sizeof(server_addr));if (result == -1) {perror("bind socket");return -1;}result = set_socket_non_blocking(listenfd);if (result == -1) {printf("set socket non blocking failed\n");return -1;}result = listen(listenfd, 200);if (-1 == result) {perror("start listen");return -1;}epfd = epoll_create1(0);if (1 == epfd) {perror("create epoll instance");return -1;}ev.data.fd = listenfd;ev.events = EPOLLIN | EPOLLET;result = epoll_ctl(epfd, EPOLL_CTL_ADD, listenfd, &ev);if (-1 == result) {perror("set epoll ctl");return -1;}for (; ;) {int wait_count = 0;wait_count = epoll_wait(epfd, events, MAX_EVENTS, -1);for (int i = 0; i < wait_count; i++) {uint32_t event = events[i].events;char host_buf[NI_MAXHOST];char port_buf[NI_MAXSERV];int _result;if ((event & EPOLLERR) || (event & EPOLLHUP) || (!(event & EPOLLIN))) {printf("epoll has error\n");close(events[i].data.fd);continue;} else if (listenfd == events[i].data.fd) {for (; ;) {struct sockaddr in_addr = {0};socklen_t in_addr_len = sizeof(in_addr);int accp_fd = accept(listenfd, &in_addr, &in_addr_len);if (-1 == accp_fd) {perror("accept");break;}_result = getnameinfo(&in_addr,	sizeof(in_addr),host_buf, sizeof(host_buf) / sizeof(host_buf[0]),port_buf, sizeof(port_buf) / sizeof(port_buf[0]),NI_NUMERICHOST | NI_NUMERICSERV);if (!_result) {printf("new connection: host = %s, port = %s\n", host_buf, port_buf);}_result = set_socket_non_blocking(accp_fd);if (-1 == _result) {printf("set accept fd failed\n");return 0;}ev.data.fd = accp_fd;ev.events = EPOLLIN | EPOLLET;_result = epoll_ctl(epfd, EPOLL_CTL_ADD, accp_fd, &ev);if (-1 == _result) {perror("epoll ctl");return 0;}}continue;} else {int done = 0;for ( ; ; ) {ssize_t result_len = 0;char buf[BUFFER_LEN] = {0};result_len = read(events[i].data.fd, buf, sizeof(buf) / sizeof(buf[0]));if (-1 == result_len) {if (EAGAIN != errno) {perror("read data");done = 1;}break;} else if (!result_len) {done = 1;break;}if (strlen(buf) == 0)continue;for (int m = 0; buf[m] != '\0'; m++) {buf[m] = toupper(buf[m]);}write(events[i].data.fd, buf, result_len);}if (done) {printf("closed connection\n");close(events[i].data.fd);}}}}close(epfd);return 0;
}

epoll客户端demo

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <signal.h>#define BUFFER_SIZE 1024
#define IP_ADDR "192.168.1.2"
#define SERVER_PORT 8081int sockfd = -1;
void sigctl(int sig) {if (sockfd != -1) {close(sockfd);}printf("bye, will exit ...\n");exit(0);
}int main() {struct sockaddr_in st_clnsock;char msg[BUFFER_SIZE] = {0};int recv_size = 0;signal(SIGINT, sigctl);if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {printf("socket error: %s (errno: %d)\n", strerror(errno), errno);exit(0);}memset(&st_clnsock, 0, sizeof(st_clnsock));st_clnsock.sin_family = AF_INET;if (inet_pton(AF_INET, IP_ADDR, &st_clnsock.sin_addr) <= 0) {printf("inet pton error: %s (errno: %d)\n", strerror(errno), errno);exit(0);}st_clnsock.sin_port = htons(SERVER_PORT);if (connect(sockfd, (struct sockaddr *)&st_clnsock, sizeof(st_clnsock)) < 0) {printf("connect error: %s (errno: %d)\n", strerror(errno), errno);exit(0);}while (1) {memset(msg, 0, sizeof(msg));fgets(msg, BUFFER_SIZE, stdin);if (write(sockfd, msg, sizeof(msg)) < 0) {printf("write error: %s (errno: %d)\n", strerror(errno), errno);exit(0);}memset(msg, 0, sizeof(msg));if ((recv_size = read(sockfd, msg, BUFFER_SIZE)) < 0) {printf("read error: %s (errno: %d)\n", strerror(errno), errno);} else if (recv_size == 0) {printf("server closed\n");} else {printf("server return: %s\n", msg);}}return 0;
}