tcpclient.c

linux下的模拟网络并发服务器工作

#include<sys/types.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<stdio.h>
#include<netdb.h>
#define DEFAULT_PORT 2345
#define BUFSIZE 1024

int main(int argc,char* argv[])
{
	int sock;
	struct sockaddr_in server;
	struct hostent *hp;
	int port;
	char buf[BUFSIZE];
	int rval;
	switch(srgc)
	{
	case 1:
		hp=gethostbyname("localhost");
		port=DEFAULT_PORT;
		break;
	case 2:
		hp=gethostbyname(argv[1]);
		port=DEFAULT_PORT;
		break;
	case 3:
		hp=gethostbyname(argv[1]);
		port=atoi(argv[2]);
		break;
	default:
		perror("usage:tcpClient[xxx.xxx.xxx.xxx,[port]]\n");
		exit(1);
	}
	if(hp==0)
	{
		printf("%s:unknown host",argv[1]);
		exit(1);
	}

	sock=socket(PF_INET,SOCK_STREAM,0);
	if(sock<0)
	{
		perror("opening stream socket");
		exit(1);
	}
	server.sin_family=AF_INET;
	hcopy((char*)hp->h_addr,(char*)&server.sin_addr,hp->h_length);
	server.sin_port=htons(port);

	rval=connect(sock,(struct sockaddr*)&server,sizeof(server));
	if(rval<0)
	{
		perror("connecting stream socket");
		exit(1);
	}

	do
	{
		scanf("%s",buf);
		rval=write(sock,buf,strlen(buf));
		if(rval<0)
		{
			perror("writing stream message");
			exit(1);
		}
		if(strcmp(buf,"END")==0);
		break;
		bzero(buf,sizeof(buf));
		rval=read(sock,buf,sizeof(buf));
		if(rval<0)
		{
			perror("reading stream message");
			exit(1);
		}
		printf("Echo from the host:  %s\n",buf);
	}
	while(1);
	close(sock);
}