libevent学习笔记 ---- 回显服务器 （２）

上一篇写了简单使用libevent的例子，本篇写一个高级一点的回显服务器程序，使用libevent提供的高级利器bufferevent，客户端程序请参考上篇文章。

#include <stdio.h>#include <stdlib.h>#include <unistd.h>#include <string.h>#include <errno.h>#include <fcntl.h>#include <sys/socket.h>#include <netinet/in.h>#include <arpa/inet.h>#include <event2/event.h>#include <event2/bufferevent.h>#define MAX_BUF_SIZE    1024void do_event_cb(struct bufferevent *bev, short event, void *arg){    if (event & BEV_EVENT_EOF)    {        printf("connection closed by peer, socket: %d ...\r\n",                 bufferevent_getfd(bev));    }    else if (event & BEV_EVENT_ERROR)    {        printf("some error happened ...\r\n");    }    bufferevent_free(bev);}void do_read_cb(struct bufferevent *bev, void *arg){    struct evbuffer *input = bufferevent_get_input(bev);    struct evbuffer *output = bufferevent_get_output(bev);    int len = evbuffer_get_length(input);    if (len)    {        evbuffer_add_buffer(output, input);    }}void do_accept_cb(int fd, short events, void *arg){    evutil_socket_t sock;    struct sockaddr_in client;    int len;    sock = accept(fd, (struct sockaddr*)&client, &len);    if (sock < 0)    {        fprintf(stderr, "accept() error: errno %d --- %s\r\n",                errno, strerror(errno));        return;    }    evutil_make_socket_nonblocking(sock);    struct event_base *base = (struct event_base *)arg;    struct bufferevent *bev = bufferevent_socket_new(base, sock,             BEV_OPT_CLOSE_ON_FREE);    bufferevent_setcb(bev, do_read_cb, NULL, do_event_cb, arg);    bufferevent_enable(bev, EV_READ | EV_PERSIST);}int init_echo_server(int port){    int sock = socket(AF_INET, SOCK_STREAM, 0);    if (sock < 0)    {        fprintf(stderr, "socket() error: errno %d --- %s\r\n",                 errno, strerror(errno));        return -1;    }    evutil_make_listen_socket_reuseable(sock);    struct sockaddr_in sin;    sin.sin_family = AF_INET;    sin.sin_addr.s_addr = 0;    sin.sin_port = htons(port);    if (bind(sock, (struct sockaddr *)&sin, sizeof(sin)) < 0)    {        fprintf(stderr, "bind() error: errno %d --- %s\r\n",                errno, strerror(errno));        goto error;    }    if (listen(sock, 32) < 0)    {        fprintf(stderr, "listen() error: errno %d --- %s\r\n",                errno, strerror(errno));        goto error;    }    struct event_base *base = event_base_new();    struct event *ev_listen = event_new(base, sock, EV_READ | EV_PERSIST,            do_accept_cb, base);    event_add(ev_listen, NULL);    event_base_dispatch(base);    event_base_free(base);    return 0;error:    close(sock);    return -1;}int main(int argc, char **argv){    int port = 9999;    if (argc >= 2)    {        port = atoi(argv[1]);        if (port < 0 || port > 65535)        {            fprintf(stderr, "Invalid port ...\r\n");            return -1;        }    }    init_echo_server(port);    return 0;}