How to use linux socket to achieve dialogue between server and client

1.服务器端 #include  #include  #include  #include  #include  #include  #include  #include  #define SERVPORT 3333 #define BACKLOG 10 #define MAX_CONNECTED_NO 10 #define MAXDATASIZE 5 int main() { struct sockaddr_in server_sockaddr,client_sockaddr; int sin_size,recvbytes; int sockfd,client_fd; char buf[MAXDATASIZE]; /*创建socket*/ if((sockfd = socket(AF_INET,SOCK_STREAM,0))==-1){ perror("socket"); exit(1); } printf("socket success!,sockfd=%d\n",sockfd); /*设置服务器sockaddr_in结构*/ server_sockaddr.sin_family=AF_INET; server_sockaddr.sin_port=htons(SERVPORT); server_sockaddr.sin_addr.s_addr=INADDR_ANY; bzero(&(server_sockaddr.sin_zero),8); /*绑定socket和端口*/ if(bind(sockfd,(struct sockaddr *)&server_sockaddr,sizeof(struct sockaddr))==-1){ perror("bind"); exit(1); } printf("bind success!\n"); /*监听客户端请求*/ if(listen(sockfd,BACKLOG)==-1){ perror("listen"); exit(1); } printf("listening....\n"); /*接受客户端请求*/ if((client_fd=accept(sockfd,(struct sockaddr *)&client_sockaddr,&sin_size))==-1){ perror("accept"); exit(1); } /*接收客户端信息*/ if((recvbytes=recv(client_fd,buf,MAXDATASIZE,0))==-1){ perror("recv"); exit(1); } printf("received a connection :%s\n",buf); /*关闭socket*/ close(sockfd); } 2.客户端 #include  #include  #include  #include  #include  #include  #include  #include  #define SERVPORT 3333 #define MAXDATASIZE 100 main(int argc,char *argv[]){ int sockfd,sendbytes; char buf[MAXDATASIZE]; struct hostent *host; struct sockaddr_in serv_addr; /*argc<2,表示没有输入主机名，主机句是IP地址形式，如“192.168.1.1”*/ if(argc < 2){ fprintf(stderr,"Please enter the server's hostname!\n"); exit(1); } /*获取主机名，地址解析函数*/ if((host=gethostbyname(argv[1]))==NULL){ perror("gethostbyname"); exit(1); } /*创建socket*/ if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1){ perror("socket"); exit(1); } /*设置serv_addr结构参数*/ serv_addr.sin_family=AF_INET; serv_addr.sin_port=htons(SERVPORT); serv_addr.sin_addr=*((struct in_addr *)host->h_addr); bzero(&(serv_addr.sin_zero),8); /*向服务器请求连接，serv_addr是服务器端地址*/ if(connect(sockfd,(struct sockaddr *)&serv_addr,\ sizeof(struct sockaddr))==-1){ perror("connect"); exit(1); } /*发送消息给服务器，此时可以在服务器端看到"hello"字样*/ if((sendbytes=send(sockfd,"hello",5,0))==-1){ perror("send"); exit(1); } /*关闭连接*/ close(sockfd); }

#gcc server.c -o server #./server //此时服务器端在监听 #gcc client.c -o client #./client 172.31.100.236 //客户端向服务器端发送“hello"，服务器端监听终止