Linux 即时聊天系统（tcp）epoll 版

简介：

　　1.系统使用TCP来实现

　　2.服务端 ctrl+d 能够使当前的客户端退出，但是服务端能够继续运行，并等待，响应其他的客户端的请求。ctrl+c 结束服务端进程

　　3.ctrl+c 结束客户端进程

　　4.服务器主要是用 epoll 模型实现，支持高并发

　　<测试并可以正常运行>

　　系统版本：Linux version 4.4.0-78-generic (buildd@lgw01-11) (gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.4) )

 //头文件
 1 #include <arpa/inet.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <netdb.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/time.h>
#include <sys/epoll.h>
#include <signal.h>

  //服务端代码
  1 #include"func.h"
    
int main(int argc,char *argv[]){
    //socket
    int sfd = socket(AF_INET,SOCK_STREAM,0);
    if(sfd == -1){
        perror("sfd");
        return -1;
    }
    //bind
    struct sockaddr_in server;
    memset(&server,0,sizeof(struct sockaddr_in));
    server.sin_family = AF_INET;
    server.sin_port = htons(atoi(argv[2]));
    server.sin_addr.s_addr = inet_addr(argv[1]);
    int ret;
    ret = bind(sfd,(struct sockaddr *)&server,sizeof(server));
    if(ret == -1){
        perror("bind");
        return -1;
    }
    //listen
    ret = listen(sfd,10);
    if(ret == -1){
        perror("listen");
        return -1;
    }
    
    printf("i am server
");
    
    //epoll创建
    int epfd = epoll_create(1);

    struct epoll_event event,evs[3];
    //注册sfd
    memset(&event,0,sizeof(event));
    event.events = EPOLLIN;
    event.data.fd = sfd;
    epoll_ctl(epfd,EPOLL_CTL_ADD,sfd,&event);
    //注册0
    memset(&event,0,sizeof(event));
    event.events = EPOLLIN;
    event.data.fd = 0;
    epoll_ctl(epfd,EPOLL_CTL_ADD,0,&event);
    
    int ret1,i,len,new_fd;
    char buf[128]={0};

    //新建client
    struct sockaddr_in client;
    while(1){
        memset(evs,0,sizeof(evs));
        int ret1 = epoll_wait(epfd,evs,3,-1);
        if(ret1 > 0){
            for(i=0; i<ret1; i++){
                //sfd 有client请求建立里连接
                if(evs[i].data.fd == sfd){                
                    memset(&client,0,sizeof(client));
                    len = sizeof(client);
                    new_fd = accept(sfd,(struct sockaddr*)&client,&len);
                    if(new_fd == -1){
                        perror("accept");
                        return -1;
                    }
                    //注册new_fd
                    memset(&event,0,sizeof(event));
                    event.events = EPOLLIN;
                    event.data.fd = new_fd;
                    epoll_ctl(epfd,EPOLL_CTL_ADD,new_fd,&event);
                    //打印客户端ip，端口
                    printf("client ip=%s,port=%d
",inet_ntoa(client.sin_addr),ntohs(client.sin_port));
                }
                //0 服务端输入
                if(evs[i].data.fd == 0){
                    memset(buf,0,sizeof(buf));
                    ret = read(0,buf,sizeof(buf));            
                    if(ret <= 0){
                        printf("bye bye
");
                        close(new_fd);
                        //删除new_fd
                        memset(&event,0,sizeof(event));
                        event.events = EPOLLIN;
                        event.data.fd = new_fd;
                        epoll_ctl(epfd,EPOLL_CTL_DEL,new_fd,&event);
                        break;
                    }
                    ret = send(new_fd,buf,strlen(buf)-1,0);
                    if(ret == -1){
                        perror("send");
                        return -1;
                    }
                }
                //new_fd 读客户端的数据
                if(evs[i].data.fd == new_fd){
                    memset(buf,0,sizeof(buf));
                    ret = recv(new_fd,buf,sizeof(buf),0);
                    if(ret == -1){
                        perror("recv");
                        return -1;
                    }else if(ret == 0){
                        printf("bye bye
");
                        close(new_fd);
                        //删除new_fd
                        memset(&event,0,sizeof(event));
                        event.events = EPOLLIN;
                        event.data.fd = new_fd;
                        epoll_ctl(epfd,EPOLL_CTL_DEL,new_fd,&event);
                        break;
                    }
                    printf("%s
",buf);
                }
            }
        }
    }
    close(sfd);//关闭sfd
    close(new_fd);//关闭new_fd
    close(epfd);//关闭epfd
    return 0;    
}

 //客户端代码(客户端并未使用epoll，有兴趣的可以自己进行修改)
 1 #include"func.h"

int main(int argc,char *argv[]){
    //socket
    int sfd = socket(AF_INET,SOCK_STREAM,0);
    if(sfd == -1){
        perror("socket");
        return -1;
    }
    //connect
    int ret;
    struct sockaddr_in ser;
    memset(&ser,0,sizeof(ser));
    ser.sin_family = AF_INET;
    ser.sin_addr.s_addr = inet_addr(argv[1]);
    ser.sin_port = htons(atoi(argv[2]));
    ret = connect(sfd,(struct sockaddr*)&ser,sizeof(ser));
    if(ret == -1){
        perror("connect");
        return -1;
    }
    printf("i am client
");
    char buf[128]={0};
    fd_set rdset;
    while(1){
        FD_ZERO(&rdset);
        FD_SET(0,&rdset);
        FD_SET(sfd,&rdset);
        ret = select(sfd+1,&rdset,NULL,NULL,NULL);
        if(ret > 0){
            if(FD_ISSET(0,&rdset)){
                memset(buf,0,sizeof(buf));
                ret = read(0,buf,sizeof(buf));            
                if(ret <= 0){
                    printf("bye bye
");
                    break;
                }
                ret = send(sfd,buf,strlen(buf)-1,0);
                if(ret == -1){
                    perror("send");
                    return -1;
                }
            }
            if(FD_ISSET(sfd,&rdset)){
                memset(buf,0,sizeof(buf));
                ret = recv(sfd,buf,sizeof(buf),0);
                if(ret == -1){
                    perror("recv");
                    return -1;
                }else if(ret == 0){
                    printf("bye bye
");
                    break;
                }
                printf("%s
",buf);
            }
        }
    }
    close(sfd);

    return 0;    
}