linux socket实现网络聊天室（二）：使用线程独立收发消息

一、引言

二、代码实现

1、服务器端

 /*tcpserver.c  2011.9.1 by yyg*/
 #include
 #include
 #include
 #include
 #include
 #include
 #include
 #include
 #include

 #define MYPORT 3490  //定义端口
 #define BACKLOG 10
 #define MAXDATASIZE 1024

 int sockfd,new_fd;
 pthread_t accthread,recthread;

 void recmessage(void){  //接收客户端信息函数
     while(1){
         int numbytes;
         char buf[MAXDATASIZE];
         if((numbytes = recv(new_fd,buf,MAXDATASIZE,0))==-1){
             perror("recv");
             exit(1);
         }
         buf[numbytes]='\0';
         if(strcmp(buf,"exit")==0){  //若收到的是exit字符，则代表退出通信
             printf("Client is closed\n");
             close(new_fd);
             close(sockfd);
             exit(1);
         }
         printf("client:%s\n",buf);
     }/*while*/
 }

 void acceptconnect(void){  //接受客户端连接请求函数
     struct sockaddr_in their_addr;
     int sin_size;
     sin_size = sizeof(struct sockaddr_in);
     if((new_fd = accept(sockfd,(struct sockaddr *)&their_addr,&sin_size))==-1){
         perror("accept");
         exit(1);
     }
     printf("server:got connection from %s\n",inet_ntoa(their_addr.sin_addr));
     /*创建子线程，用于接收信息*/
     if((pthread_create(&recthread,NULL,(void*)recmessage,NULL)) != 0){
         printf("create thread error!\r\n");
         exit(1);
     }
 }

 int main(void){
     struct sockaddr_in my_addr;
     /*创建套接字*/
     if((sockfd = socket(AF_INET,SOCK_STREAM,0)) == -1){
         perror("socket");
         exit(1);
     }
     /*初始化sockaddr_in结构体相关参数*/
     my_addr.sin_family = AF_INET;
     my_addr.sin_port = htons(MYPORT);
     my_addr.sin_addr.s_addr = INADDR_ANY;
     bzero(&(my_addr.sin_zero),8);

     /*绑定端口与套接字*/
     if(bind(sockfd,(struct sockaddr*)&my_addr,sizeof(struct sockaddr)) == -1){
         perror("bind");
         exit(1);
     }
     /*监听客户端套接字*/
     if(listen(sockfd,BACKLOG)== -1){
         perror("listen");
         exit(1);
     }
     printf("listening...\n");
     /*创建子线程，用于接收信息*/
     if((pthread_create(&accthread,NULL,(void*)acceptconnect,NULL))!=0){
         printf("create thread error!\n");
         exit(1);
     }
     while(1){
         char msg[MAXDATASIZE];
         scanf("%s",msg);
         if(send(new_fd,msg,strlen(msg),0) == -1){  //发送信息，与客户端交流
             perror("send");
             exit(1);
         }
         if(strcmp(msg,"exit") ==0){
             printf("byebye\n");
             close(new_fd);
             close(sockfd);
             exit(1);
         }
     }/*while*/
     return 0;
 }/*main*/

2.客户端

 /*tcpclient.c    2010.9.1 by yyg*/
 #include
 #include
 #include
 #include
 #include
 #include
 #include
 #include
 #include
 #include

 #define PORT 3490
 #define BACKLOG 10
 #define MAXDATASIZE 1024

 int sockfd;
 pthread_t recthread;

 /*接收信息函数*/
 void recmessage(void){
     while(1){
         int numbytes;
         char buf[MAXDATASIZE];

         if((numbytes = recv(sockfd,buf,MAXDATASIZE,0))==-1){
             perror("recv");
             exit(1);
         }
         buf[numbytes]='\0';
         if(strcmp(buf,"exit")==0){
             printf("Server is closed\n");
             close(sockfd);
             exit(1);
         }
         printf("Server:%s\n",buf);
     }/*while*/
 }

 int main(int argc,char *argv[]){
     struct hostent *he;
     struct sockaddr_in their_addr;
     /*客户端输入方式:./client 172.31.100.236,若无输入后面IP地址，会提示错误*/
     if(argc != 2){
         fprintf(stderr,"usage:client hostname\n");
         exit(1);
     }
     /*获取主机IP地址*/
     if((he = gethostbyname(argv[1])) == NULL){
         herror("gethostbyname");
         exit(1);
     }
     /*创建套接字*/
     if((sockfd = socket(AF_INET,SOCK_STREAM,0)) == -1){
         perror("socket");
         exit(1);
     }
     /*初始化sockaddr_in结构体*/
     their_addr.sin_family = AF_INET;
     their_addr.sin_port = htons(PORT);
     their_addr.sin_addr = *((struct in_addr *)he->h_addr);
     bzero(&(their_addr.sin_zero),8);
     /*向服务器发送连接请求*/
     if(connect(sockfd,(struct sockaddr *)&their_addr,sizeof(struct sockaddr)) == -1){
         perror("connect");
         exit(1);
     }
     /*创建子线程，用于接收信息*/
     if((pthread_create(&recthread,NULL,(void*)recmessage,NULL))!= 0){
         printf("create thread error!\r\n");
         exit(1);
     }
     /*发送信息。接收发送信息用的是同一端口，都 是sockfd*/
     while(1){
         char msg[MAXDATASIZE];
         scanf("%s",msg);
         if(send(sockfd,msg,strlen(msg),0) == -1){
             perror("send");
             exit(1);
         }
         if(strcmp(msg,"exit") ==0){
             printf("byebye\n");
             close(sockfd);
             exit(1);
         }
     }/*while*/
     return 0;
 }

运行结果：

终端1：

 [root@localhost net]# ./tcpserver
 server:got connection from 172.31.100.236
 Hello,World!
 client:hello
 client:xiaolian
 client:iou
 ok
 exit
 byebye

终端2：

 [root@localhost net]# ./tcpclient 172.31.100.236
 Server:Hello,World!
 hello
 xiaolian iou
 Server:ok
 Server is closed