/* Datagram client, by Rahim Moledina */

# include <sys/types.h>
# include <sys/socket.h>
# include <netinet/in.h>
# include <netdb.h>
# include <stdlib.h>
# include <stdio.h>
#include <arpa/inet.h>
#include <sys/uio.h>
#include <unistd.h>
# include <strings.h>


// Send a datagram to a reciever whose name I get from the command line args. 
//   The command line is dgramsend hotname portnumber 

int main (int argc, char *argv[])
{ 
   int sock,num=0; 
   char symbol[50],curr_symbol[4];
   char buf[1024];
   char *tempstr;
   struct sockaddr_in name;
   struct hostent *hp; 

   printf ("Please enter the ticker symbols of the Stocks: ");
   gets(symbol);        // Getting stock symbol(s) from user

   sock = socket(AF_INET, SOCK_DGRAM, 0);
   if (sock < 0) {
      perror("Opening datagram socket");
   exit (1);           // Datagram socket being opened  
   }
   
   hp = gethostbyname(argv[1]); // Looking up the host name.
   if (hp == 0) {
      fprintf (stderr, "%s: unknown host\n", argv[1]);
      exit (2);  // If host name not found, display error message.
   }
   
   
   
   bcopy(hp->h_addr, &name.sin_addr, hp->h_length);     // Copying host address.
   name.sin_family = AF_INET;      
   name.sin_port = htons(atoi(argv[2]));      // Setting up address structure
   
   /* Send a message */
   
   strcpy(curr_symbol,strtok(symbol," ")); 
   if (sendto(sock,curr_symbol,sizeof(curr_symbol), 0, (sockaddr *)&name, sizeof(name)) < 0)
     perror("Sending datagram message");    // Send the current stock symbol.
   bzero (buf,sizeof(buf));
   if (read(sock, buf, 1024) < 0)
     perror("Receiving datagram packet");  // If packet not recieved back output error.
   printf("\n%s\n",buf);
   
   while ((tempstr = strtok(NULL," ")) != NULL) {    // While there are more stock symbols to send
      strcpy(curr_symbol,tempstr);
      if (sendto(sock,curr_symbol,sizeof(curr_symbol), 0, (sockaddr *)&name, sizeof(name)) < 0)
	perror("Sending datagram message");   // Send current stock symbol.
      bzero (buf,sizeof(buf));
      if (read(sock, buf, 1024) < 0)
	perror("Receiving datagram packet");  // Display error if packet not recieved.
      printf("\n%s\n",buf);
   }
   close (sock);
}