[z]http://blog.csdn.net/luotuo44/article/details/39670221編程
本文從簡單到複雜,展現如何使用libevent。網上的許多例子都是隻有服務器端的,本文裏面客戶端和服務器端都有,以饗讀者。服務器
關於libevent編程時的一些疑問能夠閱讀《libevent編程疑難解答》。假如讀者還想了解libevent的具體實現,能夠閱讀《libevent源碼分析》系統文章。app
不說這麼多了,直接上代碼。socket
初等:
客戶端代碼:
- #include<sys/types.h>
- #include<sys/socket.h>
- #include<netinet/in.h>
- #include<arpa/inet.h>
- #include<errno.h>
- #include<unistd.h>
-
- #include<stdio.h>
- #include<string.h>
- #include<stdlib.h>
-
- #include<event.h>
- #include<event2/util.h>
-
-
-
-
- int tcp_connect_server(const char* server_ip, int port);
-
-
- void cmd_msg_cb(int fd, short events, void* arg);
- void socket_read_cb(int fd, short events, void *arg);
-
- int main(int argc, char** argv)
- {
- if( argc < 3 )
- {
- printf("please input 2 parameter\n");
- return -1;
- }
-
-
-
- int sockfd = tcp_connect_server(argv[1], atoi(argv[2]));
- if( sockfd == -1)
- {
- perror("tcp_connect error ");
- return -1;
- }
-
- printf("connect to server successful\n");
-
- struct event_base* base = event_base_new();
-
- struct event *ev_sockfd = event_new(base, sockfd,
- EV_READ | EV_PERSIST,
- socket_read_cb, NULL);
- event_add(ev_sockfd, NULL);
-
-
- struct event* ev_cmd = event_new(base, STDIN_FILENO,
- EV_READ | EV_PERSIST, cmd_msg_cb,
- (void*)&sockfd);
-
-
- event_add(ev_cmd, NULL);
-
- event_base_dispatch(base);
-
- printf("finished \n");
- return 0;
- }
-
-
-
-
-
-
- void cmd_msg_cb(int fd, short events, void* arg)
- {
- char msg[1024];
-
- int ret = read(fd, msg, sizeof(msg));
- if( ret <= 0 )
- {
- perror("read fail ");
- exit(1);
- }
-
- int sockfd = *((int*)arg);
-
-
-
- write(sockfd, msg, ret);
- }
-
-
- void socket_read_cb(int fd, short events, void *arg)
- {
- char msg[1024];
-
-
- int len = read(fd, msg, sizeof(msg)-1);
- if( len <= 0 )
- {
- perror("read fail ");
- exit(1);
- }
-
- msg[len] = '\0';
-
- printf("recv %s from server\n", msg);
- }
-
-
-
- typedef struct sockaddr SA;
- int tcp_connect_server(const char* server_ip, int port)
- {
- int sockfd, status, save_errno;
- struct sockaddr_in server_addr;
-
- memset(&server_addr, 0, sizeof(server_addr) );
-
- server_addr.sin_family = AF_INET;
- server_addr.sin_port = htons(port);
- status = inet_aton(server_ip, &server_addr.sin_addr);
-
- if( status == 0 )
- {
- errno = EINVAL;
- return -1;
- }
-
- sockfd = ::socket(PF_INET, SOCK_STREAM, 0);
- if( sockfd == -1 )
- return sockfd;
-
-
- status = ::connect(sockfd, (SA*)&server_addr, sizeof(server_addr) );
-
- if( status == -1 )
- {
- save_errno = errno;
- ::close(sockfd);
- errno = save_errno;
- return -1;
- }
-
- evutil_make_socket_nonblocking(sockfd);
-
- return sockfd;
- }
服務器端代碼:
- #include<stdio.h>
- #include<string.h>
- #include<errno.h>
-
- #include<unistd.h>
- #include<event.h>
-
-
-
- void accept_cb(int fd, short events, void* arg);
- void socket_read_cb(int fd, short events, void *arg);
-
- int tcp_server_init(int port, int listen_num);
-
- int main(int argc, char** argv)
- {
-
