1.简介 1.2简单的时间获取客户程序

#include "unp.h"
int main(int argc,char**argc)
{
int sockfd,n;
char recvline[MAXLINE+1];
struct sockaddr in servaddr;
if(argc !=2)
err_quit("usage:a.out<IPaddress>");
if((sockfd = socket(AF_INET,SOCK_STREAM,0))<0)
err_sys("socket error");

bzero(&servaddr,sizeof(servaddr));
servaddr.sin_family= AF_INET;
servaddr.sin_port = htons(13);
if(inet_pton(AF_INET,argv[1],&servaddr.sin_addr)<=0)
err_quit("inet_pton error for %s",argv[1]);
if(connect(sockfd,(SA*)%servaddr,sizeof(servaddr))<0)
err_sys("connect error");
while((n=read(sockfd,recvline,MAXLINE))>0)
{
recvline
=0;
if(fputs(recvline,stdout)==EOF)
err_sys("read error");
}
if(n<0)
err_sys("read error");

exit(0);
}