client.c

给予SOCKET通信的客户端于服务器端的程序

#include <stdio.h>

#include <sys/socket.h>

#include <unistd.h>

#include <sys/types.h>

#include <netinet/in.h>

#include <stdlib.h>

 

#define SERVER_PORT 20000 // define the defualt connect port id

#define CLIENT_PORT ((20001+rand())%65536) // define the defualt client port as a random port

 

#define BUFFER_SIZE 255

#define REUQEST_MESSAGE "welcome to connect the server.\n"

 

void usage(char *name)

{

       printf("usage: %s IpAddr\n",name);

}

 

int main(int argc, char **argv)

{     

	   char sendata[BUFFER_SIZE];
	   char receive[BUFFER_SIZE];
	   char inputdata; 
	   int servfd,clifd,length = 0;

       struct sockaddr_in servaddr,cliaddr;

       socklen_t socklen = sizeof(servaddr);

       char buf[BUFFER_SIZE];

       

       if (argc < 2)

       {

              usage(argv[0]);

              exit(1);

       }

       

       if ((clifd = socket(AF_INET,SOCK_STREAM,0)) < 0)

       {

              printf("create socket error!\n");

              exit(1);

       }

       srand(time(NULL));//initialize random generator

       bzero(&cliaddr,sizeof(cliaddr));

       cliaddr.sin_family = AF_INET;

       cliaddr.sin_port = htons(CLIENT_PORT);

       cliaddr.sin_addr.s_addr = htons(INADDR_ANY);

 

       bzero(&servaddr,sizeof(servaddr));

       servaddr.sin_family = AF_INET;

       inet_aton(argv[1],&servaddr.sin_addr);

       servaddr.sin_port = htons(SERVER_PORT);

       //servaddr.sin_addr.s_addr = htons(INADDR_ANY);

 

       if (bind(clifd,(struct sockaddr*)&cliaddr,sizeof(cliaddr))<0)

       {

              printf("bind to port %d failure!\n",CLIENT_PORT);

              exit(1);

       }

 

       if (connect(clifd,(struct sockaddr*)&servaddr, socklen) < 0)

       {

              printf("can't connect to %s!\n",argv[1]);

              exit(1);

       }



       length = recv(clifd,buf,BUFFER_SIZE,0);

       if (length < 0)

       {

              printf("error comes when recieve data from server %s!",argv[1]);

              exit(1);

       }

       printf("from server %s :\n\t%s ",argv[1],buf);
	   
	   while(1)
	   {/*
		   		  length = recv(clifd,receive,BUFFER_SIZE,0);
				  if (length = 0) 
				  {
					  printf("No data!!\n");
				  }
				  else
				  {
					  puts(receive);
				  }
				  */
			      printf("please input send data:");
	              gets(sendata);
				  printf("\n");
	              int lengthdata;
				  int i =0;
	              lengthdata = strlen(sendata);
	              send(clifd,sendata,lengthdata+2,0);
				  printf("write n stop sending data,other go on!!\n");
					  scanf("%c\n",&inputdata);
				  if(inputdata == 'n')
				  {
					                      
					  close(clifd);
                     return 0;
				  }
			//	  char inputdata;
	       //       printf("go on please input y,stop client pleaseinput n:");
				//  scanf("%c",&inputdata);
				  /*
				  while(i<3)
				  {
				 
				       if ((inputdata != 'y')& (inputdata != 'n')) 
					   {
					          printf("scanf is wrong !please input again!!\n");
                              scanf("%c",&inputdata);
					          i= i+1;
					   }
				  }
				  if (inputdata =='n'|i>=3) 
				  {       
					  close(clifd);
                      return 0;
				  }
				  if(inputdata == 'y')continue;
*/
				  		
	   }
//




}