client_dns.c

tcp通讯源码

#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <netinet/in.h>

#define PORT 9999
#define HOST_ADDR "Beauty.eeis.ustc.edu.cn"

main()
{
	struct sockaddr_in server;
	struct hostent *hp;
	int s,ns;
	int pktlen,buflen;
	char buf1[256],buf2[256];

	s=socket(AF_INET,SOCK_STREAM,0);
	server.sin_family=AF_INET;
	server.sin_port=htons(PORT);
	hp=gethostbyname(HOST_ADDR);
	memcpy(hp->h_addr,&server.sin_addr,hp->h_length);
	if(connect(s,(struct sockaddr *)&server,sizeof(server))<0)
	{
		perror("connect()");
		return;
	}
	for(;;)
	{
		printf("Enter a line:");
		gets(buf1);
		buflen=strlen(buf1);
		if(buflen==0)
			break;
		send(s,buf1,buflen+1,0);
		recv(s,buf2,sizeof(buf2),0);
		printf("Received line: %s\n",buf2);
	}
	close(s);
}