- int listener = tcp_server_init(9999, 10);
- if( listener == -1 )
- {
- perror(" tcp_server_init error ");
- return -1;
- }
-
- struct event_base* base = event_base_new();
-
-
- struct event* ev_listen = event_new(base, listener, EV_READ | EV_PERSIST,
- accept_cb, base);
- event_add(ev_listen, NULL);
-
-
- event_base_dispatch(base);
-
- return 0;
- }
-
-
-
- void accept_cb(int fd, short events, void* arg)
- {
- evutil_socket_t sockfd;
-
- struct sockaddr_in client;
- socklen_t len = sizeof(client);
-
- sockfd = ::accept(fd, (struct sockaddr*)&client, &len );
- evutil_make_socket_nonblocking(sockfd);
-
- printf("accept a client %d\n", sockfd);
-
- struct event_base* base = (event_base*)arg;
-
-
- struct event *ev = event_new(NULL, -1, 0, NULL, NULL);
-
- event_assign(ev, base, sockfd, EV_READ | EV_PERSIST,
- socket_read_cb, (void*)ev);
-
- event_add(ev, NULL);
- }
-
-
- void socket_read_cb(int fd, short events, void *arg)
- {
- char msg[4096];
- struct event *ev = (struct event*)arg;
- int len = read(fd, msg, sizeof(msg) - 1);
-
-
-
- if( len <= 0 )
- {
- printf("some error happen when read\n");
- event_free(ev);
- close(fd);
- return ;
- }
-
- msg[len] = '\0';
- printf("recv the client msg: %s", msg);
-
- char reply_msg[4096] = "I have recvieced the msg: ";
- strcat(reply_msg + strlen(reply_msg), msg);
-
- write(fd, reply_msg, strlen(reply_msg) );
- }
-
-
-
- typedef struct sockaddr SA;
- int tcp_server_init(int port, int listen_num)
- {
- int errno_save;
- evutil_socket_t listener;
-
- listener = ::socket(AF_INET, SOCK_STREAM, 0);
- if( listener == -1 )
- return -1;
-
-
- evutil_make_listen_socket_reuseable(listener);
-
- struct sockaddr_in sin;
- sin.sin_family = AF_INET;
- sin.sin_addr.s_addr = 0;
- sin.sin_port = htons(port);
-
- if( ::bind(listener, (SA*)&sin, sizeof(sin)) < 0 )
- goto error;
-
- if( ::listen(listener, listen_num) < 0)
- goto error;
-
-
-
- evutil_make_socket_nonblocking(listener);
-
- return listener;
-
- error:
- errno_save = errno;
- evutil_closesocket(listener);
- errno = errno_save;
-
- return -1;
- }
中等:
客戶端代碼:
- #include<sys/types.h>
- #include<sys/socket.h>
- #include<netinet/in.h>
- #include<arpa/inet.h>
- #include<errno.h>
- #include<unistd.h>
-
- #include<stdio.h>
- #include<string.h>
- #include<stdlib.h>
-
- #include<event.h>
- #include<event2/bufferevent.h>
- #include<event2/buffer.h>
- #include<event2/util.h>
-
-
-
-
- int tcp_connect_server(const char* server_ip, int port);
-
-
- void cmd_msg_cb(int fd, short events, void* arg);
- void server_msg_cb(struct bufferevent* bev, void* arg);
- void event_cb(struct bufferevent *bev, short event, void *arg);
-
- int main(int argc, char** argv)
- {
- if( argc < 3 )
- {
- printf("please input 2 parameter\n");
- return -1;
- }
-
-
-
- int sockfd = tcp_connect_server(argv[1], atoi(argv[2]));
- if( sockfd == -1)
- {
- perror("tcp_connect error ");
- return -1;
- }
-
- printf("connect to server successful\n");
-
- struct event_base* base = event_base_new();
