Programming

//Program client_distri.c.
//Get  and display distributed message 
#include <sys/types.h>   // for type  
#include <sys/socket.h>  // for socket API  
#include <netinet/in.h>  // for address  
#include <arpa/inet.h>   // for sockaddr_in 
#include <stdio.h>       // for printf() 
#include <stdlib.h>      // for atoi() 
#include <string.h>      // for strlen() 
#include <unistd.h>      // for close() 
////////////////////////////////////////////
char *multiHostAddress = "239.255.10.10";

void getEcho (int sock) 
{
	struct sockaddr_in read_EP; 
 	int stop = -1;
 	char *msg;

	printf ("Waiting for message... \n");
	while (stop < 0) 
	{     
	   msg = (char *)recvfromDST (&read_EP, sock);
	   if (msg != NULL) 
		printf ("%s==>%s\n",inet_ntoa(read_EP.sin_addr),msg);
	   else 
		stop = 0;
	}
}
////////////////////////////////////////////
int main(int argc, char **argv) 
{
  int sockMulti;           
  int readPort;  
  struct sockaddr_in EP_multi; 
  struct ip_mreq request; 
  unsigned char TTL=3;   

//-------------
   int MC_socket;
   struct sockaddr_in server_EP, sender_EP;
   char  msg [60];
   char *readmsg;
   int port;
   int stop = 0;
//--------------
	

//--------------
	if (argc != 4)
	{
	  	IO_error(1,"Need host, send port and receive port.(e.g localhost 9000 9001)");
	} 
//--------------

	else 
	{

//-----------------------------
//Send msg to server
		port = atoi (argv[2]);
	  	printf ("TCP Client to send message to Server %s at Port %d \n", argv[1], port);
   	 	setHostByName (&server_EP,  argv[1],  port);
  	  	MC_socket= sockTCP_create();
  	  	sock_connect(MC_socket,  &server_EP);
		
	  	while (stop == 0) 
		{ 			
	
	  		printf ("Enter message -without space- to send or 'QUIT'  \n");
	        	printf ("or 'SerEnd$$' to stop server:  ");
			//Read msg from user
	  		scanf ("%s", msg);
			//Send msg to server
	  		sendtoDST (sender_EP, MC_socket, msg);
	  		printf ("Message %s sent \n", msg);
			stop = (strncmp (msg, "QUIT", 4) == 0);
                	if (stop == 0) 
			{
		   		stop = (strncmp (msg, "SerEnd$$", 8) == 0);
               	}

//Receive msg from server

	  		readPort = atoi (argv[3]);
	  		printf ("Multicasting receiver at ports %d \n", readPort);

	  		//Initialisation
	  		sockMulti = sockUDP_create();
	  		sockUDP_reuse (sockMulti);
	  		setHostByAddr (&EP_multi, "any", readPort);
	  		sock_bind (sockMulti, readPort);
	  		sockUDP_join (sockMulti, multiHostAddress,&request);

	  		//Use service
          		getEcho (sockMulti);

	  		//Finalisation
	  		sockUDP_drop (sockMulti, request);
	  		close(sockMulti);

//----------------------------------
		  }
     	 	 sock_shutdown(MC_socket, 1);
	 	 readmsg = NULL;
	 	 while  (readmsg != NULL) 
			readmsg = (char *)readMessage(MC_socket);

//-----------------------------------

	}
}