libevent实现的简单回射服务器，客户端

1.安装libevent

我有同样的问题，就像其他答案建议我安装了“libevent”。这显然不是叫“libevent发展”（apt-get无法找到它）而做的：

 $ apt-cache search libevent

列出一堆可用的软件包。

 $ apt-get install libevent-dev (其他linux系统用yum -y install libevent-devel)

首先，安装libevent到任意目录下


wget ~provos/libevent-1.4.13-stable.tar.gz
tar –xzvf libevent-1.4.13-stable.tar.gz
cd libevent-1.4.13-stable
./configure --prefix=/home/mydir/libevent
make && make install

/*libevent server*/
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <stdio.h>
#include <string.h>
#include <event.h>
#include <stdlib.h>

#define PORT        5188
#define BACKLOG     5
#define MEM_SIZE    1024

struct event_base* base;
struct sock_ev
{
    struct event* read_ev;
    struct event* write_ev;
    char* buffer;
};

void release_sock_event(struct sock_ev* ev)
{
    event_del(ev->read_ev);
    free(ev->read_ev);
    free(ev->write_ev);
    free(ev->buffer);
    free(ev);
}

void on_write(int sock, short event, void* arg)
{
    char* buffer = (char*)arg;
    send(sock, buffer, strlen(buffer), 0);

    free(buffer);
}

void on_read(int sock, short event, void* arg)
{
    struct event* write_ev;
    int size;
    struct sock_ev* ev = (struct sock_ev*)arg;
    ev->buffer = (char*)malloc(MEM_SIZE);
    bzero(ev->buffer, MEM_SIZE);
    size = recv(sock, ev->buffer, MEM_SIZE, 0);
    printf("receive data:%s, size:%d\n", ev->buffer, size);
    if (size == 0)
    {
        release_sock_event(ev);
        close(sock);
        return;
    }
    event_set(ev->write_ev, sock, EV_WRITE, on_write, ev->buffer);
    event_base_set(base, ev->write_ev);
    event_add(ev->write_ev, NULL);
}

void on_accept(int sock, short event, void* arg)
{
    struct sockaddr_in cli_addr;
    int newfd, sin_size;
    struct sock_ev* ev = (struct sock_ev*)malloc(sizeof(struct sock_ev));
    ev->read_ev = (struct event*)malloc(sizeof(struct event));
    ev->write_ev = (struct event*)malloc(sizeof(struct event));
    sin_size = sizeof(struct sockaddr_in);
    newfd = accept(sock, (struct sockaddr*)&cli_addr, &sin_size);
    event_set(ev->read_ev, newfd, EV_READ|EV_PERSIST, on_read, ev);
    event_base_set(base, ev->read_ev);
    event_add(ev->read_ev, NULL);
}

int main(int argc, char* argv[])
{
    struct sockaddr_in my_addr;
    int sock;

    sock = socket(AF_INET, SOCK_STREAM, 0);
    int yes = 1;
    setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int));
    memset(&my_addr, 0, sizeof(my_addr));
    my_addr.sin_family = AF_INET;
    my_addr.sin_port = htons(PORT);
    my_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    bind(sock, (struct sockaddr*)&my_addr, sizeof(struct sockaddr));
    listen(sock, BACKLOG);
    /*libevent*/
    struct event listen_ev;
    base = event_base_new();
    event_set(&listen_ev, sock, EV_READ|EV_PERSIST, on_accept, NULL);
    event_base_set(base, &listen_ev);
    event_add(&listen_ev, NULL);
    event_base_dispatch(base);

    return 0;
}

$  gcc  libevent_server.c -o libserver -levent

/*libevent client*/
#include <unistd.h>
#include <stdio.h>
#include <fcntl.h>
#include <netdb.h>
#include <sys/socket.h>
#include <stdlib.h>
#include <string.h>
#define cerror(str) do{perror(str); exit(EXIT_FAILURE); }while(0)
int main()
{

    int fd;
    struct sockaddr_in sin;

    memset(&sin, 0, sizeof(sin));
    sin.sin_family = AF_INET;
    sin.sin_port = htons(5188);
    sin.sin_addr.s_addr = inet_addr("127.0.0.1");
  /* if(argc<3)
    {
        port = 8888;
    }else
    {
        port = atoi(argv[2]);
    }

    sin.sin_port = htons(port);

    if(argc<2)
    {
        strcpy(addr, argv[1]);
        if (inet_pton(AF_INET, addr, &(sin.sin_addr) )<0)
        {
             struct hostent *psh;
             psh=gethostbyname(addr);
             if(psh!=NULL)
                inet_pton(AF_INET, psh->h_addr, &(sin.sin_addr) );
             else
                cerror("inet_pton");
        }
    }
     */
    fd=socket(AF_INET, SOCK_STREAM, 0);
    /* if( */connect(fd, (struct sockaddr*)&sin, sizeof(sin));/* <0 ) */
     /* cerror("connect"); */

    char sendbuf[1024]={0};
    char recvbuf[1024]={0};
    while(fgets(sendbuf,sizeof(sendbuf),stdin)!=NULL)
    {
        write(fd,sendbuf,strlen(sendbuf));
        read(fd,recvbuf,sizeof(recvbuf));
        fputs(recvbuf,stdout);
        memset(sendbuf,0,sizeof(sendbuf));
        memset(recvbuf,0,sizeof(recvbuf));
    }
    close(fd);
    return 0;
}

$  gcc libclient.c -o libclient