-
- struct bufferevent* bev = bufferevent_socket_new(base, sockfd,
- BEV_OPT_CLOSE_ON_FREE);
-
-
- struct event* ev_cmd = event_new(base, STDIN_FILENO,
- EV_READ | EV_PERSIST, cmd_msg_cb,
- (void*)bev);
- event_add(ev_cmd, NULL);
-
-
- bufferevent_setcb(bev, server_msg_cb, NULL, event_cb, (void*)ev_cmd);
- bufferevent_enable(bev, EV_READ | EV_PERSIST);
-
-
- event_base_dispatch(base);
-
- printf("finished \n");
- return 0;
- }
-
-
-
-
-
-
- void cmd_msg_cb(int fd, short events, void* arg)
- {
- char msg[1024];
-
- int ret = read(fd, msg, sizeof(msg));
- if( ret < 0 )
- {
- perror("read fail ");
- exit(1);
- }
-
- struct bufferevent* bev = (struct bufferevent*)arg;
-
-
- bufferevent_write(bev, msg, ret);
- }
-
-
- void server_msg_cb(struct bufferevent* bev, void* arg)
- {
- char msg[1024];
-
- size_t len = bufferevent_read(bev, msg, sizeof(msg));
- msg[len] = '\0';
-
- printf("recv %s from server\n", msg);
- }
-
-
- void event_cb(struct bufferevent *bev, short event, void *arg)
- {
-
- if (event & BEV_EVENT_EOF)
- printf("connection closed\n");
- else if (event & BEV_EVENT_ERROR)
- printf("some other error\n");
-
-
- bufferevent_free(bev);
-
- struct event *ev = (struct event*)arg;
-
- event_free(ev);
- }
-
-
- typedef struct sockaddr SA;
- int tcp_connect_server(const char* server_ip, int port)
- {
- int sockfd, status, save_errno;
- struct sockaddr_in server_addr;
-
- memset(&server_addr, 0, sizeof(server_addr) );
-
- server_addr.sin_family = AF_INET;
- server_addr.sin_port = htons(port);
- status = inet_aton(server_ip, &server_addr.sin_addr);
-
- if( status == 0 )
- {
- errno = EINVAL;
- return -1;
- }
-
- sockfd = ::socket(PF_INET, SOCK_STREAM, 0);
- if( sockfd == -1 )
- return sockfd;
-
-
- status = ::connect(sockfd, (SA*)&server_addr, sizeof(server_addr) );
-
- if( status == -1 )
- {
- save_errno = errno;
- ::close(sockfd);
- errno = save_errno;
- return -1;
- }
-
- evutil_make_socket_nonblocking(sockfd);
-
- return sockfd;
- }
服務器端代碼:
- #include<stdio.h>
- #include<string.h>
- #include<errno.h>
-
- #include<event.h>
- #include<event2/bufferevent.h>
-
-
-
- void accept_cb(int fd, short events, void* arg);
- void socket_read_cb(bufferevent* bev, void* arg);
- void event_cb(struct bufferevent *bev, short event, void *arg);
- int tcp_server_init(int port, int listen_num);
-
- int main(int argc, char** argv)
- {
-
- int listener = tcp_server_init(9999, 10);
- if( listener == -1 )
- {
- perror(" tcp_server_init error ");
- return -1;
- }
-
- struct event_base* base = event_base_new();
-
-
- struct event* ev_listen = event_new(base, listener, EV_READ | EV_PERSIST,
- accept_cb, base);
- event_add(ev_listen, NULL);
-
-
- event_base_dispatch(base);
- event_base_free(base);
-
-
- return 0;
- }
-
-
-
- void accept_cb(int fd, short events, void* arg)
- {
- evutil_socket_t sockfd;
-
- struct sockaddr_in client;
- socklen_t len = sizeof(client);
-
- sockfd = ::accept(fd, (struct sockaddr*)&client, &len );
