#include<stdio.h>#include <stdlib.h>#include <errno.h>#include <string.h>#include <netdb.h>#include <sys/types.h>#include <netinet/in.h>#include <sys/socket.h>#define SERVPORT 3490#define MAXDATASIZE 100 /*每次最大數據傳輸量 */#define SERV_HOST_ADDR "192.168.1.221" main(){int sockfd, recvbytes;char buf[MAXDATASIZE];char data[MAXDATASIZE];struct hostent *host;struct sockaddr_in serv_addr;if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1){perror("socket創建出錯！");exit(1);}serv_addr.sin_family=AF_INET;serv_addr.sin_port=htons(SERVPORT);serv_addr.sin_addr.s_addr=inet_addr(SERV_HOST_ADDR);bzero(&(serv_addr.sin_zero),8);if (connect(sockfd, (struct sockaddr *)&serv_addr,  sizeof(struct sockaddr)) == -1) {perror("connect出錯！");exit(1);}printf("please enter username:");scanf("%s",data);if(send(sockfd,data,MAXDATASIZE,0)==-1){perror("send error!");exit(1);}if ((recvbytes=recv(sockfd, buf, MAXDATASIZE, 0)) ==-1) {perror("recv出錯！");exit(1);}buf[recvbytes] = '\0';printf("Received: %s",buf);close(sockfd);}