利用 select 模型,实现一个 I/O 复用模式的服务器

来源：互联网发布：php 反射函数参数类型编辑：程序博客网时间：2024/05/21 07:09

/*server.c*/

#include<sys/socket.h>
#include<stdio.h>
#include<stdlib.h>
#include<errno.h>
#include<memory.h>
#include<sys/mman.h>
#include<sys/types.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<time.h>
#include<string.h>
#include<sys/wait.h>
#define PORT 1234
#define MAX_QUE 5
#define BUF_SIZE 1024
#define MAX_SOCK_FD     FD_SETSIZE
struct sockaddr_in client;
char client_ip[20];
int main()
{
   struct sockaddr_in local_sockaddr;
   int socketfd;//本地socket套接字描述符
   int clientfd;//客户端链接描述符
   int fd;
   int recvbytes;//收到的字节数
   int sendbytes;//发送的字节数
   fd_set inset,st_inset;//文件描述符集
   char buf[BUF_SIZE];
   if((socketfd=socket(AF_INET,SOCK_STREAM,0))<0)//建立socket连接
   {
       perror("socket");
       exit(1);
   }
   printf("Socket id = %d\n",socketfd);
   local_sockaddr.sin_family = AF_INET;
   local_sockaddr.sin_port   = htons(PORT);
   local_sockaddr.sin_addr.s_addr = htonl(INADDR_ANY);
   printf("server ip =%s\n",inet_ntoa(local_sockaddr.sin_addr));//输出服务器ip地址
   memset(local_sockaddr.sin_zero,0,8);
   int i;
   setsockopt(socketfd,SOL_SOCKET,SO_REUSEADDR,&i,sizeof(i));//允许重复使用本地的地址与套接字进行绑定
   if(bind(socketfd,(struct sockaddr *)&local_sockaddr,sizeof(struct sockaddr))<0)//绑定函数bind()
   {
       perror("bind");
       exit(1);
   }
   printf("Bind success!\n");
   if(listen(socketfd,MAX_QUE)<0)//利用listen()设置被动监听
   {
       perror("listen");
       exit(1);
   }
   printf("Listening>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");

   //初始化文件描述符集
   FD_ZERO(&inset);//清空文件描述符集
   FD_SET(socketfd,&inset);//将socketfd文件描述符加入文件描述符集
   memset(buf,0,sizeof(buf));//初始化缓冲区
   for( ; ; )
   {
       st_inset=inset;//记录文件描述符集
       if(!(select(MAX_SOCK_FD,&st_inset,NULL,NULL,NULL)>0))//调用select()函数,成功返回准备好的文件描述符
       {
           perror("select");
       }
       for(fd=0;fd<MAX_SOCK_FD;fd++)
       {
           if(FD_ISSET(fd,&st_inset)>0)//fd是st_inset中的一个元素则返回>0的数
           {
               if(fd==socketfd)
               {
                   if((clientfd=accept(socketfd,(struct sockaddr*)NULL,NULL))<0)//调用accept()函数,等待客户端的链接
                   {
                       perror("accept");
                       exit(1);
                   }
                   FD_SET(clientfd,&inset);//链接成功就把新生成的套接字描述符加入文件描述符集中
                   socklen_t client_len = sizeof(client);
                   getpeername(clientfd, (struct sockaddr *)&client, &client_len);
                   inet_ntop(AF_INET, &client.sin_addr, client_ip, sizeof(client_ip));
                   printf("connect client ip:%s\tport:%d success\n", client_ip, ntohs(client.sin_port));

               }
               else //fd==clientfd
               {

                   if((recvbytes = recv(clientfd,buf,BUF_SIZE,0))>0)
                   {
                       printf("Receive messages from ip:%s\tport:%d\t:%s\n",client_ip,ntohs(client.sin_port),buf);
                   }
                   else//没有内容
                   {
                       printf("client ip:%s\tport:%d exit\n",client_ip,ntohs(client.sin_port));
                       close(fd);
                       FD_CLR(fd,&inset);//清除该链接套接字描述符
                   }
               }//end fd==clientfd
           }//end FD_ISSET
       }//end for fd
   }//end for;;
   close(socketfd);
   exit(0);
}

/*client.c*/

#include<sys/socket.h>
#include<stdio.h>
#include<stdlib.h>
#include<errno.h>
#include<memory.h>
#include<sys/mman.h>
#include<sys/types.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<time.h>
#include<string.h>
#define PORT 1234
#define BUF_SIZE 1024
int main(int argc,char *argv[])
{
   int socketfd;//客户端socket套接字描述符
   struct sockaddr_in serv_addr;//服务器地址结构体
   char   buf[BUF_SIZE];
   char        serv_ip[20], clie_ip[20];
   int    sendbytes;//发送字节数
   int    recvbytes;//接收字节数
   if(argc!=2)
   {
       printf("参数错误!正确格式:./client serverip\n");
       exit(1);
   }
   if((socketfd=socket(AF_INET,SOCK_STREAM,0))<0)//建立socket连接
   {
       perror("socket");
       exit(1);
   }
   printf("Socket id = %d\n",socketfd);
   serv_addr.sin_family = AF_INET;
   serv_addr.sin_port = htons(PORT);
   inet_aton(argv[1], &serv_addr.sin_addr);
   memset(serv_addr.sin_zero,0,8);
   if(connect(socketfd, (struct sockaddr*)&serv_addr, sizeof(struct sockaddr))< 0) //调用connect()函数连接服务器
   {
       printf("can not connect to %s, exit!\n", argv[1]);
       printf("%s\n", strerror(errno));
       exit(1);
   }
   else
       printf("connect to %s success!\n",argv[1]);
   struct sockaddr_in serv, clie;
    socklen_t serv_len = sizeof(serv);
    socklen_t clie_len = sizeof(clie);
getpeername(socketfd,(struct sockaddr*)&serv,&serv_len);
inet_ntop(AF_INET, &serv.sin_addr, serv_ip, sizeof(serv_ip));
   inet_ntop(AF_INET, &clie.sin_addr, clie_ip, sizeof(clie_ip));
   printf("server ip:%s\tport:%d\n", serv_ip, ntohs(serv.sin_port));
   snprintf(buf,sizeof(buf),"%s","this is client ");
   if((sendbytes=send(socketfd,buf,strlen(buf),0))<0)
   {
           perror("send");
           exit(1);
   }
   close(socketfd);//关闭socket连接
   return 0;
}

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