- evutil_make_socket_nonblocking(sockfd);
-
- printf("accept a client %d\n", sockfd);
-
- struct event_base* base = (event_base*)arg;
-
- bufferevent* bev = bufferevent_socket_new(base, sockfd, BEV_OPT_CLOSE_ON_FREE);
- bufferevent_setcb(bev, socket_read_cb, NULL, event_cb, arg);
-
- bufferevent_enable(bev, EV_READ | EV_PERSIST);
- }
-
-
-
- void socket_read_cb(bufferevent* bev, void* arg)
- {
- char msg[4096];
-
- size_t len = bufferevent_read(bev, msg, sizeof(msg));
-
- msg[len] = '\0';
- printf("recv the client msg: %s", msg);
-
-
- char reply_msg[4096] = "I have recvieced the msg: ";
-
- strcat(reply_msg + strlen(reply_msg), msg);
- bufferevent_write(bev, reply_msg, strlen(reply_msg));
- }
-
-
-
- void event_cb(struct bufferevent *bev, short event, void *arg)
- {
-
- if (event & BEV_EVENT_EOF)
- printf("connection closed\n");
- else if (event & BEV_EVENT_ERROR)
- printf("some other error\n");
-
-
- bufferevent_free(bev);
- }
-
-
- typedef struct sockaddr SA;
- int tcp_server_init(int port, int listen_num)
- {
- int errno_save;
- evutil_socket_t listener;
-
- listener = ::socket(AF_INET, SOCK_STREAM, 0);
- if( listener == -1 )
- return -1;
-
-
- evutil_make_listen_socket_reuseable(listener);
-
- struct sockaddr_in sin;
- sin.sin_family = AF_INET;
- sin.sin_addr.s_addr = 0;
- sin.sin_port = htons(port);
-
- if( ::bind(listener, (SA*)&sin, sizeof(sin)) < 0 )
- goto error;
-
- if( ::listen(listener, listen_num) < 0)
- goto error;
-
-
-
- evutil_make_socket_nonblocking(listener);
-
- return listener;
-
- error:
- errno_save = errno;
- evutil_closesocket(listener);
- errno = errno_save;
-
- return -1;
- }
高等:
客戶端代碼:
- #include<sys/types.h>
- #include<sys/socket.h>
- #include<netinet/in.h>
- #include<arpa/inet.h>
- #include<errno.h>
- #include<unistd.h>
-
- #include<stdio.h>
- #include<string.h>
- #include<stdlib.h>
-
- #include<event.h>
- #include<event2/bufferevent.h>
- #include<event2/buffer.h>
- #include<event2/util.h>
-
-
-
-
- int tcp_connect_server(const char* server_ip, int port);
-
-
- void cmd_msg_cb(int fd, short events, void* arg);
- void server_msg_cb(struct bufferevent* bev, void* arg);
- void event_cb(struct bufferevent *bev, short event, void *arg);
-
- int main(int argc, char** argv)
- {
- if( argc < 3 )
- {
-
- printf("please input 2 parameter\n");
- return -1;
- }
-
- struct event_base *base = event_base_new();
-
- struct bufferevent* bev = bufferevent_socket_new(base, -1,
- BEV_OPT_CLOSE_ON_FREE);
-
-
- struct event* ev_cmd = event_new(base, STDIN_FILENO,
- EV_READ | EV_PERSIST,
- cmd_msg_cb, (void*)bev);
-
-
- event_add(ev_cmd, NULL);
-
- struct sockaddr_in server_addr;
-
- memset(&server_addr, 0, sizeof(server_addr) );
-
- server_addr.sin_family = AF_INET;
- server_addr.sin_port = htons(atoi(argv[2]));
- inet_aton(argv[1], &server_addr.sin_addr);
-
- bufferevent_socket_connect(bev, (struct sockaddr *)&server_addr,
- sizeof(server_addr));
-
-
