Libevent 사용 예, 간단 함 에서 복잡 함 까지
본 고 는 간단 함 에서 복잡 함 까지 Libevent 를 어떻게 사용 하 는 지 보 여 준다.또한 인터넷 의 많은 예 는 서버 쪽 만 있 고 본 고 는 클 라 이언 트 와 서버 쪽 에 모두 있 습 니 다.이렇게 많아
초급:
클 라 이언 트 코드:
#include
");
return -1;
}
// IP 、
int sockfd = tcp_connect_server(argv[1], atoi(argv[2]));
if( sockfd == -1)
{
perror("tcp_connect error ");
return -1;
}
printf("connect to server successful
");
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
");
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
", 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 ) //the server_ip is not valid value
{
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; //the close may be error
return -1;
}
evutil_make_socket_nonblocking(sockfd);
return sockfd;
}서버 쪽 코드:
#include
", sockfd);
struct event_base* base = (event_base*)arg;
// event
struct event *ev = event_new(NULL, -1, 0, NULL, NULL);
// event
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
");
close(event_get_fd(ev));
event_free(ev);
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;
// 。 socket bind
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;
}중간:
클 라 이언 트 코드:
#include
");
return -1;
}
// IP 、
int sockfd = tcp_connect_server(argv[1], atoi(argv[2]));
if( sockfd == -1)
{
perror("tcp_connect error ");
return -1;
}
printf("connect to server successful
");
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);
// socket
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
");
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
", msg);
}
void event_cb(struct bufferevent *bev, short event, void *arg)
{
if (event & BEV_EVENT_EOF)
printf("connection closed
");
else if (event & BEV_EVENT_ERROR)
printf("some other error
");
// close free
bufferevent_free(bev);
struct event *ev = (struct event*)arg;
// socket ， event
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 ) //the server_ip is not valid value
{
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; //the close may be error
return -1;
}
evutil_make_socket_nonblocking(sockfd);
return sockfd;
}서버 쪽 코드:
#include
", 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
");
else if (event & BEV_EVENT_ERROR)
printf("some other error
");
// close free
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;
// 。 socket bind
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;
}고등:
클 라 이언 트 코드:
#include
");
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
");
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
", msg);
}
void event_cb(struct bufferevent *bev, short event, void *arg)
{
if (event & BEV_EVENT_EOF)
printf("connection closed
");
else if (event & BEV_EVENT_ERROR)
printf("some other error
");
else if( event & BEV_EVENT_CONNECTED)
{
printf("the client has connected to server
");
return ;
}
// close free
bufferevent_free(bev);
struct event *ev = (struct event*)arg;
event_free(ev);
}서버 쪽 코드:
#include
", fd);
event_base *base = (event_base*)arg;
// bufferevent
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
", 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
");
else if (events & BEV_EVENT_ERROR)
printf("some other error
");
// close free
bufferevent_free(bev);
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