- bufferevent_setcb(bev, server_msg_cb, NULL, event_cb, (void*)ev_cmd);
- bufferevent_enable(bev, EV_READ | EV_PERSIST);
-
-
-
- event_base_dispatch(base);
-
- printf("finished \n");
- return 0;
- }
-
-
-
-
-
- void cmd_msg_cb(int fd, short events, void* arg)
- {
- char msg[1024];
-
- int ret = read(fd, msg, sizeof(msg));
- if( ret < 0 )
- {
- perror("read fail ");
- exit(1);
- }
-
- struct bufferevent* bev = (struct bufferevent*)arg;
-
-
- bufferevent_write(bev, msg, ret);
- }
-
-
- void server_msg_cb(struct bufferevent* bev, void* arg)
- {
- char msg[1024];
-
- size_t len = bufferevent_read(bev, msg, sizeof(msg));
- msg[len] = '\0';
-
- printf("recv %s from server\n", msg);
- }
-
-
- void event_cb(struct bufferevent *bev, short event, void *arg)
- {
-
- if (event & BEV_EVENT_EOF)
- printf("connection closed\n");
- else if (event & BEV_EVENT_ERROR)
- printf("some other error\n");
- else if( event & BEV_EVENT_CONNECTED)
- {
- printf("the client has connected to server\n");
- return ;
- }
-
-
- bufferevent_free(bev);
-
- struct event *ev = (struct event*)arg;
- event_free(ev);
- }
服務器端代碼:
- #include<netinet/in.h>
- #include<sys/socket.h>
- #include<unistd.h>
-
- #include<stdio.h>
- #include<string.h>
-
- #include<event.h>
- #include<listener.h>
- #include<bufferevent.h>
- #include<thread.h>
-
-
- void listener_cb(evconnlistener *listener, evutil_socket_t fd,
- struct sockaddr *sock, int socklen, void *arg);
-
- void socket_read_cb(bufferevent *bev, void *arg);
- void socket_event_cb(bufferevent *bev, short events, void *arg);
-
- int main()
- {
-
-
- struct sockaddr_in sin;
- memset(&sin, 0, sizeof(struct sockaddr_in));
- sin.sin_family = AF_INET;
- sin.sin_port = htons(9999);
-
- event_base *base = event_base_new();
- evconnlistener *listener
- = evconnlistener_new_bind(base, listener_cb, base,
- LEV_OPT_REUSEABLE|LEV_OPT_CLOSE_ON_FREE,
- 10, (struct sockaddr*)&sin,
- sizeof(struct sockaddr_in));
-
- event_base_dispatch(base);
-
- evconnlistener_free(listener);
- event_base_free(base);
-
- return 0;
- }
-
-
- void listener_cb(evconnlistener *listener, evutil_socket_t fd,
- struct sockaddr *sock, int socklen, void *arg)
- {
- printf("accept a client %d\n", fd);
-
- event_base *base = (event_base*)arg;
-
-
- bufferevent *bev = bufferevent_socket_new(base, fd,
- BEV_OPT_CLOSE_ON_FREE);
-
- bufferevent_setcb(bev, socket_read_cb, NULL, socket_event_cb, NULL);
- bufferevent_enable(bev, EV_READ | EV_PERSIST);
- }
-
-
- void socket_read_cb(bufferevent *bev, void *arg)
- {
- char msg[4096];
-
- size_t len = bufferevent_read(bev, msg, sizeof(msg)-1 );
-
- msg[len] = '\0';
- printf("server read the data %s\n", msg);
-
- char reply[] = "I has read your data";
- bufferevent_write(bev, reply, strlen(reply) );
- }
-
-
- void socket_event_cb(bufferevent *bev, short events, void *arg)
- {
- if (events & BEV_EVENT_EOF)
- printf("connection closed\n");
- else if (events & BEV_EVENT_ERROR)
- printf("some other error\n");
-
-
- bufferevent_free(bev);
- }